fbpx
Wikipedia

James Webb Space Telescope

November 13, 2023

The James Webb Space Telescope (JWST) is a space telescope designed to conduct infrared astronomy. Its high-resolution and high-sensitivity instruments allow it to view objects too old, distant, or faint for the Hubble Space Telescope.[9] This enables investigations across many fields of astronomy and cosmology, such as observation of the first stars and the formation of the first galaxies, and detailed atmospheric characterization of potentially habitable exoplanets.[10][11][12]

James Webb Space Telescope
Rendering of the fully deployed James Webb Space Telescope
NamesNext Generation Space Telescope (NGST; 1996–2002)
Mission typeAstronomy
OperatorSTScI (NASA)[1] / ESA / CSA
COSPAR ID2021-130A
SATCAT no.50463[2]
WebsiteOfficial website
webbtelescope.org
Mission duration
  • 1 year, 10 months, 19 days (elapsed)
  • 5+1⁄2 years (primary mission)[3]
  • 10 years (planned)
  • 20 years (expected life)[4]
Spacecraft properties
Manufacturer
Launch mass6,500 kg (14,300 lb)[5]
Dimensions21.197 m × 14.162 m (69.54 ft × 46.46 ft),[6] sunshield
Power2 kW
Start of mission
Launch date25 December 2021 (2021-12-25), 12:20 UTC[5]
RocketAriane 5 ECA (VA256)
Launch siteCentre Spatial Guyanais, ELA-3
ContractorArianespace
Entered serviceJuly 12, 2022; 16 months ago (2022-07-12)
Orbital parameters
Reference systemSun–Earth L2 orbit
RegimeHalo orbit
Periapsis altitude250,000 km (160,000 mi)[7]
Apoapsis altitude832,000 km (517,000 mi)[7]
Period6 months
Main telescope
TypeKorsch telescope
Diameter6.5 m (21 ft)
Focal length131.4 m (431 ft)
Focal ratiof/20.2
Collecting area25.4 m2 (273 sq ft)[8]
Wavelengths0.6–28.3 μm (orange to mid-infrared)
Transponders
Band
Bandwidth
  • S-band up: 16 kbit/s
  • S-band down: 40 kbit/s
  • Ka-band down: up to 28 Mbit/s
Instruments
Elements

James Webb Space Telescope mission logo  

The Webb was launched on 25 December 2021 on an Ariane 5 rocket from Kourou, French Guiana. In January 2022 it arrived at its destination, a solar orbit near the Sun–Earth L2 Lagrange point, about 1.5 million kilometers (930,000 mi) from Earth. The telescope's first image was released to the public on 11 July 2022.[13]

The U.S. National Aeronautics and Space Administration (NASA) led Webb's design and development and partnered with two main agencies: the European Space Agency (ESA) and the Canadian Space Agency (CSA). The NASA Goddard Space Flight Center (GSFC) in Maryland managed telescope development, while the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates Webb. The primary contractor for the project was Northrop Grumman. The telescope is named after James E. Webb, who was the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and Apollo programs.

Webb's primary mirror consists of 18 hexagonal mirror segments made of gold-plated beryllium, which together create a 6.5-meter-diameter (21 ft) mirror, compared with Hubble's 2.4 m (7 ft 10 in). This gives Webb a light-collecting area of about 25 square meters, about six times that of Hubble. Unlike Hubble, which observes in the near ultraviolet and visible (0.1 to 0.8 μm), and near infrared (0.8–2.5 μm)[14] spectra, Webb observes a lower frequency range, from long-wavelength visible light (red) through mid-infrared (0.6–28.3 μm). The telescope must be kept extremely cold, below 50 K (−223 °C; −370 °F), so that the infrared light emitted by the telescope itself does not interfere with the collected light. Its five-layer sunshield protects it from warming by the Sun, Earth, and Moon.

Initial designs for the telescope, then named the Next Generation Space Telescope, began in 1996. Two concept studies were commissioned in 1999, for a potential launch in 2007 and a US$1 billion budget. The program was plagued with enormous cost overruns and delays. A major redesign was accomplished in 2005, with construction completed in 2016, followed by years of exhaustive testing, at a total cost of US$10 billion.

Features edit

The mass of the James Webb Space Telescope is about half that of the Hubble Space Telescope. Webb has a 6.5 m (21 ft)-diameter gold-coated beryllium primary mirror made up of 18 separate hexagonal mirrors. The mirror has a polished area of 26.3 m2 (283 sq ft), of which 0.9 m2 (9.7 sq ft) is obscured by the secondary support struts,[15] giving a total collecting area of 25.4 m2 (273 sq ft). This is over six times larger than the collecting area of Hubble's 2.4 m (7.9 ft) diameter mirror, which has a collecting area of 4.0 m2 (43 sq ft). The mirror has a gold coating to provide infrared reflectivity and this is covered by a thin layer of glass for durability.[16]

Webb is designed primarily for near-infrared astronomy, but can also see orange and red visible light, as well as the mid-infrared region, depending on the instrument being used.[10][11] It can detect objects up to 100 times fainter than Hubble can, and objects much earlier in the history of the universe, back to redshift z≈20 (about 180 million years cosmic time after the Big Bang).[17] For comparison, the earliest stars are thought to have formed between z≈30 and z≈20 (100–180 million years cosmic time),[18] and the first galaxies may have formed around redshift z≈15 (about 270 million years cosmic time). Hubble is unable to see further back than very early reionization[19][20] at about z≈11.1 (galaxy GN-z11, 400 million years cosmic time).[21][22][17]

The design emphasizes the near to mid-infrared for several reasons:

  • high-redshift (very early and distant) objects have their visible emissions shifted into the infrared, and therefore their light can be observed only via infrared astronomy;[14]
  • infrared light passes more easily through dust clouds than visible light;[14]
  • colder objects such as debris disks and planets emit most strongly in the infrared;
  • these infrared bands are difficult to study from the ground or by existing space telescopes such as Hubble.
 
Rough plot of Earth's atmospheric absorption (or opacity) to various wavelengths of electromagnetic radiation, including visible light

Ground-based telescopes must look through Earth's atmosphere, which is opaque in many infrared bands (see figure at right). Even where the atmosphere is transparent, many of the target chemical compounds, such as water, carbon dioxide, and methane, also exist in the Earth's atmosphere, vastly complicating analysis. Existing space telescopes such as Hubble cannot study these bands since their mirrors are insufficiently cool (the Hubble mirror is maintained at about 15 °C [288 K; 59 °F]) which means that the telescope itself radiates strongly in the relevant infrared bands.[23]

Webb can also observe objects in the Solar System at an angle of more than 85° from the Sun and having an apparent angular rate of motion less than 0.03 arc seconds per second.[a] This includes Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, their satellites, and comets, asteroids and minor planets at or beyond the orbit of Mars. Webb has the near-IR and mid-IR sensitivity to be able to observe virtually all known Kuiper Belt Objects.[18][27] In addition, it can observe opportunistic and unplanned targets within 48 hours of a decision to do so, such as supernovae and gamma ray bursts.[18]

  •  

    Three-quarter view of the top

  •  

    Bottom (Sun-facing side)

Location and orbit edit

Webb operates in a halo orbit, circling around a point in space known as the Sun–Earth L2 Lagrange point, approximately 1,500,000 km (930,000 mi) beyond Earth's orbit around the Sun. Its actual position varies between about 250,000 and 832,000 km (155,000–517,000 mi) from L2 as it orbits, keeping it out of both Earth and Moon's shadow. By way of comparison, Hubble orbits 550 km (340 mi) above Earth's surface, and the Moon is roughly 400,000 km (250,000 mi) from Earth. Objects near this Sun–Earth L2 point can orbit the Sun in synchrony with the Earth, allowing the telescope to remain at a roughly constant distance[28] with continuous orientation of its sunshield and equipment bus toward the Sun, Earth and Moon. Combined with its wide shadow-avoiding orbit, the telescope can simultaneously block incoming heat and light from all three of these bodies and avoid even the smallest changes of temperature from Earth and Moon shadows that would affect the structure, yet still maintain uninterrupted solar power and Earth communications on its sun-facing side. This arrangement keeps the temperature of the spacecraft constant and below the 50 K (−223 °C; −370 °F) necessary for faint infrared observations.[29][30]

Sunshield protection edit

Main article: James Webb Space Telescope sunshield
 
Test unit of the sunshield stacked and expanded at the Northrop Grumman facility in California, 2014

To make observations in the infrared spectrum, Webb must be kept under 50 K (−223.2 °C; −369.7 °F); otherwise, infrared radiation from the telescope itself would overwhelm its instruments. Its large sunshield blocks light and heat from the Sun, Earth, and Moon, and its position near the Sun–Earth L2 keeps all three bodies on the same side of the spacecraft at all times.[31] Its halo orbit around the L2 point avoids the shadow of the Earth and Moon, maintaining a constant environment for the sunshield and solar arrays.[28] The resulting stable temperature for the structures on the dark side is critical to maintaining precise alignment of the primary mirror segments.[29]

The five-layer sunshield, each layer as thin as a human hair,[32] is made of Kapton E film, coated with aluminum on both sides and a layer of doped silicon on the Sun-facing side of the two hottest layers to reflect the Sun's heat back into space.[29] Accidental tears of the delicate film structure during deployment testing in 2018 led to further delays to the telescope deployment.[33]

The sunshield was designed to be folded twelve times (concertina style) so that it would fit within the Ariane 5 rocket's payload fairing, which is 4.57 m (15.0 ft) in diameter, and 16.19 m (53.1 ft) long. The shield's fully deployed dimensions were planned as 14.162 m × 21.197 m (46.46 ft × 69.54 ft).[34]

Keeping within the shadow of the sunshield limits the field of regard of Webb at any given time. The telescope can see 40 percent of the sky from any one position, but can see all of the sky over a period of six months.[35]

Optics edit

Main article: Optical Telescope Element
 
Engineers cleaning a test mirror with carbon dioxide snow, 2015
 
Main mirror assembly from the front with primary mirrors attached, November 2016
 
Diffraction spikes due to mirror segments and spider color-coded

Webb's primary mirror is a 6.5 m (21 ft)-diameter gold-coated beryllium reflector with a collecting area of 25.4 m2 (273 sq ft). If it had been designed as a single, large mirror, it would have been too large for existing launch vehicles. The mirror is therefore composed of 18 hexagonal segments (a technique pioneered by Guido Horn d'Arturo), which unfolded after the telescope was launched. Image plane wavefront sensing through phase retrieval is used to position the mirror segments in the correct location using precise actuators. Subsequent to this initial configuration, they only need occasional updates every few days to retain optimal focus.[36] This is unlike terrestrial telescopes, for example the Keck telescopes, which continually adjust their mirror segments using active optics to overcome the effects of gravitational and wind loading.[37] The Webb telescope uses 132 small actuation motors to position and adjust the optics.[38] The actuators can position the mirror with 10 nanometer accuracy.[39]

Webb's optical design is a three-mirror anastigmat,[40] which makes use of curved secondary and tertiary mirrors to deliver images that are free from optical aberrations over a wide field. The secondary mirror is 0.74 m (2.4 ft) in diameter. In addition, there is a fine steering mirror which can adjust its position many times per second to provide image stabilization. Photographs taken by Webb have six spikes plus two fainter ones due to the spider supporting the secondary mirror.[41]

Scientific instruments edit

 
NIRCam wrapped up in 2013
 
The Calibration Assembly, one component of the NIRSpec instrument
 
MIRI

The Integrated Science Instrument Module (ISIM) is a framework that provides electrical power, computing resources, cooling capability as well as structural stability to the Webb telescope. It is made with bonded graphite-epoxy composite attached to the underside of Webb's telescope structure. The ISIM holds the four science instruments and a guide camera.[42]

  • NIRCam (Near Infrared Camera) is an infrared imager which has spectral coverage ranging from the edge of the visible (0.6 μm) through to the near infrared (5 μm).[43][44] There are 10 sensors each of 4 megapixels. NIRCam serves as the observatory's wavefront sensor, which is required for wavefront sensing and control activities, used to align and focus the main mirror segments. NIRCam was built by a team led by the University of Arizona, with principal investigator Marcia J. Rieke.[45]
  • NIRSpec (Near Infrared Spectrograph) performs spectroscopy over the same wavelength range. It was built by the European Space Agency at ESTEC in Noordwijk, Netherlands. The leading development team includes members from Airbus Defence and Space, Ottobrunn and Friedrichshafen, Germany, and the Goddard Space Flight Center; with Pierre Ferruit (École normale supérieure de Lyon) as NIRSpec project scientist. The NIRSpec design provides three observing modes: a low-resolution mode using a prism, an R~1000 multi-object mode, and an R~2700 integral field unit or long-slit spectroscopy mode. Switching of the modes is done by operating a wavelength preselection mechanism called the Filter Wheel Assembly, and selecting a corresponding dispersive element (prism or grating) using the Grating Wheel Assembly mechanism. Both mechanisms are based on the successful ISOPHOT wheel mechanisms of the Infrared Space Observatory. The multi-object mode relies on a complex micro-shutter mechanism to allow for simultaneous observations of hundreds of individual objects anywhere in NIRSpec's field of view. There are two sensors, each of 4 megapixels.[46]
  • MIRI (Mid-Infrared Instrument) measures the mid-to-long-infrared wavelength range from 5 to 27 μm.[47][48] It contains both a mid-infrared camera and an imaging spectrometer.[49] MIRI was developed as a collaboration between NASA and a consortium of European countries, and is led by George Rieke (University of Arizona) and Gillian Wright (UK Astronomy Technology Centre, Edinburgh, Scotland).[45] The temperature of the MIRI must not exceed 6 K (−267 °C; −449 °F): a helium gas mechanical cooler sited on the warm side of the environmental shield provides this cooling.[50]
  • FGS/NIRISS (Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph), led by the Canadian Space Agency under project scientist John Hutchings (Herzberg Astronomy and Astrophysics Research Centre), is used to stabilize the line-of-sight of the observatory during science observations. Measurements by the FGS are used both to control the overall orientation of the spacecraft and to drive the fine steering mirror for image stabilization. The Canadian Space Agency also provided a Near Infrared Imager and Slitless Spectrograph (NIRISS) module for astronomical imaging and spectroscopy in the 0.8 to 5 μm wavelength range, led by principal investigator René Doyon[51] at the Université de Montréal.[45] Although they are often referred together as a unit, the NIRISS and FGS serve entirely different purposes, with one being a scientific instrument and the other being a part of the observatory's support infrastructure.[52]

NIRCam and MIRI feature starlight-blocking coronagraphs for observation of faint targets such as extrasolar planets and circumstellar disks very close to bright stars.[48]

Spacecraft bus edit

Main article: Spacecraft bus (James Webb Space Telescope)
 
Diagram of the spacecraft bus. The solar panel is in green and the light purple panels are radiators.

The spacecraft bus is the primary support component of the James Webb Space Telescope, hosting a multitude of computing, communication, electric power, propulsion, and structural parts.[53] Along with the sunshield, it forms the spacecraft element of the space telescope.[54][55] The spacecraft bus is on the Sun-facing "warm" side of the sunshield and operates at a temperature of about 300 K (27 °C; 80 °F).[54]

The structure of the spacecraft bus has a mass of 350 kg (770 lb), and must support the 6,200 kg (13,700 lb) space telescope. It is made primarily of graphite composite material.[56] The assembly was completed in California in 2015. It was integrated with the rest of the space telescope leading to its 2021 launch. The spacecraft bus can rotate the telescope with a pointing precision of one arcsecond, and isolates vibration to two milliarcseconds.[57]

Webb has two pairs of rocket engines (one pair for redundancy) to make course corrections on the way to L2 and for station keeping – maintaining the correct position in the halo orbit. Eight smaller thrusters are used for attitude control – the correct pointing of the spacecraft.[58] The engines use hydrazine fuel (159 liters or 42 U.S. gallons at launch) and dinitrogen tetroxide as oxidizer (79.5 liters or 21.0 U.S. gallons at launch).[59]

Servicing edit

Webb is not intended to be serviced in space. A crewed mission to repair or upgrade the observatory, as was done for Hubble, would not be possible,[60] and according to NASA Associate Administrator Thomas Zurbuchen, despite best efforts, an uncrewed remote mission was found to be beyond available technology at the time Webb was designed.[61] During the long Webb testing period, NASA officials referred to the idea of a servicing mission, but no plans were announced.[62][63] Since the successful launch, NASA has stated that nevertheless limited accommodation was made to facilitate future servicing missions. These accommodations included precise guidance markers in the form of crosses on the surface of Webb, for use by remote servicing missions, as well as refillable fuel tanks, removable heat protectors, and accessible attachment points.[64][61]

Software edit

Ilana Dashevsky and Vicki Balzano write that Webb uses a modified version of JavaScript, called Nombas ScriptEase 5.00e, for its operations; it follows the ECMAScript standard and "allows for a modular design flow, where on-board scripts call lower-level scripts that are defined as functions". "The JWST science operations will be driven by ASCII (instead of binary command blocks) on-board scripts, written in a customized version of JavaScript. The script interpreter is run by the flight software, which is written in the programming language C++. The flight software operates the spacecraft and the science instruments."[65][66]

Comparison with other telescopes edit

 
Comparison with the Hubble Space Telescope primary mirror
Primary mirror size comparison between Webb and Hubble

The desire for a large infrared space telescope traces back decades. In the United States, the Space Infrared Telescope Facility (later called the Spitzer Space Telescope) was planned while the Space Shuttle was in development, and the potential for infrared astronomy was acknowledged at that time.[67] Unlike ground telescopes, space observatories are free from atmospheric absorption of infrared light. Space observatories opened a "new sky" for astronomers.

However, there is a challenge involved in the design of infrared telescopes: they need to stay extremely cold, and the longer the wavelength of infrared, the colder they need to be. If not, the background heat of the device itself overwhelms the detectors, making it effectively blind. This can be overcome by careful design. One method is to put the key instruments in a dewar with an extremely cold substance, such as liquid helium. The coolant will slowly vaporize, limiting the lifetime of the instrument from as short as a few months to a few years at most.[23]

It is also possible to maintain a low temperature by designing the spacecraft to enable near-infrared observations without a supply of coolant, as with the extended missions of the Spitzer Space Telescope and the Wide-field Infrared Survey Explorer, which operated at reduced capacity after coolant depletion. Another example is Hubble's Near Infrared Camera and Multi-Object Spectrometer (NICMOS) instrument, which started out using a block of nitrogen ice that depleted after a couple of years, but was then replaced during the STS-109 servicing mission with a cryocooler that worked continuously. The Webb Space Telescope is designed to cool itself without a dewar, using a combination of sunshields and radiators, with the mid-infrared instrument using an additional cryocooler.[68]

Selected space telescopes and instruments[69]
Name Launch year Wavelength
(μm)		 Aperture
(m) 		Cooling
Spacelab Infrared Telescope (IRT) 1985 1.7–118 0.15 Helium
Infrared Space Observatory (ISO)[70] 1995 2.5–240 0.60 Helium
Hubble Space Telescope Imaging Spectrograph (STIS) 1997 0.115–1.03 2.4 Passive
Hubble Near Infrared Camera and Multi-Object Spectrometer (NICMOS) 1997 0.8–2.4 2.4 Nitrogen, later cryocooler
Spitzer Space Telescope 2003 3–180 0.85 Helium
Hubble Wide Field Camera 3 (WFC3) 2009 0.2–1.7 2.4 Passive and thermo-electric[71]
Herschel Space Observatory 2009 55–672 3.5 Helium
James Webb Space Telescope 2021 0.6–28.5 6.5 Passive and cryocooler (MIRI)

Webb's delays and cost increases have been compared to those of its predecessor, the Hubble Space Telescope. When Hubble formally started in 1972, it had an estimated development cost of US$300 million (equivalent to $2,098,807,000 in 2022), but by the time it was sent into orbit in 1990, the cost was about four times that. In addition, new instruments and servicing missions increased the cost to at least US$9 billion by 2006[72] (equivalent to $13,064,708,000 in 2022).

Development history edit

For a chronological guide, see Timeline of the James Webb Space Telescope.

Background (development to 2003) edit

Major Milestones
Year Milestone
1996 Next Generation Space Telescope project first proposed (mirror size: 8 m)
2001 NEXUS Space Telescope, a precursor to the Next Generation Space Telescope, cancelled[73]
2002 Proposed project renamed James Webb Space Telescope, (mirror size reduced to 6 m)
2003 Northrop Grumman awarded contract to build telescope
2007 Memorandum of Understanding signed between NASA and ESA[74]
2010 Mission Critical Design Review (MCDR) passed
2011 Proposed cancellation
2016 Final assembly completed
25 December 2021 Launch

Discussions of a Hubble follow-on started in the 1980s, but serious planning began in the early 1990s.[75] The Hi-Z telescope concept was developed between 1989 and 1994:[76] a fully baffled[b] 4 m (13 ft) aperture infrared telescope that would recede to an orbit at 3 Astronomical unit (AU).[77] This distant orbit would have benefited from reduced light noise from zodiacal dust.[77] Other early plans called for a NEXUS precursor telescope mission.[78][79]

Correcting the flawed optics of the Hubble Space Telescope (HST) in its first years played a significant role in the birth of Webb.[citation needed] In 1993, NASA conducted STS-61, the Space Shuttle mission that replaced HST's camera and installed a retrofit for its imaging spectrograph to compensate for the spherical aberration in its primary mirror.

The HST & Beyond Committee was formed in 1994 "to study possible missions and programs for optical-ultraviolet astronomy in space for the first decades of the 21st century."[80] Emboldened by HST's success, its 1996 report explored the concept of a larger and much colder, infrared-sensitive telescope that could reach back in cosmic time to the birth of the first galaxies. This high-priority science goal was beyond the HST's capability because, as a warm telescope, it is blinded by infrared emission from its own optical system. In addition to recommendations to extend the HST mission to 2005 and to develop technologies for finding planets around other stars, NASA embraced the chief recommendation of HST & Beyond[81] for a large, cold space telescope (radiatively cooled far below 0 °C), and began the planning process for the future Webb telescope.

Preparation for the 2000 Astronomy and Astrophysics Decadal Survey (a literature review produced by the United States National Research Council that includes identifying research priorities and making recommendations for the upcoming decade) included further development of the scientific program for what became known as the Next Generation Space Telescope,[82] and advancements in relevant technologies by NASA. As it matured, studying the birth of galaxies in the young universe, and searching for planets around other stars – the prime goals coalesced as "Origins" by HST & Beyond became prominent.

As hoped, the NGST received the highest ranking in the 2000 Decadal Survey.[83]

An administrator of NASA, Dan Goldin, coined the phrase "faster, better, cheaper", and opted for the next big paradigm shift for astronomy, namely, breaking the barrier of a single mirror. That meant going from "eliminate moving parts" to "learn to live with moving parts" (i.e. segmented optics). With the goal to reduce mass density tenfold, silicon carbide with a very thin layer of glass on top was first looked at, but beryllium was selected at the end.[75]

The mid-1990s era of "faster, better, cheaper" produced the NGST concept, with an 8 m (26 ft) aperture to be flown to L2, roughly estimated to cost US$500 million.[84] In 1997, NASA worked with the Goddard Space Flight Center,[85] Ball Aerospace & Technologies,[86] and TRW[87] to conduct technical requirement and cost studies of the three different concepts, and in 1999 selected Lockheed Martin[88] and TRW for preliminary concept studies.[89] Launch was at that time planned for 2007, but the launch date was pushed back many times (see table further down).

