View source for Hayabusa2

{{Short description|Japanese space mission to asteroid Ryugu}}
{{about|the mission launched in 2014|the cancelled mission|Hayabusa Mk2}}
{{italic title}}
{{Use British English|date=December 2020}}
{{Use dmy dates|date=October 2019}}
{{Infobox spaceflight
| name              = ''Hayabusa2''
| image             = Hayabusa2 Ion thruster.jpg
| image_caption     = Artist's impression of ''Hayabusa2'' firing its ion thrusters
| image_size        = 300px

| mission_type      = Asteroid [[Sample-return mission|sample-return]]
| operator          = [[JAXA]]
| COSPAR_ID         = 2014-076A
| SATCAT            = 40319
| website           = {{url|http://www.hayabusa2.jaxa.jp/en/}}
| mission_duration  = 6 years (planned)<br/>({{Age in years, months and days|2014|12|3}} elapsed)

| spacecraft_type   = [[Hayabusa]]
| manufacturer      = [[NEC]]<ref name="nec-20141203">{{Cite press release |date=3 December 2014 |title=JAXA Launches Hayabusa 2 Asteroid Probe |url=https://www.nec.com/en/press/201412/global_20141203_01.html |url-status=live |archive-url=https://web.archive.org/web/20220418072603/https://www.nec.com/en/press/201412/global_20141203_01.html |archive-date=18 April 2022 |website=nec.com |publisher=[[NEC]] |at=Tokyo }}</ref>
| launch_mass       = 600 kg<ref name="nssdc" />
| dry_mass          = {{cvt|490|kg}} <ref name="spaceflight101-hb2">{{Cite web |title=Hayabusa-2 – Asteroid Exploration Mission |url=https://spaceflight101.com/spacecraft/hayabusa-2/ |url-status=live |archive-url=https://web.archive.org/web/20231029160153/https://spaceflight101.com/spacecraft/hayabusa-2/ |archive-date=29 October 2023 |access-date=30 June 2019 }}</ref>
| payload_mass      = 
| dimensions        = [[Satellite bus|Spacecraft bus]]: {{cvt|1|xx|1.6|xx|1.25|m}}<br/>[[Solar panels on spacecraft|Solar panel]]: {{cvt|6|x|4.23|m}}
| power             = 2.6 kW (at 1 [[astronomical unit|au]]), 1.4 kW (at 1.4 au)

| launch_date       = 3 December 2014,<br/>04:22:04 [[Coordinated Universal Time|UTC]]<ref name="jaxa-20140930">{{Cite press release |date=30 September 2014 |title=Launch of "Hayabusa2" by H-IIA Launch Vehicle No. 26 |url=https://global.jaxa.jp/press/2014/09/20140930_h2af26.html |url-status=live |archive-url=https://web.archive.org/web/20231028164133/https://global.jaxa.jp/press/2014/09/20140930_h2af26.html |archive-date=28 October 2023 |publisher=[[JAXA]] & [[Mitsubishi Heavy Industries]] }}</ref>
| launch_rocket     = [[H-IIA]] 202
| launch_site       = [[Tanegashima Space Center]], [[Yoshinobu Launch Complex|LA-Y]]
| launch_contractor = [[Mitsubishi Heavy Industries]]

|interplanetary =
 {{Infobox spaceflight/IP
   |type            = flyby
   |object          = [[Earth]]
   |arrival_date    = 3 December 2015
   |distance        = {{cvt|3090|km}} <ref name="jaxa-20151214">{{Cite press release |date=14 December 2015 |title=Hayabusa2 Earth Swing – by Result |url=https://global.jaxa.jp/press/2015/12/20151214_hayabusa2.html |url-status=live |archive-url=https://web.archive.org/web/20231028170751/https://global.jaxa.jp/press/2015/12/20151214_hayabusa2.html |archive-date=28 October 2023 |publisher=[[JAXA]] & [[National Research and Development Agency (Japan)|National Research and Development Agency]] }}</ref>
 }}
{{Infobox spaceflight/IP
   |type            = rendezvous
   |object          = {{ats|162173|Ryugu}}
   |arrival_date    = 27 June 2018, 09:35 UTC <ref name="jaxa-20180629">{{Cite web |date=29 June 2018 |title=Arrival at Ryugu! |url=https://www.hayabusa2.jaxa.jp/topics/20180629je/index_e.html |url-status=live |archive-url=https://web.archive.org/web/20230529145315/https://www.hayabusa2.jaxa.jp/topics/20180629je/index_e.html |archive-date=29 May 2023 |access-date=15 July 2018 |publisher=[[JAXA]] Hayabusa2 Project }}</ref>
   |sample_mass     = 5.4 [[gram]]s<ref name="japantimes-20201219">{{Cite news |title=Hayabusa2 returned with 5 grams of asteroid soil, far more than target |url=https://www.japantimes.co.jp/news/2020/12/19/national/science-health/hayabusa2-asteroid-soil/ |url-status=live |archive-url=https://web.archive.org/web/20231001002931/https://www.japantimes.co.jp/news/2020/12/19/national/science-health/hayabusa2-asteroid-soil/ |archive-date=1 October 2023 |work=[[The Japan Times]] |agency=[[Kyodo News]] }}</ref>(including gas samples)
   |departure_date  = 12 November 2019 <ref name='Departure'/>
   |distance        = 
 }}
{{Infobox spaceflight/IP
   |type            = lander
   |object          = {{ats|162173|Ryugu}}
   |arrival_date    = 21 February 2019
 }}
{{Infobox spaceflight/IP
   |type            = lander
   |object          = {{ats|162173|Ryugu}}
   |arrival_date    = 11 July 2019
 }}
{{Infobox spaceflight/IP
 |type              = flyby
 |object            = [[Earth]]
 |note              = Sample return
 |arrival_date      = 5 December 2020 UTC <ref name="ASAjointstatement">{{Cite press release |date=14 July 2020 |title=Joint Statement for Cooperation in the Hayabusa2 Sample Return Mission by the Australian Space Agency and the Japan Aerospace Exploration Agency |url=https://www.jaxa.jp/press/2020/07/20200714-1_j.html |url-status=live |archive-url=https://web.archive.org/web/20240101022938/https://www.jaxa.jp/press/2020/07/20200714-1_j.html |archive-date=1 January 2024 |access-date=14 July 2020 |publisher=[[JAXA]] & the [[Australian Space Agency]] }}</ref>
 }}

| landing_date      = Re-entry capsule:<br/>5 December 2020 UTC <ref name="ASAjointstatement"/>
| landing_site      = [[RAAF Woomera Range Complex|Woomera, Australia]]
}}

{{nihongo|'''''Hayabusa2'''''|はやぶさ2|extra={{lit|[[Peregrine falcon]] 2}}|lead=yes}} is an [[asteroid]] [[sample-return mission]] operated by the Japanese state space agency [[JAXA]]. It is a successor to the ''[[Hayabusa]]'' mission, which returned asteroid samples for the first time in June 2010.<ref name='Zukerman 2010'>{{cite web|url=https://www.newscientist.com/article/dn19332-hayabusa-2-will-seek-the-origins-of-life-in-space.html|title=Hayabusa2 will seek the origins of life in space|publisher=New Scientist|author=Wendy Zukerman|date=18 August 2010|access-date=17 November 2010}}</ref> ''Hayabusa2'' was launched on 3 December 2014 and [[Space rendezvous|rendezvoused in space]] with [[Near-Earth object|near-Earth]] asteroid [[162173 Ryugu]] on 27 June 2018.<ref name="arrival">{{Cite news |last=Clark |first=Stephen |date=28 June 2018 |title=Japanese spacecraft reaches asteroid after three-and-a-half-year journey |url=https://spaceflightnow.com/2018/06/28/japanese-spacecraft-reaches-asteroid-after-three-and-a-half-year-journey/ |url-status=live |archive-url=https://web.archive.org/web/20231024060128/https://spaceflightnow.com/2018/06/28/japanese-spacecraft-reaches-asteroid-after-three-and-a-half-year-journey/ |archive-date=24 October 2023 |access-date=2 July 2018 |work=Spaceflight Now }}</ref> It surveyed the asteroid for a year and a half and took samples. It left the asteroid in November 2019 and returned the samples to Earth on 5 December 2020 [[Coordinated Universal Time|UTC]].<ref name="Departure">{{Cite news |last=Bartels |first=Meghan |date=13 November 2019 |title=Farewell, Ryugu! Japan's Hayabusa2 Probe Leaves Asteroid for Journey Home |url=https://www.space.com/hayabusa2-spacecraft-leaves-asteroid-ryugu.html |url-status=live |archive-url=https://web.archive.org/web/20231024064540/https://www.space.com/hayabusa2-spacecraft-leaves-asteroid-ryugu.html |archive-date=24 October 2023 |work=[[Space.com]] }}</ref><ref name="NYT-20201205">{{Cite news |last=Chang |first=Kenneth |date=5 December 2020 |title=Japan's Journey to an Asteroid Ends With a Hunt in Australia's Outback |url=https://www.nytimes.com/2020/12/05/science/japan-asteroid-hayabusa2-woomera.html |url-access=subscription |url-status=live |archive-url=https://web.archive.org/web/20240120030928/https://www.nytimes.com/2020/12/05/science/japan-asteroid-hayabusa2-woomera.html |archive-date=20 January 2024 |access-date=5 December 2020 |newspaper=[[The New York Times]] }}</ref><ref name="BBC-20201206">{{Cite news |last=Rincon |first=Paul |date=6 December 2020 |title=Hayabusa-2: Capsule with asteroid samples in 'perfect' shape |url=https://www.bbc.com/news/science-environment-55201662 |url-status=live |archive-url=https://web.archive.org/web/20231024064457/https://www.bbc.com/news/science-environment-55201662 |archive-date=24 October 2023 |access-date=6 December 2020 |work=[[BBC News]] }}</ref> Its mission has now been extended through at least 2031, when it will rendezvous with the small, rapidly-rotating asteroid {{mpl|1998 KY|26}}.

