NEO Surveyor

NEO Surveyor, formerly called Near-Earth Object Camera (NEOCam), then NEO Surveillance Mission, is a planned space-based infrared telescope designed to survey the Solar System for potentially hazardous asteroids.^[3]

NEO Surveyor

NEO Surveyor spacecraft
Names	Near-Earth Object Surveillance Mission Near-Earth Object Camera NEOCam
Mission type	Asteroid impact avoidance, astronomy
Operator	NASA / JPL
Website	https://www.ipac.caltech.edu/project/neo-surveyor
Mission duration	12 years (planned)^[1]
Spacecraft properties
Manufacturer	Jet Propulsion Laboratory^[1]
Launch mass	1,300 kg (2,900 lb)^[1]
Start of mission
Launch date	2028 (planned)^[2]
Orbital parameters
Reference system	Heliocentric orbit
Regime	Sun–Earth L1
Main telescope
Diameter	50 cm (20 in)
Wavelengths	Infrared (4–5.2 and 6–10 µm)

The NEO Surveyor spacecraft will survey from the Sun–Earth L1 (inner) Lagrange point, allowing it to see objects inside Earth's orbit, and its mid-infrared detectors sensitive to thermal emission will detect asteroids independently of their illumination by the Sun.^[4][5][6] The NEO Surveyor mission will be a successor to the NEOWISE mission, and the two missions have the same principal investigator, Amy Mainzer at the University of Arizona.^[7][8]

Since first proposed in 2006, the concept repeatedly competed unsuccessfully for NASA funding against science missions unrelated to planetary defense, despite an unfunded 2005 US Congressional directive to NASA.^[1][7] In 2019, the Planetary Defense Coordination Office decided to fund this mission outside NASA's science budget due to its national security implications.^[9][10] On 11 June 2021, NASA authorized the NEO Surveyor mission to proceed to the preliminary design phase.^[11] The Jet Propulsion Laboratory will lead development of the mission.^[1]

As of December 2022, NEO Surveyor is expected to be launched no later than June 2028.^[2]

History

In 2005, the U.S. Congress mandated NASA to achieve by the year 2020 specific levels of search completeness for discovering, cataloging, and characterizing dangerous asteroids larger than 140 m (460 ft) (Act of 2005, H.R. 1022; 109th),^[12][3] but it never appropriated specific funds for this effort.^[13] NASA did not prioritize this mandate, and directed the NEOCam project to compete against science missions for general funds unrelated to planetary defense and disaster mitigation planning.^[14][15]

Proposals for NEOCam were submitted to NASA's Discovery Program in 2006, 2010, 2015, 2016 and 2017, but each time were not selected for launch.^[15][16] The mission concept nonetheless received technology development funding in 2010 to design and test new infrared detectors optimized for asteroid and comet detection and sizing.^[17][18] The project received additional funding for further technological development in September 2015 (US$3 million),^[19][20][21] and in January 2017.^[22]

Following calls to fully fund the mission outside NASA's Planetary Science Division or directly from Congress itself,^[23][24] NASA’s associate administrator for science announced on 23 September 2019 that instead of competing for funding, NEOCam will be implemented under the name NEO Surveillance Mission with budget from NASA's Planetary Defense Coordination Office, within the Planetary Science Division.^[1] The near-miss of asteroid 2019 OK, which slipped past extant detection methods in July 2019, has been suggested to have helped prompt this decision.^[16][7][25]

For funding and management purposes, the NEO Surveillance Mission is officially a new project, but it is the same space telescope, the same team, and the mission's goals remain unchanged.^[1][26]

Objectives

The main objective of the mission is to discover most of the potentially hazardous asteroids larger than 140 m (460 ft) over the course of its mission and characterize their orbits.^[1][26] Its field of view and its sensitivity will be wide and deep enough to allow the mission to discover about 200,000 to 300,000 of new NEOs with sizes as small as 10 m (33 ft) in diameter.^[27][28] Secondary science goals include detection and characterization of approximately one million asteroids in the asteroid belt and thousands of comets, as well as identification of potential NEO targets for human and robotic exploration.^[29][30]

The Jet Propulsion Laboratory (JPL) will lead development of the mission. The total cost of the mission is estimated to be between US$500 million and US$600 million.^[1][26]