In 2002, the project was renamed after NASA's second administrator (1961–1968), James E. Webb (1906–1992).[90] Webb led the agency during the Apollo program and established scientific research as a core NASA activity.[91]

In 2003, NASA awarded TRW the US$824.8 million prime contract for Webb. The design called for a de-scoped 6.1 m (20 ft) primary mirror and a launch date of 2010.[92] Later that year, TRW was acquired by Northrop Grumman in a hostile bid and became Northrop Grumman Space Technology.[89]

Early development and replanning (2003–2007) edit

 
Early full-scale model on display at NASA Goddard Space Flight Center (2005)

Development was managed by NASA's Goddard Space Flight Center in Greenbelt, Maryland, with John C. Mather as its project scientist. The primary contractor was Northrop Grumman Aerospace Systems, responsible for developing and building the spacecraft element, which included the satellite bus, sunshield, Deployable Tower Assembly (DTA) which connects the Optical Telescope Element to the spacecraft bus, and the Mid Boom Assembly (MBA) which helps to deploy the large sunshields on orbit,[93] while Ball Aerospace & Technologies was subcontracted to develop and build the OTE itself, and the Integrated Science Instrument Module (ISIM).[42]

Cost growth revealed in spring 2005 led to an August 2005 re-planning.[94] The primary technical outcomes of the re-planning were significant changes in the integration and test plans, a 22-month launch delay (from 2011 to 2013), and elimination of system-level testing for observatory modes at wavelengths shorter than 1.7 μm. Other major features of the observatory were unchanged. Following the re-planning, the project was independently reviewed in April 2006.[citation needed]

In the 2005 re-plan, the life-cycle cost of the project was estimated at US$4.5 billion. This comprised approximately US$3.5 billion for design, development, launch and commissioning, and approximately US$1.0 billion for ten years of operations.[94] The ESA agreed in 2004 to contributing about €300 million, including the launch.[95] The Canadian Space Agency pledged CA$39 million in 2007[96] and in 2012 delivered its contributions in equipment to point the telescope and detect atmospheric conditions on distant planets.[97]

Detailed design and construction (2007–2021) edit

 
A JWST mirror segment, 2010
 
Mirror segments undergoing cryogenic tests at the X-ray & Cryogenic Facility at Marshall Space Flight Center
 
The assembled telescope following environmental testing

In January 2007, nine of the ten technology development items in the project successfully passed a Non-Advocate Review.[98] These technologies were deemed sufficiently mature to retire significant risks in the project. The remaining technology development item (the MIRI cryocooler) completed its technology maturation milestone in April 2007. This technology review represented the beginning step in the process that ultimately moved the project into its detailed design phase (Phase C). By May 2007, costs were still on target.[99] In March 2008, the project successfully completed its Preliminary Design Review (PDR). In April 2008, the project passed the Non-Advocate Review. Other passed reviews include the Integrated Science Instrument Module review in March 2009, the Optical Telescope Element review completed in October 2009, and the Sunshield review completed in January 2010.[100]

In April 2010, the telescope passed the technical portion of its Mission Critical Design Review (MCDR). Passing the MCDR signified the integrated observatory can meet all science and engineering requirements for its mission.[101] The MCDR encompassed all previous design reviews. The project schedule underwent review during the months following the MCDR, in a process called the Independent Comprehensive Review Panel, which led to a re-plan of the mission aiming for a 2015 launch, but as late as 2018. By 2010, cost over-runs were impacting other projects, though Webb itself remained on schedule.[102]

By 2011, the Webb project was in the final design and fabrication phase (Phase C).

Assembly of the hexagonal segments of the primary mirror, which was done via robotic arm, began in November 2015 and was completed on 3 February 2016. The secondary mirror was installed on 3 March 2016.[103][104] Final construction of the Webb telescope was completed in November 2016, after which extensive testing procedures began.[105]

In March 2018, NASA delayed Webb's launch an additional 2 years to May 2020 after the telescope's sunshield ripped during a practice deployment and the sunshield's cables did not sufficiently tighten. In June 2018, NASA delayed the launch by an additional 10 months to March 2021, based on the assessment of the independent review board convened after the failed March 2018 test deployment.[106] The review identified that Webb launch and deployment had 344 potential single-point failures – tasks that had no alternative or means of recovery if unsuccessful, and therefore had to succeed for the telescope to work.[107] In August 2019, the mechanical integration of the telescope was completed, something that was scheduled to be done 12 years before in 2007.[108]

After construction was completed, Webb underwent final tests at Northrop Grumman's historic Space Park in Redondo Beach, California.[109] A ship carrying the telescope left California on 26 September 2021, passed through the Panama Canal, and arrived in French Guiana on 12 October 2021.[110]

Cost and schedule issues edit

NASA's lifetime cost for the project is[when?] expected to be US$9.7 billion, of which US$8.8 billion was spent on spacecraft design and development and US$861 million is planned to support five years of mission operations.[111] Representatives from ESA and CSA stated their project contributions amount to approximately €700 million and CA$200 million, respectively.[112]

A study in 1984 by the Space Science Board estimated that to build a next-generation infrared observatory in orbit would cost US$4 billion (US$7B in 2006 dollars, or $10B in 2020 dollars).[72] While this came close to the final cost of Webb, the first NASA design considered in the late 1990s was more modest, aiming for a $1 billion price tag over 10 years of construction. Over time this design expanded, added funding for contingencies, and had scheduling delays.

Progression of estimates for schedule and cost, along with major milestones
Year Planned
launch 		Budget plan
(billion USD)
1998 2007[113] 1[72]
2000 2009[47] 1.8[72]
2002 2010[114] 2.5[72]
2003 2011[115] 2.5[72]
2005 2013 3[116]
2006 2014 4.5[117]
2008: Preliminary Design Review
2008 2014 5.1[118]
2010: Critical Design Review
2010 2015 to 2016 6.5[119]
2011 2018 8.7[120]
2017 2019[121] 8.8
2018 2020[122] ≥8.8
2019 March 2021[123] 9.66
2021 Dec 2021[124] 9.70

By 2008, when the project entered preliminary design review and was formally confirmed for construction, over US$1 billion had already been spent on developing the telescope, and the total budget was estimated at about US$5 billion (equivalent to $7.49 billion in 2022).[125] In summer 2010, the mission passed its Critical Design Review (CDR) with excellent grades on all technical matters, but schedule and cost slips at that time prompted Maryland U.S. Senator Barbara Mikulski to call for external review of the project. The Independent Comprehensive Review Panel (ICRP) chaired by J. Casani (JPL) found that the earliest possible launch date was in late 2015 at an extra cost of US$1.5 billion (for a total of US$6.5 billion). They also pointed out that this would have required extra funding in FY2011 and FY2012 and that any later launch date would lead to a higher total cost.[119]

On 6 July 2011, the United States House of Representatives' appropriations committee on Commerce, Justice, and Science moved to cancel the James Webb project by proposing an FY2012 budget that removed US$1.9 billion from NASA's overall budget, of which roughly one quarter was for Webb.[126][127][128][129] US$3 billion had been spent and 75% of its hardware was in production.[130] This budget proposal was approved by subcommittee vote the following day. The committee charged that the project was "billions of dollars over budget and plagued by poor management".[126] In response, the American Astronomical Society issued a statement in support of Webb,[131] as did Senator Mikulski.[132] A number of editorials supporting Webb appeared in the international press during 2011 as well.[126][133][134] In November 2011, Congress reversed plans to cancel Webb and instead capped additional funding to complete the project at US$8 billion.[135]

While similar issues had affected other major NASA projects such as the Hubble telescope, some scientists expressed concerns about growing costs and schedule delays for the Webb telescope, worrying that its budget might be competing with those of other space science programs.[136][137] A 2010 Nature article described Webb as "the telescope that ate astronomy".[138] NASA continued to defend the budget and timeline of the program to Congress.[137][139]

In 2018, Gregory L. Robinson was appointed as the new director of the Webb program.[140] Robinson was credited with raising the program's schedule efficiency (how many measures were completed on time) from 50% to 95%.[140] For his role in improving the performance of the Webb program, Robinsons's supervisor, Thomas Zurbuchen, called him "the most effective leader of a mission I have ever seen in the history of NASA."[140] In July 2022, after Webb's commissioning process was complete and it began transmitting its first data, Robinson retired following a 33-year career at NASA.[141]

On 27 March 2018, NASA pushed back the launch to May 2020 or later,[122] with a final cost estimate to come after a new launch window was determined with the European Space Agency (ESA).[142][143][144] In 2019, its mission cost cap was increased by US$800 million.[145] After launch windows were paused in 2020 due to the COVID-19 pandemic,[146] Webb was launched at the end of 2021, with a total budget of just under US$10 billion.

Partnership edit

NASA, ESA and CSA have collaborated on the telescope since 1996. ESA's participation in construction and launch was approved by its members in 2003 and an agreement was signed between ESA and NASA in 2007. In exchange for full partnership, representation and access to the observatory for its astronomers, ESA is providing the NIRSpec instrument, the Optical Bench Assembly of the MIRI instrument, an Ariane 5 ECA launcher, and manpower to support operations.[95][147] The CSA provided the Fine Guidance Sensor and the Near-Infrared Imager Slitless Spectrograph and manpower to support operations.[148]

Several thousand scientists, engineers, and technicians spanning 15 countries have contributed to the build, test and integration of Webb.[149] A total of 258 companies, government agencies, and academic institutions participated in the pre-launch project; 142 from the United States, 104 from 12 European countries (including 21 from the U.K., 16 from France, 12 from Germany and 7 international),[150] and 12 from Canada.[149] Other countries as NASA partners, such as Australia, were involved in post-launch operation.[151]

Participating countries:

Naming concerns edit

See also: James E. Webb § NASA, and James E. Webb § Legacy

In 2002, NASA administrator (2001–2004) Sean O'Keefe made the decision to name the telescope after James E. Webb, the administrator of NASA from 1961 to 1968 during the Mercury, Gemini, and much of the Apollo programs.[90][91]

In 2015, concerns were raised around Webb's possible role in the lavender scare, the mid-20th-century persecution by the U.S. government targeting homosexuals in federal employment.[152][153] In 2022, NASA released a report of an investigation,[154] based on an examination of more than 50,000 documents. The report found "no available evidence directly links Webb to any actions or follow-up related to the firing of individuals for their sexual orientation", either in his time in the State Department or at NASA.[155][156]

Mission goals edit

The James Webb Space Telescope has four key goals:

These goals can be accomplished more effectively by observation in near-infrared light rather than light in the visible part of the spectrum. For this reason, Webb's instruments will not measure visible or ultraviolet light like the Hubble Telescope, but will have a much greater capacity to perform infrared astronomy. Webb will be sensitive to a range of wavelengths from 0.6 to 28 μm (corresponding respectively to orange light and deep infrared radiation at about 100 K or −173 °C).

Webb may be used to gather information on the dimming light of star KIC 8462852, which was discovered in 2015, and has some abnormal light-curve properties.[158]

Additionally, it will be able to tell if an exoplanet has methane in its atmosphere, allowing astronomers to determine whether or not the methane is a biosignature.[159][160]

Orbit design edit

 
Webb is not exactly at the L2 point, but circles around it in a halo orbit.
 
Alternative Hubble Space Telescope views of the Carina Nebula, comparing ultraviolet and visible (top) and infrared (bottom) astronomy. Far more stars are visible in the latter.

Webb orbits the Sun near the second Lagrange point (L2) of the Sun–Earth system, which is 1,500,000 km (930,000 mi) farther from the Sun than the Earth's orbit, and about four times farther than the Moon's orbit. Normally an object circling the Sun farther out than Earth would take longer than one year to complete its orbit. But near the L2 point, the combined gravitational pull of the Earth and the Sun allow a spacecraft to orbit the Sun in the same time that it takes the Earth. Staying close to Earth allows data rates to be much faster for a given size of antenna.

The telescope circles about the Sun–Earth L2 point in a halo orbit, which is inclined with respect to the ecliptic, has a radius varying between about 250,000 km (160,000 mi) and 832,000 km (517,000 mi), and takes about half a year to complete.[28] Since L2 is just an equilibrium point with no gravitational pull, a halo orbit is not an orbit in the usual sense: the spacecraft is actually in orbit around the Sun, and the halo orbit can be thought of as controlled drifting to remain in the vicinity of the L2 point.[161] This requires some station-keeping: around 2.5 m/s per year[162] from the total ∆v budget of 93 m/s.[163]: 10  Two sets of thrusters constitute the observatory's propulsion system.[164] Because the thrusters are located solely on the Sun-facing side of the observatory, all station-keeping operations are designed to slightly undershoot the required amount of thrust in order to avoid pushing Webb beyond the semi-stable L2 point, a situation which would be unrecoverable. Randy Kimble, the Integration and Test Project Scientist for the James Webb Space Telescope, compared the precise station-keeping of Webb to "Sisyphus [...] rolling this rock up the gentle slope near the top of the hill – we never want it to roll over the crest and get away from him".[165]

Animation of James Webb Space Telescope trajectory
 
Top view
 
Side view
 
Side view from the Sun

Infrared astronomy edit

 
Infrared observations can see objects hidden in visible light, such as the HUDF-JD2 shown here.
 
Atmospheric windows in the infrared: Much of this type of light is blocked when viewed from the Earth's surface. It would be like looking at a rainbow but only seeing one color.

Webb is the formal successor to the Hubble Space Telescope (HST), and since its primary emphasis is on infrared astronomy, it is also a successor to the Spitzer Space Telescope. Webb will far surpass both those telescopes, being able to see many more and much older stars and galaxies.[166] Observing in the infrared spectrum is a key technique for achieving this, because of cosmological redshift, and because it better penetrates obscuring dust and gas. This allows observation of dimmer, cooler objects. Since water vapor and carbon dioxide in the Earth's atmosphere strongly absorbs most infrared, ground-based infrared astronomy is limited to narrow wavelength ranges where the atmosphere absorbs less strongly. Additionally, the atmosphere itself radiates in the infrared spectrum, often overwhelming light from the object being observed. This makes a space telescope preferable for infrared observation.[167]

The more distant an object is, the younger it appears; its light has taken longer to reach human observers. Because the universe is expanding, as the light travels it becomes red-shifted, and objects at extreme distances are therefore easier to see if viewed in the infrared.[168] Webb's infrared capabilities are expected to let it see back in time to the first galaxies forming just a few hundred million years after the Big Bang.[169]

Infrared radiation can pass more freely through regions of cosmic dust that scatter visible light. Observations in infrared allow the study of objects and regions of space which would be obscured by gas and dust in the visible spectrum,[168] such as the molecular clouds where stars are born, the circumstellar disks that give rise to planets, and the cores of active galaxies.[168]

Relatively cool objects (temperatures less than several thousand degrees) emit their radiation primarily in the infrared, as described by Planck's law. As a result, most objects that are cooler than stars are better studied in the infrared.[168] This includes the clouds of the interstellar medium, brown dwarfs, planets both in our own and other solar systems, comets, and Kuiper belt objects that will be observed with the Mid-Infrared Instrument (MIRI).[47][169]

Some of the missions in infrared astronomy that impacted Webb development were Spitzer and the Wilkinson Microwave Anisotropy Probe (WMAP).[170] Spitzer showed the importance of mid-infrared, which is helpful for tasks such as observing dust disks around stars.[170] Also, the WMAP probe showed the universe was "lit up" at redshift 17, further underscoring the importance of the mid-infrared.[170] Both these missions were launched in the early 2000s, in time to influence Webb development.[170]

Ground support and operations edit

The Space Telescope Science Institute (STScI), in Baltimore, Maryland, on the Homewood Campus of Johns Hopkins University, was selected in 2003 as the Science and Operations Center (S&OC) for Webb with an initial budget of US$162.2 million intended to support operations through the first year after launch.[171] In this capacity, STScI was to be responsible for the scientific operation of the telescope and delivery of data products to the astronomical community. Data was to be transmitted from Webb to the ground via the NASA Deep Space Network, processed and calibrated at STScI, and then distributed online to astronomers worldwide. Similar to how Hubble is operated, anyone, anywhere in the world, will be allowed to submit proposals for observations. Each year several committees of astronomers will peer review the submitted proposals to select the projects to observe in the coming year. The authors of the chosen proposals will typically have one year of private access to the new observations, after which the data will become publicly available for download by anyone from the online archive at STScI.[citation needed]

The bandwidth and digital throughput of the satellite is designed to operate at 458 gigabits of data per day for the length of the mission (equivalent to a sustained rate of 5.42 Mbps).[38] Most of the data processing on the telescope is done by conventional single-board computers.[172] The digitization of the analog data from the instruments is performed by the custom SIDECAR ASIC (System for Image Digitization, Enhancement, Control And Retrieval Application Specific Integrated Circuit). NASA stated that the SIDECAR ASIC will include all the functions of a 9.1 kg (20 lb) instrument box in a 3 cm (1.2 in) package and consume only 11 milliwatts of power.[173] Since this conversion must be done close to the detectors, on the cold side of the telescope, the low power dissipation is crucial for maintaining the low temperature required for optimal operation of Webb.[173]

The telescope is equipped with a solid-state drive (SSD) with a capacity of 68GB, used as temporary storage for data collected from its scientific instruments. By the end of the 10-year mission, the usable capacity of the drive is expected to decrease to 60GB due to the effects of radiation and read/write operations.[174]

Micrometeoroid strike edit

The C3[c] mirror segment suffered a micrometeoroid strike from a large dust mote-sized particle between 23 and 25 May, the fifth and largest strike since launch, reported 8 June 2022, which required engineers to compensate for the strike using a mirror actuator.[176] Despite the strike, a NASA characterization report states "all JWST observing modes have been reviewed and confirmed to be ready for science use" as of July 10, 2022.[177]

From launch through commissioning edit

Main article: Launch and commissioning of the James Webb Space Telescope

Launch edit

Main article: Ariane flight VA256

The launch (designated Ariane flight VA256) took place as scheduled at 12:20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana.[178][179] The telescope was confirmed to be receiving power, starting a two-week deployment phase of its parts[180] and traveling to its target destination.[181][182][183] The telescope was released from the upper stage 27 minutes 7 seconds after launch, beginning a 30-day adjustment to place the telescope in a Lissajous orbit[184] around the L2 Lagrange point.

The telescope was launched with slightly less speed than needed to reach its final orbit, and slowed down as it travelled away from Earth, in order to reach L2 with only the velocity needed to enter its orbit there. The telescope reached L2 on 24 January 2022. The flight included three planned course corrections to adjust its speed and direction. This is because the observatory could recover from underthrust (going too slowly), but could not recover from overthrust (going too fast) – to protect highly temperature-sensitive instruments, the sunshield must remain between telescope and Sun, so the spacecraft could not turn around or use its thrusters to slow down.[185]

An L2 orbit is unstable, so JWST needs to use propellant to maintain its halo orbit around L2 (known as station-keeping) to prevent the telescope from drifting away from its orbital position.[186] It was designed to carry enough propellant for 10 years,[187] but the precision of the Ariane 5 launch and the first midcourse correction were credited with saving enough onboard fuel that JWST may be able to maintain its orbit for around 20 years instead.[188][189][190] Space.com called the launch "flawless".[191]

  •  

    Diagram of Webb inside Ariane 5

  •  

    Ariane 5 and Webb at the ELA-3 launch pad

  •  

    Ariane 5 containing the James Webb Space Telescope lifting-off from the launch pad

  •  

    Ariane 5 containing Webb moments after lift-off

  •  

    Webb as seen from the ESC-D Cryotechnic upper stage shortly after separation, approximately 29 minutes after launch. Part of the Earth with the Gulf of Aden is visible in the background of the image.[192]

Transit and structural deployment edit

 
Structural deployment timeline[49]

Webb was released from the rocket upper stage 27 minutes after a flawless launch.[178][193] Starting 31 minutes after launch, and continuing for about 13 days, Webb began the process of deploying its solar array, antenna, sunshield, and mirrors.[194] Nearly all deployment actions are commanded by the Space Telescope Science Institute in Baltimore, Maryland, except for two early automatic steps, solar panel unfolding and communication antenna deployment.[195][196] The mission was designed to give ground controllers flexibility to change or modify the deployment sequence in case of problems.[197]

Structural deployment sequence

At 7:50 p.m. EST on 25 December 2021, about 12 hours after launch, the telescope's pair of primary rockets began firing for 65 minutes to make the first of three planned mid-course corrections.[198] On day two, the high gain communication antenna deployed automatically.[197]

On 27 December 2021, at 60 hours after launch, Webb's rockets fired for nine minutes and 27 seconds to make the second of three mid-course corrections for the telescope to arrive at its L2 destination.[199] On 28 December 2021, three days after launch, mission controllers began the multi-day deployment of Webb's all-important sunshield. On 30 December 2021, controllers successfully completed two more steps in unpacking the observatory. First, commands deployed the aft "momentum flap", a device that provides balance against solar pressure on the sunshield, saving fuel by reducing the need for thruster firing to maintain Webb's orientation.[200]

On 31 December 2021, the ground team extended the two telescoping "mid booms" from the left and right sides of the observatory.[201] The left side deployed in 3 hours and 19 minutes; the right side took 3 hours and 42 minutes.[202][201] Commands to separate and tension the membranes followed between 3 and 4 January and were successful.[201] On 5 January 2022, mission control successfully deployed the telescope's secondary mirror, which locked itself into place to a tolerance of about one and a half millimeters.[203]

The last step of structural deployment was to unfold the wings of the primary mirror. Each panel consists of three primary mirror segments and had to be folded to allow the space telescope to be installed in the fairing of the Ariane rocket for the launch of the telescope. On 7 January 2022, NASA deployed and locked in place the port-side wing,[204] and on 8 January, the starboard-side mirror wing. This successfully completed the structural deployment of the observatory.[205][206][207]

On 24 January 2022, at 2:00 p.m. Eastern Standard Time,[208] nearly a month after launch, a third and final course correction took place, inserting Webb into its planned halo orbit around the Sun–Earth L2 point.[209][210]

The MIRI instrument has four observing modes—imaging, low-resolution spectroscopy, medium-resolution spectroscopy and coronagraphic imaging. “On Aug. 24, a mechanism that supports medium-resolution spectroscopy (MRS), exhibited what appears to be increased friction during setup for a science observation. This mechanism is a grating wheel that allows scientists to select between short, medium, and longer wavelengths when making observations using the MRS mode,” said NASA in a press statement.[211]

Animation of Webb's halo orbit

Commissioning and testing edit

On 12 January 2022, while still in transit, mirror alignment began. The primary mirror segments and secondary mirror were moved away from their protective launch positions. This took about 10 days, because the 132[212] actuator motors are designed to fine-tune the mirror positions at microscopic accuracy (10 nanometer increments) and must each move over 1.2 million increments (12.5 mm) during initial alignment.[213][39]

Mirror alignment requires each of the 18 mirror segments, and the secondary mirror, to be positioned to within 50 nanometers. NASA compares the required accuracy by analogy: "If the Webb primary mirror were the size of the United States, each [mirror] segment would be the size of Texas, and the team would need to line the height of those Texas-sized segments up with each other to an accuracy of about 1.5 inches".[214]

  • James Webb Space Telescope Mirror alignment animations
  •  

    Segment image identification. 18 mirror segments are moved to determine which segment creates which segment image. After matching the mirror segments to their respective images, the mirrors are tilted to bring all the images near a common point for further analysis.

  •  

    Segment alignment begins by defocusing the segment images by moving the secondary mirror slightly. Mathematical analysis, called phase retrieval, is applied to the defocused images to determine the precise positioning errors of the segments. Adjustments of the segments then result in 18 well-corrected "telescopes". However, the segments still do not work together as a single mirror.

  •  

    Image stacking. To put all of the light in a single place, each segment image must be stacked on top of one another. In the image stacking step, the individual segment images are moved so that they fall precisely at the center of the field to produce one unified image. This process prepares the telescope for coarse phasing.

  •  

    Telescope alignment over instrument fields of view. After fine phasing, the telescope is well aligned at one place in the NIRCam field of view. Next the alignment must be extended to the rest of the instruments.

