fbpx
Wikipedia

EPOXI

April 07, 2024

EPOXI was a compilation of NASA Discovery program missions led by the University of Maryland and principal investigator Michael A'Hearn, with co-operation from the Jet Propulsion Laboratory and Ball Aerospace. EPOXI uses the Deep Impact spacecraft in a campaign consisting of two missions: the Deep Impact Extended Investigation (DIXI) and Extrasolar Planet Observation and Characterization (EPOCh). DIXI aimed to send the Deep Impact spacecraft on a flyby of another comet, after its primary mission was completed in July 2005, while EPOCh saw the spacecraft's photographic instruments as a space observatory, studying extrasolar planets.[2][3][4]

EPOXI
The Deep Impact spacecraft at Ball Aerospace & Technologies in July 2004.
Mission type
OperatorNASA
COSPAR ID2005-001A
Websiteepoxi.umd.edu
Mission duration8 years, 18 days
Spacecraft properties
SpacecraftDeep Impact
ManufacturerJPL · Ball Aerospace · University of Maryland
Launch mass650 kg[1]
Power620.0 W
Start of mission
Entered serviceJuly 21, 2005 (2005-07-21)
(18 years, 8 months and 16 days ago)
End of mission
Last contactAugust 8, 2013 (2013-08-08)
(10 years, 7 months and 29 days ago)
Flyby of Hartley 2
Closest approachNovember 4, 2010 (2010-11-04) ~03:00 UTC
(13 years, 5 months and 2 days ago)
Distance694 kilometres (431 mi)

Official insignia for the re-targeted DIXI mission to Hartley 2  

DIXI successfully sent the Deep Impact spacecraft on a flyby of comet Hartley 2 on November 4, 2010, revealing a "hyperactive, small and feisty" comet, after three gravity assists from Earth in December 2007, December 2008 and June 2010. The DIXI mission was not without problems, however; the spacecraft had initially been targeted for a December 5, 2008 flyby of comet Boethin, though, the comet could not be located, and was later declared a lost comet, prompting mission planners to reorganize a flyby of an alternative target, Hartley 2. After its flyby of Hartley 2, the spacecraft was also set to make a close flyby of the Apollo asteroid (163249) 2002 GT in 2020. The mission was suspended altogether, however, after contact with the spacecraft was suddenly lost in August 2013 and attempts to re-establish contact in the month following had failed.[5] Mission scientists theorized that a Y2K-like problem had plagued the spacecraft's software.

Mission edit

 
EPOXI mission observation of Hartley 2's jets

The Deep Impact mission was finished with the visit to comet Tempel 1. But the spacecraft still had plenty of maneuvering fuel left, so NASA approved a second mission, called EPOXI (Extrasolar Planet Observation and Deep Impact Extended Investigation), which included a visit to a second comet (DIXI component) as well as observations of extrasolar planets (EPOCh component).[6]

Comet Boethin lost edit

On July 21, 2005, Deep Impact executed a trajectory correction maneuver that placed the spacecraft on course to fly past Earth on December 31, 2007. The maneuver allowed the spacecraft to use Earth's gravity to begin a new mission in a path towards another comet. In January 2008 Deep Impact began studying the stars with several known extrasolar planets in an attempt to find other such stars nearby. The larger of the spacecraft's two telescopes attempts to find the planets using the transit method.[6]

The initial plan was for a December 5, 2008 flyby of Comet Boethin, with the spacecraft coming within 435 miles (700 km). The spacecraft did not carry a second impactor to collide with the comet and would observe the comet to compare it to various characteristics found on 9P/Tempel. A'Hearn, the Deep Impact team leader reflected on the upcoming project at that time: "We propose to direct the spacecraft for a flyby of Comet Boethin to investigate whether the results found at Comet Tempel 1 are unique or are also found on other comets."[7] He explained that the mission would provide only about half of the information collected during the collision with Tempel 1 but at a fraction of the cost.[7] (EPOXI's low mission cost of $40 million is achieved by reusing the existing Deep Impact spacecraft.) Deep Impact would use its spectrometer to study the comet's surface composition and its telescopes for viewing the surface features.[6]

 
Animation of the Moon transiting the Earth on 28–29 May 2008 by EPOXI.

