Hayabusa2

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Hayabusa2
Hayabusa probe
Artist's impression of Hayabusa2
Mission type Asteroid sample return
Operator JAXA
COSPAR ID 2014-076A
SATCAT no. 40319
Website global.jaxa.jp/projects/sat/hayabusa2/
Spacecraft properties
Manufacturer NEC[1]
Launch mass 609 kg (1,343 lb)
Dimensions 1 × 1.6 × 1.25 m (3.3 × 5.2 × 4.1 ft) (spacecraft core), 6 m × 4.23 m (19.7 ft × 13.9 ft) (solar panel)
Power 2.6 kW (at 1 au), 1.4 kW (at 1.4 au)
Start of mission
Launch date 3 December 2014, 04:22 UTC (2014-12-03UTC04:22Z)[2]
Rocket H-IIA 202
Launch site LA-Y, Tanegashima Space Center
End of mission
Landing date December 2020 (planned)
Landing site Woomera, Australia
Flyby of Earth
Closest approach 3 December 2015
Distance 3,090 km (1,920 mi)[3]
(162173) Ryugu orbiter
Orbital insertion June 27, 2018, 09:35 UTC[4]
Orbital departure December 2019 (planned)
Animation of Hayabusa2 orbit from 3 December 2014 to 9 December 2019
  Hayabusa2   162173 Ryugu   Earth   Sun

Hayabusa2 is an asteroid sample-return mission operated by the Japanese space agency, JAXA. It follows on from Hayabusa and addresses weak points identified in that mission.[5] Hayabusa2 was launched on 3 December 2014 and rendezvoused at near-Earth asteroid 162173 Ryugu on 27 June 2018.[6] It is intended to survey the asteroid for a year and a half, depart in December 2019, and return to Earth in December 2020.

Hayabusa2 carries multiple payloads for science: remote sensing, sampling, and lander/rovers—four small probes that will investigate the asteroid surface.

Mission overview[edit]

Initially, launch was planned for 30 November 2014 (13:23 local time),[7][8][9] but was delayed to 3 December 2014 04:22 UTC (4 December 2014 13:22:04 local time).[10]

Hayabusa2 arrived at the target asteroid 162173 Ryugu (formerly designated 1999 JU3) on 27 June 2018.[6] It is expected to survey the asteroid, which is a near-Earth asteroid, for a year and a half during which time it will collect samples multiple times, depart in December 2019, and return the samples to Earth in December 2020.[9]

Compared to the previous Hayabusa mission, the spacecraft features improved ion engines, guidance and navigation technology, antennas, and attitude control systems.[11] An additional explosive device will be used to excavate the asteroid subsurface for sample material.[9]

Funding[edit]

Following the partial success of Hayabusa, JAXA began studying a potential successor mission in 2007.[12] In July 2009, Makoto Yoshikawa of JAXA presented a proposal titled "Hayabusa Follow-on Asteroid Sample Return Missions". In August 2010, JAXA obtained approval from the Japanese government to begin development of Hayabusa2. The cost of the project estimated in 2010 was 16.4 billion yen (US$146 million).[13][14]

The primary contractor NEC built the 590 kg (1,300 lb) spacecraft, its Ka band communications system and a mid-infrared camera.[15]

Instruments[edit]

The Hayabusa2 payload incorporates multiple scientific instruments:[16][17]

  • Remote sensing: Optical Navigation Camera (ONC-T, ONC-W1, ONC-W2), Near-Infrared Camera (NIR3), Thermal-Infrared Camera (TIR), Light Detection And Ranging (LIDAR)
  • Sampling: Sampling device (SMP), Small Carry-on Impactor (SCI), Deployable Camera (DCAM3)
  • Lander/rovers: Mobile Asteroid Surface Scout (MASCOT), MINERVA-II (ROVER 1A, ROVER 1B, ROVER 2)

Remote sensing[edit]

The Optical Navigation Cameras (ONCs) are used for spacecraft navigation during the asteroid approach and proximity operations. They will also remotely image the surface and search for interplanetary dust around the asteroid. ONC-T is a telephoto camera with a 6.35°×6.35° field of view and several optical filters carried in a carousel. ONC-W1 and ONC-W2 are wide angle (65.24°×65.24°) panchromatic (485–655nm) cameras.