Spacecraft

The NEO Surveyor spacecraft will have a total mass of no more than 1,300 kg (2,900 lb), allowing it to launch on a vehicle like a Falcon 9 Block 5 to the Sun–Earth L1 Lagrange point. The mission should reach the 90% congressional goal within 10 years, with an anticipated mission lifetime of 12 years.^[31]

Telescope and camera

Asteroids are dark, with albedos of at most 30% and as low as 5%. An optical telescope looks for the light they reflect and can therefore only see them when looking away from the Sun at the sunlit side of the asteroids, and not when looking towards the Sun at the unlit backside of the object. In addition, opposition surge makes asteroids even brighter when the Earth is close to the axis of sunlight. The combined effect is equivalent to the comparison of a Full moon at night to a New Moon in daytime, and the light of the Sun-lit asteroids has been called "full asteroid" similar to a "full moon". Evidencing this bias, over half (53%) of the known Near Earth objects were discovered in just 3.8% of the sky, in a 22.5° cone facing directly away from the Sun, and the vast majority (87%) were first found in only 15% of the sky, in the 45° cone facing away from the Sun.^[32] A telescope operating at thermal infrared wavelengths instead detects their surfaces that have been warmed by the Sun and is almost equally sensitive to their lit and unlit sides, but needs to operate in space to achieve good sensitivity over a wide field of view.^[33]

The NEO Surveillance Mission will employ a 50 cm (20 in) infrared telescope operating wide-field cameras at two thermal infrared wavelength channels for a total wavelength range between 4 µm and 10 µm.^[3] The camera will have two channels: NC1 has a wavelength range of 4-5.2 µm and NC2 spans 6-10 µm. NC1 is intended to detect background stars for astrometric registration and calibration, as well as the measurement of effective temperatures. NC2 is optimized to maximize sensitivity to typical NEO thermal emission at 200-300 K.^[27] Its field of view is 11.56 square degrees.^[34] It will use a modified version of the Astronomical Wide Area Infrared Imager (HAWAII) mercury–cadmium–telluride detector developed by Teledyne Imaging Sensors.^[35] The mission prototype detector was successfully tested in April 2013.^[36][37] The detector array is 2,048 × 2,048 pixels and will produce 82 gigabits of data per day.^[34] For good infrared performance without the use of cryogenic fluid refrigeration,^[35] the detector will be passively cooled to 30 K (−243.2 °C; −405.7 °F) using techniques proven by the Spitzer Space Telescope.^[34] Unlike its predecessor NEOWISE, it will therefore not suffer from a performance degradation due to running out of coolant (its mission duration will however still be limited, as the orbital station keeping needed to maintain its position at SEL1 uses propellant).

Operations

The NEO Surveyor spacecraft will operate in a halo orbit around the Sun–Earth L1, and employ a sunshade.^[34] This orbit will allow fast data downlink speeds to Earth, allowing full-frame images to be downloaded from the telescope.^[38]

One advantage over NEOWISE is the wide field of regard. NEO Surveyor will be able to point anywhere from 45-120° in longitudinal distance from the sun and stopping at ±40° ecliptic latitude. The survey will be optimized to detect potentially hazardous objects and be performed continuously during the baseline mission (5 years). The survey will be halted each day for 2.25 hours to downlink the data. It will also be halted for calibration, station-keeping and momentum management maneuvers. NEO Surveyor will also be able to conduct targeted follow-up (TFO) to obtain more information for an object of special interest.^[27]

It is planned that moving object tracklets are delivered to the Minor Planet Center 2 to 3 times a day, on average 72 hours after their discovery. Additionally deep co-added images are published every 12 months.^[27] These deep co-added images most likely will be used by astronomers to study stars and brown dwarfs. It was also proposed that NEO Surveyor will include a transient alerting infrastructure,^[39] but none are planned to this date (October 2023).^[27]

Animation of NEO Surveyor

 

Around the Earth

 

Around the Sun - Frame rotating with Earth - Top view

 

Around the Sun - Frame rotating with Earth - Viewed from the Sun

   Earth ·    NEO Surveyor  ·   L1 point

Images

 