However, as the Earth gravity assist approached, astronomers were unable to locate Comet Boethin, which is too faint to be observed. Consequently, its orbit could not be calculated with sufficient precision to permit a flyby. Instead, the team decided to send Deep Impact to comet 103P/Hartley requiring an extra two years. NASA approved the additional funding required and retargeted the spacecraft.[8] Mission controllers at the Jet Propulsion Laboratory began redirecting EPOXI on November 1, 2007. They commanded the spacecraft to perform a three-minute rocket burn that changed the spacecraft's velocity. EPOXI's new trajectory set the stage for three Earth flybys, the first on December 31, 2007. This placed the spacecraft into an orbital "holding pattern" so that it could encounter comet 103P/Hartley in 2010.

"It's exciting that we can send the Deep Impact spacecraft on a new mission that combines two totally independent science investigations, both of which can help us better understand how solar systems form and evolve," said in December 2007 Deep Impact leader and University of Maryland astronomer Michael A'Hearn who is principal investigator for both the overall EPOXI mission and its DIXI component.[4]

In June 2009,[9] EPOXI's spectrometer scanned the Moon on its way to Hartley, and discovered traces of "water or hydroxyl", confirming a Moon Mineralogy Mapper observation — a discovery announced in late September, 2009.[10]

EPOCh edit

Before the 2008 flyby to re-orient for the comet 103P/Hartley encounter, the spacecraft used the High Resolution Instrument, the larger of its two telescopes, to perform photometric observations of previously discovered transiting extrasolar planets from January to August 2008.[11] The goal of photometric observations is to measure the quantity of light, not necessarily resolve an image. An aberration in the primary mirror of the HRI [12] allowed the HRI to spread the light from observations over more pixels without saturating the CCD, effectively obtaining better data. A total of 198,434 images were exposed.[13] EPOCh's goals were to study the physical properties of giant planets and search for rings, moons and planets[14] as small as three Earth masses.[15] It also looked at Earth as though it were an extrasolar planet to provide data that could characterize Earth-type planets for future missions, and it imaged the Earth over 24 hours to capture the Moon passing in front on 2008-05-29.[11]

Comet flyby edit

 
Animation of Deep Impact's trajectory from 12 January 2005 to 8 August 2013
   Deep Impact 1   Tempel 1   Earth   103P/Hartley
See also: 103P/Hartley
See also: Tempel 1
 
The nucleus of comet 103P/Hartley measuring approximately 2 kilometers in length and .4 kilometers at its most narrow portion or neck. Jets can be seen streaming out of the nucleus.

The spacecraft used Earth's gravity for the second gravity assist in December 2008 and made two distant flybys of Earth in June and December 2009. On May 30, 2010 it successfully fired its engines for an 11.3 second trajectory correction maneuver, for a velocity change (Δv) of 0.1 meters per second (0.22 mph), in preparation for the third Earth flyby on June 27. Observations of 103P/Hartley began on September 5 and ended November 25, 2010.[16] For a diagram of the EPOXI solar orbits see .

 
Another view of the comet, taken near closest approach.

The mission's closest approach to 103P/Hartley occurred at 10 am EDT on 4 November 2010, passing to within 694 kilometers (431 mi) of this small comet. The flyby speed was 12.3 km/s. The spacecraft employed the same suite of three science instruments—two telescopes and an infrared spectrometer—that the Deep Impact spacecraft used during its prime mission to guide an impactor into comet Tempel 1 in July 2005 and observe the results.[17]

Early results of the observations show that the comet is powered by dry ice, not water vapor as was previously thought. The images were clear enough for scientists to link jets of dust and gas with specific surface features.[17]

"When comet Boethin could not be located, we went to our backup, which is every bit as interesting but about two years farther down the road," said Tom Duxbury, EPOXI project manager at NASA's Jet Propulsion Laboratory in Pasadena, California. "Hartley 2 is scientifically just as interesting as comet Boethin because both have relatively small, active nuclei," said Michael A'Hearn, principal investigator for EPOXI at the University of Maryland, College Park.[3]