''Hayabusa2'' carries multiple science payloads for remote sensing and sampling, and four small rovers to investigate the asteroid surface and analyze the environmental and geological context of the samples collected.

== Mission overview ==
[[File:Mission overview of Hayabusa2 and MASCOT.webm|thumb|upright=1.3|left|''Hayabusa2'' mission overview animation]]
[[File:.Animation of Hayabusa2 orbit.gif|300px|thumb|upright=1.3|right|Animation of ''Hayabusa2'' orbit from 3 December 2014<br/>{{legend2|magenta|''Hayabusa2''}} {{legend2|lime|[[162173 Ryugu]]}} {{legend2|royalblue|[[Earth]]}} {{legend2|yellow|[[Sun]]}}<br>See [[:File:Animation of Hayabusa2 orbit - extended mission.webm|detailed video including the extended mission]]]]

Asteroid [[162173 Ryugu]] (formerly designated {{mp|1999 JU|3}}) is a primitive [[C-type asteroid|carbonaceous]] [[Near-Earth object|near-Earth asteroid]]. Carbonaceous asteroids are thought to preserve the most pristine, untainted materials in the [[Solar System]], a mixture of minerals, ice, and [[organic compound]]s that interact with each other.<ref name='Tachibana 2014'>{{cite journal | doi=10.2343/geochemj.2.0350 | title=Hayabusa2: Scientific importance of samples returned from C-type near-Earth asteroid (162173) 1999 JU3 | year=2014 | last1=Tachibana | first1=S. | last2=Abe | first2=M. | last3=Arakawa | first3=M. | last4=Fujimoto | first4=M. | last5=Iijima | first5=Y. | last6=Ishiguro | first6=M. | last7=Kitazato | first7=K. | last8=Kobayashi | first8=N. | last9=Namiki | first9=N. | last10=Okada | first10=T. | last11=Okazaki | first11=R. | last12=Sawada | first12=H. | last13=Sugita | first13=S. | last14=Takano | first14=Y. | last15=Tanaka | first15=S. | last16=Watanabe | first16=S. | last17=Yoshikawa | first17=M. | last18=Kuninaka | first18=H. | journal=Geochemical Journal | volume=48 | issue=6 | pages=571–587 | bibcode=2014GeocJ..48..571T | doi-access=free }}</ref> Studying it is expected to provide additional knowledge on the origin and evolution of the inner planets and, in particular, the origin of water and organic compounds on [[Earth]],<ref name='Tachibana 2014'/><ref name='Tsuda 2013'>{{cite journal|author=Yuichi Tsuda|author2=Makoto Yoshikawa|author3=Masanao Abe|author4=Hiroyuki Minamino|author5=Satoru Nakazawa|title=System design of the Hayabusa 2 – Asteroid sample return mission to 1999 JU3|doi=10.1016/j.actaastro.2013.06.028|journal=Acta Astronautica|volume=91|date=October–November 2013|pages=356–362|bibcode=2013AcAau..91..356T}}</ref> all relevant to the [[Abiogenesis|origin of life]] on Earth.<ref name="newscientist-20100818">{{Cite magazine |last=Zukerman |first=Wendy |date=18 August 2010 |title=Hayabusa 2 will seek the origins of life in space |url=https://www.newscientist.com/article/dn19332-hayabusa-2-will-seek-the-origins-of-life-in-space/ |url-status=live |archive-url=https://web.archive.org/web/20231024061100/https://www.newscientist.com/article/dn19332-hayabusa-2-will-seek-the-origins-of-life-in-space/ |archive-date=24 October 2023 |magazine=[[New Scientist]] |issn=0262-4079 }}</ref>

Initially, launch was planned for 30 November 2014,<ref name="jaxa-report-20140521">{{Cite web |date=21 May 2014 |title=JAXA Report on Hayabusa2 |url=http://science.nasa.gov/media/medialibrary/2014/06/04/NAC-PPS-Yano-140521c-11.pdf |url-status=live |archive-url=https://web.archive.org/web/20160304195136/http://science.nasa.gov/media/medialibrary/2014/06/04/NAC-PPS-Yano-140521c-11.pdf |archive-date=4 March 2016 |publisher=[[JAXA]] }}</ref><ref>{{cite journal|last=Vilas |first=Faith|date=25 February 2008|title=Spectral characteristics of Hayabusa 2 near-Earth asteroid targets 162173 1999 JU3 AND 2001 QC34|journal=The Astronomical Journal|volume=135|page=1101|doi=10.1088/0004-6256/135/4/1101|quote=target for the planned Japanese mission Hayabusa2|bibcode=2008AJ....135.1101V|issue=4|doi-access=free}}</ref><ref name=yoshikawa2011>{{cite conference |url=https://www.isas.jaxa.jp/j/researchers/symp/sss11/paper/S3-04_20110209174216.pdf |archive-url=https://web.archive.org/web/20240123202307/https://www.isas.jaxa.jp/j/researchers/symp/sss11/paper/S3-04_20110209174216.pdf |archive-date=23 January 2024 |url-status=live |script-title=ja:小惑星探査ミッション「はやぶさ2|language=ja|trans-title=Asteroid Exploration Mission "Hayabusa2"|first=Makoto |last=Yoshikawa |date=6 January 2011 |conference=11th Symposium on Space Science|access-date=20 February 2011 }}</ref> but was delayed to 3 December 2014 at 04:22:04 UTC (3 December 2014, 13:22:04 local time) on a [[H-IIA]] launch vehicle.<ref name="sfn-20141203">{{Cite news |last=Clark |first=Stephen |date=3 December 2014 |title=Hayabusa2 launches on audacious asteroid adventure |url=https://spaceflightnow.com/2014/12/03/hayabusa-2-launches-on-audacious-asteroid-adventure/ |url-status=live |archive-url=https://web.archive.org/web/20231014085158/https://spaceflightnow.com/2014/12/03/hayabusa-2-launches-on-audacious-asteroid-adventure/ |archive-date=14 October 2023 |access-date=3 December 2014 |work=Spaceflight Now }}</ref> ''Hayabusa2'' launched together with [[PROCYON]] asteroid flyby space probe. PROCYON's mission was a failure. ''Hayabusa2'' arrived at Ryugu on 27 June 2018,<ref name=arrival/> where it surveyed the asteroid for a year and a half and collected samples.<ref name='Tachibana 2014'/> It departed the asteroid in November 2019 and returned the samples to Earth in December 2020.<ref name=yoshikawa2011/>

Compared to the previous ''[[Hayabusa]]'' mission, the spacecraft features improved [[Ion thruster|ion engines]], guidance and navigation technology, antennas, and [[Spacecraft attitude control|attitude control]] systems.<ref name=sfn-20120129 /> A kinetic penetrator (a high-explosive shaped charge) was shot into the asteroid surface to expose pristine sample material which was later collected for return to Earth.<ref name='Tsuda 2013'/><ref name=yoshikawa2011/>

== Funding and history ==
Following the initial success of ''Hayabusa'', JAXA began studying a potential successor mission in 2007.<ref>{{cite web|url=http://www.jaxa.jp/article/interview/vol27/p3_e.html|author=Keiji Tachikawa|title=The President's New Year Interview|date=2007|website=jaxa.jp|publisher=JAXA|access-date=28 April 2007|archive-date=5 February 2012|archive-url=https://web.archive.org/web/20120205072752/http://www.jaxa.jp/article/interview/vol27/p3_e.html|url-status=dead}}</ref> 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 ([[United States dollar|US$]]{{format price|{{To USD|16400000000|JPN|round=-5}}}}).<ref name='Zukerman 2010'/><ref name="sfn-20100811">{{Cite news |last=Clark |first=Stephen |date=11 August 2010 |title=Asteroid probe, rocket get nod from Japanese panel |url=https://www.spaceflightnow.com/news/n1008/11japan/ |url-status=live |archive-url=https://web.archive.org/web/20240112145547/https://spaceflightnow.com/news/n1008/11japan/ |archive-date=12 January 2024 |access-date=29 October 2012 |work=Spaceflight Now }}</ref>

''Hayabusa2'' was launched on 3 December 2014, arrived at asteroid Ryugu on 27 June 2018, and remained stationary at a distance of about {{cvt|20|km}} to study and map the asteroid. In the week of 16 July 2018, commands were sent to move to a lower hovering altitude.<ref name="jaxa-20180725">{{Cite web |date=25 July 2018 |title=Imaging Ryugu from an altitude of 6km |url=https://global.jaxa.jp/projects/sat/hayabusa2/topics.html#topics12394 |url-status=live |archive-url=https://web.archive.org/web/20231028163015/https://global.jaxa.jp/projects/sat/hayabusa2/topics.html#topics12394 |archive-date=28 October 2023 |publisher=[[JAXA]] }}</ref>