Mirror alignment was a complex operation split into seven phases, that had been repeatedly rehearsed using a 1:6 scale model of the telescope.[214] Once the mirrors reached 120 K (−153 °C; −244 °F),[215] NIRCam targeted the 6th magnitude star HD 84406 in Ursa Major.[d][217][218] To do this, NIRCam took 1560 images of the sky and used these wide-ranging images to determine where in the sky each segment of the main mirror initially pointed.[219] At first, the individual primary mirror segments were greatly misaligned, so the image contained 18 separate, blurry, images of the star field, each containing an image of the target star. The 18 images of HD 84406 are matched to their respective mirror segments, and the 18 segments are brought into approximate alignment centered on the star ("Segment Image Identification"). Each segment was then individually corrected of its major focusing errors, using a technique called phase retrieval, resulting in 18 separate good quality images from the 18 mirror segments ("Segment Alignment"). The 18 images from each segment, were then moved so they precisely overlap to create a single image ("Image Stacking").[214]

With the mirrors positioned for almost correct images, they had to be fine tuned to their operational accuracy of 50 nanometers, less than one wavelength of the light that will be detected. A technique called dispersed fringe sensing was used to compare images from 20 pairings of mirrors, allowing most of the errors to be corrected ("Coarse Phasing"), and then introduced light defocus to each segment's image, allowing detection and correction of almost all remaining errors ("Fine Phasing"). These two processes were repeated three times, and Fine Phasing will be routinely checked throughout the telescope's operation. After three rounds of Coarse and Fine Phasing, the telescope was well aligned at one place in the NIRCam field of view. Measurements will be made at various points in the captured image, across all instruments, and corrections calculated from the detected variations in intensity, giving a well-aligned outcome across all instruments ("Telescope Alignment Over Instrument Fields of View"). Finally, a last round of Fine Phasing and checks of image quality on all instruments was performed, to ensure that any small residual errors remaining from the previous steps, were corrected ("Iterate Alignment for Final Correction"). The telescope's mirror segments were then aligned and able to capture precise focused images.[214]

In preparation for alignment, NASA announced at 19:28 UTC on 3 February 2022, that NIRCam had detected the telescope's first photons (although not yet complete images).[214][220] On 11 February 2022, NASA announced the telescope had almost completed phase 1 of alignment, with every segment of its primary mirror having located and imaged the target star HD 84406, and all segments brought into approximate alignment.[219] Phase 1 alignment was completed on 18 February 2022,[221] and a week later, phases 2 and 3 were also completed.[222] This meant the 18 segments were working in unison, however until all 7 phases are complete, the segments were still acting as 18 smaller telescopes rather than one larger one.[222] At the same time as the primary mirror was being commissioned, hundreds of other instrument commissioning and calibration tasks were also ongoing.[223]

  •  

    Phase 1 interim image, annotated with the related mirror segments that took each image

  •  

    Phase 1 annotated completion image of HD 84406

  •  

    Phase 2 completion, showing "before and after" effects of segment alignment

  •  

    Phase 3 completion, showing 18 segments "stacked" as a single image of HD 84406

  •  

    Star 2MASS J17554042+6551277[e] captured by NIRCam instrument

  •  

    A "selfie" taken by the NIRCam during the alignment process

  •  

    Image comparison between "old" Spitzer and new Webb[226]

  •  

    Alignment of the NASA/ESA/CSA James Webb Space Telescope's sensors.[227]

  •  

    Webb’s Fine Guidance Sensor (FGS).[228]

Allocation of observation time edit

Webb observing time is allocated through a General Observers (GO) program, a Guaranteed Time Observations (GTO) program, and a Director's Discretionary Early Release Science (DD-ERS) program.[229] The GTO program provides guaranteed observing time for scientists who developed hardware and software components for the observatory. The GO program provides all astronomers the opportunity to apply for observing time and will represent the bulk of the observing time. GO programs are selected through peer review by a Time Allocation Committee (TAC), similar to the proposal review process used for the Hubble Space Telescope.

Early Release Science program edit

In November 2017, the Space Telescope Science Institute announced the selection of 13 Director's Discretionary Early Release Science (DD-ERS) programs, chosen through a competitive proposal process.[230][231] The observations for these programs—Early Release Observations (ERO)[232][233] – were to be obtained during the first five months of Webb science operations after the end of the commissioning period. A total of 460 hours of observing time was awarded to these 13 programs, which span science topics including the Solar System, exoplanets, stars and star formation, nearby and distant galaxies, gravitational lenses, and quasars. These 13 ERS programs were to use a total of 242.8 hours of observing time on the telescope (not including Webb observing overheads and slew time).

Early Release Science programs
Name Principal Investigator Category Observation time (hours)
Radiative Feedback from Massive Stars as Traced by Multiband Imaging and Spectroscopic Mosaics Olivier Berné Stellar Physics 8.3[234]
IceAge: Chemical Evolution of Ices during Star Formation Melissa McClure Stellar Physics 13.4[235]
Through the Looking GLASS: A JWST Exploration of Galaxy Formation and Evolution from Cosmic Dawn to Present Day Tommaso Treu Galaxies and the IGM 24.3[236]
A JWST Study of the Starburst-AGN Connection in Merging LIRGs Lee Armus Galaxies and the IGM 8.7[237]
The Resolved Stellar Populations Early Release Science Program Daniel Weisz Stellar Populations 20.3[238]
Q-3D: Imaging Spectroscopy of Quasar Hosts with JWST Analyzed with a Powerful New PSF Decomposition and Spectral Analysis Package Dominika Wylezalek Massive Black Holes and their Galaxies 17.4[239]
The Cosmic Evolution Early Release Science (CEERS) Survey Steven Finkelstein Galaxies and the IGM 36.6[240]
Establishing Extreme Dynamic Range with JWST: Decoding Smoke Signals in the Glare of a Wolf-Rayet Binary Ryan Lau Stellar Physics 6.5[241]
TEMPLATES: Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star Formation Jane Rigby Galaxies and the IGM 26.0[242]
Nuclear Dynamics of a Nearby Seyfert with NIRSpec Integral Field Spectroscopy Misty Bentz Massive Black Holes and their Galaxies 1.5[243]
The Transiting Exoplanet Community Early Release Science Program Natalie Batalha Planets and Planet Formation 52.1[244]
ERS observations of the Jovian System as a Demonstration of JWST's Capabilities for Solar System Science Imke de Pater Solar System 9.3[245]
High Contrast Imaging of Exoplanets and Exoplanetary Systems with JWST Sasha Hinkley Planets and Planet Formation 18.4[246]

General Observer Program edit

For GO Cycle 1 there were 6,000 hours of observation time available to allocate, and 1,173 proposals were submitted requesting a total of 24,500 hours of observation time.[247] Selection of Cycle 1 GO programs was announced on 30 March 2021, with 266 programs approved. These included 13 large programs and treasury programs producing data for public access.[248] The Cycle 2 GO program was announced on May 10, 2023.[249] Webb science observations are nominally scheduled in weekly increments. The observation plan for every week is published on Mondays by the Space Telescope Science Institute.[250]

Scientific results edit

James Webb Space Telescope completed its commissioning and was ready to begin full scientific operations on 11 July 2022.[251] With some exceptions, most experiment data is kept private for one year for the exclusive use of scientists running that particular experiment, and then the raw data will be released to the public.[252]

Hubble (2017) compared to Webb (2022)[253][254]
 
 
Deep Field – Galaxy cluster
SMACS J0723.3-7327[255][256][257][258][226]

First full-color images edit

The first full-color images and spectroscopic data were released on 12 July 2022, which also marked the official beginning of Webb's general science operations. United States President Joe Biden revealed the first image, Webb's First Deep Field, on 11 July 2022.[255][256] Additional releases around this time include:[259][260][261]

On 14 July 2022, NASA presented images of Jupiter and related areas by the James Webb Space Telescope, including infrared views.[263]

In a preprint released around the same time, NASA, ESA and CSA scientists stated that "almost across the board, the science performance of JWST is better than expected". The document described a series of observations during the commissioning, when the instruments captured spectra of transiting exoplanets with a precision better than 1000 ppm per data point, and tracked moving objects with speeds up to 67 milliarcseconds/second, more than twice as fast as the requirement.[a] It also obtained the spectra of hundreds of stars simultaneously in a dense field towards the Milky Way Galactic Center. Other targets included:[25]

Bright early galaxies edit

Within two weeks of the first Webb images, several preprint papers described a wide range of high redshift and very luminous (presumably large) galaxies believed to date from 235 million years (z=16.7) to 280 million years after the Big Bang, far earlier than previously known.[232][233] On 17 August 2022, NASA released a large mosaic image of 690 individual frames taken by the Near Infrared Camera (NIRCam) on Webb of numerous very early galaxies.[265][266] Some early galaxies observed by Webb like CEERS-93316, which has an estimated redshift of approximately z=16.7 corresponding to 235.8 million years after the Big Bang, are high redshift galaxy candidates.[267][268] In September 2022, primordial black holes were proposed as explaining these unexpectedly large and early galaxies.[269][270][271]

Subsequent noteworthy observations and interpretations edit

In June 2023 detection of organic molecules 12 billion light-years away in a galaxy called SPT0418-47 using the Webb telescope was announced.[272]

On 12 July 2023, NASA celebrated the first year of operations with the release of Webb’s image of a small star-forming region in the Rho Ophiuchi cloud complex, 390 light years away.[273]

In September 2023, two astrophysicists questioned the accepted Standard Model of Cosmology, based on the latest James Webb Space Telescope studies.[274]

Gallery edit

  Media related to Images by the James Webb Space Telescope at Wikimedia Commons

See also edit

Notes edit

  1. ^ a b JWST was designed with the requirement to track objects that move as fast as Mars, which has a maximum apparent speed on the sky of 30 mas/s, which is the value given in the technical specification, i.e. the nominal value.[24]
    During commissioning, various asteroids were observed to determine the actual limitation for the speed of objects and it turned out to be 67 mas/s, which is more than twice the nominal value. Tracking at rates of 30–67 mas/s showed accuracies similar to tracking of slower targets. Thus, the telescope is able to observe also near-Earth asteroids (NEAs), comets closer to perihelion and interstellar objects.[25]: 8 
    Later, after more experience with FGS had been gained, the tracking speed limit was finally set to 75 mas/s for routine observations. Higher rates up to 100 mas/s are also possible on special request, as FGS needs multiple guide stars to this end, which introduces complexity and inefficiency. The first observation with a super-fast rate was the DART impact experiment on 26 September 2022.[26]
  2. ^ "Baffled", in this context, means enclosed in a tube in a similar manner to a conventional optical telescope, which helps to stop stray light entering the telescope from the side. For an actual example, see the following link: Freniere, E.R. (1981). "First-order design of optical baffles". Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, First-order design of optical baffles. Radiation Scattering in Optical Systems. Vol. 257. pp. 19–28. Bibcode:1981SPIE..257...19F. doi:10.1117/12.959598.
  3. ^ The C3 mirror segment is positioned in the outer ring of segments, located at the '5 o'clock' number of a clock face, when viewing the primary mirror face-on.[175]
  4. ^ HD 84406 is a star approximately 258.5 light-years away in the constellation of Ursa Major. The star is a spectral type G star and has a high proper motion.[216]
  5. ^ 2MASS J17554042+6551277, also known as UNSW-V 084 and TYC 4212-1079-1,[224] is a star in the constellation Draco, in the Milky Way. It is located almost 2,000 light years away from Earth, within a degree of the north ecliptic pole. Its visual apparent magnitude mv is 10.95, which makes it much too faint to be observed with the naked eye. It is cooler than the Sun, but some 13 to 16 times brighter in visible light,[225] and is consequently not a sun-like star. Its motion vector in the direction of the Sun is 51 km/s.[224]