The Near-Infrared Spectrometer (NIRS3) is a spectrograph operating at wavelengths 1.8–3.2 μm, intended for analysis of surface mineral composition.

The Thermal-Infrared Imager (TIR) is a thermal infrared camera working at 8-12 μm, using a two-dimensional microbolometer array. Its spatial resolution is 20 m at 20 km distance or 5 cm at 50 m distance. It will be able to determine surface temperatures in the range -40 – 150°C.[16]

The Light Detection And Ranging (LIDAR) instrument will measure the distance from spacecraft to the asteroid surface by measuring the time of flight of laser light reflection. It operates over the altitude range 30m–25km.[16]

When the spacecraft is closer to the surface than 30m during the sampling operation, Laser Range Finders (LRF-S1, LRF-S3) are used to measure the distance and the attitude of spacecraft relative to the terrain.[18][19] Another device LRF-S2 monitors the sampling horn to trigger the sampling projectile.

LIDAR and ONC data will be combined to determine the detailed topography (dimensions and shape) of the asteroid. Monitoring of a radio signal from Earth will allow measurement of the asteroid's gravitational field.

Sampling[edit]

Hayabusa2's sampling device is similar to Hayabusa's. The spacecraft will approach the surface of the asteroid with a sampling horn. When the horn touches the surface, a projectile (5-gram tantalum bullet) will be fired at 300 m/s into the surface. The resulting ejecta particles are collected by a catcher at the top of the horn, which the ejecta will reach under their own momentum under microgravity conditions.

Diagram of the SCI and DCAM3 deployment and operations

An additional sample will be taken of material deeper into the surface, which has not been subjected to space weathering. This requires removing a larger volume of surface material with a more substantial impactor. For this purpose, Hayabusa2 will deploy the Small Carry-on Impactor (SCI), an explosively formed penetrator consisting of a 2.5 kg (5.5 lb) copper projectile contained in a 4.5 kg (9.9 lb) shaped charge of plasticized HMX.[20][21] SCI will separate from Hayabusa2 at an altitude of about 500 meters and descend toward the asteroid under gravity,[citation needed] as it has no thrusters. Following SCI deployment, Hayabusa2 will maneuver to the far side of the asteroid, in order to avoid debris from the explosion. Hayabusa2 will leave behind a deployable camera (DCAM3) to observe the explosion of SCI. Approximately 40 minutes after separation, SCI will explode and drive the copper impactor onto the asteroid. Hayabusa2 will wait about two weeks for the debris to clear from the impact site, before descending into the newly-formed crater to retrieve samples.[22]

The spacecraft is planned to depart the asteroid in December 2019, and return samples to Earth in December 2020.[9]

Rovers[edit]

Four small rovers are carried by Hayabusa2 to investigate the asteroid surface in situ,[23] and provide context information for the returned samples. They will be deployed at about 60 m altitude and fall freely to the surface under the asteroid's weak gravity.[24]

MINERVA-II[edit]

MINERVA-II is a successor to the MINERVA lander carried by Hayabusa. It consists of several separate subsystems.

MINERVA-II-1 is a container that will deploy two rovers, ROVER-1A and ROVER-1B, developed by JAXA and the University of Aizu. These are identical rovers with a cylindrical shape, 18 cm diameter and 7 cm tall, and a mass of 1.1 kg (2.4 lb).[16][25] They will move by tumbling in the low gravitational field, using a torque generated by rotating masses within the rover. Their scientific payload is a stereo camera, wide-angle camera, and thermometer. Solar cells and double-layer capacitors provide the electrical power.