On 21 September 2018, the ''Hayabusa2'' spacecraft ejected the first two rovers, Rover-1A (HIBOU)<ref>"hibou" is not Japanese nor abbreviation; it is the French word for owl and pronounced as such, イブー (i-boo).</ref> and Rover-1B (OWL), from about a {{cvt|55|m}} altitude that dropped independently to the surface of the asteroid.<ref name='Rincon 20Sep'>[https://www.bbc.com/news/science-environment-45578795 Hayabusa-2: Japan's rovers ready for touchdown on asteroid], Paul Rincon, ''BBC News'' 20 September 2018</ref><ref name='First Drop'>{{cite web|title=Japanese Probe Drops Tiny Hopping Robots Toward Big Asteroid Ryugu|url=https://www.space.com/41898-hayabusa2-deploys-hopping-robots-asteroid-ryugu.html|publisher=Space.com|date=21 September 2018}}</ref> They functioned nominally and transmitted data.<ref name="space20180922" /> The MASCOT rover deployed successfully on 3 October 2018 and operated for about 16 hours as planned.<ref>[https://www.dlr.de/dlr/presse/en/desktopdefault.aspx/tabid-10172/213_read-30118/year-all/#/gallery/32227 MASCOT lands safely on asteroid Ryugu], Press release, ''DLR Press Portal'', 3 October 2018</ref>

The first sample collection was scheduled to start in late October 2018, but the rovers encountered a landscape with large and small boulders but no surface soil for sampling. Therefore, it was decided to postpone the sample collection plans to 2019 and further evaluate various options for the landing.<ref name='sampling postponed'/><ref name="Mynavi190109">{{Cite news |last=Otsuka |first=Minoru |date=9 January 2019 |title=はやぶさ2のタッチダウン候補地は2カ所に、どちらが最適？ |trans-title=Hayabusa2's touchdown candidate sites narrowed down to two, which is the most optimal? |url=https://news.mynavi.jp/article/20190109-753844/ |url-status=live |archive-url=https://web.archive.org/web/20231028170946/https://news.mynavi.jp/techplus/article/20190109-753844/ |archive-date=28 October 2023 |access-date=9 January 2019 |language=ja |newspaper=Mynavi news }}</ref> The first surface sample retrieval took place on 21 February 2019. On 5 April 2019, ''Hayabusa2'' released an impactor to create an artificial crater on the asteroid surface. However, ''Hayabusa2'' initially failed on 14 May 2019 to drop special reflective markers necessary onto the surface for guiding the descent and sampling processes,<ref name=Marker/> but later it successfully dropped one from an altitude of {{cvt|9|m}} on 4 June 2019.<ref name='Ryan June5'>[Japan's Hayabusa2 spacecraft grabs epic close-up shot just 30 feet above asteroid], Jackson Ryan, ''C-net'', 5 June 2019</ref> The sub-surface sampling took place on 11 July 2019.<ref name='Kyoto July 2019'>{{cite web|first=Kyoko|last=Hasegawa|url=https://phys.org/news/2019-07-japan-hayabusa2-probe-touchdown-asteroid.html|title=Japan's Hayabusa2 probe makes "perfect" touchdown on asteroid |website=phys.org|date=11 July 2019}}</ref> The spacecraft departed the asteroid on 13 November 2019 (with departure command sent at 01:05 UTC on 13 November 2019). It successfully delivered the samples back to Earth on 6 December 2020 ([[Japan Standard Time|JST]]), dropping the contents by parachute in a special container at a location in [[southern Australia]]. The samples were retrieved the same day for secure transport back to the JAXA labs in Japan.<ref name='Departure'/><ref>[https://www.bbc.co.uk/news/science-environment-55201662 Hayabusa-2 capsule located in Australian desert]</ref><ref>[http://www.planetary.org/blogs/jason-davis/why-sample-return.html What's the benefit of sample-return?]</ref>

== Spacecraft ==
{| class="wikitable floatright"
|-
! ''Hayabusa2'' !! Performance<ref name='Kazutaka 2017'>[https://jaxa.repo.nii.ac.jp/?action=repository_uri&item_id=15670&file_id=31&file_no=1 Operation Status of Ion Engines of Asteroid Explorer Hayabusa2], Nishiyama, Kazutaka; Hosoda, Satoshi; Tsukizaki, Ryudo; Kuninaka, Hitoshi; [[JAXA]], January 2017</ref><ref>[http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2011index/IEPC-2011-309.pdf The Ion Engine System for Hayabusa2] {{Webarchive|url=https://web.archive.org/web/20141106202235/http://erps.spacegrant.org/uploads/images/images/iepc_articledownload_1988-2007/2011index/IEPC-2011-309.pdf |date=6 November 2014 }}, The 32nd International Electric Propulsion Conference, Wiesbaden, Germany, September 11–15, 2011</ref>
|-
| Propulsion || {{center| μ10 [[ion thruster]]}}
|-
| Number of thrusters || {{center| 4 (one is a spare)}}
|-
| Total thrust (ion drive) || {{center| 28 mN}}
|-
| [[Specific impulse]] (''I<sub>sp</sub>'') || {{center| 3000 seconds}}
|-
| Acceleration || {{center|49 μm/s<sup>2</sup>}}
|-
| Power || {{center| 1250 W}}
|-
| Spacecraft wet mass || {{center| 600 kg}}
|-
| Ion engine system<br/>dry mass || {{center| 66 kg}}
|-
| Ion engine system<br/>wet mass || {{center| 155 kg}}
|-
| Solar array || {{center| 23 kg}}
|-
| [[Xenon]] propellant || {{center| 66 kg}}
|-
| Hydrazine/MON-3 propellant || {{center| 48 kg}}
|-
| Thrust (chemical propellants) || {{center| 20 N}}
|}

The design of ''Hayabusa2'' is based on the first ''Hayabusa'' spacecraft, with some improvements.<ref name='Tachibana 2014'/><ref name='Fact Sheet Hayabusa2'>[http://www.hayabusa2.jaxa.jp/en/enjoy/material/factsheet/FactSheet_en_v2.31s.pdf Hayabusa2 Information Fact Sheet] [[JAXA]] 29 July 2018</ref> It has a mass of {{convert|600|kg}} including fuel,<ref name='Fact Sheet Hayabusa2'/> and electric power is generated by two sets of [[Solar panels on spacecraft|solar arrays]] with an output of 2.6&nbsp;kW at 1 [[astronomical unit|AU]], and 1.4&nbsp;kW at 1.4 AU.<ref name='Fact Sheet Hayabusa2'/> The power is stored in eleven inline-mounted 13.2 Ah [[Lithium-ion battery|lithium-ion batteries]].<ref name='Fact Sheet Hayabusa2'/>

;Propulsion
The spacecraft features four solar-electric ion thrusters for propulsion called μ10,<ref name='Kazutaka 2017'/> one of which is a backup. These engines use [[microwave]]s to convert [[xenon]] into [[Plasma (physics)|plasma]] ([[ion]]s), which are accelerated by a voltage applied by the [[solar panel]]s and ejected out the back of the engine. The simultaneous operation of three engines generates thrusts of up to 28&nbsp;mN.<ref name='Fact Sheet Hayabusa2'/> Although this thrust is very small, the engines are also extremely efficient; the {{cvt|66|kg}} of [[xenon]]<ref name='Kazutaka 2017'/> [[reaction mass]] can [[delta-v|change the speed of the spacecraft]] by up to 2&nbsp;km/s.<ref name='Fact Sheet Hayabusa2'/>

The spacecraft has four redundant [[reaction wheel]]s and a chemical [[reaction control system]] featuring twelve thrusters for [[Spacecraft attitude control|attitude control]] (orientation) and orbital control at the asteroid.<ref name='Kazutaka 2017'/><ref name='Fact Sheet Hayabusa2'/> The chemical thrusters use [[hydrazine]] and [[Mixed oxides of nitrogen|MON-3]], with a total mass of {{cvt|48|kg}} of chemical propellant.<ref name='Fact Sheet Hayabusa2'/>

;Communication
The primary contractor [[NEC]] built the {{cvt|590|kg}} spacecraft, its [[Ka band|Ka-band]] communications system and a [[Thermographic camera|mid-infrared camera]].<ref name="sfn-20120129">{{Cite news |last=Clark |first=Stephen |date=29 January 2012 |title=Japan's next asteroid probe approved for development |url=https://www.spaceflightnow.com/news/n1201/29hayabusa2/ |url-status=live |archive-url=https://web.archive.org/web/20231029152402/https://spaceflightnow.com/news/n1201/29hayabusa2/ |archive-date=29 October 2023 |access-date=29 October 2012 }}</ref> The spacecraft has two [[Directional antenna|high-gain directional antennas]] for [[X band|X-band]] and [[Ka band|K<sub>a</sub>-band]].<ref name='Kazutaka 2017'/> Bit rates are 8 bit/s to 32 kbit/s.<ref name='Fact Sheet Hayabusa2'/> The ground stations are the [[Usuda Deep Space Center]], [[Uchinoura Space Center]], [[NASA Deep Space Network]] and [[Malargüe Station]] ([[European Space Agency|ESA]]).<ref name='Fact Sheet Hayabusa2'/>