References edit

  1. ^ a b "NASA JWST "Who are the partners in the Webb project?"". NASA. from the original on 29 November 2011. Retrieved 18 November 2011.   This article incorporates text from this source, which is in the public domain.
  2. ^ Kelso, Thomas S. (25 December 2021). "JWST". Celestrak. from the original on 18 January 2022. Retrieved 26 December 2021.
  3. ^ "FAQ Full General Public Webb Telescope/NASA". jwst.nasa.gov. from the original on 23 July 2019. Retrieved 13 January 2022.
  4. ^ "NASA Says Webb's Excess Fuel Likely to Extend its Lifetime Expectations – James Webb Space Telescope". blogs.nasa.gov. 29 December 2021. from the original on 6 January 2022. Retrieved 30 December 2021.
  5. ^ a b "James Webb Space Telescope (JWST)". NASA Space Science Data Coordinated Archive. Retrieved 10 February 2023.
  6. ^ "Webb Key Facts". Goddard Space Flight Center, NASA. Retrieved 7 April 2023.
  7. ^ a b "JWST Orbit". JWST User Documentation. Space Telescope Science Institute. from the original on 11 July 2022. Retrieved 25 December 2021.
  8. ^ "JWST Telescope". James Webb Space Telescope User Documentation. Space Telescope Science Institute. 23 December 2019. from the original on 11 July 2022. Retrieved 11 June 2020.   This article incorporates text from this source, which is in the public domain.
  9. ^ Moskowitz, Clara (1 December 2022). "How JWST Is Changing Our View of the Universe – The James Webb Space Telescope has sparked a new era in astronomy". Scientific American. from the original on 15 November 2022. Retrieved 15 November 2022.
  10. ^ a b Overbye, Dennis (23 August 2022). "How the Webb Telescope Expanded My Universe – As new images of Jupiter and a galactic survey spring forth from NASA's new observatory, our cosmic affairs correspondent confesses he didn't anticipate their power". The New York Times. from the original on 24 August 2022. Retrieved 24 August 2022.
  11. ^ a b Achenbach, Joel (5 August 2022). "The Webb telescope is astonishing. But the universe is even more so – This new tool can't do everything, but it's capturing some of the first light emitted after the big bang, and that is already revealing wonders". The Washington Post. from the original on 7 August 2022. Retrieved 7 August 2022.
  12. ^ O'Callaghan, Jonathan (23 January 2023). "JWST Heralds a New Dawn for Exoplanet Science – The James Webb Space Telescope is opening an exciting new chapter in the study of exoplanets and the search for life beyond Earth". Scientific American. Retrieved 25 January 2023.
  13. ^ Fisher, Alise; Pinol, Natasha; Betz, Laura (11 July 2022). "President Biden Reveals First Image from NASA's Webb Telescope". NASA. from the original on 12 July 2022. Retrieved 12 July 2022.
  14. ^ a b c "Comparison: Webb vs Hubble Telescope – Webb/NASA". www.jwst.nasa.gov. from the original on 21 January 2022. Retrieved 12 July 2022.
  15. ^ Lallo, Matthew D. (2012). "Experience with the Hubble Space Telescope: 20 years of an archetype". Optical Engineering. 51 (1): 011011–011011–19. arXiv:1203.0002. Bibcode:2012OptEn..51a1011L. doi:10.1117/1.OE.51.1.011011. S2CID 15722152.
  16. ^ "Mirrors Webb/NASA". webb.nasa.gov. from the original on 4 February 2022. Retrieved 12 July 2022.
  17. ^ a b "A Deeper Sky | by Brian Koberlein". briankoberlein.com. from the original on 19 March 2022. Retrieved 5 January 2022.
  18. ^ a b c "FAQ for Scientists Webb Telescope/NASA". jwst.nasa.gov. from the original on 5 January 2022. Retrieved 5 January 2022.
  19. ^ Shelton, Jim (3 March 2016). "Shattering the cosmic distance record, once again". Yale University. from the original on 13 March 2016. Retrieved 4 March 2016.
  20. ^ "Hubble breaks cosmic distance record". SpaceTelescope.org. 3 March 2016. heic1604. from the original on 8 March 2016. Retrieved 3 March 2016.
  21. ^ Oesch, P. A.; Brammer, G.; van Dokkum, P.; et al. (March 2016). "A Remarkably Luminous Galaxy at z=11.1 Measured with Hubble Space Telescope Grism Spectroscopy". The Astrophysical Journal. 819 (2). 129. arXiv:1603.00461. Bibcode:2016ApJ...819..129O. doi:10.3847/0004-637X/819/2/129. S2CID 119262750.
  22. ^ Atkinson, Nancy. "Hubble Has Looked Back in Time as Far as It Can And Still Can't Find The First Stars". Universe Today. from the original on 9 January 2022. Retrieved 9 January 2022 – via ScienceAlert.
  23. ^ a b . Infrared Processing and Analysis Center, NASA Spitzer Science Center, California Institute of Technology. 2017. Archived from the original on 21 December 2016.   This article incorporates text from this source, which is in the public domain.
  24. ^ Fisher, Alise (14 July 2022). "Webb Images of Jupiter and More Now Available in Commissioning Data". James Webb Space Telescope (NASA Blogs). from the original on 16 January 2023. Retrieved 8 August 2022.
  25. ^ a b c Rigby, Jane; Perrin, Marshall; McElwain, Michael; Kimble, Randy; Friedman, Scott; Lallo, Matt; Doyon, René; Feinberg, Lee; Ferruit, Pierre; Glasse, Alistair; Rieke, Marcia; Rieke, George; et al. (2023). "The Science Performance of JWST as Characterized in Commissioning". Publications of the Astronomical Society of the Pacific. 135 (1046): 048001. arXiv:2207.05632. Bibcode:2023PASP..135d8001R. doi:10.1088/1538-3873/acb293. S2CID 253735464.
  26. ^ Thaddeus, Cesari (8 February 2023). "Breaking the Tracking Speed Limit With Webb". James Webb Space Telescope (NASA Blogs). Retrieved 11 February 2023.
  27. ^ "Technical FAQ Specifically On Solar System Observations". James Webb Space Telescope. NASA. from the original on 12 July 2022. Retrieved 29 July 2022.
  28. ^ a b c "L2 Orbit". Space Telescope Science Institute. Archived from the original on 3 February 2014. Retrieved 28 August 2016.
  29. ^ a b c "The Sunshield". nasa.gov. NASA. from the original on 10 August 2017. Retrieved 28 August 2016.   This article incorporates text from this source, which is in the public domain.
  30. ^ Drake, Nadia (24 April 2015). "Hubble Still Wows At 25, But Wait Till You See What's Next". National Geographic. from the original on 23 June 2019. Retrieved 24 April 2015.
  31. ^ "The James Webb Space Telescope". nasa.gov. from the original on 30 June 2019. Retrieved 28 August 2016.   This article incorporates text from this source, which is in the public domain.
  32. ^ "Sunshield Coatings Webb/NASA". jwst.nasa.gov. from the original on 29 December 2021. Retrieved 3 May 2020.   This article incorporates text from this source, which is in the public domain.
  33. ^ Clery, Daniel (27 March 2018). "NASA announces more delays for giant space telescope". Science. from the original on 24 December 2021. Retrieved 5 June 2018.
  34. ^ Morring, Frank Jr. (16 December 2013). "JWST Sunshade Folding, Deployment In Test". Aviation Week & Space Technology. pp. 48–49. ISSN 0005-2175. from the original on 19 March 2022. Retrieved 27 December 2021.
  35. ^ Fisher, Alise (30 December 2021). "Webb Ready for Sunshield Deployment and Cooldown". James Webb Space Telescope (NASA Blogs). from the original on 30 December 2021. Retrieved 31 December 2021.
  36. ^ "JWST Wavefront Sensing and Control". Space Telescope Science Institute. Archived from the original on 5 August 2012. Retrieved 9 June 2011.
  37. ^ "Keck I and Keck II Telescopes". W. M. Keck Observatory. from the original on 1 April 2022. Retrieved 12 July 2022.
  38. ^ a b Mallonee, Laura (22 October 2019). "NASA's Biggest Telescope Ever Prepares for a 2021 Launch". Wired. from the original on 16 May 2022. Retrieved 4 June 2021.
  39. ^ a b "Mirror, Mirror…On Its Way! – James Webb Space Telescope". Blogs.nasa.gov. 13 January 2022. from the original on 27 January 2022. Retrieved 12 February 2022.
  40. ^ "JWST Mirrors". Space Telescope Science Institute. Archived from the original on 5 August 2012. Retrieved 9 June 2011.
  41. ^ Amos, Jonathan (16 March 2022). "James Webb: 'Fully focused' telescope beats expectations". BBC News. from the original on 11 July 2022. Retrieved 15 July 2022.
  42. ^ a b "JWST: Integrated Science Instrument Module (ISIM)". NASA. 2017. from the original on 2 June 2019. Retrieved 2 February 2017.   This article incorporates text from this source, which is in the public domain.
  43. ^ "James Webb Space Telescope Near Infrared Camera". STScI. Archived from the original on 21 March 2013. Retrieved 24 October 2013.
  44. ^ "NIRCam for the James Webb Space Telescope". University of Arizona. from the original on 3 November 2021. Retrieved 24 October 2013.
  45. ^ a b c "JWST Current Status". STScI. Archived from the original on 15 July 2009. Retrieved 5 July 2008.
  46. ^ "NIRSpec – the near-infrared spectrograph on JWST". European Space Agency. 22 February 2015. from the original on 3 April 2019. Retrieved 2 February 2017.
  47. ^ a b c . Archived from the original on 27 September 2011.
  48. ^ a b "JWST: Mid-Infrared Instrument (MIRI)". NASA. 2017. from the original on 12 June 2019. Retrieved 3 February 2017.   This article incorporates text from this source, which is in the public domain.
  49. ^ a b "JWST". NASA. from the original on 26 June 2015. Retrieved 29 June 2015.   This article incorporates text from this source, which is in the public domain.
  50. ^ Banks, Kimberly; Larson, Melora; Aymergen, Cagatay; Zhang, Burt (2008). Angeli, George Z.; Cullum, Martin J. (eds.). "James Webb Space Telescope Mid-Infrared Instrument Cooler systems engineering" (PDF). Proceedings of SPIE. Modeling, Systems Engineering, and Project Management for Astronomy III. 7017: 5. Bibcode:2008SPIE.7017E..0AB. doi:10.1117/12.791925. S2CID 17507846. (PDF) from the original on 6 October 2021. Retrieved 6 February 2016. Fig. 1. Cooler Architecture Overview
  51. ^ "JWST is ready for launch and amazing science". The Planetary Society. Retrieved 22 August 2023.
  52. ^ Doyon, René; Hutchings, John B.; Beaulieu, Mathilde; Albert, Loic; Lafrenière, David; Willott, Chris; Touahri, Driss; Rowlands, Neil; Maszkiewicz, Micheal; Fullerton, Alex W.; Volk, Kevin; Martel, André R.; Chayer, Pierre; Sivaramakrishnan, Anand; Abraham, Roberto; Ferrarese, Laura; Jayawardhana, Ray; Johnstone, Doug; Meyer, Michael; Pipher, Judith L.; Sawicki, Marcin (22 August 2012). Clampin, Mark C; Fazio, Giovanni G; MacEwen, Howard A; Oschmann, Jacobus M (eds.). "The JWST Fine Guidance Sensor (FGS) and Near-Infrared Imager and Slitless Spectrograph (NIRISS)". Proceedings of SPIE. Space Telescopes and Instrumentation 2012: Optical, Infrared, and Millimeter Wave. 8442: 84422R. Bibcode:2012SPIE.8442E..2RD. doi:10.1117/12.926578. S2CID 120702854. "FGS features two modules: an infrared camera dedicated to fine guiding of the observatory and a science camera module, the Near-Infrared Imager and Slitless Spectrograph (NIRISS)"
  53. ^ "The Spacecraft Bus". NASA James Webb Space Telescope. 2017. from the original on 6 July 2019. Retrieved 26 November 2016.   This article incorporates text from this source, which is in the public domain.
  54. ^ a b "The JWST Observatory". NASA. 2017. from the original on 20 May 2019. Retrieved 28 December 2016. The Observatory is the space-based portion of the James Webb Space Telescope system and is comprisedof three elements: the Integrated Science Instrument Module (ISIM), the Optical Telescope Element (OTE), which includes the mirrors and backplane, and the Spacecraft Element, which includes the spacecraft bus and the sunshield   This article incorporates text from this source, which is in the public domain.
  55. ^ . NASA James Webb Space Telescope. 2017. Archived from the original on 3 December 2016. Retrieved 30 November 2016.   This article incorporates text from this source, which is in the public domain.
  56. ^ Willoughby, Scott P. (February 2012). "PRIME: The Untold Story Of NASA's James Webb Space Telescope". SatMagazine. Satnews. from the original on 11 August 2022. Retrieved 6 April 2021.
  57. ^ Sloan, Jeff (12 October 2015). . Composites World. Archived from the original on 24 October 2019. Retrieved 28 December 2016.
  58. ^ "JWST Propulsion". JWST User Documentation. Space Telescope Science Institute. from the original on 11 July 2022. Retrieved 29 December 2021.
  59. ^ Clark, Stephen (28 November 2021). "NASA gives green light to fuel James Webb Space Telescope". Spaceflight Now. from the original on 25 June 2022. Retrieved 2 December 2021.
  60. ^ "Why is Webb not serviceable like Hubble?". James Webb Space Telescope (FAQ). from the original on 3 July 2022. Retrieved 31 December 2021.
  61. ^ a b "Relief as NASA's most powerful space telescope finishes risky unfolding". Science. 8 January 2022. from the original on 31 January 2022. Retrieved 11 January 2022.
  62. ^ Smith, Marcia (30 August 2018). "Zurbuchen Taking One Last Look at JWST Servicing Compatiblity [sic]". SpacePolicyOnline. from the original on 31 December 2021. Retrieved 31 December 2021.
  63. ^ Foust, Jeff (2 February 2018). "Scientists, engineers push for servicing and assembly of future space observatories". SpaceNews. from the original on 15 July 2022. Retrieved 31 December 2021.
  64. ^ Grush, Loren (28 December 2021). "NASA's James Webb Space Telescope is about to transform into its final form". The Verge. from the original on 9 July 2022. Retrieved 11 January 2022.
  65. ^ Dashevsky, Ilana; Balzano, Vicki (2007). "JWST: Maximizing. Efficiency and Minimizing Ground Systems" (PDF). International Symposium on Reducing the Costs of Spacecraft Ground Systems and Operations Proceedings. (PDF) from the original on 4 December 2022. Retrieved 4 December 2022.
  66. ^ Greenhouse, Matthew A. Status of the James Webb Space Telescope Integrated Science Instrument Module System (PDF) (Report). Goddard Space Flight Center. (PDF) from the original on 13 July 2022. Retrieved 4 December 2022.
  67. ^ McCarthy, S. G.; Autio, G. W. (1978). Infrared Detector Performance In The Shuttle Infrared Telescope Facility (SIRTF). 1978 Los Angeles Technical Symposium. Utilization of Infrared Detectors. Vol. 81. Society of Photographic Instrumentation Engineers. pp. 81–88. Bibcode:1978SPIE..132...81M. doi:10.1117/12.956060. from the original on 5 March 2017. Retrieved 8 December 2016. The tenuous atmosphere above the 400 km nominal flight altitude has no measurable absorption so that detectors operating at all wavelengths from 5 μm to 1000 μm can achieve high radiometric sensitivity.
  68. ^ "How cold can you go? Cooler tested for NASA telescope". Phys.org. 14 June 2016. from the original on 11 July 2022. Retrieved 31 January 2017.
  69. ^ "JPL: Herschel Space Observatory: Related Missions". NASA, Jet Propulsion Laboratory, Goddard Flight Center, California Institute of Technology. from the original on 3 December 2016. Retrieved 4 June 2012.   This article incorporates text from this source, which is in the public domain.
  70. ^ "What is ISO?". ESA. 2016. from the original on 10 November 2021. Retrieved 4 June 2021.
  71. ^ "Hubble Space Telescope – Wide Field Camera 3". NASA. 22 August 2016. from the original on 13 November 2021. Retrieved 9 December 2016.   This article incorporates text from this source, which is in the public domain.
  72. ^ a b c d e f Reichhardt, Tony (March 2006). "US astronomy: Is the next big thing too big?". Nature. 440 (7081): 140–143. Bibcode:2006Natur.440..140R. doi:10.1038/440140a. PMID 16525437.
  73. ^ "Nexus Space Telescope". MIT. from the original on 29 August 2011. Retrieved 23 August 2011.
  74. ^ Brown, Dwayne; Braukus, Michael. "NASA – NASA and ESA Sign Agreements for Future Cooperation". www.nasa.gov. Retrieved 2 August 2023.
  75. ^ a b Gur, Haviv Rettig (5 January 2022). "Space is changing. Webb is just the start, says ex-Israeli who was in from its dawn". The Times of Israel. from the original on 19 March 2022. Retrieved 7 January 2022.
  76. ^ . NASA Space Optics Manufacturing Technology Center. Archived from the original on 15 October 2011.   This article incorporates text from this source, which is in the public domain.
  77. ^ a b "STSCI JWST History 1994". Archived from the original on 3 February 2014. Retrieved 29 December 2018.
  78. ^ "Astrononmy and Astrophysics in the New Millennium". NASA. from the original on 25 December 2021. Retrieved 27 July 2011.   This article incorporates text from this source, which is in the public domain.
  79. ^ de Weck, Olivier L.; Miller, David W.; Mosier, Gary E. (2002). "Multidisciplinary analysis of the NEXUS precursor space telescope" (PDF). In MacEwen, Howard A. (ed.). Highly Innovative Space Telescope Concepts. Vol. 4849. p. 294. Bibcode:2002SPIE.4849..294D. CiteSeerX 10.1.1.664.8727. doi:10.1117/12.460079. S2CID 18725988. (PDF) from the original on 23 September 2017. Retrieved 27 July 2011.
  80. ^ Brown, R. A. (1996). "1996swhs.conf..603B Page 603". Science with the Hubble Space Telescope – II: 603. Bibcode:1996swhs.conf..603B. from the original on 14 January 2022. Retrieved 23 September 2022.
  81. ^ Dressler, A., ed. (1996). "Exploration and the Search for Origins: A Vision for Ultraviolet-Optical-Infrared Space Astronomy Report of the 'HST & Beyond' Committee" (PDF). Stsci.edu. Association of Universities for Research in Astronomy. (PDF) from the original on 15 July 2022. Retrieved 12 February 2022.
  82. ^ Stockman, H. S. (June 1997). "The Next Generation Space Telescope. Visiting a time when galaxies were young". Space Telescope Science Institute, Baltimore, Maryland. The Association of Universities for Research in Astronomy, Washington, D.C.
  83. ^ Astronomy and Astrophysics Survey Committee; Board on Physics and Astronomy; Space Studies Board; Commission on Physical Sciences, Mathematics, and Applications; National Research Council (16 January 2001). Astronomy and Astrophysics in the New Millennium. Washington, D.C.: National Academies Press. doi:10.17226/9839. ISBN 978-0-309-07031-7. from the original on 15 July 2022. Retrieved 15 December 2021.
  84. ^ "STSCI JWST History 1996". Stsci.edu. Archived from the original on 3 February 2014. Retrieved 16 January 2012.
  85. ^ information@eso.org. "Goddard Space Flight Center design". www.spacetelescope.org. Retrieved 2 August 2023.
  86. ^ "ESA Science & Technology: Ball Aerospace design for JWST". Archived 12 December 2012 at archive.today. Sci.esa.int. Retrieved 21 August 2013
  87. ^ "ESA Science & Technology: TRW design for JWST". Archived 12 December 2012 at archive.today. Sci.esa.int. Retrieved 21 August 2013
  88. ^ "ESA Science & Technology: Lockheed-Martin design for JWST". Archived 13 December 2012 at archive.today. Sci.esa.int. Retrieved 21 August 2013
  89. ^ a b "HubbleSite – Webb: Past and Future". Archived from the original on 10 December 2012. Retrieved 13 January 2012.
  90. ^ a b "NASA ANNOUNCES CONTRACT FOR NEXT-GENERATION SPACE TELESCOPE NAMED AFTER SPACE PIONEER". NASA. 10 September 2002. from the original on 27 August 2022. Retrieved 26 August 2022.
  91. ^ a b "About James Webb". NASA. from the original on 27 March 2018. Retrieved 15 March 2013.   This article incorporates text from this source, which is in the public domain.
  92. ^ "TRW Selected as JWST Prime Contractor". STCI. 11 September 2003. Archived from the original on 5 August 2012. Retrieved 13 January 2012.
  93. ^ "Northrop Grumman Completes Fabrication Of Sunshield Deployment Flight Structure For JWST". Space Daily. 13 December 2011. from the original on 18 January 2022. Retrieved 10 December 2014.
  94. ^ a b Mather, John. (PDF). National Academy of Science. Archived from the original (PDF) on 10 November 2008. Retrieved 5 July 2008.   This article incorporates text from this source, which is in the public domain.
  95. ^ a b (Press release). ESA Media Relations Service. 9 June 2004. Archived from the original on 18 May 2009. Retrieved 6 May 2009.
  96. ^ "Canada's contribution to NASA's James Webb Space Telescope". canada.ca. Canadian Space Agency. 4 June 2007. from the original on 18 January 2022. Retrieved 3 July 2021.
  97. ^ "Canadian Space Agency Delivers Canada's Contributions to the James Webb Space Telescope". SpaceQ. 30 July 2012. from the original on 18 January 2022. Retrieved 3 July 2021.
  98. ^ "JWST Passes TNAR". STScI. Archived from the original on 5 August 2012. Retrieved 5 July 2008.
  99. ^ Berger, Brian (23 May 2007). "NASA Adds Docking Capability For Next Space Observatory". SPACE.com. from the original on 30 June 2008. Retrieved 5 July 2008.
  100. ^ "James Webb Space Telescope sunshield is ready to fabricate". www.laserfocusworld.com. 3 February 2010. from the original on 30 December 2021. Retrieved 30 December 2021.
  101. ^ "NASA's Webb Telescope Passes Key Mission Design Review Milestone". NASA. from the original on 1 May 2010. Retrieved 2 May 2010.   This article incorporates text from this source, which is in the public domain.
  102. ^ Clark, Stephen (12 August 2010). "NASA says JWST cost crunch impeding new missions". Spaceflight Now. from the original on 29 April 2021. Retrieved 13 August 2010.
  103. ^ "NASA's James Webb Space Telescope Primary Mirror Fully Assembled". nasa.gov. 3 February 2016. from the original on 4 February 2016. Retrieved 4 February 2016.   This article incorporates text from this source, which is in the public domain.
  104. ^ "NASA's James Webb Space Telescope Secondary Mirror Installed". NASA. 7 March 2016. from the original on 17 March 2016. Retrieved 23 March 2016.   This article incorporates text from this source, which is in the public domain.
  105. ^ Yuhas, Alan (4 November 2016). "Nasa begins testing enormous space telescope made of gold mirrors". The Guardian. from the original on 5 November 2016. Retrieved 5 November 2016.
  106. ^ "NASA Completes Webb Telescope Review, Commits to Launch in Early 2021". NASA. 27 June 2018. from the original on 14 March 2020. Retrieved 27 June 2018.   This article incorporates text from this source, which is in the public domain.
  107. ^ Achenbach, Joel (26 July 2018). "Northrop Grumman CEO is grilled about James Webb Space Telescope errors". The Washington Post. from the original on 28 December 2019. Retrieved 28 December 2019.
  108. ^ "The two halves of Hubble's US$10 billion successor have finally come together after 12 years of waiting". Business Insider. from the original on 15 July 2022. Retrieved 29 August 2019.
  109. ^ Clark, Stephen (30 September 2021). "After two decades, the Webb telescope is finished and on the way to its launch site". Spaceflight Now. from the original on 6 October 2021. Retrieved 6 October 2021.
  110. ^ Wall, Mike (12 October 2021). "NASA's James Webb Space Telescope arrives in French Guiana ahead of December 18 launch". Space.com. from the original on 12 October 2021. Retrieved 13 October 2021.
  111. ^ "FY 2022 NASA Congressional Budget Justification" (PDF). NASA. p. JWST-2. (PDF) from the original on 10 June 2021. Retrieved 21 October 2021.   This article incorporates text from this source, which is in the public domain.
  112. ^ Foust, Jeff (2 June 2021). "JWST launch slips to November". SpaceNews. from the original on 15 July 2022. Retrieved 21 October 2021.
  113. ^ Lilly, Simon (27 November 1998). "The Next Generation Space Telescope (NGST)". University of Toronto. from the original on 25 December 2021. Retrieved 23 August 2011.
  114. ^ "NGST Weekly Missive". 25 April 2002. from the original on 15 July 2022. Retrieved 23 August 2011.
  115. ^ "NASA Modifies James Webb Space Telescope Contract". 12 November 2003. from the original on 25 December 2021. Retrieved 23 August 2011.   This article incorporates text from this source, which is in the public domain.
  116. ^ "Problems for JWST". 21 May 2005. from the original on 25 December 2021. Retrieved 25 August 2011.
  117. ^ "Refocusing NASA's vision". Nature. 440 (7081): 127. 9 March 2006. Bibcode:2006Natur.440..127.. doi:10.1038/440127a. PMID 16525425.
  118. ^ Cowen, Ron (25 August 2011). . ScienceInsider. Archived from the original on 14 January 2012.
  119. ^ a b "Independent Comprehensive Review Panel, Final Report" (PDF). 29 October 2010. (PDF) from the original on 17 November 2021. Retrieved 10 June 2011.   This article incorporates text from this source, which is in the public domain.
  120. ^ Amos, Jonathan (22 August 2011). "JWST price tag now put at over $8 bn". BBC. from the original on 25 December 2021. Retrieved 22 June 2018.
  121. ^ "NASA's James Webb Space Telescope to be Launched Spring 2019". NASA. 28 September 2017. from the original on 7 February 2018. Retrieved 28 September 2017.   This article incorporates text from this source, which is in the public domain.
  122. ^ a b "NASA Delays Launch of James Webb Space Telescope to 2020". Space.com. from the original on 28 April 2022. Retrieved 27 March 2018.
  123. ^ "NASA Completes Webb Telescope Review, Commits to Launch in Early 2021". nasa.gov. NASA. 27 June 2018. from the original on 14 March 2020. Retrieved 28 June 2018.   This article incorporates text from this source, which is in the public domain.
  124. ^ "NASA delays launch of Webb telescope to no earlier than Dec. 24". 14 December 2021. from the original on 15 December 2021. Retrieved 14 December 2021.   This article incorporates text from this source, which is in the public domain.
  125. ^ 1634–1699: McCusker, J. J. (1997). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States: Addenda et Corrigenda (PDF). American Antiquarian Society. 1700–1799: McCusker, J. J. (1992). How Much Is That in Real Money? A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States (PDF). American Antiquarian Society. 1800–present: Federal Reserve Bank of Minneapolis. "Consumer Price Index (estimate) 1800–". Retrieved 28 May 2023.
  126. ^ a b c McKie, Robin (9 July 2011). "Nasa fights to save the James Webb space telescope from the axe". The Guardian. London. from the original on 17 March 2017. Retrieved 14 December 2016.
  127. ^ "Appropriations Committee Releases the Fiscal Year 2012 Commerce, Justice, Science Appropriations". US House of representatives Committee on Appropriations. 6 July 2011. from the original on 23 March 2012. Retrieved 7 July 2011.   This article incorporates text from this source, which is in the public domain.
  128. ^ "US lawmakers vote to kill Hubble successor". SpaceDaily. 7 July 2011. from the original on 10 July 2011. Retrieved 8 July 2011.
  129. ^ "Proposed NASA Budget Bill Would Cancel Major Space Telescope". Space.com. 6 July 2011. from the original on 9 July 2011. Retrieved 11 July 2011.
  130. ^ Bergin, Chris (7 January 2015). "James Webb Space Telescope hardware entering key test phase". NASASpaceFlight.com. from the original on 7 November 2017. Retrieved 28 August 2016.
  131. ^ Hand, E. (7 July 2011). "AAS Issues Statement on Proposed Cancellation of James Webb Space Telescope". American Astronomical Society. from the original on 19 March 2018. Retrieved 1 February 2017.
  132. ^ "Mikulski Statement on House Appropriations Subcommittee Termination of James Webb Telescope". SpaceRef. 11 July 2011. from the original on 15 July 2022. Retrieved 1 February 2017.
  133. ^ "Way Above the Shuttle Flight". The New York Times. 9 July 2011. from the original on 19 March 2018. Retrieved 27 February 2017.
  134. ^ Harrold, Max (7 July 2011). "Bad news for Canada: U.S. could scrap new space telescope". The Vancouver Sun. from the original on 31 July 2018. Retrieved 27 January 2019.
  135. ^ "NASA budget plan saves telescope, cuts space taxis". Reuters. 16 November 2011. from the original on 24 September 2015. Retrieved 1 July 2017.
  136. ^ Leone, Dan (7 November 2012). "NASA Acknowledges James Webb Telescope Costs Will Delay Other Science Missions". SpaceNews. from the original on 22 January 2013. Retrieved 12 January 2013.
  137. ^ a b Moskowitz, Clara (30 March 2015). "NASA Assures Skeptical Congress That the James Webb Telescope Is on Track". Scientific American. from the original on 2 February 2017. Retrieved 29 January 2017.
  138. ^ Billings, Lee (27 October 2010). "The telescope that ate astronomy". Nature. 467 (7319): 1028–1030. doi:10.1038/4671028a. PMID 20981068.
  139. ^ Koren, Marina (7 December 2016). "The Extreme Hazing of the Most Expensive Telescope Ever Built". The Atlantic. from the original on 2 February 2017. Retrieved 29 January 2017.
  140. ^ a b c Cohen, Ben (8 July 2022). "The NASA Engineer Who Made the James Webb Space Telescope Work". The Wall Street Journal. ISSN 0099-9660. from the original on 11 July 2022. Retrieved 12 July 2022.
  141. ^ Potter, Sean (22 July 2022). "NASA Webb Program Director Greg Robinson Announces Retirement". NASA. from the original on 23 July 2022. Retrieved 22 July 2022.
  142. ^ Wang, Jen Rae; Cole, Steve; Northon, Karen (27 March 2018). "NASA's Webb Observatory Requires More Time for Testing and Evaluation". NASA. from the original on 29 March 2018. Retrieved 27 March 2018.   This article incorporates text from this source, which is in the public domain.
  143. ^ Amos, Jonathan (27 March 2018). "Hubble 'successor' faces new delay". BBC News. from the original on 28 March 2018. Retrieved 27 March 2018.
  144. ^ Witze, Alexandra (27 March 2018). "NASA reveals major delay for $8-billion Hubble successor". Nature. 556 (7699): 11–12. Bibcode:2018Natur.556...11W. doi:10.1038/d41586-018-03863-5. PMID 29620740.