The MINERVA-II-2 container holds the ROVER-2, developed by a consortium of universities led by Tohoku University. This is an octagonal prism shape, 15 cm diameter and 16 cm tall, with a mass of about 1 kg (2.2 lb). It has two cameras, a thermometer, and an accelerometer. It has optical and ultraviolet LEDs for illumination to detect floating dust particles. ROVER-2 carries four mechanisms to hop and relocate.

MASCOT[edit]

The Mobile Asteroid Surface Scout (MASCOT) was developed by the German Aerospace Center in cooperation with the French space agency CNES.[26] It measures 29.5 cm × 27.5 cm × 19.5 cm and has a mass of 9.6 kg (21 lb).[27] MASCOT carries an infrared spectrometer, a magnetometer, a radiometer and a camera that will image the small-scale structure, distribution and texture of the regolith.[28] and is capable of tumbling to reposition itself for further measurements.[23][20] It will investigate the surface structure and mineralogical composition, the thermal behaviour and the magnetic properties of the asteroid.[29] The infrared radiometer on the InSight Mars lander, launched in 2018, is based on the MASCOT radiometer.[30][31]

See also[edit]

Japanese minor body probes

References[edit]

  1. ^ NEC. "JAXA Launches Hayabusa 2 Asteroid Probe: Press Releases - NEC". www.nec.com. 
  2. ^ "JAXA - Launch of "Hayabusa2" by H-IIA Launch Vehicle No. 26". 
  3. ^ "JAXA - Hayabusa2 Earth Swing-by Result". 
  4. ^ "Arrival at Ryugu!". JAXA Hayabusa2 Project. 29 June 2018. Retrieved 2018-07-15. 
  5. ^ Wendy Zukerman (18 August 2010). "Hayabusa2 will seek the origins of life in space". New Scientist. Retrieved 17 November 2010. 
  6. ^ a b Clark, Stephen (28 June 2018). "Japanese spacecraft reaches asteroid after three-and-a-half-year journey". Spaceflight Now. Retrieved 2 July 2018. 
  7. ^ JAXA Report on Hayabusa2, May 21st, 2014 Archived 4 March 2016 at the Wayback Machine.
  8. ^ Vilas, Faith (25 February 2008). "Spectral characteristics of Hayabusa 2 near-Earth asteroid targets 162173 1999 JU3 AND 2001 QC34". The Astronomical Journal. 135 (4): 1101. Bibcode:2008AJ....135.1101V. doi:10.1088/0004-6256/135/4/1101. target for the planned Japanese mission Hayabusa2 
  9. ^ a b c d Makoto Yoshikawa (6 January 2011). 小惑星探査ミッション「はやぶさ2」 [Asteroid Exploration Mission "Hayabusa2"] (PDF). 11th Symposium on Space Science (in Japanese). Retrieved 20 February 2011. [permanent dead link]
  10. ^ Clark, Stephen (3 December 2014). "Hayabusa2 launches on audacious asteroid adventure". spaceflightnow. Retrieved 3 December 2014. 
  11. ^ "Spaceflight Now - Breaking News - Japan's next asteroid probe approved for development". spaceflightnow.com. 
  12. ^ "JAXA - Keiji Tachikawa - The President's New Year Interview, 2007 -". www.jaxa.jp. 
  13. ^ Zukerman, Wendy (18 August 2010). "Hayabusa2 will seek the origins of life in space". New Scientist. Retrieved 17 November 2010. 
  14. ^ "Asteroid probe, rocket get nod from Japanese panel". Spaceflight Now. 11 August 2010. Retrieved 29 October 2012. 
  15. ^ "Japan's next asteroid probe approved for development". Spaceflight Now. 29 January 2012. Retrieved 29 October 2012. 
