Double Asteroid Redirection Test

Double Asteroid Redirection Test (DART) is a planned space probe that will visit the double asteroid Didymos and demonstrate the kinetic effects of crashing an impactor spacecraft into an asteroid moon for planetary defense purposes. The mission is intended to test whether a spacecraft impact could successfully deflect an asteroid on a collision course with Earth.

This article is about the impactor mission. For the Earth orbiter, see DART (satellite).

Double Asteroid Redirection Test
DART mission in space
Mission typeAsteroid impactor
OperatorNASA / APL
Websitenasa.gov/planetarydefense/dart
dart.jhuapl.edu
Spacecraft properties
ManufacturerApplied Physics Laboratory
Launch mass500 kg (1,100 lb)
Dimensions12.5 m × 2.4 m (41.0 ft × 7.9 ft)
Power3.5 kW [1]
Start of mission
Launch date22 July 2021 [2]
RocketFalcon 9 [3]
Launch siteVandenberg, SLC-4E
ContractorSpaceX
(65803) Didymos [4] impactor
Spacecraft componentDART
Impact dateOctober 2022
 

A demonstration of an asteroid deflection is a key test that NASA and other agencies wish to perform before the actual need of planetary defense is present. DART is a joint project between NASA and the Johns Hopkins Applied Physics Laboratory (APL), and it is being developed under the auspices of NASA's Planetary Defense Coordination Office.

In August 2018, NASA approved the project to start the final design and assembly phase.

Background

Originally, the European Space Agency (ESA) and NASA had independent plans for missions to test asteroid deflection strategies, and by 2015 they struck a collaboration called AIDA involving two separate spacecraft launches that work in synergy.[5][6][7] Under the proposal, the European spacecraft, AIM, would have launched in December 2020, and DART in July 2021. AIM would have orbited the larger asteroid to study its composition and that of its moon. DART would then impact the asteroid's moon in October 2022, during a close approach to Earth.[6] AIM would have studied the asteroid's strength, surface physical properties, and its internal structure, as well as measure the effect on the asteroid moon's orbit around the larger asteroid. Since the AIM orbiter was cancelled, the full characterization of the asteroids will not be obtained, and the effects of the impact by DART will be monitored from ground-based telescopes and radar.[8][7]

In June 2017, NASA approved a move from concept development to the preliminary design phase,[9] and in August 2018 NASA approved the project to start the final design and assembly phase.[10]

On 11 April 2019, NASA announced that a SpaceX Falcon 9 would be used to launch DART.[11] It was originally planned for DART to be a secondary payload on a commercial launch to keep costs low, however a mission update presentation in November 2018 noted that the mission has a dedicated launch vehicle.

Scientists estimate 25,000 large asteroids are in the Solar System, though to date, surveys have detected about 8000, therefore NASA officials think it is imperative to develop an effective plan should a near-Earth object threaten Earth.[12]

Mission
The NASA's Evolutionary Xenon Thruster (NEXT) operating in a vacuum chamber.

DART is an impactor that hosts no scientific payload other than a Sun sensor, a star tracker, and a 20 cm aperture camera (DRACO) to support autonomous navigation to impact the small asteroid's moon at its center. It is estimated that the impact of the 500 kg (1,100 lb)[13] DART at 6 km/s (3.7 mi/s)[4] will produce a velocity change on the order of 0.4 mm/s, which leads to a small change in trajectory of the asteroid system, but over time, it leads to a large shift of path.[14][6][15] Overall, DART is expected to alter the speed of Dimorphos (Didymos B) orbit by about half a millimeter per second, resulting in an orbital period change of perhaps 10 minutes.[16] Over a span of millions of kilometers, the cumulative trajectory change would turn a collision with a genuinely Earth-bound asteroid or comet into a safe outcome.[17] The actual velocity change and orbital shift will be measured a few years later by a small spacecraft called Hera that would do a detailed reconnaissance and assessment.[18] Hera was approved in November 2019.[19]

DART spacecraft will use the NEXT ion thruster, a type of solar electric propulsion.[8][20] It will be powered by 22 m2 solar arrays to generate the ~3.5 kW needed to power the NASA Evolutionary Xenon Thruster–Commercial (NEXT-C) engine.[1] The spacecraft's solar arrays use a Roll Out Solar Array (ROSA) design, and this was tested on the International Space Station in June 2017 as part of Expedition 52, delivered to the station by the CRS-11 commercial cargo mission.[21]

The DART impactor is proposed to make flyby observations of other near-Earth asteroids such as 2001 CB21 and 3361 Orpheus during its trajectory to 65803 Didymos.[22][23][24] It will obtain some images in the visible spectrum.