  145. ^ Dreier, Casey (15 February 2019). "NASA just got its best budget in a decade". from the original on 16 February 2019. Retrieved 7 March 2019.
  146. ^ Foust, Jeff (20 March 2020). "Coronavirus pauses work on JWST". SpaceNews. from the original on 15 July 2022. Retrieved 15 April 2020.
  147. ^ "ESA Science & Technology – Europe's Contributions to the JWST Mission". European Space Agency. from the original on 19 March 2022. Retrieved 19 December 2021.
  148. ^ . Canadian Space Agency. 12 April 2013. Archived from the original on 12 April 2013.
  149. ^ a b Jenner, Lynn (1 June 2020). "NASA's Webb Telescope is an International Endeavor". NASA. from the original on 19 March 2022. Retrieved 23 September 2021.
  150. ^ "Institutional Partners Webb/NASA". jwst.nasa.gov. Retrieved 2 August 2023.
  151. ^ Shepherd, Tony (25 December 2021). "James Webb: world's most powerful telescope makes its first call to Australia on Christmas Day". The Guardian. from the original on 19 March 2022. Retrieved 5 January 2022.
  152. ^ Francis, Matthew. "The Problem With Naming Observatories For Bigots". Forbes. from the original on 11 April 2022. Retrieved 11 April 2022.
  153. ^ Savage, Dan (21 January 2015). "Should NASA Name a Telescope After a Dead Guy Who Persecuted Gay People in the 1950s?". The Stranger. from the original on 24 January 2015. Retrieved 11 April 2022.
  154. ^ Fisher, Alise (18 November 2022). "NASA Shares James Webb History Report". NASA. from the original on 24 November 2022. Retrieved 25 November 2022.
  155. ^ Odom, Brian C. "NASA Historical Investigation into James E. Webb's Relationship to the Lavender Scare. Final Report" (PDF). nasa.gov. NASA. (PDF) from the original on 24 November 2022. Retrieved 25 November 2022.
  156. ^ Witze, Alexandra (18 November 2022). "NASA really, really won't rename Webb telescope despite community pushback". Nature. doi:10.1038/d41586-022-03787-1. PMID 36400961. S2CID 253671586. from the original on 22 November 2022. Retrieved 21 November 2022.
  157. ^ Masetti, Maggie; Krishnamurthi, Anita (2009). "JWST Science". NASA. from the original on 24 November 2017. Retrieved 14 April 2013.   This article incorporates text from this source, which is in the public domain.
  158. ^ "NASA's Next Telescope Could ID Alien Megastructures". 9 February 2016. from the original on 9 October 2019. Retrieved 1 September 2016.
  159. ^ Zimmer, Carl (2 July 2022). "Webb Telescope Will Look for Signs of Life Way Out There – The first question astronomers want to answer about exoplanets: Do they have atmospheres friendly to life?". The New York Times. from the original on 2 July 2022. Retrieved 2 July 2022.
  160. ^ updated, Stefanie Waldek last (29 March 2022). "NASA's new James Webb Space Telescope will be able to sniff out methane. Here's how to tell if it's a sign of life". Space.com. Retrieved 2 August 2023.
  161. ^ "Basics of Space Flight". Jet Propulsion Laboratory. from the original on 11 June 2012. Retrieved 28 August 2016.   This article incorporates text from this source, which is in the public domain.
  162. ^ Dichmann, Donald J.; Alberding, Cassandra M.; Yu, Wayne H. (5 May 2014). (PDF). NASA Goddard Space Flight Center. Archived from the original (PDF) on 17 December 2021. Retrieved 29 December 2021.   This article incorporates text from this source, which is in the public domain.
  163. ^ Greenhouse, Matt (1 April 2016). "The James Webb Space Telescope Mission" (PDF). NASA Goddard Space Flight Center. (PDF) from the original on 29 December 2021. Retrieved 29 December 2021.
  164. ^ Petersen, Jeremy; Tichy, Jason; Wawrzyniak, Geoffrey; Richon, Karen (21 April 2014). "James Webb Space Telescope Initial Mid-Course Correction Monte Carlo Implementation using Task Parallelism". {{cite journal}}: Cite journal requires |journal= (help)
  165. ^ Kimble, Randy (27 December 2021). "More Than You Wanted to Know About Webb's Mid-Course Corrections!". NASA. from the original on 27 December 2021. Retrieved 27 December 2021.   This article incorporates text from this source, which is in the public domain.
  166. ^ Howard, Rick, "James Webb Space Telescope (JWST)" 21 December 2021 at the Wayback Machine, nasa.gov, 6 March 2012   This article incorporates text from this source, which is in the public domain.
  167. ^ . Cool Cosmos. Archived from the original on 11 October 2018. Retrieved 28 August 2016.
  168. ^ a b c d . NASA Infrared Astronomy and Processing Center. Archived from the original on 8 December 2006. Retrieved 30 October 2006.   This article incorporates text from this source, which is in the public domain.
  169. ^ a b "Webb Science: The End of the Dark Ages: First Light and Reionization". NASA. from the original on 22 November 2017. Retrieved 9 June 2011.   This article incorporates text from this source, which is in the public domain.
  170. ^ a b c d Mather, John (13 June 2006). "James Webb Space Telescope (JWST) Science Summary for SSB" (PDF). NASA. (PDF) from the original on 27 March 2021. Retrieved 4 June 2021.   This article incorporates text from this source, which is in the public domain.
  171. ^ Savage, Donald; Neal, Nancy (6 June 2003). "Webb Spacecraft Science & Operations Center Contract Awarded". NASA. from the original on 3 January 2022. Retrieved 1 February 2017.   This article incorporates text from this source, which is in the public domain.
  172. ^ "Single Board Computer". FBO Daily Issue, FBO #0332. 30 October 2002. from the original on 18 May 2009. Retrieved 23 April 2008.
  173. ^ a b "Amazing Miniaturized 'SIDECAR' Drives Webb Telescope's Signal". NASA. 20 February 2008. from the original on 27 February 2008. Retrieved 22 February 2008.   This article incorporates text from this source, which is in the public domain.
  174. ^ Hecht, Jeff; Potter, Ned; Koziol, Michael (2022). "Inside the Universe Machine". IEEE Spectrum. 59 (9): 48.
  175. ^ Sutherland, Scott (10 June 2022). "Webb's primary mirror was just hit by a meteoroid, but it was built to endure". The Weather Network. from the original on 9 June 2022. Retrieved 10 June 2022.
  176. ^ Harwood, William (9 June 2022). "Webb telescope still performing well after micrometeoroid impact on mirror segment, NASA says". CBS News. from the original on 9 June 2022. Retrieved 10 June 2022.
  177. ^ Howell, Elizabeth (18 July 2022) James Webb Space Telescope picture shows noticeable damage from micrometeoroid strike cites a NASA-ESA-CSA joint report (12 July 2022) by 611 co-authors from 44 institutions.[25]: 2 
  178. ^ a b "Ariane 5 goes down in history with successful launch of Webb". Arianespace (Press release). 25 December 2021. from the original on 10 March 2022. Retrieved 25 December 2021.
  179. ^ Pinoi, Natasha; Fiser, Alise; Betz, Laura (27 December 2021). "NASA's Webb Telescope Launches to See First Galaxies, Distant Worlds – NASA's James Webb Space Telescope launched at 7:20 a.m. EST Saturday [Dec. 25, 2021] on an Ariane 5 rocket French Guiana, South America". NASA. from the original on 12 April 2022. Retrieved 28 December 2021.
  180. ^ "How to track James Webb Space Telescope, mission timeline". Space Explored. 31 December 2021. from the original on 1 January 2022. Retrieved 1 January 2022.
  181. ^ Achenbach, Joel (25 December 2021). "NASA's James Webb Space Telescope launches in French Guiana – $10 billion successor to Hubble telescope will capture light from first stars and study distant worlds". The Washington Post. from the original on 25 December 2021. Retrieved 25 December 2021.
  182. ^ "Live Updates: Webb Telescope Launches on Long-Awaited Journey". The New York Times. 25 December 2021. from the original on 25 December 2021. Retrieved 25 December 2021.
  183. ^ Overbye, Dennis; Roulette, Joey (25 December 2021). "James Webb Space Telescope Launches on Journey to See the Dawn of Starlight – Astronomers were jubilant as the spacecraft made it off the launchpad, following decades of delays and cost overruns. The Webb is set to offer a new keyhole into the earliest moments of our universe". The New York Times. from the original on 29 December 2021. Retrieved 25 December 2021.
  184. ^ "Lissajous orbit". Oxford Reference. from the original on 5 February 2022. Retrieved 5 February 2022.
  185. ^ "James Webb Space Telescope". blogs.nasa.gov. from the original on 18 November 2021. Retrieved 22 November 2021.
  186. ^ "JWST Orbit". James Webb Space Telescope User Documentation. from the original on 11 July 2022. Retrieved 10 July 2022.
  187. ^   This article incorporates text from this source, which is in the public domain: "Frequently asked questions: How long will the Webb mission last?". NASA James Webb Space Telescope. 2017. from the original on 16 June 2019. Retrieved 29 June 2015.
  188. ^ Fox, Karen (29 December 2021). "NASA Says Webb's Excess Fuel Likely to Extend its Lifetime Expectations". James Webb Space Telescope (NASA Blogs).
November 13, 2023
james, webb, space, telescope, jwst, space, telescope, designed, conduct, infrared, astronomy, high, resolution, high, sensitivity, instruments, allow, view, objects, distant, faint, hubble, space, telescope, this, enables, investigations, across, many, fields. The James Webb Space Telescope JWST is a space telescope designed to conduct infrared astronomy Its high resolution and high sensitivity instruments allow it to view objects too old distant or faint for the Hubble Space Telescope 9 This enables investigations across many fields of astronomy and cosmology such as observation of the first stars and the formation of the first galaxies and detailed atmospheric characterization of potentially habitable exoplanets 10 11 12 James Webb Space TelescopeRendering of the fully deployed James Webb Space TelescopeNamesNext Generation Space Telescope NGST 1996 2002 Mission typeAstronomyOperatorSTScI NASA 1 ESA CSACOSPAR ID2021 130ASATCAT no 50463 2 WebsiteOfficial website webbtelescope wbr orgMission duration1 year 10 months 19 days elapsed 5 1 2 years primary mission 3 10 years planned 20 years expected life 4 Spacecraft propertiesManufacturerNorthrop GrummanBall Aerospace amp TechnologiesL3Harris 1 Launch mass6 500 kg 14 300 lb 5 Dimensions21 197 m 14 162 m 69 54 ft 46 46 ft 6 sunshieldPower2 kWStart of missionLaunch date25 December 2021 2021 12 25 12 20 UTC 5 RocketAriane 5 ECA VA256 Launch siteCentre Spatial Guyanais ELA 3ContractorArianespaceEntered serviceJuly 12 2022 16 months ago 2022 07 12 Orbital parametersReference systemSun Earth L2 orbitRegimeHalo orbitPeriapsis altitude250 000 km 160 000 mi 7 Apoapsis altitude832 000 km 517 000 mi 7 Period6 monthsMain telescopeTypeKorsch telescopeDiameter6 5 m 21 ft Focal length131 4 m 431 ft Focal ratiof 20 2Collecting area25 4 m2 273 sq ft 8 Wavelengths0 6 28 3 mm orange to mid infrared TranspondersBandS band telemetry and telecommandKa band science data downlinkBandwidthS band up 16 kbit sS band down 40 kbit sKa band down up to 28 Mbit sInstrumentsFGS NIRISSMIRINIRCamNIRSpecElementsIntegrated Science Instrument Module Optical Telescope Element Spacecraft Bus and Sunshield James Webb Space Telescope mission logo The Webb was launched on 25 December 2021 on an Ariane 5 rocket from Kourou French Guiana In January 2022 it arrived at its destination a solar orbit near the Sun Earth L2 Lagrange point about 1 5 million kilometers 930 000 mi from Earth The telescope s first image was released to the public on 11 July 2022 13 The U S National Aeronautics and Space Administration NASA led Webb s design and development and partnered with two main agencies the European Space Agency ESA and the Canadian Space Agency CSA The NASA Goddard Space Flight Center GSFC in Maryland managed telescope development while the Space Telescope Science Institute in Baltimore on the Homewood Campus of Johns Hopkins University operates Webb The primary contractor for the project was Northrop Grumman The telescope is named after James E Webb who was the administrator of NASA from 1961 to 1968 during the Mercury Gemini and Apollo programs Webb s primary mirror consists of 18 hexagonal mirror segments made of gold plated beryllium which together create a 6 5 meter diameter 21 ft mirror compared with Hubble s 2 4 m 7 ft 10 in This gives Webb a light collecting area of about 25 square meters about six times that of Hubble Unlike Hubble which observes in the near ultraviolet and visible 0 1 to 0 8 mm and near infrared 0 8 2 5 mm 14 spectra Webb observes a lower frequency range from long wavelength visible light red through mid infrared 0 6 28 3 mm The telescope must be kept extremely cold below 50 K 223 C 370 F so that the infrared light emitted by the telescope itself does not interfere with the collected light Its five layer sunshield protects it from warming by the Sun Earth and Moon Initial designs for the telescope then named the Next Generation Space Telescope began in 1996 Two concept studies were commissioned in 1999 for a potential launch in 2007 and a US 1 billion budget The program was plagued with enormous cost overruns and delays A major redesign was accomplished in 2005 with construction completed in 2016 followed by years of exhaustive testing at a total cost of US 10 billion Contents 1 Features 1 1 Location and orbit 1 2 Sunshield protection 1 3 Optics 1 4 Scientific instruments 1 5 Spacecraft bus 1 6 Servicing 1 7 Software 2 Comparison with other telescopes 3 Development history 3 1 Background development to 2003 3 2 Early development and replanning 2003 2007 3 3 Detailed design and construction 2007 2021 3 4 Cost and schedule issues 3 5 Partnership 3 6 Naming concerns 4 Mission goals 4 1 Orbit design 4 2 Infrared astronomy 5 Ground support and operations 5 1 Micrometeoroid strike 6 From launch through commissioning 6 1 Launch 6 2 Transit and structural deployment 6 3 Commissioning and testing 7 Allocation of observation time 7 1 Early Release Science program 7 2 General Observer Program 8 Scientific results 8 1 First full color images 8 2 Bright early galaxies 8 3 Subsequent noteworthy observations and interpretations 8 4 Gallery 9 See also 10 Notes 11 References 12 Further reading 13 External linksFeatures editThe mass of the James Webb Space Telescope is about half that of the Hubble Space Telescope Webb has a 6 5 m 21 ft diameter gold coated beryllium primary mirror made up of 18 separate hexagonal mirrors The mirror has a polished area of 26 3 m2 283 sq ft of which 0 9 m2 9 7 sq ft is obscured by the secondary support struts 15 giving a total collecting area of 25 4 m2 273 sq ft This is over six times larger than the collecting area of Hubble s 2 4 m 7 9 ft diameter mirror which has a collecting area of 4 0 m2 43 sq ft The mirror has a gold coating to provide infrared reflectivity and this is covered by a thin layer of glass for durability 16 Webb is designed primarily for near infrared astronomy but can also see orange and red visible light as well as the mid infrared region depending on the instrument being used 10 11 It can detect objects up to 100 times fainter than Hubble can and objects much earlier in the history of the universe back to redshift z 20 about 180 million years cosmic time after the Big Bang 17 For comparison the earliest stars are thought to have formed between z 30 and z 20 100 180 million years cosmic time 18 and the first galaxies may have formed around redshift z 15 about 270 million years cosmic time Hubble is unable to see further back than very early reionization 19 20 at about z 11 1 galaxy GN z11 400 million years cosmic time 21 22 17 The design emphasizes the near to mid infrared for several reasons high redshift very early and distant objects have their visible emissions shifted into the infrared and therefore their light can be observed only via infrared astronomy 14 infrared light passes more easily through dust clouds than visible light 14 colder objects such as debris disks and planets emit most strongly in the infrared these infrared bands are difficult to study from the ground or by existing space telescopes such as Hubble nbsp Rough plot of Earth s atmospheric absorption or opacity to various wavelengths of electromagnetic radiation including visible lightGround based telescopes must look through Earth s atmosphere which is opaque in many infrared bands see figure at right Even where the atmosphere is transparent many of the target chemical compounds such as water carbon dioxide and methane also exist in the Earth s atmosphere vastly complicating analysis Existing space telescopes such as Hubble cannot study these bands since their mirrors are insufficiently cool the Hubble mirror is maintained at about 15 C 288 K 59 F which means that the telescope itself radiates strongly in the relevant infrared bands 23 Webb can also observe objects in the Solar System at an angle of more than 85 from the Sun and having an apparent angular rate of motion less than 0 03 arc seconds per second a This includes Mars Jupiter Saturn Uranus Neptune Pluto their satellites and comets asteroids and minor planets at or beyond the orbit of Mars Webb has the near IR and mid IR sensitivity to be able to observe virtually all known Kuiper Belt Objects 18 27 In addition it can observe opportunistic and unplanned targets within 48 hours of a decision to do so such as supernovae and gamma ray bursts 18 nbsp Three quarter view of the top nbsp Bottom Sun facing side Location and orbit edit Webb operates in a halo orbit circling around a point in space known as the Sun Earth L2 Lagrange point approximately 1 500 000 km 930 000 mi beyond Earth s orbit around the Sun Its actual position varies between about 250 000 and 832 000 km 155 000 517 000 mi from L2 as it orbits keeping it out of both Earth and Moon s shadow By way of comparison Hubble orbits 550 km 340 mi above Earth s surface and the Moon is roughly 400 000 km 250 000 mi from Earth Objects near this Sun Earth L2 point can orbit the Sun in synchrony with the Earth allowing the telescope to remain at a roughly constant distance 28 with continuous orientation of its sunshield and equipment bus toward the Sun Earth and Moon Combined with its wide shadow avoiding orbit the telescope can simultaneously block incoming heat and light from all three of these bodies and avoid even the smallest changes of temperature from Earth and Moon shadows that would affect the structure yet still maintain uninterrupted solar power and Earth communications on its sun facing side This arrangement keeps the temperature of the spacecraft constant and below the 50 K 223 C 370 F necessary for faint infrared observations 29 30 Sunshield protection edit Main article James Webb Space Telescope sunshield nbsp Test unit of the sunshield stacked and expanded at the Northrop Grumman facility in California 2014To make observations in the infrared spectrum Webb must be kept under 50 K 223 2 C 369 7 F otherwise infrared radiation from the telescope itself would overwhelm its instruments Its large sunshield blocks light and heat from the Sun Earth and Moon and its position near the Sun Earth L2 keeps all three bodies on the same side of the spacecraft at all times 31 Its halo orbit around the L2 point avoids the shadow of the Earth and Moon maintaining a constant environment for the sunshield and solar arrays 28 The resulting stable temperature for the structures on the dark side is critical to maintaining precise alignment of the primary mirror segments 29 The five layer sunshield each layer as thin as a human hair 32 is made of Kapton E film coated with aluminum on both sides and a layer of doped silicon on the Sun facing side of the two hottest layers to reflect the Sun s heat back into space 29 Accidental tears of the delicate film structure during deployment testing in 2018 led to further delays to the telescope deployment 33 The sunshield was designed to be folded twelve times concertina style so that it would fit within the Ariane 5 rocket s payload fairing which is 4 57 m 15 0 ft in diameter and 16 19 m 53 1 ft long The shield s fully deployed dimensions were planned as 14 162 m 21 197 m 46 46 ft 69 54 ft 34 Keeping within the shadow of the sunshield limits the field of regard of Webb at any given time The telescope can see 40 percent of the sky from any one position but can see all of the sky over a period of six months 35 Optics edit Main article Optical Telescope Element nbsp Engineers cleaning a test mirror with carbon dioxide snow 2015 nbsp Main mirror assembly from the front with primary mirrors attached November 2016 nbsp Diffraction spikes due to mirror segments and spider color codedWebb s primary mirror is a 6 5 m 21 ft diameter gold coated beryllium reflector with a collecting area of 25 4 m2 273 sq ft If it had been designed as a single large mirror it would have been too large for existing launch vehicles The mirror is therefore composed of 18 hexagonal segments a technique pioneered by Guido Horn d Arturo which unfolded after the telescope was launched Image plane wavefront sensing through phase retrieval is used to position the mirror segments in the correct location using precise actuators Subsequent to this initial configuration they only need occasional updates every few days to retain optimal focus 36 This is unlike terrestrial telescopes for example the Keck telescopes which continually adjust their mirror segments using active optics to overcome the effects of gravitational and wind loading 37 The Webb telescope uses 132 small actuation motors to position and adjust the optics 38 The actuators can position the mirror with 10 nanometer accuracy 39 Webb s optical design is a three mirror anastigmat 40 which makes use of curved secondary and tertiary mirrors to deliver images that are free from optical aberrations over a wide field The secondary mirror is 0 74 m 2 4 ft in diameter In addition there is a fine steering mirror which can adjust its position many times per second to provide image stabilization Photographs taken by Webb have six spikes plus two fainter ones due to the spider supporting the secondary mirror 41 Scientific instruments edit nbsp NIRCam wrapped up in 2013 nbsp The Calibration Assembly one component of the NIRSpec instrument nbsp MIRIThe Integrated Science Instrument Module ISIM is a framework that provides electrical power computing resources cooling capability as well as structural stability to the Webb telescope It is made with bonded graphite epoxy composite attached to the underside of Webb s telescope structure The ISIM holds the four science instruments and a guide camera 42 NIRCam Near Infrared Camera is an infrared imager which has spectral coverage ranging from the edge of the visible 0 6 mm through to the near infrared 5 mm 43 44 There are 10 sensors each of 4 megapixels NIRCam serves as the observatory s wavefront sensor which is required for wavefront sensing and control activities used to align and focus the main mirror segments NIRCam was built by a team led by the University of Arizona with principal investigator Marcia J Rieke 45 NIRSpec Near Infrared Spectrograph performs spectroscopy over the same wavelength range It was built by the European Space Agency at ESTEC in Noordwijk Netherlands The leading development team includes members from Airbus Defence and Space Ottobrunn and Friedrichshafen Germany and the Goddard Space Flight Center with Pierre Ferruit Ecole normale superieure de Lyon as NIRSpec project scientist The NIRSpec design provides three observing modes a low resolution mode using a prism an R 1000 multi object mode and an R 2700 integral field unit or long slit spectroscopy mode Switching of the modes is done by operating a wavelength preselection mechanism called the Filter Wheel Assembly and selecting a corresponding dispersive element prism or grating using the Grating Wheel Assembly mechanism Both mechanisms are based on the successful ISOPHOT wheel mechanisms of the Infrared Space Observatory The multi object mode relies on a complex micro shutter mechanism to allow for simultaneous observations of hundreds of individual objects anywhere in NIRSpec s field of view There are two sensors each of 4 megapixels 46 MIRI Mid Infrared Instrument measures the mid to long infrared wavelength range from 5 to 27 mm 47 48 It contains both a mid infrared camera and an imaging spectrometer 49 MIRI was developed as a collaboration between NASA and a consortium of European countries and is led by George Rieke University of Arizona and Gillian Wright UK Astronomy Technology Centre Edinburgh Scotland 45 The temperature of the MIRI must not exceed 6 K 267 C 449 F a helium gas mechanical cooler sited on the warm side of the environmental shield provides this cooling 50 FGS NIRISS Fine Guidance Sensor and Near Infrared Imager and Slitless Spectrograph led by the Canadian Space Agency under project scientist John Hutchings Herzberg Astronomy and Astrophysics Research Centre is used to stabilize the line of sight of the observatory during science observations Measurements by the FGS are used both to control the overall orientation of the spacecraft and to drive the fine steering mirror for image stabilization The Canadian Space Agency also provided a Near Infrared Imager and Slitless Spectrograph NIRISS module for astronomical imaging and spectroscopy in the 0 8 to 5 mm wavelength range led by principal investigator Rene Doyon 51 at the Universite de Montreal 45 Although they are often referred together as a unit the NIRISS and FGS serve entirely different purposes with one being a scientific instrument and the other being a part of the observatory s support infrastructure 52 NIRCam and MIRI feature starlight blocking coronagraphs for observation of faint targets such as extrasolar planets and circumstellar disks very close to bright stars 48 Spacecraft bus edit Main article Spacecraft bus James Webb Space Telescope nbsp Diagram of the spacecraft bus The solar panel is in green and the light purple panels are radiators The spacecraft bus is the primary support component of the James Webb Space Telescope hosting a multitude of computing communication electric power propulsion and structural parts 53 Along with the sunshield it forms the spacecraft element of the space telescope 54 55 The spacecraft bus is on the Sun facing warm side of the sunshield and operates at a temperature of about 300 K 27 C 80 F 54 The structure of the spacecraft bus has a mass of 350 kg 770 lb and must support the 6 200 kg 13 700 lb space telescope It is made primarily of graphite composite material 56 The assembly was completed in California in 2015 It was integrated with the rest of the space telescope leading to its 2021 launch The spacecraft bus can rotate the telescope with a pointing precision of one arcsecond and isolates vibration to two milliarcseconds 57 Webb has two pairs of rocket engines one pair for redundancy to make course corrections on the way to L2 and for station keeping maintaining the correct position in the halo orbit Eight smaller thrusters are used for attitude control the correct pointing of the spacecraft 58 The engines use hydrazine fuel 159 liters or 42 U S gallons at launch and dinitrogen tetroxide as oxidizer 79 5 liters or 21 0 U S gallons at launch 59 Servicing edit Webb is not intended to be serviced in space A crewed mission to repair or upgrade the observatory as was done for Hubble would not be possible 60 and according to NASA Associate Administrator Thomas Zurbuchen despite best efforts an uncrewed remote mission was found to be beyond available technology at the time Webb was designed 61 During the long Webb testing period NASA officials referred to the idea of a servicing mission but no plans were announced 62 63 Since the successful launch NASA has stated that nevertheless limited accommodation was made to facilitate future servicing missions These accommodations included precise guidance markers in the form of crosses on the surface of Webb for use by remote servicing missions as well as refillable fuel tanks removable heat protectors and accessible attachment points 64 61 Software edit Ilana Dashevsky and Vicki Balzano write that Webb uses a modified version of JavaScript called Nombas ScriptEase 5 00e for its operations it follows the ECMAScript standard and allows for a modular design flow where on board scripts call lower level scripts that are defined as functions The JWST science operations will be driven by ASCII instead of binary command blocks on board scripts written in a customized version of JavaScript The script interpreter is run by the flight software which is written in the programming language C The flight software operates the spacecraft and the science instruments 65 66 Comparison with other telescopes edit nbsp Comparison with the Hubble Space Telescope primary mirror source source source source source source source source Primary mirror size comparison between Webb and HubbleThe desire for a large infrared space telescope traces back decades In the United States the Space Infrared Telescope Facility later called the Spitzer Space Telescope was planned while the Space Shuttle was in development and the potential for infrared astronomy was acknowledged at that time 67 Unlike ground telescopes space observatories are free from atmospheric absorption of infrared light Space observatories opened a new sky for