Plot of orbits of known potentially hazardous asteroids (size over 140 m (460 ft) and passing within 7.6×10^⁶ km (4.7×10^⁶ mi) of Earth's orbit) as of early 2013.(alternate image)

 

Annually discovered NEAs by survey since 1995

 

Large NEAs (at least 1 km in diameter) discovered each year

See also

• Asteroid impact prediction
• Asteroid impact avoidance
• List of largest infrared telescopes
• List of near-Earth object observation projects
• Wide-field Infrared Survey Explorer (WISE & NEOWISE)
• List of proposed space observatories

NEOs search projects

• B612 Foundation, an organization that studied NEOs and proposed a similar mission
• Sentinel Space Telescope, B612's failed space telescope proposal similar to NEOSM
• Near Earth Object Surveillance Satellite, a Canadian small satellite intended to detect NEOs
• The Spaceguard Foundation, an organization that attempts to locate NEOs
• Whipple (spacecraft), a proposed space telescope in the Discovery program
• Asteroid Terrestrial-impact Last Alert System, a ground-based NEO detection system funded by NASA since the end of 2015

References

1. "NASA to develop mission to search for near-Earth asteroids". SpaceNews. 23 September 2019. Retrieved 10 July 2020.
2. Foust, Jeff (7 December 2022). "NASA confirms NEO Surveyor for 2028 launch". SpaceNews. Retrieved 8 December 2022.
3. Finding Asteroids Before They Find Us NEOCam Home site at NASA's Jet Propulsion Laboratory - Caltech
4. Smith, Marcia (19 January 2020). "NASA's New NEO Mission Will Substantially Reduce Time to Find Hazardous Asteroids". Space Policy Online. Retrieved 9 June 2020.
5. . NASA/Jet Propulsion Laboratory. Archived from the original on 30 September 2019. Retrieved 6 July 2013.   This article incorporates text from this source, which is in the public domain.
6. Mainzer, Amy K. (September 2006). "NEOCam: The Near-Earth Object Camera". Bulletin of the American Astronomical Society. 38 (3): 568. Bibcode:2006DPS....38.4509M.
7. NASA Announces New Mission To Search for Asteroids Marcia Smith, Space Policy Online 23 September 2019
8. . NASA / JPL. 25 August 2003. Archived from the original on 15 June 2018. Retrieved 6 July 2013.   This article incorporates text from this source, which is in the public domain.
9. Millions of Small Asteroids That Could Threaten Our World Remain Uncatalogued Lee Billings, Scientific American 1 January 2016
10. Updated: NASA taps missions to tiny metal world and Jupiter Trojans Paul Voosen, Science. 4 January 2017
11. Talbert, Tricia (11 June 2021). "NASA Approves Asteroid Hunting Space Telescope to Continue Development". NASA. Retrieved 11 June 2021.   This article incorporates text from this source, which is in the public domain.
12. H.R. 1022 (109th): George E. Brown, Jr. Near-Earth Object Survey Act - Original text Tracking the United States Congress Accessed: 31 October 2018   This article incorporates text from this source, which is in the public domain.
13. 290 Asteroid News: Time Is Running Out Kevin Anderton, Forbes 31 October 2018
14. A space-based survey, not luck, must be our plan against hazardous asteroids Richard P. Binzel, Donald K. Yeomans and Timothy D. Swindle. SpaceNews 12 October 2018
15. Mosher, Dave (13 January 2017). "City-killing asteroids will inevitably strike Earth — but NASA isn't launching this mission to hunt them down". Business Insider. Retrieved 31 October 2018.
16. This Summer's Asteroid Near-Miss Helped Greenlight NASA's NEOCam Mission to Search the Skies for Killer Spacerocks Evan Gough, Universe Today 25 September 2019
17. . NASA/Jet Propulsion Laboratory. Archived from the original on 29 November 2020. Retrieved 6 July 2013.   This article incorporates text from this source, which is in the public domain.
18. . Discovery News. NASA. 5 May 2011. Archived from the original on 14 June 2013.   This article incorporates text from this source, which is in the public domain.