Sundry opportunities edit

In November 2010, EPOXI was used to make some test-training deep sky observations, using the MRI camera that is optimised for cometary imagery. Images were made of the Dumbbell Nebula (M27), the Veil Nebula (NGC6960) and the Whirlpool Galaxy (M51a).[18]

References edit

  1. ^ "EPOXI". NASA's Solar System Exploration website. Retrieved November 30, 2022.
  2. ^ (Press release). NASA. July 3, 2007. Archived from the original on 17 April 2011. Retrieved 7 August 2009.
  3. ^ a b (Press release). NASA. Dec 13, 2007. Archived from the original on 3 August 2009. Retrieved 7 August 2009.
  4. ^ a b (Press release). University of Maryland. December 13, 2007. Archived from the original on 20 June 2009. Retrieved 7 August 2009.
  5. ^ NASA calls off search for lost Deep Impact comet probe - Australian Broadcasting Corporation - Retrieved September 21, 2013.
  6. ^ a b c "Science Daily". Deep Impact Mission: Aiming For Close-ups Of Extrasolar Planets. Retrieved June 3, 2007.
  7. ^ a b . Deep Impact will fly to new comet. Archived from the original on December 14, 2014. Retrieved June 12, 2007.
  8. ^ EPOXI Mission Status 2010-11-15 at the Wayback Machine, NASA/University of Maryland, December 2, 2007.
  9. ^ Deep Impact and Other Spacecraft Find Clear Evidence of Water on Moon: Thin layer of surface 'dew' appears to form, then dissipate each day Archived 2012-07-17 at archive.today
  10. ^ . Archived from the original on 2009-09-27. Retrieved 2009-09-25.
  11. ^ a b . Archived from the original on 2010-11-15. Retrieved 2009-03-07.
  12. ^ "Beyond Deep Impact: Possible Targets After Fireworks". Space.com. 29 June 2005. Retrieved 2010-03-01.
  13. ^ Rieber, Richard R.; Sharrow, Robert F. (7 March 2009). "The contingency of success: operations for Deep Impact's planet hunt". Retrieved 24 April 2022.
  14. ^ "Sarah Ballard: Preliminary Results from the NASA EPOXI Mission". Archived from the original (Mov) on 2012-12-15. Retrieved 2009-03-07. (at 2 minutes 20 seconds in video)
  15. ^ "EPOXI Mission Science". Archived from the original on 2012-12-15. Retrieved 2009-03-07.
  16. ^ . NASA. Archived from the original on 2021-04-08. Retrieved 2010-06-01.
  17. ^ a b A'Hearn, M. F.; Belton, M. J. S.; Delamere, W. A.; Feaga, L. M.; Hampton, D.; Kissel, J.; Klaasen, K. P.; McFadden, L. A.; Meech, K. J.; Melosh, H. J.; Schultz, P. H.; Sunshine, J. M.; Thomas, P. C.; Veverka, J.; Wellnitz, D. D.; Yeomans, D. K.; Besse, S.; Bodewits, D.; Bowling, T. J.; Carcich, B. T.; Collins, S. M.; Farnham, T. L.; Groussin, O.; Hermalyn, B.; Kelley, M. S.; Kelley, M. S.; Li, J. -Y.; Lindler, D. J.; Lisse, C. M.; McLaughlin, S. A. (2011). "EPOXI at Comet Hartley 2". Science. 332 (6036): 1396–1400. Bibcode:2011Sci...332.1396A. doi:10.1126/science.1204054. PMID 21680835. S2CID 6218729.
  18. ^ Deep Sky Feasibility Demonstration 2012-05-13 at the Wayback Machine, NASA, accessed 7 December 2011

External links edit

 
Wikimedia Commons has media related to EPOXI.
External image
  Deep Impact trajectory
  • home page
  • NASA's EPOXI 2016-02-13 at the Wayback Machine page
  • NASA's Deep Impact Begins Hunt For Alien Worlds - 8 Feb 2008[permanent dead link]
  • EPOXI Mission Archive at the NASA Planetary Data System, Small Bodies Node