astronomers However there is a challenge involved in the design of infrared telescopes they need to stay extremely cold and the longer the wavelength of infrared the colder they need to be If not the background heat of the device itself overwhelms the detectors making it effectively blind This can be overcome by careful design One method is to put the key instruments in a dewar with an extremely cold substance such as liquid helium The coolant will slowly vaporize limiting the lifetime of the instrument from as short as a few months to a few years at most 23 It is also possible to maintain a low temperature by designing the spacecraft to enable near infrared observations without a supply of coolant as with the extended missions of the Spitzer Space Telescope and the Wide field Infrared Survey Explorer which operated at reduced capacity after coolant depletion Another example is Hubble s Near Infrared Camera and Multi Object Spectrometer NICMOS instrument which started out using a block of nitrogen ice that depleted after a couple of years but was then replaced during the STS 109 servicing mission with a cryocooler that worked continuously The Webb Space Telescope is designed to cool itself without a dewar using a combination of sunshields and radiators with the mid infrared instrument using an additional cryocooler 68 Selected space telescopes and instruments 69 Name Launch year Wavelength mm Aperture m CoolingSpacelab Infrared Telescope IRT 1985 1 7 118 0 15 HeliumInfrared Space Observatory ISO 70 1995 2 5 240 0 60 HeliumHubble Space Telescope Imaging Spectrograph STIS 1997 0 115 1 03 2 4 PassiveHubble Near Infrared Camera and Multi Object Spectrometer NICMOS 1997 0 8 2 4 2 4 Nitrogen later cryocoolerSpitzer Space Telescope 2003 3 180 0 85 HeliumHubble Wide Field Camera 3 WFC3 2009 0 2 1 7 2 4 Passive and thermo electric 71 Herschel Space Observatory 2009 55 672 3 5 HeliumJames Webb Space Telescope 2021 0 6 28 5 6 5 Passive and cryocooler MIRI Webb s delays and cost increases have been compared to those of its predecessor the Hubble Space Telescope When Hubble formally started in 1972 it had an estimated development cost of US 300 million equivalent to 2 098 807 000 in 2022 but by the time it was sent into orbit in 1990 the cost was about four times that In addition new instruments and servicing missions increased the cost to at least US 9 billion by 2006 72 equivalent to 13 064 708 000 in 2022 Development history editFor a chronological guide see Timeline of the James Webb Space Telescope Background development to 2003 edit Major Milestones Year Milestone1996 Next Generation Space Telescope project first proposed mirror size 8 m 2001 NEXUS Space Telescope a precursor to the Next Generation Space Telescope cancelled 73 2002 Proposed project renamed James Webb Space Telescope mirror size reduced to 6 m 2003 Northrop Grumman awarded contract to build telescope2007 Memorandum of Understanding signed between NASA and ESA 74 2010 Mission Critical Design Review MCDR passed2011 Proposed cancellation2016 Final assembly completed25 December 2021 LaunchDiscussions of a Hubble follow on started in the 1980s but serious planning began in the early 1990s 75 The Hi Z telescope concept was developed between 1989 and 1994 76 a fully baffled b 4 m 13 ft aperture infrared telescope that would recede to an orbit at 3 Astronomical unit AU 77 This distant orbit would have benefited from reduced light noise from zodiacal dust 77 Other early plans called for a NEXUS precursor telescope mission 78 79 Correcting the flawed optics of the Hubble Space Telescope HST in its first years played a significant role in the birth of Webb citation needed In 1993 NASA conducted STS 61 the Space Shuttle mission that replaced HST s camera and installed a retrofit for its imaging spectrograph to compensate for the spherical aberration in its primary mirror The HST amp Beyond Committee was formed in 1994 to study possible missions and programs for optical ultraviolet astronomy in space for the first decades of the 21st century 80 Emboldened by HST s success its 1996 report explored the concept of a larger and much colder infrared sensitive telescope that could reach back in cosmic time to the birth of the first galaxies This high priority science goal was beyond the HST s capability because as a warm telescope it is blinded by infrared emission from its own optical system In addition to recommendations to extend the HST mission to 2005 and to develop technologies for finding planets around other stars NASA embraced the chief recommendation of HST amp Beyond 81 for a large cold space telescope radiatively cooled far below 0 C and began the planning process for the future Webb telescope Preparation for the 2000 Astronomy and Astrophysics Decadal Survey a literature review produced by the United States National Research Council that includes identifying research priorities and making recommendations for the upcoming decade included further development of the scientific program for what became known as the Next Generation Space Telescope 82 and advancements in relevant technologies by NASA As it matured studying the birth of galaxies in the young universe and searching for planets around other stars the prime goals coalesced as Origins by HST amp Beyond became prominent As hoped the NGST received the highest ranking in the 2000 Decadal Survey 83 An administrator of NASA Dan Goldin coined the phrase faster better cheaper and opted for the next big paradigm shift for astronomy namely breaking the barrier of a single mirror That meant going from eliminate moving parts to learn to live with moving parts i e segmented optics With the goal to reduce mass density tenfold silicon carbide with a very thin layer of glass on top was first looked at but beryllium was selected at the end 75 The mid 1990s era of faster better cheaper produced the NGST concept with an 8 m 26 ft aperture to be flown to L2 roughly estimated to cost US 500 million 84 In 1997 NASA worked with the Goddard Space Flight Center 85 Ball Aerospace amp Technologies 86 and TRW 87 to conduct technical requirement and cost studies of the three different concepts and in 1999 selected Lockheed Martin 88 and TRW for preliminary concept studies 89 Launch was at that time planned for 2007 but the launch date was pushed back many times see table further down In 2002 the project was renamed after NASA s second administrator 1961 1968 James E Webb 1906 1992 90 Webb led the agency during the Apollo program and established scientific research as a core NASA activity 91 In 2003 NASA awarded TRW the US 824 8 million prime contract for Webb The design called for a de scoped 6 1 m 20 ft primary mirror and a launch date of 2010 92 Later that year TRW was acquired by Northrop Grumman in a hostile bid and became Northrop Grumman Space Technology 89 Early development and replanning 2003 2007 edit nbsp Early full scale model on display at NASA Goddard Space Flight Center 2005 Development was managed by NASA s Goddard Space Flight Center in Greenbelt Maryland with John C Mather as its project scientist The primary contractor was Northrop Grumman Aerospace Systems responsible for developing and building the spacecraft element which included the satellite bus sunshield Deployable Tower Assembly DTA which connects the Optical Telescope Element to the spacecraft bus and the Mid Boom Assembly MBA which helps to deploy the large sunshields on orbit 93 while Ball Aerospace amp Technologies was subcontracted to develop and build the OTE itself and the Integrated Science Instrument Module ISIM 42 Cost growth revealed in spring 2005 led to an August 2005 re planning 94 The primary technical outcomes of the re planning were significant changes in the integration and test plans a 22 month launch delay from 2011 to 2013 and elimination of system level testing for observatory modes at wavelengths shorter than 1 7 mm Other major features of the observatory were unchanged Following the re planning the project was independently reviewed in April 2006 citation needed In the 2005 re plan the life cycle cost of the project was estimated at US 4 5 billion This comprised approximately US 3 5 billion for design development launch and commissioning and approximately US 1 0 billion for ten years of operations 94 The ESA agreed in 2004 to contributing about 300 million including the launch 95 The Canadian Space Agency pledged CA 39 million in 2007 96 and in 2012 delivered its contributions in equipment to point the telescope and detect atmospheric conditions on distant planets 97 Detailed design and construction 2007 2021 edit nbsp A JWST mirror segment 2010 nbsp Mirror segments undergoing cryogenic tests at the X ray amp Cryogenic Facility at Marshall Space Flight Center nbsp The assembled telescope following environmental testingIn January 2007 nine of the ten technology development items in the project successfully passed a Non Advocate Review 98 These technologies were deemed sufficiently mature to retire significant risks in the project The remaining technology development item the MIRI cryocooler completed its technology maturation milestone in April 2007 This technology review represented the beginning step in the process that ultimately moved the project into its detailed design phase Phase C By May 2007 costs were still on target 99 In March 2008 the project successfully completed its Preliminary Design Review PDR In April 2008 the project passed the Non Advocate Review Other passed reviews include the Integrated Science Instrument Module review in March 2009 the Optical Telescope Element review completed in October 2009 and the Sunshield review completed in January 2010 100 In April 2010 the telescope passed the technical portion of its Mission Critical Design Review MCDR Passing the MCDR signified the integrated observatory can meet all science and engineering requirements for its mission 101 The MCDR encompassed all previous design reviews The project schedule underwent review during the months following the MCDR in a process called the Independent Comprehensive Review Panel which led to a re plan of the mission aiming for a 2015 launch but as late as 2018 By 2010 cost over runs were impacting other projects though Webb itself remained on schedule 102 By 2011 the Webb project was in the final design and fabrication phase Phase C Assembly of the hexagonal segments of the primary mirror which was done via robotic arm began in November 2015 and was completed on 3 February 2016 The secondary mirror was installed on 3 March 2016 103 104 Final construction of the Webb telescope was completed in November 2016 after which extensive testing procedures began 105 In March 2018 NASA delayed Webb s launch an additional 2 years to May 2020 after the telescope s sunshield ripped during a practice deployment and the sunshield s cables did not sufficiently tighten In June 2018 NASA delayed the launch by an additional 10 months to March 2021 based on the assessment of the independent review board convened after the failed March 2018 test deployment 106 The review identified that Webb launch and deployment had 344 potential single point failures tasks that had no alternative or means of recovery if unsuccessful and therefore had to succeed for the telescope to work 107 In August 2019 the mechanical integration of the telescope was completed something that was scheduled to be done 12 years before in 2007 108 After construction was completed Webb underwent final tests at Northrop Grumman s historic Space Park in Redondo Beach California 109 A ship carrying the telescope left California on 26 September 2021 passed through the Panama Canal and arrived in French Guiana on 12 October 2021 110 Cost and schedule issues edit NASA s lifetime cost for the project is when expected to be US 9 7 billion of which US 8 8 billion was spent on spacecraft design and development and US 861 million is planned to support five years of mission operations 111 Representatives from ESA and CSA stated their project contributions amount to approximately 700 million and CA 200 million respectively 112 A study in 1984 by the Space Science Board estimated that to build a next generation infrared observatory in orbit would cost US 4 billion US 7B in 2006 dollars or 10B in 2020 dollars 72 While this came close to the final cost of Webb the first NASA design considered in the late 1990s was more modest aiming for a 1 billion price tag over 10 years of construction Over time this design expanded added funding for contingencies and had scheduling delays Progression of estimates for schedule and cost along with major milestones Year Plannedlaunch Budget plan billion USD 1998 2007 113 1 72 2000 2009 47 1 8 72 2002 2010 114 2 5 72 2003 2011 115 2 5 72 2005 2013 3 116 2006 2014 4 5 117 2008 Preliminary Design Review2008 2014 5 1 118 2010 Critical Design Review2010 2015 to 2016 6 5 119 2011 2018 8 7 120 2017 2019 121 8 82018 2020 122 8 82019 March 2021 123 9 662021 Dec 2021 124 9 70By 2008 when the project entered preliminary design review and was formally confirmed for construction over US 1 billion had already been spent on developing the telescope and the total budget was estimated at about US 5 billion equivalent to 7 49 billion in 2022 125 In summer 2010 the mission passed its Critical Design Review CDR with excellent grades on all technical matters but schedule and cost slips at that time prompted Maryland U S Senator Barbara Mikulski to call for external review of the project The Independent Comprehensive Review Panel ICRP chaired by J Casani JPL found that the earliest possible launch date was in late 2015 at an extra cost of US 1 5 billion for a total of US 6 5 billion They also pointed out that this would have required extra funding in FY2011 and FY2012 and that any later launch date would lead to a higher total cost 119 On 6 July 2011 the United States House of Representatives appropriations committee on Commerce Justice and Science moved to cancel the James Webb project by proposing an FY2012 budget that removed US 1 9 billion from NASA s overall budget of which roughly one quarter was for Webb 126 127 128 129 US 3 billion had been spent and 75 of its hardware was in production 130 This budget proposal was approved by subcommittee vote the following day The committee charged that the project was billions of dollars over budget and plagued by poor management 126 In response the American Astronomical Society issued a statement in support of Webb 131 as did Senator Mikulski 132 A number of editorials supporting Webb appeared in the international press during 2011 as well 126 133 134 In November 2011 Congress reversed plans to cancel Webb and instead capped additional funding to complete the project at US 8 billion 135 While similar issues had affected other major NASA projects such as the Hubble telescope some scientists expressed concerns about growing costs and schedule delays for the Webb telescope worrying that its budget might be competing with those of other space science programs 136 137 A 2010 Nature article described Webb as the telescope that ate astronomy 138 NASA continued to defend the budget and timeline of the program to Congress 137 139 In 2018 Gregory L Robinson was appointed as the new director of the Webb program 140 Robinson was credited with raising the program s schedule efficiency how many measures were completed on time from 50 to 95 140 For his role in improving the performance of the Webb program Robinsons s supervisor Thomas Zurbuchen called him the most effective leader of a mission I have ever seen in the history of NASA 140 In July 2022 after Webb s commissioning process was complete and it began transmitting its first data Robinson retired following a 33 year career at NASA 141 On 27 March 2018 NASA pushed back the launch to May 2020 or later 122 with a final cost estimate to come after a new launch window was determined with the European Space Agency ESA 142 143 144 In 2019 its mission cost cap was increased by US 800 million 145 After launch windows were paused in 2020 due to the COVID 19 pandemic 146 Webb was launched at the end of 2021 with a total budget of just under US 10 billion Partnership edit NASA ESA and CSA have collaborated on the telescope since 1996 ESA s participation in construction and launch was approved by its members in 2003 and an agreement was signed between ESA and NASA in 2007 In exchange for full partnership representation and access to the observatory for its astronomers ESA is providing the NIRSpec instrument the Optical Bench Assembly of the MIRI instrument an Ariane 5 ECA launcher and manpower to support operations 95 147 The CSA provided the Fine Guidance Sensor and the Near Infrared Imager Slitless Spectrograph and manpower to support operations 148 Several thousand scientists engineers and technicians spanning 15 countries have contributed to the build test and integration of Webb 149 A total of 258 companies government agencies and academic institutions participated in the pre launch project 142 from the United States 104 from 12 European countries including 21 from the U K 16 from France 12 from Germany and 7 international 150 and 12 from Canada 149 Other countries as NASA partners such as Australia were involved in post launch operation 151 Participating countries nbsp Austria nbsp Belgium nbsp Canada nbsp Czech Republic nbsp Denmark nbsp Finland nbsp France nbsp Germany nbsp Greece nbsp Ireland nbsp Italy nbsp Luxembourg nbsp Netherlands nbsp Norway nbsp Portugal nbsp Spain nbsp Sweden nbsp Switzerland nbsp United Kingdom nbsp United States Naming concerns edit See also James E Webb NASA and James E Webb Legacy In 2002 NASA administrator 2001 2004 Sean O Keefe made the decision to name the telescope after James E Webb the administrator of NASA from 1961 to 1968 during the Mercury Gemini and much of the Apollo programs 90 91 In 2015 concerns were raised around Webb s possible role in the lavender scare the mid 20th century persecution by the U S government targeting homosexuals in federal employment 152 153 In 2022 NASA released a report of an investigation 154 based on an examination of more than 50 000 documents The report found no available evidence directly links Webb to any actions or follow up related to the firing of individuals for their sexual orientation either in his time in the State Department or at NASA 155 156 Mission goals editThe James Webb Space Telescope has four key goals to search for light from the first stars and galaxies that formed in the universe after the Big Bang to study galaxy formation and evolution to understand star formation and planet formation to study planetary systems and the origins of life 157 These goals can be accomplished more effectively by observation in near infrared light rather than light in the visible part of the spectrum For this reason Webb s instruments will not measure visible or ultraviolet light like the Hubble Telescope but will have a much greater capacity to perform infrared astronomy Webb will be sensitive to a range of wavelengths from 0 6 to 28 mm corresponding respectively to orange light and deep infrared radiation at about 100 K or 173 C Webb may be used to gather information on the dimming light of star KIC 8462852 which was discovered in 2015 and has some abnormal light curve properties 158 Additionally it will be able to tell if an exoplanet has methane in its atmosphere allowing astronomers to determine whether or not the methane is a biosignature 159 160 Orbit design edit nbsp Webb is not exactly at the L2 point but circles around it in a halo orbit nbsp Alternative Hubble Space Telescope views of the Carina Nebula comparing ultraviolet and visible top and infrared bottom astronomy Far more stars are visible in the latter Webb orbits the Sun near the second Lagrange point L2 of the Sun Earth system which is 1 500 000 km 930 000 mi farther from the Sun than the Earth s orbit and about four times farther than the Moon s orbit Normally an object circling the Sun farther out than Earth would take longer than one year to complete its orbit But near the L2 point the combined gravitational pull of the Earth and the Sun allow a spacecraft to orbit the Sun in the same time that it takes the Earth Staying close to Earth allows data rates to be much faster for a given size of antenna The telescope circles about the Sun Earth L2 point in a halo orbit which is inclined with respect to the ecliptic has a radius varying between about 250 000 km 160 000 mi and 832 000 km 517 000 mi and takes about half a year to complete 28 Since L2 is just an equilibrium point with no gravitational pull a halo orbit is not an orbit in the usual sense the spacecraft is actually in orbit around the Sun and the halo orbit can be thought of as controlled drifting to remain in the vicinity of the L2 point 161 This requires some station keeping around 2 5 m s per year 162 from the total v budget of 93 m s 163 10 Two sets of thrusters constitute the observatory s propulsion system 164 Because the thrusters are located solely on the Sun facing side of the observatory all station keeping operations are designed to slightly undershoot the required amount of thrust in order to avoid pushing Webb beyond the semi stable L2 point a situation which would be unrecoverable Randy Kimble the Integration and Test Project Scientist for the James Webb Space Telescope compared the precise station keeping of Webb to Sisyphus rolling this rock up the gentle slope near the top of the hill we never want it to roll over the crest and get away from him 165 Animation of James Webb Space Telescope trajectory nbsp Top view nbsp Side view nbsp Side view from the Sun Infrared astronomy edit nbsp Infrared observations can see objects hidden in visible light such as the HUDF JD2 shown here nbsp Atmospheric windows in the infrared Much of this type of light is blocked when viewed from the Earth s surface It would be like looking at a rainbow but only seeing one color Webb is the formal successor to the Hubble Space Telescope HST and since its primary emphasis is on infrared astronomy it is also a successor to the Spitzer Space Telescope Webb will far surpass both those telescopes being able to see many more and much older stars and galaxies 166 Observing in the infrared spectrum is a key technique for achieving this because of cosmological redshift and because it better penetrates obscuring dust and gas This allows observation of dimmer cooler objects Since water vapor and carbon dioxide in the Earth s atmosphere strongly absorbs most infrared ground based infrared astronomy is limited to narrow wavelength ranges where the atmosphere absorbs less strongly Additionally the atmosphere itself radiates in the infrared spectrum often overwhelming light from the object being observed This makes a space telescope preferable for infrared observation 167 The more distant an object is the younger it appears its light has taken longer to reach human observers Because the universe is expanding as the light travels it becomes red shifted and objects at extreme distances are therefore easier to see if viewed in the infrared 168 Webb s infrared capabilities are expected to let it see back in time to the first galaxies forming just a few hundred million years after the Big Bang 169 Infrared radiation can pass more freely through regions of cosmic dust that scatter visible light Observations in infrared allow the study of objects and regions of space which would be obscured by gas and dust in the visible spectrum 168 such as the molecular clouds where stars are born the circumstellar disks that give rise to planets and the cores of active galaxies 168 Relatively cool objects temperatures less than several thousand degrees emit their radiation primarily in the infrared as described by Planck s law As a result most objects that are cooler than stars are better studied in the infrared 168 This includes the clouds of the interstellar medium brown dwarfs planets both in our own and other solar systems comets and Kuiper belt objects that will be observed with the Mid Infrared Instrument MIRI 47 169 Some of the missions in infrared astronomy that impacted Webb development were Spitzer and the Wilkinson Microwave Anisotropy Probe WMAP 170 Spitzer showed the importance of mid infrared which is helpful for tasks such as observing dust disks around stars 170 Also the WMAP probe showed the universe was lit up at redshift 17 further underscoring the importance of the mid infrared 170 Both these missions were launched in the early 2000s in time to influence Webb development 170 Ground support and operations editThe Space Telescope Science Institute STScI in Baltimore Maryland on the Homewood Campus of Johns Hopkins University was selected in 2003 as the Science and Operations Center S amp OC for Webb with an initial budget of US 162 2 million intended to support operations through the first year after launch 171 In this capacity STScI was to be responsible for the scientific operation of the telescope and delivery of data products to the astronomical community Data was to be transmitted from Webb to the ground via the NASA Deep Space Network processed and calibrated at STScI and then distributed online to astronomers worldwide Similar to how Hubble is operated anyone anywhere in the world will be allowed to submit proposals for observations Each year several committees of astronomers will peer review the submitted proposals to select the projects to observe in the coming year The authors of the chosen proposals will typically have one year of private access to the new observations after which the data will become publicly available for download by anyone from the online archive at STScI citation needed The bandwidth and digital throughput of the satellite is designed to operate at 458 gigabits of data per day for the length of the mission equivalent to a sustained rate of 5 42 Mbps 38 Most of the data processing on the telescope is done by conventional single board computers 172 The digitization of the analog data from the instruments is performed by the custom SIDECAR ASIC System for Image Digitization Enhancement Control And Retrieval Application Specific Integrated Circuit NASA stated that the SIDECAR ASIC will include all the functions of a 9 1 kg 20 lb instrument box in a 3 cm 1 2 in package and consume only 11 milliwatts of power 173 Since this conversion must be done close to the detectors on the cold side of the telescope the low power dissipation is crucial for maintaining the low temperature required for optimal operation of Webb 173 The telescope is equipped with a solid state drive SSD with a capacity of 68GB used as temporary storage for data collected from its scientific instruments By the end of the 10 year mission the usable capacity of the drive is expected to decrease to 60GB due to the effects of radiation and read write operations 174 Micrometeoroid strike edit The C3 c mirror segment suffered a micrometeoroid strike from a large dust mote sized particle between 23 and 25 May the fifth and largest strike since launch reported 8 June 2022 which required engineers to compensate for the strike using a mirror actuator 176 Despite the strike a NASA characterization report states all JWST observing modes have been reviewed and confirmed to be ready for science use as of July 10 2022 177 From launch through commissioning editMain article Launch and commissioning of the James Webb Space Telescope Launch edit Main article Ariane flight VA256 The launch designated Ariane flight VA256 took place as scheduled at 12 20 UTC on 25 December 2021 on an Ariane 5 rocket that lifted off from the Guiana Space Centre in French Guiana 178 179 The telescope was confirmed to be receiving power starting a two week deployment phase of its parts 180 and traveling to its target destination 181 182 183 The telescope was released from the upper stage 27 minutes 7 seconds after launch beginning a 30 day adjustment to place the telescope in a Lissajous orbit 184 around the L2 Lagrange point The telescope was launched with slightly less speed than needed to reach its final orbit and slowed down as it travelled away from Earth in order to reach L2 with only the velocity needed to enter its orbit there The telescope reached L2 on 24 January 2022 The flight included three planned course corrections to adjust its speed and direction This is because the observatory could recover from underthrust going too slowly but could not recover from overthrust going too fast to protect highly temperature sensitive instruments the sunshield must remain between telescope and Sun so the spacecraft could not turn around or use its thrusters to slow down 185 An L2 orbit is unstable so JWST needs to use propellant to maintain its halo orbit around L2 known as station keeping to prevent the telescope from drifting away from its orbital position 186 It was designed to carry enough propellant for 10 years 187 but the precision of the Ariane 5 launch and the first midcourse correction were credited with saving enough onboard fuel that JWST may be able to maintain its orbit for around 20 years instead 188 189 190 Space com called the launch