  16. ^ a b c d はやぶさ2情報源 Fact Sheet 小惑星到着直前版 (PDF) (in Japanese). JAXA. 19 April 2018. Retrieved 20 June 2018. 
  17. ^ "Current status of the asteroid explorer, Hayabusa2, leading up to arrival at asteroid Ryugu in 2018" (PDF). JAXA. 14 June 2018. Retrieved 20 June 2018. 
  18. ^ Terui, Fuyuto; Tsuda, Yuichi; Ogawa, Naoko; Mimasu, Yuya (July 2014). 小惑星探査機「はやぶさ2」の航法誘導制御における自動・自律機 [Autonomy for Guidance, Navigation and Control of Hayabusa2] (PDF). Artificial Intelligence (in Japanese). Japanese Society for Artificial Intelligence. ISSN 2188-2266. Retrieved 9 July 2018. 
  19. ^ Yoshikawa, Makoto (16 January 2012). はやぶさ2プロジェクトについて (PDF). Retrieved 9 July 2018. 
  20. ^ a b Graham, William (2 December 2014). "Japanese H-IIA kicks off Hayabusa2's asteroid mission". NASASpaceFlight.com. Retrieved 4 December 2014. 
  21. ^ Saiki, Takanao; Sawada, Hirotaka; Okamoto, Chisato; Yano, Hajime; Takagi, Yasuhiko; Akahoshi, Yasuhiro; Yoshikawa, Makoto (2013). "Small carry-on impactor of Hayabusa2 mission". Acta Astronautica. 84: 227. Bibcode:2013AcAau..84..227S. doi:10.1016/j.actaastro.2012.11.010. 
  22. ^ "Small Carry-on Impactor (SCI): Its scientific purpose, operation, and observation plan in Hayabysa-2 mission" (PDF). 
  23. ^ a b A detailed look at Japan's Hayabusa2 asteroid exploration mission. Phillip Keane, SpaceTech. 21 June 2018.
  24. ^ Okada, Tatsuaki; Fukuhara, Tetsuya; Tanaka, Satoshi; Taguchi, Makoto; Imamura, Takeshi; Arai, Takehiko; Senshu, Hiroki; Ogawa, Yoshiko; Demura, Hirohide; Kitazato, Kohei; Nakamura, Ryosuke; Kouyama, Toru; Sekiguchi, Tomohiko; Hasegawa, Sunao; Matsunaga, Tsuneo (July 2017). "Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2". Space Science Reviews. 208 (1–4): 255–286. Bibcode:2017SSRv..208..255O. doi:10.1007/s11214-016-0286-8. 
  25. ^ Minoru Ōtsuka (28 March 2016). 車輪なしでどうやって移動する?ローバー「ミネルバ2」の仕組み(後編). MONOist. Retrieved 22 June 2018. 
  26. ^ DLR Asteroid Lander MASCOT Archived 15 November 2012 at the Wayback Machine.
  27. ^ "Hayabusa2/MASCOT at a glance - Technical specifications and mission timeline". DLR. Retrieved 22 June 2018. 
  28. ^ A Mobile Asteroid Aurface Scout (MASCOT) for the Hayabuse 2 Mision to Ryugu. (PDF) R. Jaumann, J.P. Bibring, K.H. Glassmeier, at al. EPSC Abstracts. Vol. 11, EPSC2017-548, 2017. European Planetary Science Congress 2017.
  29. ^ MASCOT—The Mobile Asteroid Surface Scout Onboard the Hayabusa2 Mission. Tra-Mi Ho, Volodymyr Baturkin, Christian Grimm, Jan Thimo Grundmann, Catherin Hobbie, Eugen Ksenik, Caroline Lange, Kaname Sasaki, Markus Schlotterer, Maria Talapina, Nawarat Termtanasombat, Elisabet Wejmo, Lars Witte, Michael Wrasmann, Guido Wübbels, et al. Space Science Reviews. July 2017, Volume 208, Issue 1–4, pp 339–374. doi:10.1007/s11214-016-0251-6
  30. ^ [1]
  31. ^ Grott, M.; Knollenberg, J.; Borgs, B.; Hänschke, F.; Kessler, E.; Helbert, J.; Maturilli, A.; Müller, N. (1 August 2016). "The MASCOT Radiometer MARA for the Hayabusa 2 Mission". Space Science Reviews. 208 (1-4): 413–431. Bibcode:2017SSRv..208..413G. doi:10.1007/s11214-016-0272-1. 

External links[edit]