April 07, 2024
epoxi, compilation, nasa, discovery, program, missions, university, maryland, principal, investigator, michael, hearn, with, operation, from, propulsion, laboratory, ball, aerospace, uses, deep, impact, spacecraft, campaign, consisting, missions, deep, impact,. EPOXI was a compilation of NASA Discovery program missions led by the University of Maryland and principal investigator Michael A Hearn with co operation from the Jet Propulsion Laboratory and Ball Aerospace EPOXI uses the Deep Impact spacecraft in a campaign consisting of two missions the Deep Impact Extended Investigation DIXI and Extrasolar Planet Observation and Characterization EPOCh DIXI aimed to send the Deep Impact spacecraft on a flyby of another comet after its primary mission was completed in July 2005 while EPOCh saw the spacecraft s photographic instruments as a space observatory studying extrasolar planets 2 3 4 EPOXIThe Deep Impact spacecraft at Ball Aerospace amp Technologies in July 2004 Mission typeFlyby 85D Boethin 103P Hartley 163249 2002 GT Space observatoryOperatorNASACOSPAR ID2005 001AWebsiteepoxi wbr umd wbr eduMission duration8 years 18 daysSpacecraft propertiesSpacecraftDeep ImpactManufacturerJPL Ball Aerospace University of MarylandLaunch mass650 kg 1 Power620 0 WStart of missionEntered serviceJuly 21 2005 2005 07 21 18 years 8 months and 16 days ago End of missionLast contactAugust 8 2013 2013 08 08 10 years 7 months and 29 days ago Flyby of Hartley 2Closest approachNovember 4 2010 2010 11 04 03 00 UTC 13 years 5 months and 2 days ago Distance694 kilometres 431 mi Official insignia for the re targeted DIXI mission to Hartley 2 DIXI successfully sent the Deep Impact spacecraft on a flyby of comet Hartley 2 on November 4 2010 revealing a hyperactive small and feisty comet after three gravity assists from Earth in December 2007 December 2008 and June 2010 The DIXI mission was not without problems however the spacecraft had initially been targeted for a December 5 2008 flyby of comet Boethin though the comet could not be located and was later declared a lost comet prompting mission planners to reorganize a flyby of an alternative target Hartley 2 After its flyby of Hartley 2 the spacecraft was also set to make a close flyby of the Apollo asteroid 163249 2002 GT in 2020 The mission was suspended altogether however after contact with the spacecraft was suddenly lost in August 2013 and attempts to re establish contact in the month following had failed 5 Mission scientists theorized that a Y2K like problem had plagued the spacecraft s software Contents 1 Mission 1 1 Comet Boethin lost 1 2 EPOCh 1 3 Comet flyby 1 4 Sundry opportunities 2 References 3 External linksMission edit nbsp EPOXI mission observation of Hartley 2 s jetsThe Deep Impact mission was finished with the visit to comet Tempel 1 But the spacecraft still had plenty of maneuvering fuel left so NASA approved a second mission called EPOXI Extrasolar Planet Observation and Deep Impact Extended Investigation which included a visit to a second comet DIXI component as well as observations of extrasolar planets EPOCh component 6 Comet Boethin lost edit On July 21 2005 Deep Impact executed a trajectory correction maneuver that placed the spacecraft on course to fly past Earth on December 31 2007 The maneuver allowed the spacecraft to use Earth s gravity to begin a new mission in a path towards another comet In January 2008 Deep Impact began studying the stars with several known extrasolar planets in an attempt to find other such stars nearby The larger of the spacecraft s two telescopes attempts to find the planets using the transit method 6 The initial plan was for a December 5 2008 flyby of Comet Boethin with the spacecraft coming within 435 miles 700 km The spacecraft did not carry a second impactor to collide with the comet and would observe the comet to compare it to various characteristics found on 9P Tempel A Hearn the Deep Impact team leader reflected on the upcoming project at that time We propose to direct the spacecraft for a flyby of Comet Boethin to investigate whether the results found at Comet Tempel 1 are unique or are also found on other comets 7 He explained that the mission would