flawless 191 nbsp Diagram of Webb inside Ariane 5 nbsp Ariane 5 and Webb at the ELA 3 launch pad nbsp Ariane 5 containing the James Webb Space Telescope lifting off from the launch pad nbsp Ariane 5 containing Webb moments after lift off nbsp Webb as seen from the ESC D Cryotechnic upper stage shortly after separation approximately 29 minutes after launch Part of the Earth with the Gulf of Aden is visible in the background of the image 192 Transit and structural deployment edit nbsp Structural deployment timeline 49 Webb was released from the rocket upper stage 27 minutes after a flawless launch 178 193 Starting 31 minutes after launch and continuing for about 13 days Webb began the process of deploying its solar array antenna sunshield and mirrors 194 Nearly all deployment actions are commanded by the Space Telescope Science Institute in Baltimore Maryland except for two early automatic steps solar panel unfolding and communication antenna deployment 195 196 The mission was designed to give ground controllers flexibility to change or modify the deployment sequence in case of problems 197 source source source source source source source source source source Structural deployment sequenceAt 7 50 p m EST on 25 December 2021 about 12 hours after launch the telescope s pair of primary rockets began firing for 65 minutes to make the first of three planned mid course corrections 198 On day two the high gain communication antenna deployed automatically 197 On 27 December 2021 at 60 hours after launch Webb s rockets fired for nine minutes and 27 seconds to make the second of three mid course corrections for the telescope to arrive at its L2 destination 199 On 28 December 2021 three days after launch mission controllers began the multi day deployment of Webb s all important sunshield On 30 December 2021 controllers successfully completed two more steps in unpacking the observatory First commands deployed the aft momentum flap a device that provides balance against solar pressure on the sunshield saving fuel by reducing the need for thruster firing to maintain Webb s orientation 200 On 31 December 2021 the ground team extended the two telescoping mid booms from the left and right sides of the observatory 201 The left side deployed in 3 hours and 19 minutes the right side took 3 hours and 42 minutes 202 201 Commands to separate and tension the membranes followed between 3 and 4 January and were successful 201 On 5 January 2022 mission control successfully deployed the telescope s secondary mirror which locked itself into place to a tolerance of about one and a half millimeters 203 The last step of structural deployment was to unfold the wings of the primary mirror Each panel consists of three primary mirror segments and had to be folded to allow the space telescope to be installed in the fairing of the Ariane rocket for the launch of the telescope On 7 January 2022 NASA deployed and locked in place the port side wing 204 and on 8 January the starboard side mirror wing This successfully completed the structural deployment of the observatory 205 206 207 On 24 January 2022 at 2 00 p m Eastern Standard Time 208 nearly a month after launch a third and final course correction took place inserting Webb into its planned halo orbit around the Sun Earth L2 point 209 210 The MIRI instrument has four observing modes imaging low resolution spectroscopy medium resolution spectroscopy and coronagraphic imaging On Aug 24 a mechanism that supports medium resolution spectroscopy MRS exhibited what appears to be increased friction during setup for a science observation This mechanism is a grating wheel that allows scientists to select between short medium and longer wavelengths when making observations using the MRS mode said NASA in a press statement 211 source source source source source source source source Animation of Webb s halo orbitCommissioning and testing edit On 12 January 2022 while still in transit mirror alignment began The primary mirror segments and secondary mirror were moved away from their protective launch positions This took about 10 days because the 132 212 actuator motors are designed to fine tune the mirror positions at microscopic accuracy 10 nanometer increments and must each move over 1 2 million increments 12 5 mm during initial alignment 213 39 Mirror alignment requires each of the 18 mirror segments and the secondary mirror to be positioned to within 50 nanometers NASA compares the required accuracy by analogy If the Webb primary mirror were the size of the United States each mirror segment would be the size of Texas and the team would need to line the height of those Texas sized segments up with each other to an accuracy of about 1 5 inches 214 James Webb Space Telescope Mirror alignment animations nbsp Segment image identification 18 mirror segments are moved to determine which segment creates which segment image After matching the mirror segments to their respective images the mirrors are tilted to bring all the images near a common point for further analysis nbsp Segment alignment begins by defocusing the segment images by moving the secondary mirror slightly Mathematical analysis called phase retrieval is applied to the defocused images to determine the precise positioning errors of the segments Adjustments of the segments then result in 18 well corrected telescopes However the segments still do not work together as a single mirror nbsp Image stacking To put all of the light in a single place each segment image must be stacked on top of one another In the image stacking step the individual segment images are moved so that they fall precisely at the center of the field to produce one unified image This process prepares the telescope for coarse phasing nbsp Telescope alignment over instrument fields of view After fine phasing the telescope is well aligned at one place in the NIRCam field of view Next the alignment must be extended to the rest of the instruments Mirror alignment was a complex operation split into seven phases that had been repeatedly rehearsed using a 1 6 scale model of the telescope 214 Once the mirrors reached 120 K 153 C 244 F 215 NIRCam targeted the 6th magnitude star HD 84406 in Ursa Major d 217 218 To do this NIRCam took 1560 images of the sky and used these wide ranging images to determine where in the sky each segment of the main mirror initially pointed 219 At first the individual primary mirror segments were greatly misaligned so the image contained 18 separate blurry images of the star field each containing an image of the target star The 18 images of HD 84406 are matched to their respective mirror segments and the 18 segments are brought into approximate alignment centered on the star Segment Image Identification Each segment was then individually corrected of its major focusing errors using a technique called phase retrieval resulting in 18 separate good quality images from the 18 mirror segments Segment Alignment The 18 images from each segment were then moved so they precisely overlap to create a single image Image Stacking 214 With the mirrors positioned for almost correct images they had to be fine tuned to their operational accuracy of 50 nanometers less than one wavelength of the light that will be detected A technique called dispersed fringe sensing was used to compare images from 20 pairings of mirrors allowing most of the errors to be corrected Coarse Phasing and then introduced light defocus to each segment s image allowing detection and correction of almost all remaining errors Fine Phasing These two processes were repeated three times and Fine Phasing will be routinely checked throughout the telescope s operation After three rounds of Coarse and Fine Phasing the telescope was well aligned at one place in the NIRCam field of view Measurements will be made at various points in the captured image across all instruments and corrections calculated from the detected variations in intensity giving a well aligned outcome across all instruments Telescope Alignment Over Instrument Fields of View Finally a last round of Fine Phasing and checks of image quality on all instruments was performed to ensure that any small residual errors remaining from the previous steps were corrected Iterate Alignment for Final Correction The telescope s mirror segments were then aligned and able to capture precise focused images 214 In preparation for alignment NASA announced at 19 28 UTC on 3 February 2022 that NIRCam had detected the telescope s first photons although not yet complete images 214 220 On 11 February 2022 NASA announced the telescope had almost completed phase 1 of alignment with every segment of its primary mirror having located and imaged the target star HD 84406 and all segments brought into approximate alignment 219 Phase 1 alignment was completed on 18 February 2022 221 and a week later phases 2 and 3 were also completed 222 This meant the 18 segments were working in unison however until all 7 phases are complete the segments were still acting as 18 smaller telescopes rather than one larger one 222 At the same time as the primary mirror was being commissioned hundreds of other instrument commissioning and calibration tasks were also ongoing 223 nbsp Phase 1 interim image annotated with the related mirror segments that took each image nbsp Phase 1 annotated completion image of HD 84406 nbsp Phase 2 completion showing before and after effects of segment alignment nbsp Phase 3 completion showing 18 segments stacked as a single image of HD 84406 nbsp Star 2MASS J17554042 6551277 e captured by NIRCam instrument nbsp A selfie taken by the NIRCam during the alignment process nbsp Image comparison between old Spitzer and new Webb 226 nbsp Alignment of the NASA ESA CSA James Webb Space Telescope s sensors 227 nbsp Webb s Fine Guidance Sensor FGS 228 Allocation of observation time editWebb observing time is allocated through a General Observers GO program a Guaranteed Time Observations GTO program and a Director s Discretionary Early Release Science DD ERS program 229 The GTO program provides guaranteed observing time for scientists who developed hardware and software components for the observatory The GO program provides all astronomers the opportunity to apply for observing time and will represent the bulk of the observing time GO programs are selected through peer review by a Time Allocation Committee TAC similar to the proposal review process used for the Hubble Space Telescope Early Release Science program edit In November 2017 the Space Telescope Science Institute announced the selection of 13 Director s Discretionary Early Release Science DD ERS programs chosen through a competitive proposal process 230 231 The observations for these programs Early Release Observations ERO 232 233 were to be obtained during the first five months of Webb science operations after the end of the commissioning period A total of 460 hours of observing time was awarded to these 13 programs which span science topics including the Solar System exoplanets stars and star formation nearby and distant galaxies gravitational lenses and quasars These 13 ERS programs were to use a total of 242 8 hours of observing time on the telescope not including Webb observing overheads and slew time Early Release Science programs Name Principal Investigator Category Observation time hours Radiative Feedback from Massive Stars as Traced by Multiband Imaging and Spectroscopic Mosaics Olivier Berne Stellar Physics 8 3 234 IceAge Chemical Evolution of Ices during Star Formation Melissa McClure Stellar Physics 13 4 235 Through the Looking GLASS A JWST Exploration of Galaxy Formation and Evolution from Cosmic Dawn to Present Day Tommaso Treu Galaxies and the IGM 24 3 236 A JWST Study of the Starburst AGN Connection in Merging LIRGs Lee Armus Galaxies and the IGM 8 7 237 The Resolved Stellar Populations Early Release Science Program Daniel Weisz Stellar Populations 20 3 238 Q 3D Imaging Spectroscopy of Quasar Hosts with JWST Analyzed with a Powerful New PSF Decomposition and Spectral Analysis Package Dominika Wylezalek Massive Black Holes and their Galaxies 17 4 239 The Cosmic Evolution Early Release Science CEERS Survey Steven Finkelstein Galaxies and the IGM 36 6 240 Establishing Extreme Dynamic Range with JWST Decoding Smoke Signals in the Glare of a Wolf Rayet Binary Ryan Lau Stellar Physics 6 5 241 TEMPLATES Targeting Extremely Magnified Panchromatic Lensed Arcs and Their Extended Star Formation Jane Rigby Galaxies and the IGM 26 0 242 Nuclear Dynamics of a Nearby Seyfert with NIRSpec Integral Field Spectroscopy Misty Bentz Massive Black Holes and their Galaxies 1 5 243 The Transiting Exoplanet Community Early Release Science Program Natalie Batalha Planets and Planet Formation 52 1 244 ERS observations of the Jovian System as a Demonstration of JWST s Capabilities for Solar System Science Imke de Pater Solar System 9 3 245 High Contrast Imaging of Exoplanets and Exoplanetary Systems with JWST Sasha Hinkley Planets and Planet Formation 18 4 246 General Observer Program edit For GO Cycle 1 there were 6 000 hours of observation time available to allocate and 1 173 proposals were submitted requesting a total of 24 500 hours of observation time 247 Selection of Cycle 1 GO programs was announced on 30 March 2021 with 266 programs approved These included 13 large programs and treasury programs producing data for public access 248 The Cycle 2 GO program was announced on May 10 2023 249 Webb science observations are nominally scheduled in weekly increments The observation plan for every week is published on Mondays by the Space Telescope Science Institute 250 Scientific results editJames Webb Space Telescope completed its commissioning and was ready to begin full scientific operations on 11 July 2022 251 With some exceptions most experiment data is kept private for one year for the exclusive use of scientists running that particular experiment and then the raw data will be released to the public 252 Hubble 2017 compared to Webb 2022 253 254 nbsp nbsp Deep Field Galaxy clusterSMACS J0723 3 7327 255 256 257 258 226 First full color images edit The first full color images and spectroscopic data were released on 12 July 2022 which also marked the official beginning of Webb s general science operations United States President Joe Biden revealed the first image Webb s First Deep Field on 11 July 2022 255 256 Additional releases around this time include 259 260 261 Carina Nebula young star forming region called NGC 3324 displaying Cosmic Cliffs about 8500 light years from Earth WASP 96b including an analysis of atmosphere with evidence of water around a giant gas planet orbiting a distant star 1120 light years from Earth Southern Ring Nebula clouds of gas and dust expelled by a dying star 2500 light years from Earth Stephan s Quintet a visual display of five galaxies with colliding gas and dust clouds creating new stars four central galaxies are 290 million light years from Earth SMACS J0723 3 7327 a galaxy cluster at redshift 0 39 with distant background galaxies whose images are distorted and magnified due to gravitational lensing by the cluster This image has been called Webb s First Deep Field 260 262 On 14 July 2022 NASA presented images of Jupiter and related areas by the James Webb Space Telescope including infrared views 263 In a preprint released around the same time NASA ESA and CSA scientists stated that almost across the board the science performance of JWST is better than expected The document described a series of observations during the commissioning when the instruments captured spectra of transiting exoplanets with a precision better than 1000 ppm per data point and tracked moving objects with speeds up to 67 milliarcseconds second more than twice as fast as the requirement a It also obtained the spectra of hundreds of stars simultaneously in a dense field towards the Milky Way Galactic Center Other targets included 25 Moving targets Jupiter including rings and the moons Europa Thebe and Metis asteroids 2516 Roman 118 Peitho 6481 Tenzing 1773 Rumpelstilz 216 Kleopatra 2035 Stearns 4015 Wilson Harrington and 2004 JX20 NIRCam grism time series NIRISS SOSS and NIRSpec BOTS mode the Jupiter sized planet HAT P 14b NIRISS aperture masking interferometry AMI A clear detection of the very low mass companion star AB Doradus C which had a separation of only 0 3 arcseconds to the primary This observation was the first demonstration of AMI in space MIRI low resolution spectroscopy LRS a hot super Earth planet L 168 9 b TOI 134 around a bright M dwarf star red dwarf star 264 Bright early galaxies edit Within two weeks of the first Webb images several preprint papers described a wide range of high redshift and very luminous presumably large galaxies believed to date from 235 million years z 16 7 to 280 million years after the Big Bang far earlier than previously known 232 233 On 17 August 2022 NASA released a large mosaic image of 690 individual frames taken by the Near Infrared Camera NIRCam on Webb of numerous very early galaxies 265 266 Some early galaxies observed by Webb like CEERS 93316 which has an estimated redshift of approximately z 16 7 corresponding to 235 8 million years after the Big Bang are high redshift galaxy candidates 267 268 In September 2022 primordial black holes were proposed as explaining these unexpectedly large and early galaxies 269 270 271 Subsequent noteworthy observations and interpretations edit In June 2023 detection of organic molecules 12 billion light years away in a galaxy called SPT0418 47 using the Webb telescope was announced 272 On 12 July 2023 NASA celebrated the first year of operations with the release of Webb s image of a small star forming region in the Rho Ophiuchi cloud complex 390 light years away 273 In September 2023 two astrophysicists questioned the accepted Standard Model of Cosmology based on the latest James Webb Space Telescope studies 274 Gallery edit First images by the James Webb Space Telescope released 12 July 2022 nbsp Cosmic Cliffs of Carina Nebula NGC 3324 NIRCam nbsp Carina Nebula NGC 3324 MIRI nbsp Southern Ring Nebula NGC 3132 Left NIRCam Right MIRI nbsp Webb s First Deep Field SMACS 0723 Left MIRI Right NIRCam nbsp Stephan s Quintet NIRCam MIRI composite nbsp Spectrum of WASP 96b nbsp Media related to Images by the James Webb Space Telescope at Wikimedia CommonsSee also editSpacecraft attitude control Process of controlling orientation of an aerospace vehicle Timeline of the James Webb Space Telescope Libration point orbit Quasiperiodic orbit around a Lagrange point List of deep fields List of largest infrared telescopes List of largest optical reflecting telescopes List of space telescopes Nancy Grace Roman Space Telescope planned launch no later than May 2027 New Worlds Mission proposed occulter for the JWST Physical cosmology Branch of cosmology which studies mathematical models of the universe Satellite bus Main body and structural component of the satellite Solar panels on spacecraft Photovoltaic solar panels on spacecraft operating in the inner Solar System Spacecraft design Spacecraft thermal control Process of keeping all parts of a spacecraft within acceptable temperature ranges Collier Trophy presented to the JWST in 2023 for the greatest achievement in aeronautics or astronautics in America during the preceding year Notes edit a b JWST was designed with the requirement to track objects that move as fast as Mars which has a maximum apparent speed on the sky of 30 mas s which is the value given in the technical specification i e the nominal value 24 During commissioning various asteroids were observed to determine the actual limitation for the speed of objects and it turned out to be 67 mas s which is more than twice the nominal value Tracking at rates of 30 67 mas s showed accuracies similar to tracking of slower targets Thus the telescope is able to observe also near Earth asteroids NEAs comets closer to perihelion and interstellar objects 25 8 Later after more experience with FGS had been gained the tracking speed limit was finally set to 75 mas s for routine observations Higher rates up to 100 mas s are also possible on special request as FGS needs multiple guide stars to this end which introduces complexity and inefficiency The first observation with a super fast rate was the DART impact experiment on 26 September 2022 26 Baffled in this context means enclosed in a tube in a similar manner to a conventional optical telescope which helps to stop stray light entering the telescope from the side For an actual example see the following link Freniere E R 1981 First order design of optical baffles Society of Photo Optical Instrumentation Engineers SPIE Conference Series First order design of optical baffles Radiation Scattering in Optical Systems Vol 257 pp 19 28 Bibcode 1981SPIE 257 19F doi 10 1117 12 959598 The C3 mirror segment is positioned in the outer ring of segments located at the 5 o clock number of a clock face when viewing the primary mirror face on 175 HD 84406 is a star approximately 258 5 light years away in the constellation of Ursa Major The star is a spectral type G star and has a high proper motion 216 2MASS J17554042 6551277 also known as UNSW V 084 and TYC 4212 1079 1 224 is a star in the constellation Draco in the Milky Way It is located almost 2 000 light years away from Earth within a degree of the north ecliptic pole Its visual apparent magnitude mv is 10 95 which makes it much too faint to be observed with the naked eye It is cooler than the Sun but some 13 to 16 times brighter in visible light 225 and is consequently not a sun like star Its motion vector in the direction of the Sun is 51 km s 224 References edit a b NASA JWST Who are the partners in the Webb project NASA Archived from the original on 29 November 2011 Retrieved 18 November 2011 nbsp This article incorporates text from this source which is in the public domain Kelso Thomas S 25 December 2021 JWST Celestrak Archived from the original on 18 January 2022 Retrieved 26 December 2021 FAQ Full General Public Webb Telescope NASA jwst nasa gov Archived from the original on 23 July 2019 Retrieved 13 January 2022 NASA Says Webb s Excess Fuel Likely to Extend its Lifetime Expectations James Webb Space Telescope blogs nasa gov 29 December 2021 Archived from the original on 6 January 2022 Retrieved 30 December 2021 a b James Webb Space Telescope JWST NASA Space Science Data Coordinated Archive Retrieved 10 February 2023 Webb Key Facts Goddard Space Flight Center NASA Retrieved 7 April 2023 a b JWST Orbit JWST User Documentation Space Telescope Science Institute Archived from the original on 11 July 2022 Retrieved 25 December 2021 JWST Telescope James Webb Space Telescope User Documentation Space Telescope Science Institute 23 December 2019 Archived from the original on 11 July 2022 Retrieved 11 June 2020 nbsp This article incorporates text from this source which is in the public domain Moskowitz Clara 1 December 2022 How JWST Is Changing Our View of the Universe The James Webb Space Telescope has sparked a new era in astronomy Scientific American Archived from the original on 15 November 2022 Retrieved 15 November 2022 a b Overbye Dennis 23 August 2022 How the Webb Telescope Expanded My Universe As new images of Jupiter and a galactic survey spring forth from NASA s new observatory our cosmic affairs correspondent confesses he didn t anticipate their power The New York Times Archived from the original on 24 August 2022 Retrieved 24 August 2022 a b Achenbach Joel 5 August 2022 The Webb telescope is astonishing But the universe is even more so This new tool can t do everything but it s capturing some of the first light emitted after the big bang and that is already revealing wonders The Washington Post Archived from the original on 7 August 2022 Retrieved 7 August 2022 O Callaghan Jonathan 23 January 2023 JWST Heralds a New Dawn for Exoplanet Science The James Webb Space Telescope is opening an exciting new chapter in the study of exoplanets and the search for life beyond Earth Scientific American Retrieved 25 January 2023 Fisher Alise Pinol Natasha Betz Laura 11 July 2022 President Biden Reveals First Image from NASA s Webb Telescope NASA Archived from the original on 12 July 2022 Retrieved 12 July 2022 a b c Comparison Webb vs Hubble Telescope Webb NASA www jwst nasa gov Archived from the original on 21 January 2022 Retrieved 12 July 2022 Lallo Matthew D 2012 Experience with the Hubble Space Telescope 20 years of an archetype Optical Engineering 51 1 011011 011011 19 arXiv 1203 0002 Bibcode 2012OptEn 51a1011L doi 10 1117 1 OE 51 1 011011 S2CID 15722152 Mirrors Webb NASA webb nasa gov Archived from the original on 4 February 2022 Retrieved 12 July 2022 a b A Deeper Sky by Brian Koberlein briankoberlein com Archived from the original on 19 March 2022 Retrieved 5 January 2022 a b c FAQ for Scientists Webb Telescope NASA jwst nasa gov Archived from the original on 5 January 2022 Retrieved 5 January 2022 Shelton Jim 3 March 2016 Shattering the cosmic distance record once again Yale University Archived from the original on 13 March 2016 Retrieved 4 March 2016 Hubble breaks cosmic distance record SpaceTelescope org 3 March 2016 heic1604 Archived from the original on 8 March 2016 Retrieved 3 March 2016 Oesch P A Brammer G van Dokkum P et al March 2016 A Remarkably Luminous Galaxy at z 11 1 Measured with Hubble Space Telescope Grism Spectroscopy The Astrophysical Journal 819 2 129 arXiv 1603 00461 Bibcode 2016ApJ 819 129O doi 10 3847 0004 637X 819 2 129 S2CID 119262750 Atkinson Nancy Hubble Has Looked Back in Time as Far as It Can And Still Can t Find The First Stars Universe Today Archived from the original on 9 January 2022 Retrieved 9 January 2022 via ScienceAlert a b Infrared astronomy from earth orbit Infrared Processing and Analysis Center NASA Spitzer Science Center California Institute of Technology 2017 Archived from the original on 21 December 2016 nbsp This article incorporates text from this source which is in the public domain Fisher Alise 14 July 2022 Webb Images of Jupiter and More Now Available in Commissioning Data James Webb Space Telescope NASA Blogs Archived from the original on 16 January 2023 Retrieved 8 August 2022 a b c Rigby Jane Perrin Marshall McElwain Michael Kimble Randy Friedman Scott Lallo Matt Doyon Rene Feinberg Lee Ferruit Pierre Glasse Alistair Rieke Marcia Rieke George et al 2023 The Science Performance of JWST as Characterized in Commissioning Publications of the Astronomical Society of the Pacific 135 1046 048001 arXiv 2207 05632 Bibcode 2023PASP 135d8001R doi 10 1088 1538 3873 acb293 S2CID 253735464 Thaddeus Cesari 8 February 2023 Breaking the Tracking Speed Limit With Webb James Webb Space Telescope NASA Blogs Retrieved 11 February 2023 Technical FAQ Specifically On Solar System Observations James Webb Space Telescope NASA Archived from the original on 12 July 2022 Retrieved 29 July 2022 a b c L2 Orbit Space Telescope Science Institute Archived from the original on 3 February 2014 Retrieved 28 August 2016 a b c The Sunshield nasa gov NASA Archived from the original on 10 August 2017 Retrieved 28 August 2016 nbsp This article incorporates text from this source which is in the public domain Drake Nadia 24 April 2015 Hubble Still Wows At 25 But Wait Till You See What s Next National Geographic Archived from the original on 23 June 2019 Retrieved 24 April 2015 The James Webb Space Telescope nasa gov Archived from the original on 30 June 2019 Retrieved 28 August 2016 nbsp This article incorporates text from this source which is in the public domain Sunshield Coatings Webb NASA jwst nasa gov Archived from the original on 29 December 2021 Retrieved 3 May 2020 nbsp This article incorporates text from this source which is in the public domain Clery Daniel 27 March 2018 NASA announces more delays for giant space telescope Science Archived from the original on 24 December 2021 Retrieved 5 June 2018 Morring Frank Jr 16 December 2013 JWST Sunshade Folding Deployment In Test Aviation Week amp Space Technology pp 48 49 ISSN 0005 2175 Archived from the original on 19 March 2022 Retrieved 27 December 2021 Fisher Alise 30 December 2021 Webb Ready for Sunshield Deployment and Cooldown James Webb Space Telescope NASA Blogs Archived from the original on 30 December 2021 Retrieved 31 December 2021 JWST Wavefront Sensing and Control Space Telescope Science Institute Archived from the original on 5 August 2012 Retrieved 9 June 2011 Keck I and Keck II Telescopes W M Keck Observatory Archived from the original on 1 April 2022 Retrieved 12 July 2022 a b Mallonee Laura 22 October 2019 NASA s Biggest Telescope Ever Prepares for a 2021 Launch Wired Archived from the original on 16 May 2022 Retrieved 4 June 2021 a b Mirror Mirror On Its Way James Webb Space Telescope Blogs nasa gov 13 January 2022 Archived from the original on 27 January 2022 Retrieved 12 February 2022 JWST Mirrors Space Telescope Science Institute Archived from the original on 5 August 2012 Retrieved 9 June 2011 Amos Jonathan 16 March 2022 James Webb Fully focused telescope beats expectations BBC News Archived from the original on 11 July 2022 Retrieved 15 July 2022 a