Secondary spacecraft

The Italian Space Agency (ASI) will contribute a secondary spacecraft called LICIACube (Light Italian CubeSat for Imaging of Asteroids), a small 6-unit CubeSat that will piggyback with DART and will separate shortly before impact to acquire images of the impact and ejecta as it drifts past the asteroid.[18][25][26][27] LICIACube will communicate directly with Earth, sending back images of the ejecta after the Dimorphos (Didymos B) flyby.[28]

In a collaborating project, the European Space Agency is developing Hera, a spacecraft that will be launched to Didymos in 2024 [29] — after DART's impact — to do a detailed reconnaissance and assessment.[29] Hera would carry two CubeSats, APEX and Juventas.[29]

Proposed secondary spacecraft for AIDA
Host spacecraftSecondary spacecraftRemarks
DARTLICIACube [30]
Hera Juventas [31]
APEX [33]
  • By Swedish/Finnish/Czech/German consortium
  • 6U CubeSat orbiter
  • Camera, VIS/Near-IR spectrometer, volatile analyser, and magnetometer [32]
  • Will attempt to land on the asteroid surface [33]
SCI

Target asteroid

The mission's target is 65803 Didymos, a binary asteroid system in which one asteroid is orbited by a smaller one. The primary asteroid (Didymos A) is about 780 m (2,560 ft) in diameter; its small satellite Dimorphos (Didymos B) is about 160 m (520 ft) in diameter in an orbit about 1 km from the primary.[8] DART will target the smaller asteroid, Dimorphos. Didymos is not an Earth-crossing asteroid, and there is no possibility that the deflection experiment could create an impact hazard.[15]