;Navigation
The optical navigation camera telescope (ONC-T) is a telescopic framing camera with seven colors to optically navigate the spacecraft.<ref>{{cite journal | doi=10.1007/s11214-015-0227-y | title=Preflight Calibration Test Results for Optical Navigation Camera Telescope (ONC-T) Onboard the Hayabusa2 Spacecraft | year=2017 | last1=Kameda | first1=S. | last2=Suzuki | first2=H. | last3=Takamatsu | first3=T. | last4=Cho | first4=Y. | last5=Yasuda | first5=T. | last6=Yamada | first6=M. | last7=Sawada | first7=H. | last8=Honda | first8=R. | last9=Morota | first9=T. | last10=Honda | first10=C. | last11=Sato | first11=M. | last12=Okumura | first12=Y. | last13=Shibasaki | first13=K. | last14=Ikezawa | first14=S. | last15=Sugita | first15=S. | journal=Space Science Reviews | volume=208 | issue=1–4 | pages=17–31 | bibcode=2017SSRv..208...17K | s2cid=255069232 }}</ref> It works in synergy with the optical navigation camera wide-field (ONC-W2) and with two [[star tracker]]s.<ref name='Fact Sheet Hayabusa2'/>

In order to descend to the asteroid surface to perform sampling, the spacecraft released one of five target markers in the selected landing zones as artificial guide marks, with highly reflective outer material that is recognized by a strobe light mounted on the spacecraft.<ref name='Fact Sheet Hayabusa2'/> The spacecraft also used its laser altimeter and ranging ([[Lidar|LIDAR]]) as well as Ground Control Point Navigation (GCP-NAV) sensors during sampling.<ref name='Fact Sheet Hayabusa2'/>

== Firsts ==
The ''Hayabusa2'' spacecraft was the first to deploy operating rovers on an asteroid.

== Science payload ==
[[File:20190605 hayabusa-diagram-tpr-01.png|thumb|upright=2.5|right|Hayabusa2 instrument inventory]]

The ''Hayabusa2'' payload is equipped with multiple scientific instruments:<ref name='Fact Sheet Hayabusa2'/><ref name="jaxa20180614">{{Cite web |date=14 June 2018 |title=Current status of the asteroid explorer, Hayabusa2, leading up to arrival at asteroid Ryugu in 2018 |url=https://global.jaxa.jp/projects/sat/hayabusa2/pdf/Hayabusa2_Press20180614e.pdf |url-status=live |archive-url=https://web.archive.org/web/20231028170603/https://global.jaxa.jp/projects/sat/hayabusa2/pdf/Hayabusa2_Press20180614e.pdf |archive-date=28 October 2023 |access-date=20 June 2018 |publisher=[[JAXA]] }}</ref>
* [[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)
* Four rovers: Mobile Asteroid Surface Scout (MASCOT), Rover-1A, Rover-1B, Rover-2.

=== Remote sensing ===
The Optical Navigation Cameras (ONCs) were used for spacecraft navigation during the asteroid approach and proximity operations. They also remotely imaged the surface to 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 filter]]s carried in a carousel. ONC-W1 and ONC-W2 are wide angle (65.24° × 65.24°) [[panchromatic]] (485–655&nbsp;nm) cameras with [[nadir]] and oblique views, respectively.<ref name='Fact Sheet Hayabusa2'/>

The Near-Infrared Spectrometer (NIRS3) is a [[spectrograph]] operating at a wavelength of 1.8–3.2 μm. NIRS3 was used for analysis of surface mineral composition.<ref name='Fact Sheet Hayabusa2'/>

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&nbsp;km distance or 5&nbsp;cm at 50&nbsp;m distance (70&nbsp;ft at 12&nbsp;mi, or 2 in at 160&nbsp;ft). It was used to determine surface temperatures in the range {{cvt|-40|to|150|°C}}.<ref name='Fact Sheet Hayabusa2'/>

The Light Detection And Ranging ([[Lidar|LIDAR]]) instrument measured the distance from the spacecraft to the asteroid surface by measuring the reflected laser light. It operated over an altitude range between 30 m and 25&nbsp;km (100&nbsp;ft and 16&nbsp;mi).<ref name='Fact Sheet Hayabusa2'/>

When the spacecraft was closer to the surface than {{cvt|30|m}} during the sampling operation, the Laser Range Finders (LRF-S1, LRF-S3) were used to measure the distance and the attitude (orientation) of the spacecraft relative to the terrain.<ref>{{Cite journal |last1=Terui |first1=Fuyuto |last2=Tsuda |first2=Yuichi |last3=Ogawa |first3=Naoko |last4=Mimasu |first4=Yuya |date=July 2014 |script-title=ja: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 |trans-title=Autonomy for Guidance, Navigation and Control of Hayabusa2 |url=https://jaxa.repo.nii.ac.jp/record/22515/files/PA1510013000.pdf |url-status=live |journal=Artificial Intelligence |language=ja |publisher=[[JAXA]] |volume=29 |issue=4 |issn=2188-2266 |archive-url=https://web.archive.org/web/20240124133610/https://jaxa.repo.nii.ac.jp/record/22515/files/PA1510013000.pdf |archive-date=24 January 2024 |access-date=9 July 2018 }}</ref><ref>{{Cite web |last1=Yoshikawa |first1=Makoto |date=16 January 2012 |script-title=ja:はやぶさ２プロジェクトについて |trans-title=About the Hayabusa2 Project |url=https://www.mext.go.jp/component/b_menu/shingi/toushin/__icsFiles/afieldfile/2012/02/13/1316064_02.pdf |url-status=live |archive-url=https://web.archive.org/web/20231102104355/https://www.mext.go.jp/component/b_menu/shingi/toushin/__icsFiles/afieldfile/2012/02/13/1316064_02.pdf |archive-date=2 November 2023 |access-date=9 July 2018 |language=ja }}</ref> The LRF-S2 monitored the sampling horn to trigger the sampling projectile.

LIDAR and ONC data are being combined to determine the detailed [[topography]] (dimensions and shape) of the asteroid. Monitoring of a radio signal from Earth allowed measurement of the asteroid's [[gravitational field]].<ref name='Fact Sheet Hayabusa2'/>

== Rovers ==
''Hayabusa2'' carried four small rovers to explore the asteroid surface ''[[in situ]]'',<ref name="Keane">{{Cite news |last=Keane |first=Phillip |date=21 June 2018 |title=A detailed look at Japan's Hayabusa2 asteroid exploration mission |url=https://www.spacetechasia.com/a-detailed-look-at-japans-hayabusa2-asteroid-exploration-mission/ |url-status=live |archive-url=https://web.archive.org/web/20231101170833/https://www.spacetechasia.com/a-detailed-look-at-japans-hayabusa2-asteroid-exploration-mission/ |archive-date=1 November 2023 |work=SpaceTech Asia }}</ref> and provide context information for the returned samples. Due to the minimal gravity of the asteroid, all four rovers were designed to move around by short hops instead of using normal wheels. They were deployed at different dates from about {{cvt|60|m}} altitude and fell freely to the surface under the asteroid's weak gravity.<ref name=okada2017>{{cite journal|title=Thermal Infrared Imaging Experiments of C-Type Asteroid 162173 Ryugu on Hayabusa2|first1=Tatsuaki|last1=Okada|first2=Tetsuya|last2=Fukuhara |first3=Satoshi|last3=Tanaka|first4=Makoto|last4=Taguchi|first5=Takeshi|last5=Imamura|first6=Takehiko|last6=Arai|first7=Hiroki|last7=Senshu|first8=Yoshiko|last8=Ogawa|first9=Hirohide|last9=Demura|first10=Kohei |last10=Kitazato|first11=Ryosuke|last11=Nakamura|first12=Toru|last12=Kouyama|first13=Tomohiko|last13=Sekiguchi|first14=Sunao|last14=Hasegawa|first15=Tsuneo|last15=Matsunaga|journal=Space Science Reviews |volume=208|issue=1–4|pages=255–286|date=July 2017|bibcode=2017SSRv..208..255O|doi=10.1007/s11214-016-0286-8|doi-access=free|hdl=1893/26994|hdl-access=free}}</ref> The first two rovers, called HIBOU (previously Rover-1A) and OWL (previously Rover-1B), landed on asteroid Ryugu on 21 September 2018.<ref name="space20180922">{{Cite news |last=Bartels |first=Meghaan |date=22 September 2018 |title=They Made It! Japan's Two Hopping Rovers Successfully Land on Asteroid Ryugu |url=https://www.space.com/41912-japanese-hopping-rovers-land-on-asteroid.html |url-status=live |archive-url=https://web.archive.org/web/20231025102622/https://www.space.com/41912-japanese-hopping-rovers-land-on-asteroid.html |archive-date=25 October 2023 |work=[[Space.com]] }}</ref> The third rover, called MASCOT, was deployed 3 October 2018. Its mission was successful.<ref name="plansoc-20181005">{{Cite web |last=Lakdawalla |first=Emily |date=5 October 2018 |title=MASCOT landing on Ryugu a success |url=https://www.planetary.org/articles/mascot-landing-on-ryugu-successful |url-status=live |archive-url=https://web.archive.org/web/20231024063432/https://www.planetary.org/articles/mascot-landing-on-ryugu-successful |archive-date=24 October 2023 |publisher=[[The Planetary Society]] }}</ref> The fourth rover, known as Rover-2 or [[MINERVA (spacecraft)|MINERVA-II-2]], failed before release from the orbiter. It was released on 2 October 2019 to orbit the asteroid and perform gravitational measurements before being allowed to impact the asteroid a few days later.