b JWST Integrated Science Instrument Module ISIM NASA 2017 Archived from the original on 2 June 2019 Retrieved 2 February 2017 nbsp This article incorporates text from this source which is in the public domain James Webb Space Telescope Near Infrared Camera STScI Archived from the original on 21 March 2013 Retrieved 24 October 2013 NIRCam for the James Webb Space Telescope University of Arizona Archived from the original on 3 November 2021 Retrieved 24 October 2013 a b c JWST Current Status STScI Archived from the original on 15 July 2009 Retrieved 5 July 2008 NIRSpec the near infrared spectrograph on JWST European Space Agency 22 February 2015 Archived from the original on 3 April 2019 Retrieved 2 February 2017 a b c MIRI spectrometer for NGST Archived from the original on 27 September 2011 a b JWST Mid Infrared Instrument MIRI NASA 2017 Archived from the original on 12 June 2019 Retrieved 3 February 2017 nbsp This article incorporates text from this source which is in the public domain a b JWST NASA Archived from the original on 26 June 2015 Retrieved 29 June 2015 nbsp This article incorporates text from this source which is in the public domain Banks Kimberly Larson Melora Aymergen Cagatay Zhang Burt 2008 Angeli George Z Cullum Martin J eds James Webb Space Telescope Mid Infrared Instrument Cooler systems engineering PDF Proceedings of SPIE Modeling Systems Engineering and Project Management for Astronomy III 7017 5 Bibcode 2008SPIE 7017E 0AB doi 10 1117 12 791925 S2CID 17507846 Archived PDF from the original on 6 October 2021 Retrieved 6 February 2016 Fig 1 Cooler Architecture Overview JWST is ready for launch and amazing science The Planetary Society Retrieved 22 August 2023 Doyon Rene Hutchings John B Beaulieu Mathilde Albert Loic Lafreniere David Willott Chris Touahri Driss Rowlands Neil Maszkiewicz Micheal Fullerton Alex W Volk Kevin Martel Andre R Chayer Pierre Sivaramakrishnan Anand Abraham Roberto Ferrarese Laura Jayawardhana Ray Johnstone Doug Meyer Michael Pipher Judith L Sawicki Marcin 22 August 2012 Clampin Mark C Fazio Giovanni G MacEwen Howard A Oschmann Jacobus M eds The JWST Fine Guidance Sensor FGS and Near Infrared Imager and Slitless Spectrograph NIRISS Proceedings of SPIE Space Telescopes and Instrumentation 2012 Optical Infrared and Millimeter Wave 8442 84422R Bibcode 2012SPIE 8442E 2RD doi 10 1117 12 926578 S2CID 120702854 FGS features two modules an infrared camera dedicated to fine guiding of the observatory and a science camera module the Near Infrared Imager and Slitless Spectrograph NIRISS The Spacecraft Bus NASA James Webb Space Telescope 2017 Archived from the original on 6 July 2019 Retrieved 26 November 2016 nbsp This article incorporates text from this source which is in the public domain a b The JWST Observatory NASA 2017 Archived from the original on 20 May 2019 Retrieved 28 December 2016 The Observatory is the space based portion of the James Webb Space Telescope system and is comprisedof three elements the Integrated Science Instrument Module ISIM the Optical Telescope Element OTE which includes the mirrors and backplane and the Spacecraft Element which includes the spacecraft bus and the sunshield nbsp This article incorporates text from this source which is in the public domain Integrated Science Instrument Module ISIM NASA James Webb Space Telescope 2017 Archived from the original on 3 December 2016 Retrieved 30 November 2016 nbsp This article incorporates text from this source which is in the public domain Willoughby Scott P February 2012 PRIME The Untold Story Of NASA s James Webb Space Telescope SatMagazine Satnews Archived from the original on 11 August 2022 Retrieved 6 April 2021 Sloan Jeff 12 October 2015 James Webb Space Telescope spacecraft inches towards full assembly Composites World Archived from the original on 24 October 2019 Retrieved 28 December 2016 JWST Propulsion JWST User Documentation Space Telescope Science Institute Archived from the original on 11 July 2022 Retrieved 29 December 2021 Clark Stephen 28 November 2021 NASA gives green light to fuel James Webb Space Telescope Spaceflight Now Archived from the original on 25 June 2022 Retrieved 2 December 2021 Why is Webb not serviceable like Hubble James Webb Space Telescope FAQ Archived from the original on 3 July 2022 Retrieved 31 December 2021 a b Relief as NASA s most powerful space telescope finishes risky unfolding Science 8 January 2022 Archived from the original on 31 January 2022 Retrieved 11 January 2022 Smith Marcia 30 August 2018 Zurbuchen Taking One Last Look at JWST Servicing Compatiblity sic SpacePolicyOnline Archived from the original on 31 December 2021 Retrieved 31 December 2021 Foust Jeff 2 February 2018 Scientists engineers push for servicing and assembly of future space observatories SpaceNews Archived from the original on 15 July 2022 Retrieved 31 December 2021 Grush Loren 28 December 2021 NASA s James Webb Space Telescope is about to transform into its final form The Verge Archived from the original on 9 July 2022 Retrieved 11 January 2022 Dashevsky Ilana Balzano Vicki 2007 JWST Maximizing Efficiency and Minimizing Ground Systems PDF International Symposium on Reducing the Costs of Spacecraft Ground Systems and Operations Proceedings Archived PDF from the original on 4 December 2022 Retrieved 4 December 2022 Greenhouse Matthew A Status of the James Webb Space Telescope Integrated Science Instrument Module System PDF Report Goddard Space Flight Center Archived PDF from the original on 13 July 2022 Retrieved 4 December 2022 McCarthy S G Autio G W 1978 Infrared Detector Performance In The Shuttle Infrared Telescope Facility SIRTF 1978 Los Angeles Technical Symposium Utilization of Infrared Detectors Vol 81 Society of Photographic Instrumentation Engineers pp 81 88 Bibcode 1978SPIE 132 81M doi 10 1117 12 956060 Archived from the original on 5 March 2017 Retrieved 8 December 2016 The tenuous atmosphere above the 400 km nominal flight altitude has no measurable absorption so that detectors operating at all wavelengths from 5 mm to 1000 mm can achieve high radiometric sensitivity How cold can you go Cooler tested for NASA telescope Phys org 14 June 2016 Archived from the original on 11 July 2022 Retrieved 31 January 2017 JPL Herschel Space Observatory Related Missions NASA Jet Propulsion Laboratory Goddard Flight Center California Institute of Technology Archived from the original on 3 December 2016 Retrieved 4 June 2012 nbsp This article incorporates text from this source which is in the public domain What is ISO ESA 2016 Archived from the original on 10 November 2021 Retrieved 4 June 2021 Hubble Space Telescope Wide Field Camera 3 NASA 22 August 2016 Archived from the original on 13 November 2021 Retrieved 9 December 2016 nbsp This article incorporates text from this source which is in the public domain a b c d e f Reichhardt Tony March 2006 US astronomy Is the next big thing too big Nature 440 7081 140 143 Bibcode 2006Natur 440 140R doi 10 1038 440140a PMID 16525437 Nexus Space Telescope MIT Archived from the original on 29 August 2011 Retrieved 23 August 2011 Brown Dwayne Braukus Michael NASA NASA and ESA Sign Agreements for Future Cooperation www nasa gov Retrieved 2 August 2023 a b Gur Haviv Rettig 5 January 2022 Space is changing Webb is just the start says ex Israeli who was in from its dawn The Times of Israel Archived from the original on 19 March 2022 Retrieved 7 January 2022 Advanced Concepts Studies The 4 m Aperture Hi Z Telescope NASA Space Optics Manufacturing Technology Center Archived from the original on 15 October 2011 nbsp This article incorporates text from this source which is in the public domain a b STSCI JWST History 1994 Archived from the original on 3 February 2014 Retrieved 29 December 2018 Astrononmy and Astrophysics in the New Millennium NASA Archived from the original on 25 December 2021 Retrieved 27 July 2011 nbsp This article incorporates text from this source which is in the public domain de Weck Olivier L Miller David W Mosier Gary E 2002 Multidisciplinary analysis of the NEXUS precursor space telescope PDF In MacEwen Howard A ed Highly Innovative Space Telescope Concepts Vol 4849 p 294 Bibcode 2002SPIE 4849 294D CiteSeerX 10 1 1 664 8727 doi 10 1117 12 460079 S2CID 18725988 Archived PDF from the original on 23 September 2017 Retrieved 27 July 2011 Brown R A 1996 1996swhs conf 603B Page 603 Science with the Hubble Space Telescope II 603 Bibcode 1996swhs conf 603B Archived from the original on 14 January 2022 Retrieved 23 September 2022 Dressler A ed 1996 Exploration and the Search for Origins A Vision for Ultraviolet Optical Infrared Space Astronomy Report of the HST amp Beyond Committee PDF Stsci edu Association of Universities for Research in Astronomy Archived PDF from the original on 15 July 2022 Retrieved 12 February 2022 Stockman H S June 1997 The Next Generation Space Telescope Visiting a time when galaxies were young Space Telescope Science Institute Baltimore Maryland The Association of Universities for Research in Astronomy Washington D C Astronomy and Astrophysics Survey Committee Board on Physics and Astronomy Space Studies Board Commission on Physical Sciences Mathematics and Applications National Research Council 16 January 2001 Astronomy and Astrophysics in the New Millennium Washington D C National Academies Press doi 10 17226 9839 ISBN 978 0 309 07031 7 Archived from the original on 15 July 2022 Retrieved 15 December 2021 STSCI JWST History 1996 Stsci edu Archived from the original on 3 February 2014 Retrieved 16 January 2012 information eso org Goddard Space Flight Center design www spacetelescope org Retrieved 2 August 2023 ESA Science amp Technology Ball Aerospace design for JWST Archived 12 December 2012 at archive today Sci esa int Retrieved 21 August 2013 ESA Science amp Technology TRW design for JWST Archived 12 December 2012 at archive today Sci esa int Retrieved 21 August 2013 ESA Science amp Technology Lockheed Martin design for JWST Archived 13 December 2012 at archive today Sci esa int Retrieved 21 August 2013 a b HubbleSite Webb Past and Future Archived from the original on 10 December 2012 Retrieved 13 January 2012 a b NASA ANNOUNCES CONTRACT FOR NEXT GENERATION SPACE TELESCOPE NAMED AFTER SPACE PIONEER NASA 10 September 2002 Archived from the original on 27 August 2022 Retrieved 26 August 2022 a b About James Webb NASA Archived from the original on 27 March 2018 Retrieved 15 March 2013 nbsp This article incorporates text from this source which is in the public domain TRW Selected as JWST Prime Contractor STCI 11 September 2003 Archived from the original on 5 August 2012 Retrieved 13 January 2012 Northrop Grumman Completes Fabrication Of Sunshield Deployment Flight Structure For JWST Space Daily 13 December 2011 Archived from the original on 18 January 2022 Retrieved 10 December 2014 a b Mather John James Webb Space Telescope JWST PDF National Academy of Science Archived from the original PDF on 10 November 2008 Retrieved 5 July 2008 nbsp This article incorporates text from this source which is in the public domain a b European agreement on James Webb Space Telescope s Mid Infrared Instrument MIRI signed Press release ESA Media Relations Service 9 June 2004 Archived from the original on 18 May 2009 Retrieved 6 May 2009 Canada s contribution to NASA s James Webb Space Telescope canada ca Canadian Space Agency 4 June 2007 Archived from the original on 18 January 2022 Retrieved 3 July 2021 Canadian Space Agency Delivers Canada s Contributions to the James Webb Space Telescope SpaceQ 30 July 2012 Archived from the original on 18 January 2022 Retrieved 3 July 2021 JWST Passes TNAR STScI Archived from the original on 5 August 2012 Retrieved 5 July 2008 Berger Brian 23 May 2007 NASA Adds Docking Capability For Next Space Observatory SPACE com Archived from the original on 30 June 2008 Retrieved 5 July 2008 James Webb Space Telescope sunshield is ready to fabricate www laserfocusworld com 3 February 2010 Archived from the original on 30 December 2021 Retrieved 30 December 2021 NASA s Webb Telescope Passes Key Mission Design Review Milestone NASA Archived from the original on 1 May 2010 Retrieved 2 May 2010 nbsp This article incorporates text from this source which is in the public domain Clark Stephen 12 August 2010 NASA says JWST cost crunch impeding new missions Spaceflight Now Archived from the original on 29 April 2021 Retrieved 13 August 2010 NASA s James Webb Space Telescope Primary Mirror Fully Assembled nasa gov 3 February 2016 Archived from the original on 4 February 2016 Retrieved 4 February 2016 nbsp This article incorporates text from this source which is in the public domain NASA s James Webb Space Telescope Secondary Mirror Installed NASA 7 March 2016 Archived from the original on 17 March 2016 Retrieved 23 March 2016 nbsp This article incorporates text from this source which is in the public domain Yuhas Alan 4 November 2016 Nasa begins testing enormous space telescope made of gold mirrors The Guardian Archived from the original on 5 November 2016 Retrieved 5 November 2016 NASA Completes Webb Telescope Review Commits to Launch in Early 2021 NASA 27 June 2018 Archived from the original on 14 March 2020 Retrieved 27 June 2018 nbsp This article incorporates text from this source which is in the public domain Achenbach Joel 26 July 2018 Northrop Grumman CEO is grilled about James Webb Space Telescope errors The Washington Post Archived from the original on 28 December 2019 Retrieved 28 December 2019 The two halves of Hubble s US 10 billion successor have finally come together after 12 years of waiting Business Insider Archived from the original on 15 July 2022 Retrieved 29 August 2019 Clark Stephen 30 September 2021 After two decades the Webb telescope is finished and on the way to its launch site Spaceflight Now Archived from the original on 6 October 2021 Retrieved 6 October 2021 Wall Mike 12 October 2021 NASA s James Webb Space Telescope arrives in French Guiana ahead of December 18 launch Space com Archived from the original on 12 October 2021 Retrieved 13 October 2021 FY 2022 NASA Congressional Budget Justification PDF NASA p JWST 2 Archived PDF from the original on 10 June 2021 Retrieved 21 October 2021 nbsp This article incorporates text from this source which is in the public domain Foust Jeff 2 June 2021 JWST launch slips to November SpaceNews Archived from the original on 15 July 2022 Retrieved 21 October 2021 Lilly Simon 27 November 1998 The Next Generation Space Telescope NGST University of Toronto Archived from the original on 25 December 2021 Retrieved 23 August 2011 NGST Weekly Missive 25 April 2002 Archived from the original on 15 July 2022 Retrieved 23 August 2011 NASA Modifies James Webb Space Telescope Contract 12 November 2003 Archived from the original on 25 December 2021 Retrieved 23 August 2011 nbsp This article incorporates text from this source which is in the public domain Problems for JWST 21 May 2005 Archived from the original on 25 December 2021 Retrieved 25 August 2011 Refocusing NASA s vision Nature 440 7081 127 9 March 2006 Bibcode 2006Natur 440 127 doi 10 1038 440127a PMID 16525425 Cowen Ron 25 August 2011 Webb Telescope Delayed Costs Rise to 8 Billion ScienceInsider Archived from the original on 14 January 2012 a b Independent Comprehensive Review Panel Final Report PDF 29 October 2010 Archived PDF from the original on 17 November 2021 Retrieved 10 June 2011 nbsp This article incorporates text from this source which is in the public domain Amos Jonathan 22 August 2011 JWST price tag now put at over 8 bn BBC Archived from the original on 25 December 2021 Retrieved 22 June 2018 NASA s James Webb Space Telescope to be Launched Spring 2019 NASA 28 September 2017 Archived from the original on 7 February 2018 Retrieved 28 September 2017 nbsp This article incorporates text from this source which is in the public domain a b NASA Delays Launch of James Webb Space Telescope to 2020 Space com Archived from the original on 28 April 2022 Retrieved 27 March 2018 NASA Completes Webb Telescope Review Commits to Launch in Early 2021 nasa gov NASA 27 June 2018 Archived from the original on 14 March 2020 Retrieved 28 June 2018 nbsp This article incorporates text from this source which is in the public domain NASA delays launch of Webb telescope to no earlier than Dec 24 14 December 2021 Archived from the original on 15 December 2021 Retrieved 14 December 2021 nbsp This article incorporates text from this source which is in the public domain 1634 1699 McCusker J J 1997 How Much Is That in Real Money A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States Addenda et Corrigenda PDF American Antiquarian Society 1700 1799 McCusker J J 1992 How Much Is That in Real Money A Historical Price Index for Use as a Deflator of Money Values in the Economy of the United States PDF American Antiquarian Society 1800 present Federal Reserve Bank of Minneapolis Consumer Price Index estimate 1800 Retrieved 28 May 2023 a b c McKie Robin 9 July 2011 Nasa fights to save the James Webb space telescope from the axe The Guardian London Archived from the original on 17 March 2017 Retrieved 14 December 2016 Appropriations Committee Releases the Fiscal Year 2012 Commerce Justice Science Appropriations US House of representatives Committee on Appropriations 6 July 2011 Archived from the original on 23 March 2012 Retrieved 7 July 2011 nbsp This article incorporates text from this source which is in the public domain US lawmakers vote to kill Hubble successor SpaceDaily 7 July 2011 Archived from the original on 10 July 2011 Retrieved 8 July 2011 Proposed NASA Budget Bill Would Cancel Major Space Telescope Space com 6 July 2011 Archived from the original on 9 July 2011 Retrieved 11 July 2011 Bergin Chris 7 January 2015 James Webb Space Telescope hardware entering key test phase NASASpaceFlight com Archived from the original on 7 November 2017 Retrieved 28 August 2016 Hand E 7 July 2011 AAS Issues Statement on Proposed Cancellation of James Webb Space Telescope American Astronomical Society Archived from the original on 19 March 2018 Retrieved 1 February 2017 Mikulski Statement on House Appropriations Subcommittee Termination of James Webb Telescope SpaceRef 11 July 2011 Archived from the original on 15 July 2022 Retrieved 1 February 2017 Way Above the Shuttle Flight The New York Times 9 July 2011 Archived from the original on 19 March 2018 Retrieved 27 February 2017 Harrold Max 7 July 2011 Bad news for Canada U S could scrap new space telescope The Vancouver Sun Archived from the original on 31 July 2018 Retrieved 27 January 2019 NASA budget plan saves telescope cuts space taxis Reuters 16 November 2011 Archived from the original on 24 September 2015 Retrieved 1 July 2017 Leone Dan 7 November 2012 NASA Acknowledges James Webb Telescope Costs Will Delay Other Science Missions SpaceNews Archived from the original on 22 January 2013 Retrieved 12 January 2013 a b Moskowitz Clara 30 March 2015 NASA Assures Skeptical Congress That the James Webb Telescope Is on Track Scientific American Archived from the original on 2 February 2017 Retrieved 29 January 2017 Billings Lee 27 October 2010 The telescope that ate astronomy Nature 467 7319 1028 1030 doi 10 1038 4671028a PMID 20981068 Koren Marina 7 December 2016 The Extreme Hazing of the Most Expensive Telescope Ever Built The Atlantic Archived from the original on 2 February 2017 Retrieved 29 January 2017 a b c Cohen Ben 8 July 2022 The NASA Engineer Who Made the James Webb Space Telescope Work The Wall Street Journal ISSN 0099 9660 Archived from the original on 11 July 2022 Retrieved 12 July 2022 Potter Sean 22 July 2022 NASA Webb Program Director Greg Robinson Announces Retirement NASA Archived from the original on 23 July 2022 Retrieved 22 July 2022 Wang Jen Rae Cole Steve Northon Karen 27 March 2018 NASA s Webb Observatory Requires More Time for Testing and Evaluation NASA Archived from the original on 29 March 2018 Retrieved 27 March 2018 nbsp This article incorporates text from this source which is in the public domain Amos Jonathan 27 March 2018 Hubble successor faces new delay BBC News Archived from the original on 28 March 2018 Retrieved 27 March 2018 Witze Alexandra 27 March 2018 NASA reveals major delay for 8 billion Hubble successor Nature 556 7699 11 12 Bibcode 2018Natur 556 11W doi 10 1038 d41586 018 03863 5 PMID 29620740 Dreier Casey 15 February 2019 NASA just got its best budget in a decade Archived from the original on 16 February 2019 Retrieved 7 March 2019 Foust Jeff 20 March 2020 Coronavirus pauses work on JWST SpaceNews Archived from the original on 15 July 2022 Retrieved 15 April 2020 ESA Science amp Technology Europe s Contributions to the JWST Mission European Space Agency Archived from the original on 19 March 2022 Retrieved 19 December 2021 Canadian Space Agency Eyes Hubble s Successor Canada Delivers its Contribution to the World s Most Powerful Space Telescope Canadian Space Agency 12 April 2013 Archived from the original on 12 April 2013 a b Jenner Lynn 1 June 2020 NASA s Webb Telescope is an International Endeavor NASA Archived from the original on 19 March 2022 Retrieved 23 September 2021 Institutional Partners Webb NASA jwst nasa gov Retrieved 2 August 2023 Shepherd Tony 25 December 2021 James Webb world s most powerful telescope makes its first call to Australia on Christmas Day The Guardian Archived from the original on 19 March 2022 Retrieved 5 January 2022 Francis Matthew The Problem With Naming Observatories For Bigots Forbes Archived from the original on 11 April 2022 Retrieved 11 April 2022 Savage Dan 21 January 2015 Should NASA Name a Telescope After a Dead Guy Who Persecuted Gay People in the 1950s The Stranger Archived from the original on 24 January 2015 Retrieved 11 April 2022 Fisher Alise 18 November 2022 NASA Shares James Webb History Report NASA Archived from the original on 24 November 2022 Retrieved 25 November 2022 Odom Brian C NASA Historical Investigation into James E Webb s Relationship to the Lavender Scare Final Report PDF nasa gov NASA Archived PDF from the original on 24 November 2022 Retrieved 25 November 2022 Witze Alexandra 18 November 2022 NASA really really won t rename Webb telescope despite community pushback Nature doi 10 1038 d41586 022 03787 1 PMID 36400961 S2CID 253671586 Archived from the original on 22 November 2022 Retrieved 21 November 2022 Masetti Maggie Krishnamurthi Anita 2009 JWST Science NASA Archived from the original on 24 November 2017 Retrieved 14 April 2013 nbsp This article incorporates text from this source which is in the public domain NASA s Next Telescope Could ID Alien Megastructures 9 February 2016 Archived from the original on 9 October 2019 Retrieved 1 September 2016 Zimmer Carl 2 July 2022 Webb Telescope Will Look for Signs of Life Way Out There The first question astronomers want to answer about exoplanets Do they have atmospheres friendly to life The New York Times Archived from the original on 2 July 2022 Retrieved 2 July 2022 updated Stefanie Waldek last 29 March 2022 NASA s new James Webb Space Telescope will be able to sniff out methane Here s how to tell if it s a sign of life Space com Retrieved 2 August 2023 Basics of Space Flight Jet Propulsion Laboratory Archived from the original on 11 June 2012 Retrieved 28 August 2016 nbsp This article incorporates text from this source which is in the public domain Dichmann Donald J Alberding Cassandra M Yu Wayne H 5 May 2014 STATIONKEEPING MONTE CARLO SIMULATION FOR THE JAMES WEBB SPACE TELESCOPE PDF NASA Goddard Space Flight Center Archived from the original PDF on 17 December 2021 Retrieved 29 December 2021 nbsp This article incorporates text from this source which is in the public domain Greenhouse Matt 1 April 2016 The James Webb Space Telescope Mission PDF NASA Goddard Space Flight Center Archived PDF from the original on 29 December 2021 Retrieved 29 December 2021 Petersen Jeremy Tichy Jason Wawrzyniak Geoffrey Richon Karen 21 April 2014 James Webb Space Telescope Initial Mid Course Correction Monte Carlo Implementation using Task Parallelism a href Template Cite journal html title Template Cite journal cite journal a Cite journal requires journal help Kimble Randy 27 December 2021 More Than You Wanted to Know About Webb s Mid Course Corrections NASA Archived from the original on 27 December 2021 Retrieved 27 December 2021 nbsp This article incorporates text from this source which is in the public domain Howard Rick James Webb Space Telescope JWST Archived 21 December 2021 at the Wayback Machine nasa gov 6 March 2012 nbsp This article incorporates text from this source which is in the public domain Infrared Atmospheric Windows Cool Cosmos Archived from the original on 11 October 2018 Retrieved 28 August 2016 a b c d Infrared Astronomy Overview NASA Infrared Astronomy and Processing Center Archived from the original on 8 December 2006 Retrieved 30 October 2006 nbsp This article incorporates text from this source which is in the public domain a b Webb Science The End of the Dark Ages First Light and Reionization NASA Archived from the original on 22 November 2017 Retrieved 9 June 2011 nbsp This article incorporates text from this source which is in the public domain a b c d Mather John 13 June 2006 James Webb Space Telescope JWST Science Summary for SSB PDF NASA Archived PDF from the original on 27 March 2021 Retrieved 4 June 2021 nbsp This article incorporates text from this source which is in the public domain Savage Donald Neal Nancy 6 June 2003 Webb Spacecraft Science amp Operations Center Contract Awarded NASA Archived from the original on 3 January 2022 Retrieved 1 February 2017 nbsp This article incorporates text from this source which is in the public domain Single Board Computer FBO Daily Issue FBO 0332 30 October 2002 Archived from the original on 18 May 2009 Retrieved 23 April 2008 a b Amazing Miniaturized SIDECAR Drives Webb Telescope s Signal NASA 20 February 2008 Archived from the original on 27 February 2008 Retrieved 22 February 2008 nbsp This article incorporates text from this source which is in the public domain Hecht Jeff Potter Ned Koziol Michael 2022 Inside the Universe Machine IEEE Spectrum 59 9 48 Sutherland Scott 10 June 2022 Webb s primary mirror was just hit by a meteoroid but it was built to endure The Weather Network Archived from the original on 9 June 2022 Retrieved 10 June 2022 Harwood William 9 June 2022 Webb telescope still performing well after micrometeoroid impact on mirror segment NASA says CBS News Archived from the original on 9 June 2022 Retrieved 10 June 2022 Howell Elizabeth 18 July 2022 James Webb Space Telescope picture shows noticeable damage from micrometeoroid strike cites a NASA ESA CSA joint report 12 July 2022 by 611 co authors from 44 institutions 25 2 a b Ariane 5 goes down in history with successful launch of Webb Arianespace Press release 25 December 2021 Archived from the original on 10 March 2022 Retrieved 25 December 2021 Pinoi Natasha Fiser Alise Betz Laura 27 December 2021 NASA s Webb Telescope Launches to See First Galaxies Distant Worlds NASA s James Webb Space Telescope launched at 7 20 a m EST Saturday Dec 25 2021 on an Ariane 5 rocket French Guiana South America NASA Archived from the original on 12 April 2022 Retrieved 28 December 2021 How to track James Webb Space Telescope mission timeline Space Explored 31 December 2021 Archived from the original on 1 January 2022 Retrieved 1 January 2022 Achenbach Joel 25 December 2021 NASA s James Webb Space Telescope launches in French Guiana 10 billion successor to Hubble telescope will capture light from first stars and study distant worlds The Washington Post Archived from the original on 25 December 2021 Retrieved 25 December 2021 Live Updates Webb Telescope Launches on Long Awaited Journey The New York Times 25 December 2021 Archived from the original on 25 December 2021 Retrieved 25 December 2021 Overbye Dennis Roulette Joey 25 December 2021 James Webb Space Telescope Launches on Journey to See the Dawn of Starlight Astronomers were jubilant as the spacecraft made it off the launchpad following decades of delays and cost overruns The Webb is set to offer a new keyhole into the earliest moments of our universe The New York Times Archived from the original on 29 December 2021 Retrieved 25 December 2021 Lissajous orbit Oxford Reference Archived from the original on 5 February 2022 Retrieved 5 February 2022 James Webb Space Telescope blogs nasa gov Archived from the original on 18 November 2021 Retrieved 22 November 2021 JWST Orbit James Webb Space Telescope User Documentation Archived from the original on 11 July 2022 Retrieved 10 July 2022 nbsp This article incorporates text from this source which is in the public domain Frequently asked questions How long will the Webb mission last NASA James Webb Space Telescope 2017 Archived from the original on 16 June 2019 Retrieved 29 June 2015 Fox Karen 29 December 2021 NASA Says Webb s Excess Fuel Likely to Extend its Lifetime Expectations James Webb Space Telescope NASA Blogs a, wikipedia, wiki, book, books, library,

article

, read, download, free, free download, mp3, video, mp4, 3gp, jpg, jpeg, gif, png, picture, music, song, movie, book, game, games.