See also

References
  1. Adams, Elena; Oshaughnessy, Daniel; Reinhart, Matthew; John, Jeremy; Congdon, Elizabeth; Gallagher, Daniel; Abel, Elisabeth; Atchison, Justin; Fletcher, Zachary; Chen, Michelle; Heistand, Christopher; Huang, Philip; Smith, Evan; Sibol, Deane; Bekker, Dmitriy; Carrelli, David (2019). "Double Asteroid Redirection Test: The Earth Strikes Back". 2019 IEEE Aerospace Conference. pp. 1–11. doi:10.1109/AERO.2019.8742007. ISBN 978-1-5386-6854-2.
  2. https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=DART This article incorporates text from this source, which is in the public domain.
  3. C19-009 (12 April 2019). "NASA Awards Launch Services Contract for Asteroid Redirect Test Mission". NASA. NASA. Retrieved 12 April 2019. This article incorporates text from this source, which is in the public domain.
  4. Andone, Dakin (25 July 2017). "NASA unveils plan to test asteroid defense technique". CNN. Retrieved 25 July 2017.
  5. AIDA DART. Home page at APL.
  6. Asteroid Impact & Deflection Assessment (AIDA) study Archived 2015-06-07 at the Wayback Machine.
  7. DART at Applied Physics Laboratory Johns Hopkins University
  8. Planetary Defense: Double Asteroid Redirection Test (DART) Mission NASA 2017 This article incorporates text from this source, which is in the public domain.
  9. NASA plans to test asteroid deflection technique designed to prevent Earth impact G. Brown 4 July 2017
  10. Asteroid-deflection mission passes key development milestone 7 September 2018
  11. Northon, Karen (11 April 2019). "NASA Awards Launch Services Contract for Asteroid Redirect Test". NASA. Retrieved 12 April 2019. This article incorporates text from this source, which is in the public domain.
  12. NASA is planning an asteroid deflection test mission in case the unthinkable happens Science Alert 5 July 2017
  13. DART: Home page at APL Archived 2018-05-10 at the Wayback Machine DART Spacecraft APL 2017
  14. Cheng, A.F.; Michel, P.; Reed, C.; Galvez, A.; Carnelli, I. (2012). DART: Double Asteroid Redirection Test (PDF). European Planetary Science Congress 2012. EPSC Abstracts.
  15. Michel, P.; Cheng, A.; Carnelli, I.; A. Rivkin, C.; Galvez, A.; Ulamec, S.; Reed, C. (February 2015). "AIDA: Asteroid Impact and Deflection Assessment Mission Under Study at ESA and NASA" (PDF). Observatoire de la Côte d'Azur. 1829: 6008. Bibcode:2015LPICo1829.6008M. Retrieved 29 March 2015.
  16. Course corrector Adam Hadhazy Aerospace America October 2017
  17. NASA Pushes Through With Asteroid Deflection Mission That Could One Day Save Earth The Inquisitr 5 July 2017
  18. Asteroids have been hitting the Earth for billions of years. In 2022, we hit back. Archived 2018-10-31 at the Wayback Machine Andy Rivkin, The Johns Hopkins University Applied Physics Laboratory September 27, 2018
  19. Hera mission is approved as ESA receives biggest ever budget Kerry Hebden Room Space Journal 29 November 2019
  20. Kantsiper, Brian (2017). "The Double Asteroid Redirection Test (DART) mission electric propulsion trade". 2017 IEEE Aerospace Conference. pp. 1–7. doi:10.1109/AERO.2017.7943736. ISBN 978-1-5090-1613-6.
  21. Talbert, Tricia (30 June 2017). "Double Asteroid Redirection Test (DART) Mission". NASA. Retrieved 21 January 2018. This article incorporates text from this source, which is in the public domain.
  22. Cheng, Andrew F.; et al. (2018). "AIDA DART asteroid deflection test: Planetary defense and science objectives" (PDF). Planetary and Space Science. 157: 104–115. Bibcode:2018P&SS..157..104C. doi:10.1016/j.pss.2018.02.015.
  23. Adams, Elena. "DART – Double Asteroid Redirection Test Status NASA's mission" (PDF). Lunar and Planetary Institute. Retrieved 27 November 2019.
  24. Cheng, A.F.; Michel, P.; Jutzi, M.; Rivkin, A.S.; Stickle, A.; Barnouin, O.; Ernst, C.; Atchison, J.; Pravec, P.; Richardson, D.C. (2016). "Asteroid Impact & Deflection Assessment mission: Kinetic impactor". Planetary and Space Science. 121: 27–35. Bibcode:2016P&SS..121...27C. doi:10.1016/j.pss.2015.12.004.
  25. Kretschmar, Peter; Küppers, Michael (20 December 2018). "The CubeSat Revolution" (PDF). ESA. Retrieved 24 January 2019.
  26. Adams, Elena; Oshaughnessy, Daniel; Reinhart, Matthew; John, Jeremy; Congdon, Elizabeth; Gallagher, Daniel; Abel, Elisabeth; Atchison, Justin; Fletcher, Zachary; Chen, Michelle; Heistand, Christopher; Huang, Philip; Smith, Evan; Sibol, Deane; Bekker, Dmitriy; Carrelli, David (2019). "Double Asteroid Redirection Test: The Earth Strikes Back". 2019 IEEE Aerospace Conference. pp. 1–11. doi:10.1109/AERO.2019.8742007. ISBN 978-1-5386-6854-2. In addition, DART is carrying a 6U CubeSat provided by Agenzia Spaziale Italiana (ASI). The CubeSat will provide imagery documentation of the impact, as well as in situ observation of the impact site and resultant ejecta plume
  27. Fahnestock, E.; Yu, Y.; Cheng, A. F. (2018). "DART Impact Ejecta Simulation and Visualization for Fly-Along CubeSat Operational Planning". AGU Fall Meeting Abstracts. 2018: P51A–07. Bibcode:2018AGUFM.P51A..07F.
  28. Cheng, Andy (15 November 2018). "DART Mission Update". ESA. Retrieved 14 January 2019.
  29. Bergin, Chris (7 January 2019). "Hera adds objectives to planetary defense test mission". NASASpaceflight.com. Retrieved 11 January 2019.
  30. Asteroids have been hitting the Earth for billions of years. In 2022, we hit back. Archived 2018-10-31 at the Wayback Machine Andy Rivkin The Johns Hopkins University Applied Physics Laboratory September 27, 2018
  31. A Low-Frequency Radar to Fathom Asteroids from Juventas Cubesat on HERA. Alain Herique, Dirk Plettemeier, Wlodek Kofman, Yves Rogez, Christopher Buck, and Hannah Goldberg; EPSC Abstracts, Vol. 13, EPSC-DPS2019-807-2, 2019. EPSC-DPS Joint Meeting 2019
  32. Exploration of the binary asteroid 65803 Didymos by the Hera mission. EPSC Abstracts, Vol. 13, EPSC-DPS2019-583-1; EPSC-DPS Joint Meeting 2019, 15-20 September 2019
  33. "CubeSats joining Hera mission to asteroid system". Space Daily. 8 January 2019. Retrieved 11 January 2019.
  34. Michel, Patrick; Kueppers, Michael; Sierks, Holger; Carnelli, Ian (26 April 2017). "European component of the AIDA mission to a binary asteroid: Characterization and interpretation of the impact of the DART mission" (PDF). Advances in Space Research (Article) (published 18 December 2017). 62 (8): 2261–2272. doi:10.1016/j.asr.2017.12.020.
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