=== MINERVA-II ===
{{Main|MINERVA-II}}
[[File:Surface of Ryugu from MINERVA-II1 Rover-1A.jpg|thumb|The first photograph from the surface of an asteroid, taken by ''HIBOU'' on 22 September 2018 during one of its "hops".]]

MINERVA-II is a successor to the [[Hayabusa#MINERVA mini-lander|MINERVA lander carried by ''Hayabusa'']]. It consists of two containers with 3 rovers.

MINERVA-II-1 is a container that deployed two rovers, '''Rover-1A''' ('''HIBOU''') and '''Rover-1B''' ('''OWL'''), on 21 September 2018.<ref name="MINERVA-II-1 Landings">{{Cite web |last1=Yoshimitsu |first1=Tetsuo |last2=Kubota |first2=Takashi |last3=Tsuda |first3=Yuichi |last4=Yoshikawa |first4=Makoto |date=23 September 2018 |title=MINERVA-II1: Successful image capture, landing on Ryugu and hop! |url=https://www.hayabusa2.jaxa.jp/en/topics/20180922e/ |url-status=live |archive-url=https://web.archive.org/web/20230929092912/https://www.hayabusa2.jaxa.jp/en/topics/20180922e/ |archive-date=29 September 2023 |access-date=24 September 2018 |website=JAXA Hayabusa2 Project |publisher=[[JAXA]] }}</ref><ref name="jaxa-20181213">{{Cite web |date=13 December 2018 |title=Naming our MINERVA-II1 rovers |url=http://www.hayabusa2.jaxa.jp/en/topics/20181213e_MNRV-II1/ |url-status=live |archive-url=https://web.archive.org/web/20230815220553/https://www.hayabusa2.jaxa.jp/en/topics/20181213e_MNRV-II1/ |archive-date=15 August 2023 |publisher=[[JAXA]] }}</ref> It was developed by JAXA and the [[University of Aizu]]. The rovers are identical having a cylindrical shape, {{cvt|18|cm}} diameter and {{cvt|7|cm}} tall, and a mass of {{cvt|1.1|kg}} each.<ref name='Fact Sheet Hayabusa2' /><ref name="otsuka20160328">{{Cite news |last=Ōtsuka |first=Minoru |date=28 March 2016 |script-title=ja: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） |trans-title=How Does It Move Without Wheels? The Mechanism of the Rover 'MINERVA-II' (Part 2) |url=http://monoist.atmarkit.co.jp/mn/articles/1603/28/news015.html |url-status=live |archive-url=https://web.archive.org/web/20231213001614/https://monoist.itmedia.co.jp/mn/articles/1603/28/news015.html |archive-date=13 December 2023 |access-date=22 June 2018 |work=MONOist |language=ja }}</ref> They move by hopping in the low gravitational field, using a [[torque]] generated by rotating masses within the rovers.<ref>{{cite report|title=Advanced robotic system of hopping rovers for small solar system bodies|first1=Tetsuo|last1=Yoshimitsu|first2=Takashi|last2=Kubota|first3=Tadashi|last3=Adachi|first4=Yoji|last4=Kuroda|s2cid=16105096|year=2012 |url=https://robotics.estec.esa.int/i-SAIRAS/isairas2012/Papers/Session%206A/06A_01_yoshimitsu.pdf |archive-url=https://web.archive.org/web/20210418232709/http://robotics.estec.esa.int/i-SAIRAS/isairas2012/Papers/Session%206A/06A_01_yoshimitsu.pdf |archive-date=2021-04-18 |url-status=live }}</ref> Their scientific payload is a [[stereo camera]], [[wide-angle camera]], and [[thermometer]]s. [[Solar cell]]s and [[double-layer capacitor]]s provide the electrical power.<ref name="nssdc"/><ref>{{cite web |url=https://www.hayabusa2.jaxa.jp/en/enjoy/material/press/Hayabusa2_Press20181213_verK_EN2.pdf|publisher=JAXA|title=Asteroid explorer, Hayabusa2 press conference|page=21}}</ref> The MINERVA-II-1 rovers were successfully deployed 21 September 2018. Both rovers performed successfully on the asteroid surface, sending images and video from the surface. Rover-1A operated for 113 asteroid days (36 Earth days) returning 609 images from the surface, and Rover-1B operated for 10 asteroid days (3 Earth days) returning 39 images from the surface.<ref name="MINVERA-II results" />

The MINERVA-II-2 container held the '''ROVER-2''' (sometimes referred to as MINERVA-II-2), developed by a consortium of universities led by [[Tohoku University]] in Japan. This was an [[octagonal prism]] shape, {{cvt|15|cm}} diameter and {{cvt|16|cm}} tall, with a mass of about {{cvt|1|kg}}. It had two cameras, a thermometer and an [[accelerometer]]. It was equipped with optical and ultraviolet [[Light-emitting diode|LEDs]] to illuminate and detect floating dust particles. ROVER-2 carried four mechanisms to move around using short hops.<ref name="nssdc">{{Cite web |date=14 May 2020 |title=Display: Hayabusa2 2014-076A |url=https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2014-076A |url-status=live |archive-url=https://web.archive.org/web/20230608224344/https://nssdc.gsfc.nasa.gov/nmc/spacecraft/display.action?id=2014-076A |archive-date=8 June 2023 |access-date=27 January 2021 |publisher=[[NASA]] |id=2014-076A }} {{PD-notice}}</ref> Rover-2 had problems prior to deployment from the orbiter but was released on 2 October 2019 to orbit the asteroid and perform gravitational measurements. It was then crashed onto the asteroid surface a few days later on 8 October 2019.

=== MASCOT ===
{{redirect|MASCOT||Mascot (disambiguation)}}
[[File:SPB MASCOT 08 HiRes-cropped.jpg|thumb|Mission overview]]
The '''Mobile Asteroid Surface Scout''' ('''MASCOT''') was developed by the [[German Aerospace Center]] (DLR) in cooperation with the French space agency [[CNES]].<ref>{{Cite web |last=Ho |first=Tra-Mi |title=MASCOT – Mobile Asteroid Surface Scout |url=http://www.dlr.de/irs/en/desktopdefault.aspx/tabid-7902/13482_read-34316 |url-status=dead |archive-url=https://web.archive.org/web/20121115020544/http://www.dlr.de/irs/en/desktopdefault.aspx/tabid-7902/13482_read-34316 |archive-date=15 November 2012 |publisher=[[German Aerospace Center]] }}</ref> Its dimensions measure {{cvt|29.5|×|27.5|×|19.5|cm}} and it weighs {{cvt|9.6|kg}}.<ref>{{Cite web |title=Hayabusa2/MASCOT at a glance – Technical specifications and mission timeline |url=https://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10977/1757_read-24573/ |url-status=dead |archive-url=https://web.archive.org/web/20180622111523/https://www.dlr.de/dlr/en/desktopdefault.aspx/tabid-10977/1757_read-24573/ |archive-date=22 June 2018 |access-date=22 June 2018 |publisher=[[German Aerospace Center]] }}</ref> MASCOT carries four instruments: an [[Infrared spectroscopy|infrared spectrometer]] (MicrOmega), a [[magnetometer]] (MASMAG), a [[radiometer]] (MARA), and a camera (MASCAM) that imaged the small-scale structure, distribution and texture of the regolith.<ref>{{Cite journal |last1=Jaumann |first1=R. |last2=Bibring |first2=J. P. |last3=Glassmeier |first3=K. H. |last4=Grott |first4=M. |last5=Ho |first5=T.-M. |last6=Ulamec |first6=S. |last7=Schmitz |first7=N. |last8=Auster |first8=H.-U. |last9=Herčik |first9=D. |last10=Biele |first10=J. |last11=Krause |first11=C. |last12=Kuninaka |first12=H. |last13=Okada |first13=T. |last14=Yoshikawa |first14=M. |last15=Watanabe |first15=S. |last16=Fujimoto |first16=M. |last17=Pilogret |first17=C. |last18=Hamm |first18=V. |last19=Koncz |first19=A. |last20=Spohn |first20=T. |year=2017 |title=A Mobile Asteroid Surface Scout (MASCOT) for the Hayabuse 2 Mision to Ryugu |url=https://meetingorganizer.copernicus.org/EPSC2017/EPSC2017-548.pdf |url-status=live |journal=EPSC Abstracts |volume=11 |id=EPSC2017-548 |archive-url=https://web.archive.org/web/20231024065057/https://meetingorganizer.copernicus.org/EPSC2017/EPSC2017-548.pdf |archive-date=24 October 2023 }}</ref> The rover is capable of tumbling once to reposition itself for further measurements.<ref name=Keane/><ref name="NASASpaceFlight.com">{{cite news|last1=Graham|first1=William|title=Japanese H-IIA kicks off Hayabusa2's asteroid mission |url=http://www.nasaspaceflight.com/2014/12/japanese-h-iia-rocket-hayabusa-2s-asteroid-mission/|access-date=4 December 2014|publisher=NASASpaceFlight.com|date=2 December 2014}}</ref> It collected data on the surface structure and mineralogical composition, the thermal behaviour and the magnetic properties of the asteroid.<ref>{{cite journal | doi=10.1007/s11214-016-0251-6 | title=MASCOT—The Mobile Asteroid Surface Scout Onboard the Hayabusa2 Mission | year=2017 | last1=Ho | first1=Tra-Mi | last2=Baturkin | first2=Volodymyr | last3=Grimm | first3=Christian | last4=Grundmann | first4=Jan Thimo | last5=Hobbie | first5=Catherin | last6=Ksenik | first6=Eugen | last7=Lange | first7=Caroline | last8=Sasaki | first8=Kaname | last9=Schlotterer | first9=Markus | last10=Talapina | first10=Maria | last11=Termtanasombat | first11=Nawarat | last12=Wejmo | first12=Elisabet | last13=Witte | first13=Lars | last14=Wrasmann | first14=Michael | last15=Wübbels | first15=Guido | last16=Rößler | first16=Johannes | last17=Ziach | first17=Christian | last18=Findlay | first18=Ross | last19=Biele | first19=Jens | last20=Krause | first20=Christian | last21=Ulamec | first21=Stephan | last22=Lange | first22=Michael | last23=Mierheim | first23=Olaf | last24=Lichtenheldt | first24=Roy | last25=Maier | first25=Maximilian | last26=Reill | first26=Josef | last27=Sedlmayr | first27=Hans-Jürgen | last28=Bousquet | first28=Pierre | last29=Bellion | first29=Anthony | last30=Bompis | first30=Olivier | journal=Space Science Reviews | volume=208 | issue=1–4 | pages=339–374 | bibcode=2017SSRv..208..339H | s2cid=255067977 | display-authors=1 }}</ref> It has a non-rechargeable battery that allowed for operations for approximately 16 hours.<ref name='Safe'/><ref name='MASCOT 17h'/> The infrared radiometer on the ''[[InSight]]'' Mars lander, launched in 2018, is based on the MASCOT radiometer.<ref>[https://sites.nationalacademies.org/cs/groups/ssbsite/documents/webpage/ssb_086912.pdf InSight: A Geophysical Mission to a Terrestrial Planet Interior], Bruce Banerdt, Jet Propulsion Laboratory, NASA, 7 March 2013 {{PD-notice}}</ref><ref>{{cite journal|title=The MASCOT Radiometer MARA for the Hayabusa 2 Mission|first1=M.|last1=Grott|first2=J.|last2=Knollenberg|first3=B. |last3=Borgs|first4=F.|last4=Hänschke|first5=E.|last5=Kessler|first6=J.|last6=Helbert|first7=A.|last7=Maturilli|first8=N.|last8=Müller|date=1 August 2016|journal=Space Science Reviews|volume=208|issue=1–4 |pages=413–431|doi=10.1007/s11214-016-0272-1|bibcode=2017SSRv..208..413G|s2cid=118245538}}</ref>