provide only about half of the information collected during the collision with Tempel 1 but at a fraction of the cost 7 EPOXI s low mission cost of 40 million is achieved by reusing the existing Deep Impact spacecraft Deep Impact would use its spectrometer to study the comet s surface composition and its telescopes for viewing the surface features 6 nbsp Animation of the Moon transiting the Earth on 28 29 May 2008 by EPOXI However as the Earth gravity assist approached astronomers were unable to locate Comet Boethin which is too faint to be observed Consequently its orbit could not be calculated with sufficient precision to permit a flyby Instead the team decided to send Deep Impact to comet 103P Hartley requiring an extra two years NASA approved the additional funding required and retargeted the spacecraft 8 Mission controllers at the Jet Propulsion Laboratory began redirecting EPOXI on November 1 2007 They commanded the spacecraft to perform a three minute rocket burn that changed the spacecraft s velocity EPOXI s new trajectory set the stage for three Earth flybys the first on December 31 2007 This placed the spacecraft into an orbital holding pattern so that it could encounter comet 103P Hartley in 2010 It s exciting that we can send the Deep Impact spacecraft on a new mission that combines two totally independent science investigations both of which can help us better understand how solar systems form and evolve said in December 2007 Deep Impact leader and University of Maryland astronomer Michael A Hearn who is principal investigator for both the overall EPOXI mission and its DIXI component 4 In June 2009 9 EPOXI s spectrometer scanned the Moon on its way to Hartley and discovered traces of water or hydroxyl confirming a Moon Mineralogy Mapper observation a discovery announced in late September 2009 10 EPOCh edit Before the 2008 flyby to re orient for the comet 103P Hartley encounter the spacecraft used the High Resolution Instrument the larger of its two telescopes to perform photometric observations of previously discovered transiting extrasolar planets from January to August 2008 11 The goal of photometric observations is to measure the quantity of light not necessarily resolve an image An aberration in the primary mirror of the HRI 12 allowed the HRI to spread the light from observations over more pixels without saturating the CCD effectively obtaining better data A total of 198 434 images were exposed 13 EPOCh s goals were to study the physical properties of giant planets and search for rings moons and planets 14 as small as three Earth masses 15 It also looked at Earth as though it were an extrasolar planet to provide data that could characterize Earth type planets for future missions and it imaged the Earth over 24 hours to capture the Moon passing in front on 2008 05 29 11 Planetary systems observed Star Constellation Distance ly PlanetXO 2 Lynx 486 bGliese 436 Leo 33 48 bHAT P 4 Bootes 1010 bGSC 03089 00929 Hercules 1300 TrES 3bWASP 3 Lyra 727 bGSC 03549 02811 Draco 718 TrES 2bHAT P 7 Cygnus 1044 bComet flyby edit nbsp Animation of Deep Impact s trajectory from 12 January 2005 to 8 August 2013 Deep Impact 1 Tempel 1 Earth 103P HartleySee also 103P Hartley See also Tempel 1 nbsp The nucleus of comet 103P Hartley measuring approximately 2 kilometers in length and 4 kilometers at its most narrow portion or neck Jets can be seen streaming out of the nucleus The spacecraft used Earth s gravity for the second gravity assist in December 2008 and made two distant flybys of Earth in June and December 2009 On May 30 2010 it successfully fired its engines for an 11 3 second trajectory correction maneuver for a velocity change Dv of 0 1 meters per second 0 22 mph in preparation for the third Earth flyby on June 27 Observations of 103P Hartley began on September 5 and ended November 25 2010 16 For a diagram of the EPOXI solar orbits see here nbsp Another view of the comet taken near closest approach The mission s closest approach to 103P Hartley occurred at 10 am EDT on 4 November 2010 passing to within 694 kilometers 431 mi of this small comet The flyby speed was 12 3 km s The spacecraft employed the same suite of three science instruments two