19. Clark, Stephen (7 September 2016). "NASA official says new mission selections on track despite InSight woes". Spaceflight Now. Retrieved 8 September 2016.
20. Clark, Stephen (24 February 2014). "NASA receives proposals for new planetary science mission". Spaceflight Now. Retrieved 25 February 2015.
21. Kane, Van (2 December 2014). "Selecting the Next Creative Idea for Exploring the Solar System". The Planetary Society. Retrieved 10 February 2015.
22. Voosen, Paul (4 January 2017). "Updated: NASA taps missions to tiny metal world and Jupiter Trojans". Science (journal). Retrieved 4 January 2017.
23. About 17,000 Big Near-Earth Asteroids Remain Undetected: How NASA Could Spot Them. Mike Wall, SPACE.com 10 April 2018
24. NASA won't launch a mission to hunt deadly asteroids Tim Fernholz, Quartz 5 July 2019
25. NASA will develop a $600 million telescope to detect near-Earth objects Chrissy Sexton, Earth.com 27 September 2019
26. NASA to build telescope for detecting asteroids that threaten Earth Paul Voosen, Science Magazine 23 September 2019 Quote: [...] the mission is the same, says Mark Sykes, CEO of the Planetary Science Institute in Tucson, Arizona, and a member of NEOCam's science team. "There is no independent or new spacecraft or operational design here. This mission is NEOCam".
27. NEO Surveyor Mission Team (19 October 2023). "The Near-Earth Object Surveyor Mission". PSJ. arXiv:2310.12918.
28. . NASA/Jet Propulsion Laboratory. Archived from the original on 30 September 2019. Retrieved 12 November 2015.   This article incorporates text from this source, which is in the public domain.
29. . NASA/Jet Propulsion Laboratory. Archived from the original on 18 May 2019. Retrieved 6 July 2013.   This article incorporates text from this source, which is in the public domain.
30. Mainzer, Amy K. (October 2016). NEOCam: The Near-Earth Object Camera. 48th Meeting of the Division for Planetary Sciences. 16–21 October 2016. Pasadena, California. Bibcode:2016DPS....4832701M.
31. NEO Surveillance Mission Gunter's Space Page' Accessed on 28 September 2019
32. "NEO Earth Close Approach data". NASA JPL. NASA. Retrieved 7 July 2018.
33. NEOCam - Why Infrared? 29 November 2020 at the Wayback Machine NASA Accessed on 30 September 2019   This article incorporates text from this source, which is in the public domain.
34. Mainzer, Amy K. (18 November 2009). (PDF). 2nd Small Bodies Assessment Group Meeting 18–19 November 2009 Boulder, Colorado. Archived from the original (PDF) on 24 June 2016. Retrieved 13 January 2018.
35. . Teledyne Scientific & Imaging. Archived from the original on 28 September 2015.
36. "NASA-Funded Asteroid Tracking Sensor Passes Key Test". NASA. 15 April 2015. Retrieved 12 November 2015.   This article incorporates text from this source, which is in the public domain.
37. A monolithic 2k × 2k LWIR HgCdTe detector array for passively cooled space missions Meghan Dorn; Craig McMurtry; Judith Pipher; William Forrest; Mario Cabrera; Andre Wong; A. K. Mainzer; Donald Lee; Jianmei Pan. Proceedings, Volume 10709, High Energy, Optical, and Infrared Detectors for Astronomy VIII; 1070907 (2018) doi:10.1117/12.2313521
38. Mainzer, A.; et al. (May 2015). "Survey Simulations of a New Near-Earth Asteroid Detection System". The Astronomical Journal. 149 (5): 17. arXiv:1501.01063. Bibcode:2015AJ....149..172M. doi:10.1088/0004-6256/149/5/172. S2CID 2366920.
39. Kirkpatrick, J. Davy; Metchev, Stanimir A.; Hillenbrand, Lynne A.; Hankins, Matthew; Jencson, Jacob E.; Marsh, Kenneth A.; Kasliwal, Mansi M.; De, Kishalay; Marocco, Federico; Marley, Mark S.; Cushing, Michael C.; Cutri, Roc M.; Wright, Edward L.; Mainzer, Amanda K. (1 May 2019). "Opportunities in Time-domain Stellar Astrophysics with the NASA Near-Earth Object Camera (NEOCam)". Bulletin of the American Astronomical Society. 51: 108.

External links

• NEOCam website by Caltech