MASCOT was deployed on 3 October 2018, with a successful landing and ensuing surface mission. Two papers were published describing the results from MASCOT in the scientific journals ''[[Nature Astronomy]]''<ref>{{cite journal|last1=Yada |first1=T. |last2=Abe |first2=M. |last3=Okada|first3=T. |display-authors=etal |title=Preliminary analysis of the Hayabusa2 samples returned from C-type asteroid Ryugu |journal=Nat Astron |volume=6 |pages=214–220 |year=2022|issue=2 |doi=10.1038/s41550-021-01550-6 |s2cid=245366019 |doi-access=free }}</ref> and ''[[Science (journal)|Science]]''.<ref>{{cite journal|title=Images from the surface of asteroid Ryugu show rocks similar to carbonaceous chondrite meteorites |first1=R. |last1=Jaumann |first2=N. |last2=Schmitz |first3=T.-M. |last3=Ho |first4= S. E. |last4=SchroderÖ |first5= K. A. |last5=Otto |first6= K. |last6=Stephan |first7= S. |last7=Elgner |first8=K. |last8=Krohn |first9=F.|last9=Preusker|first10= T.|last10=Kouyam |journal=Science|date=23 August 2019 |volume=365 |number=6455 |pages=817–820 |doi=10.1126/science.aaw8627 |pmid=31439797 |bibcode=2019Sci...365..817J |s2cid=201616571 |doi-access=free }}</ref> One finding of the research was that [[C-type asteroid]]s consist of more porous material than previously thought, explaining a deficit of this [[meteorite]] type. Meteorites of this type are too porous to survive the entry into the [[atmosphere]] of planet Earth. Another finding was that [[162173 Ryugu|Ryugu]] consists of two different almost black types of rock with little internal [[Cohesion (geology)|cohesion]], but no dust was detected.<ref>{{cite web|url=https://www.dlr.de/content/en/articles/news/2019/03/20190715_mascot-confirms-what-scientists-have-long-suspected.html|title=MASCOT confirms what scientists have long suspected|website=dlr.de|access-date=2020-03-07}}</ref><ref>{{cite web|url=https://www.dlr.de/content/en/articles/news/2019/03/20190822_the-near-earth-asteroid-ryugu-a-fragile-cosmic-rubble-pile.html|title=The near-Earth asteroid Ryugu – a fragile cosmic rubble pile|website=dlr.de|access-date=2020-03-07}}</ref> A third paper describing results from MASCOT was published in the [[Journal of Geophysical Research]] and describes the [[Magnetism|magnetic]] properties of Ryugu, showing that Ryugu does not have a magnetic field on a boulder scale.<ref>{{cite journal|last1=Hercik|first1=David|last2=Auster|first2=Hans-Ulrich|last3=Constantinescu|first3=Dragos|last4=Blum|first4=Jürgen|last5=Fornaçon|first5=Karl-Heinz|last6=Fujimoto|first6=Masaki|last7=Gebauer |first7=Kathrin|last8=Grundmann|first8=Jan-Thimo|last9=Güttler|first9=Carsten|last10=Hillenmaier|first10=Olaf|last11=Ho|first11=Tra-Mi|date=2020|title=Magnetic Properties of Asteroid (162173) Ryugu |journal=Journal of Geophysical Research: Planets|volume=125|issue=1|pages=e2019JE006035|doi=10.1029/2019JE006035|bibcode=2020JGRE..12506035H|issn=2169-9100|doi-access=free|hdl=1721.1/136097.2|hdl-access=free}}</ref>
{{-}}