telescopes and an infrared spectrometer that the Deep Impact spacecraft used during its prime mission to guide an impactor into comet Tempel 1 in July 2005 and observe the results 17 Early results of the observations show that the comet is powered by dry ice not water vapor as was previously thought The images were clear enough for scientists to link jets of dust and gas with specific surface features 17 When comet Boethin could not be located we went to our backup which is every bit as interesting but about two years farther down the road said Tom Duxbury EPOXI project manager at NASA s Jet Propulsion Laboratory in Pasadena California Hartley 2 is scientifically just as interesting as comet Boethin because both have relatively small active nuclei said Michael A Hearn principal investigator for EPOXI at the University of Maryland College Park 3 Sundry opportunities edit In November 2010 EPOXI was used to make some test training deep sky observations using the MRI camera that is optimised for cometary imagery Images were made of the Dumbbell Nebula M27 the Veil Nebula NGC6960 and the Whirlpool Galaxy M51a 18 References edit EPOXI NASA s Solar System Exploration website Retrieved November 30 2022 NASA Gives Two Successful Spacecraft New Assignments Press release NASA July 3 2007 Archived from the original on 17 April 2011 Retrieved 7 August 2009 a b NASA Sends Spacecraft on Mission to Comet Hartley 2 Press release NASA Dec 13 2007 Archived from the original on 3 August 2009 Retrieved 7 August 2009 a b Deep Impact Extended Mission Heads for Comet Hartley 2 Press release University of Maryland December 13 2007 Archived from the original on 20 June 2009 Retrieved 7 August 2009 NASA calls off search for lost Deep Impact comet probe Australian Broadcasting Corporation Retrieved September 21 2013 a b c Science Daily Deep Impact Mission Aiming For Close ups Of Extrasolar Planets Retrieved June 3 2007 a b Skymania News Deep Impact will fly to new comet Archived from the original on December 14 2014 Retrieved June 12 2007 EPOXI Mission Status Archived 2010 11 15 at the Wayback Machine NASA University of Maryland December 2 2007 Deep Impact and Other Spacecraft Find Clear Evidence of Water on Moon Thin layer of surface dew appears to form then dissipate each day Archived 2012 07 17 at archive today Science A Whiff of Water Found on the Moon Archived from the original on 2009 09 27 Retrieved 2009 09 25 a b EPOXI Mission Status Reports Archived from the original on 2010 11 15 Retrieved 2009 03 07 Beyond Deep Impact Possible Targets After Fireworks Space com 29 June 2005 Retrieved 2010 03 01 Rieber Richard R Sharrow Robert F 7 March 2009 The contingency of success operations for Deep Impact s planet hunt Retrieved 24 April 2022 Sarah Ballard Preliminary Results from the NASA EPOXI Mission Archived from the original Mov on 2012 12 15 Retrieved 2009 03 07 at 2 minutes 20 seconds in video EPOXI Mission Science Archived from the original on 2012 12 15 Retrieved 2009 03 07 NASA Spacecraft Burns for Home Then Comet NASA Archived from the original on 2021 04 08 Retrieved 2010 06 01 a b A Hearn M F Belton M J S Delamere W A Feaga L M Hampton D Kissel J Klaasen K P McFadden L A Meech K J Melosh H J Schultz P H Sunshine J M Thomas P C Veverka J Wellnitz D D Yeomans D K Besse S Bodewits D Bowling T J Carcich B T Collins S M Farnham T L Groussin O Hermalyn B Kelley M S Kelley M S Li J Y Lindler D J Lisse C M McLaughlin S A 2011 EPOXI at Comet Hartley 2 Science 332 6036 1396 1400 Bibcode 2011Sci 332 1396A doi 10 1126 science 1204054 PMID 21680835 S2CID 6218729 Deep Sky Feasibility Demonstration Archived 2012 05 13 at the Wayback Machine NASA accessed 7 December 2011External links edit nbsp Wikimedia Commons has media related to EPOXI External image nbsp Deep Impact trajectoryEPOXI home page NASA s EPOXI Archived 2016 02 13 at the Wayback Machine page NASA s Deep Impact Begins Hunt For Alien Worlds 8 Feb 2008 permanent dead link Movie of the Moon transiting the Earth EPOXI Mission Archive at the NASA Planetary Data System Small Bodies Node Retrieved from https en wikipedia org w index php title EPOXI amp oldid 1208928946, 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.