== Objects deployed by ''Hayabusa2'' ==
{| class="wikitable"
|-
! Object !! Developed by !! Mass !! Dimensions !! Power !! Science payload !! Landing or deployed date !! Status
|-
| MINERVA-II-1 rovers: <br/>Rover-1A (HIBOU)<br/>Rover-1B (OWL) || JAXA and [[University of Aizu]] || {{cvt|1.1|kg}} each || Diameter: {{cvt|18|cm}}<br/>Height: {{cvt|7|cm}} || [[Solar panels on spacecraft|Solar panels]] || Wide-angle camera, [[stereo camera]], thermometers || {{center|21 September 2018}} || Successful landing. Rover-1A operated for 36 days and Rover-1B operated for 3 days.<ref name="MINVERA-II results">{{cite conference|title=Operation results of MINERVA-II twin rovers onboard Hayabusa2 asteroid explorer|first1=Tetsuo|last1=Yoshimitsu|first2=Takashi|last2=Kubota|first3=Atsushi |last3=Tomiki|first4=Kent|last4=Yoshikaw|conference=70th International Astronautical Congress|date=2019-10-24|publisher=International Astronautical Federation |url=https://iafastro.directory/iac/paper/id/52276/abstract-pdf/IAC-19,A3,4A,4,x52276.brief.pdf?2019-03-28.10:24:51|access-date=2020-01-25}}</ref>
|-
| Rover-2 (MINERVA-II-2) || [[Tohoku University]] || {{cvt|1.0|kg}} || Diameter: {{cvt|15|cm}}<br/>Height: {{cvt|16|cm}} || Solar panels || Two cameras, thermometer, [[accelerometer]]. Optical and ultraviolet [[LED lamp|LEDs]] for illumination || {{center|Released: 2 October 2019, 16:38 UTC}}|| Rover failed before deployment, so it was released in orbit around the asteroid to perform gravitational measurements before it impacted a few days later.<ref>[http://www.planetary.org/blogs/jason-davis/the-downlink-station-crew-home-hb2-rover.html The Downlink: Station Crew Home, Hayabusa2 Deploys Rover], Jason Davis, ''The Planetary Society'', 4 October 2019</ref><ref>{{cite tweet|number=1179440763752480769|user=haya2e_jaxa|title=[MINERVA-II2] MINERVA-II2 is confirmed to have separated today (10/3) at 01:38 JST. The separation time was 00:57 J…|date=2 October 2019}}</ref>
|-
| MASCOT || [[German Aerospace Center]] and [[CNES]]|| {{cvt|9.6|kg}} || {{cvt|29.5|x|27.5|x|19.5|cm}} || Non-rechargeable<br/>battery<ref name='Safe'>[https://www.space.com/41903-hayabusa2-hopping-robots-asteroid-ryugu.html Are Japanese hopping robots safe on asteroid Ryugu?] Mike Wall, ''Space.com'', 21 September 2018</ref> || Camera, [[infrared spectrometer]], [[magnetometer]], [[radiometer]] || {{center|3 October 2018<ref>[https://www.space.com/42004-asteroid-ryugu-mascot-lander-first-photo.html See the First Photo of Asteroid Ryugu from the Hopping MASCOT Lander!], Tariq Malik, ''Space.com'', 3 October 2018</ref>}} || Successful landing. Operated on battery for more than 17 hours<ref name='MASCOT 17h'>{{cite tweet|number=1047806424334655488|user=MASCOT2018|title=All done with work! Oh my... can that be right? I explored Ryugu for more than 17 hours. That is more than my team…<!-- full text of tweet that Twitter returned to the bot (excluding links) added by TweetCiteBot. This may be better truncated or may need expanding (TW limits responses to 140 characters) or case changes. --> |date=4 October 2018}}</ref>
|-
| Deployable camera 3 (DCAM3) || {{center|JAXA}} || about {{cvt|2|kg}} || Diameter: {{cvt|7.8|cm}}<br/>Height: {{cvt|7.8|cm}} || Non-rechargeable battery || DCAM3-A lens, DCAM3-D lens || {{center|5 April 2019}} || Deployed to observe impact of SCI impactor. Inactive now and presumed to have fallen on the asteroid.
|-
| Small Carry-On Impactor (SCI) || {{center|JAXA}}|| {{cvt|2.5|kg}} || Diameter: {{cvt|30|cm}}<br/>Height: {{cvt|21.7|cm}} || Non-rechargeable battery || {{center|None}} || {{center|5 April 2019}} || Successful. Shot to the surface 40 minutes after separation.
|-
|Target Marker B || {{center|JAXA}}|| {{cvt|300|g}} || {{cvt|10|cm}} sphere || {{center|None}} || {{center|None}} || {{center|25 October 2018}} || Successful. Used for first touchdown.
|-
|Target Marker A || {{center|JAXA}} || {{cvt|300|g}} || {{cvt|10|cm}} sphere || {{center|None}} || {{center|None}} || {{center|30 May 2019}} || Successful. Used for second touchdown.
|-
|Target Marker E (Explorer) || {{center|JAXA}} || {{cvt|300|g}} || {{cvt|10|cm}} sphere || {{center|None}} || {{center|None}} || {{center|17 September 2019}} || Successful. Injected to equatorial orbit and confirmed to land.
|-
|Target Marker C (Sputnik/Спутник) || {{center|JAXA}} || {{cvt|300|g}} || {{cvt|10|cm}} sphere || {{center|None}} || {{center|None}} || {{center|17 September 2019}} || Successful. Injected to polar orbit and confirmed to land.
|-
|Target Marker D || {{center|JAXA}} || {{cvt|300|g}} || {{cvt|10|cm}} sphere || {{center|None}} || {{center|None}} || {{center|—}} || Was not deployed.
|-
|Sample Return Capsule || {{center|JAXA}} || 16&nbsp;kg || Diameter: 40&nbsp;cm Height: 20&nbsp;cm || Non-rechargeable battery || Sample container, Reentry flight Environment Measurement Module|| {{center|5 December 2020 UTC}} || Successful landing. All the parts including the sample container were collected.
|}

== Sampling ==
{| class="wikitable floatright"
|-
! Sampling !! Date
|-
| 1st surface sampling || 21 February 2019
|-
| Sub-surface sampling|| SCI impactor: 5 April 2019<br/>Target marker: 5 June 2019<ref name='Ryan June5'/><br/>Sampling: 11 July 2019<ref name='Kyoto July 2019'/>
|-
| 2nd surface sampling || Optional;<ref name='Press conference 5 March 2019'/> was not done.
|}

[[File:Hayabusa hover.jpg|thumb|upright=1.3|right|Artistic rendering of ''Hayabusa'' collecting a surface sample.]]

The original plan was for the spacecraft to collect up to three samples:
1) surface material that exhibits traits of hydrous minerals;
2) surface material with either unobservable or weak evidence of aqueous alterations;
3) excavated sub-surface material.<ref name='Shogo Tachibana 2013'>[https://www.wakusei.jp/book/pp/2013/2013-4/2013-4-261.pdf Bringing back a C-type asteroid sample] (in Japanese), Shogo Tachibana, JAXA, 2013</ref>

The first two surface samples were scheduled to start in late October 2018, but the rovers showed large and small boulders and insufficient surface area to sample, so the mission team decided to postpone sampling to 2019 and evaluate various options.<ref name='sampling postponed'>[http://www.hayabusa2.jaxa.jp/en/topics/20181014e_TD/ Schedule changes for the touchdown operation], JAXA, University of Tokyo and collaborators, ''Hayabusa2 Project'', 14 October 2018</ref> The first surface sampling was completed on 22 February 2019 and obtained a substantial amount of topsoil,<ref name='Press conference 5 March 2019'/><ref name='First sampling'/> so the second surface sampling was postponed and was eventually cancelled to decrease the risks to the mission.<ref name='Press conference 5 March 2019'>[http://fanfun.jaxa.jp/jaxatv/files/20190305_hayabusa2.pdf#page=7 Hayabusa2 Mission Update], JAXA Press conference on 5 March 2019, Quote/translation:<br/> • The second touchdown will be done inside or near the artificial crater created by SCI. (Final decision will be made after SCI operation whether or not to actually perform the second try.)<br/> • There is a high probability that a third touchdown will not be done.<br/> ※ Reason for choosing to give priority to experiments with collision equipment<br/> • It was judged that sample was sufficiently collected with the first touchdown.<br/> • There is a case in which the amount of light received by some of the optical systems of the bottom surface has decreased due to the first touchdown. There is no problem with normal operation, but a careful preliminary investigation is necessary for touchdown operation. Because it takes time to investigate, SCI operation was done first.</ref>

The second and final sample was collected from material that was dislodged from beneath the surface by the kinetic impactor (SCI impactor) shot from a distance of {{cvt|300|m}}.<ref>{{cite web|title=Here's an Update on Hayabusa2's Crater-Creating Explosion|url=https://www.planetary.org/articles/hayabusa2-sci-update|access-date=2020-08-24|publisher=The Planetary Society}}</ref><ref name="Mission schedule">[http://www.hayabusa2.jaxa.jp/en/news/schedule/ Hayabusa2 Mission Schedule], JAXA, Accessed 4 October 2018</ref> All samples are stored in separate sealed containers inside the [[Sample-return mission|sample return capsule]] (SRC).

=== Surface sample ===
''Hayabusa2''{{'s}} sampling device is based on ''Hayabusa''{{'s}}. The first surface sample retrieval was conducted on 21 February 2019, which began with the spacecraft's descent, approaching the surface of the asteroid. When the sampler horn attached to ''Hayabusa2''{{'s}} underside touched the surface, a {{cvt|5|g}} [[tantalum]] projectile (bullet) was fired at {{cvt|300|m/s}} into the surface.<ref name='First sampling'>[https://www.bbc.com/news/science-environment-47293317 Hayabusa-2: Japan spacecraft touches down on asteroid], Paul Rincon, ''BBC News'', 22 February 2019</ref> The resulting ejected materials were collected by a "catcher" at the top of the horn, which the ejecta reached under their own momentum under microgravity conditions.<ref name='reentry'/>

=== Sub-surface sample ===
[[File:Hayabusa2 SCI impact and subsurface sampling.gif|thumb|upright=1.25|left|Animation illustrating SCI deployment and subsequent sampling from the resulting crater.]]

The sub-surface sample collection required an impactor to create a crater in order to retrieve material under the surface, not subjected to [[space weathering]]. This required removing a large volume of surface material with a powerful impactor. For this purpose, ''Hayabusa2'' deployed on 5 April 2019 a free-flying gun with one "bullet", called the '''Small Carry-on Impactor''' ('''SCI'''); the system contained a {{cvt|2.5|kg}} [[copper]] projectile, shot onto the surface with an explosive propellant charge. Following SCI deployment, ''Hayabusa2'' also left behind a deployable camera ('''DCAM3''')<ref group="Note">DCAM3 is numbered as such because it is a follow-on to the DCAM1 and DCAM2 used for the [[IKAROS]] interplanetary solar sail</ref> to observe and map the precise location of the SCI impact, while the orbiter maneuvered to the far side of the asteroid to avoid being hit by debris from the impact.

It was expected that the SCI deployment would induce seismic shaking of the asteroid, a process considered important in the resurfacing of small airless bodies. However, post-impact images from the spacecraft revealed that little shaking had occurred, indicating the asteroid was significantly less cohesive than was expected.<ref>{{Cite journal|last1=Nishiyama|first1=G.|last2=Kawamura|first2=T.|last3=Namiki|first3=N.|last4=Fernando|first4=B.|last5=Leng|first5=K.|last6=Onodera|first6=K.|last7=Sugita|first7=S.|last8=Saiki|first8=T.|last9=Imamura|first9=H.|last10=Takagi|first10=Y.|last11=Yano|first11=H.|title=Simulation of Seismic Wave Propagation on Asteroid Ryugu Induced by The Impact Experiment of The Hayabusa2 Mission: Limited Mass Transport by Low Yield Strength of Porous Regolith|url=https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2020JE006594|journal=Journal of Geophysical Research: Planets|year=2021|volume=126|issue=2|language=en|pages=e2020JE006594|doi=10.1029/2020JE006594|bibcode=2021JGRE..12606594N|s2cid=230574308 |issn=2169-9100}}</ref>

[[File:Movie before and after touchdown on Ryugu taken with Hayabusa2's small monitor camera (CAM-H).webm|thumb|The touchdown on and sampling of Ryugu on 11 July]]
Approximately 40 minutes after separation, when the spacecraft was at a safe distance, the impactor was fired into the asteroid surface by detonating a {{cvt|4.5|kg}} [[shaped charge]] of plasticized [[HMX]] for acceleration.<ref name="NASASpaceFlight.com"/><ref>{{cite journal|doi=10.1016/j.actaastro.2012.11.010|bibcode=2013AcAau..84..227S|title=Small carry-on impactor of Hayabusa2 mission|year=2013
|last1=Saiki|first1=Takanao|last2=Sawada|first2=Hirotaka|last3=Okamoto|first3=Chisato|last4=Yano|first4=Hajime|last5=Takagi|first5=Yasuhiko|last6=Akahoshi|first6=Yasuhiro|last7=Yoshikawa|first7=Makoto
|journal=Acta Astronautica|volume=84|pages=227–236}}</ref> The copper impactor was shot onto the surface from an altitude of about {{cvt|500|m}} and it excavated a crater of about {{cvt|10|m}} in diameter, exposing pristine material.<ref name='Tsuda 2013'/><ref name=Marker>[https://gizmodo.com/new-photos-show-the-surprisingly-big-crater-blasted-int-1834298147 New Photos Show the Surprisingly Big Crater Blasted Into Asteroid Ryugu by Japan's Hayabusa2 Probe], George Dvorsky, ''Gizmodo'', 22 May 2019</ref> The next step was the deployment on 4 June 2019 of a reflective target marker in the area near the crater to assist with navigation and descent.<ref name='Ryan June5'/> The touchdown and sampling took place on 11 July 2019.<ref name='Kyoto July 2019'/>

== Sample return ==
[[File:Replica of Hayabusa capsule at JAXA i.jpg|thumb|upright=1.3|right|Replica of ''Hayabusa''{{'s}} sample-return capsule (SRC) used for re-entry. ''Hayabusa2''{{'s}} capsule is of the same size, measuring {{cvt|40|cm}} in diameter and using a parachute for touchdown.]]

The spacecraft collected and stored the samples in separate sealed containers inside the sample-return capsule (SRC), which is equipped with [[thermal insulation]]. The container is {{cvt|40|cm}} external diameter, {{cvt|20|cm}} in height, and a mass of about {{cvt|16|kg}}.<ref name='Fact Sheet Hayabusa2'/>

At the end of the science phase in November 2019,<ref name='Departure'/> ''Hayabusa2'' used its ion engines to change orbit and return to Earth.<ref name='reentry'>[http://global.jaxa.jp/projects/sat/hayabusa2/instruments.html Major onboard instruments – Re-entry Capsule], Accessed: 2 September 2018</ref> Hours before ''Hayabusa2'' flew past Earth in late 2020, it released the capsule, on 5 December 2020 at 05:30 UTC.<ref>{{cite news|date=December 5, 2020|title=はやぶさ2、カプセル分離に成功 6日未明に着地へ|url=https://www.nikkei.com/article/DGXMZO67050290V01C20A2I00000 |language=ja|newspaper=The Nikkei|access-date=2020-12-05}}</ref> The capsule was released spinning at one revolution per three seconds, and re-entered the Earth's atmosphere at {{cvt|12|km/s}}. Deploying a radar-reflective parachute at an altitude of about {{cvt|10|km}}, it ejected its heat shield while transmitting a position beacon signal.<ref name='Fact Sheet Hayabusa2'/><ref name='reentry'/> The sample capsule landed at the [[RAAF Woomera Range Complex|Woomera Test Range]] in Australia.<ref name="BBC-20201206"/><ref>[http://www.planetary.org/blogs/jason-davis/why-sample-return.html What's the benefit of sample-return?], Jason Davis, ''The Planetary Society'', 5 July 2018</ref> The total flight distance was {{cvt|5.24|e9km}}.<ref name='Fact Sheet Hayabusa2'/>

Any volatile substances will be collected before the sealed containers are opened.<ref name='Shogo Tachibana 2013'/> The samples will be curated and analyzed at JAXA's [[Extraterrestrial Sample Curation Center]],<ref>[https://curation.isas.jaxa.jp/ Extraterrestrial Sample Curation Center]</ref> where international scientists can request a small portion of the samples. The spacecraft brought back a capsule containing carbon-rich [[asteroid]] fragments that scientists believe could provide clues about the ancient delivery of water and organic molecules to Earth.<ref>{{cite web|last=Normile|first=Dennis|date=2020-12-07|title=Japan's Hayabusa2 capsule lands with carbon-rich asteroid samples|url=https://www.science.org/content/article/japan-s-hayabusa2-capsule-lands-carbon-rich-asteroid-samples|access-date=2020-12-09 |website=Science {{!}} AAAS}}</ref><ref>{{cite web|title=Japan's Hayabusa2 spacecraft brings pieces of asteroid back to earth|url=https://newsasiatoday.com/japans-hayabusa2-spacecraft-brings-pieces-of-asteroid-back-to-earth/|access-date=2020-12-09|website=News Asia Today|date=7 December 2020 }}</ref>

[[File:Jsc2021e062389.jpg|thumb|One of the facility-to-facility transfer containers (FFTC) of Hayabusa2 returned samples given to NASA by JAXA.]]
JAXA is sharing a portion of these samples with NASA. In exchange, NASA will provide JAXA a percentage of a sample of asteroid Bennu, when the agency's OSIRIS-REx spacecraft returned to Earth from the space rock on 24 September 2023.<ref>{{cite news |first1=Dante |last1=Lauretta |date=20 October 2014 |title=Collaboration between OSIRIS-REx and Hayabusa2 |publisher=The Planetary Society |url=https://www.planetary.org/blogs/guest-blogs/dante-lauretta/20141020-collaboration-between.html |access-date=12 February 2020 |archive-date=13 February 2020 |archive-url=https://web.archive.org/web/20200213071311/https://www.planetary.org/blogs/guest-blogs/dante-lauretta/20141020-collaboration-between.html |url-status=live }}</ref>

A November 2024 study published in [[Meteoritics & Planetary Science]] examined a sample returned from the asteroid Ryugu by the Hayabusa2 mission. Despite stringent contamination control measures, terrestrial microorganisms rapidly colonized the sample. Researchers concluded that the observed microbial growth originated from Earthly contamination during sample preparation rather than being indigenous to the asteroid. This finding underscores the difficulty of preventing microbial contamination, even in highly controlled laboratory environments.<ref>{{cite web | title=Ryugu asteroid sample rapidly colonized by terrestrial life despite strict contamination control | website=Phys.org | date=2024-11-22 | url=https://phys.org/news/2024-11-ryugu-asteroid-sample-rapidly-colonized.html | access-date=2024-12-01}}</ref><ref>{{cite web|url=https://www.scientificamerican.com/article/earth-life-found-inside-ryugu-asteroid-samples/|date=2024-12-19|access-date=2024-12-30|title=Scientists Discover Earth Life inside an Asteroid Sample|first=Sharmila|last=Kuthunur|work=Scientific American}}</ref>{{undue weight inline|Sample contamination|date=January 2025}}

== Mission extension (Hayabusa2♯) ==
[[File:Animation of Hayabusa2 orbit - extended mission.webm|thumb|right|Animation of Hayabusa2 orbit – extended mission<br>{{legend2|magenta|''Hayabusa2''}}{{·}}{{legend2|lime|[[162173 Ryugu]]}}{{·}}{{legend2|Royalblue|[[Earth]]}}{{·}}{{legend2|yellow|[[Sun]]}}{{·}}{{legend2|cyan|[[98943 Torifune]]}}{{·}}{{legend2|gold|[[1998 KY26]]}}]]
With the successful return and retrieval of the sample capsule on 6 December 2020 ([[Japan Standard Time|JST]]), Hayabusa2 is planned to use its remaining {{cvt|30|kg}} of [[xenon]] propellant (from the initial {{cvt|66|kg}}) to extend its service life and fly out to explore new targets.<ref name='Mission extension'>{{cite journal|title=Hayabusa2 extension plan: Asteroid selection and trajectory design|journal=Acta Astronautica|volume=138|pages=225–232|doi=10.1016/j.actaastro.2017.05.016|year=2017|last1=Sarli|first1=Bruno Victorino|last2=Tsuda|first2=Yuichi|bibcode=2017AcAau.138..225S}}</ref> As of September 2020, a fly-by of [[98943 Torifune]] in July 2026 and a rendezvous with {{mpl|1998 KY|26}} in July 2031 were selected for the mission extension.<ref name="Yomiuri20200913">{{cite news|date=September 13, 2020|title=はやぶさ２、次のミッションは小惑星「１９９８ＫＹ２６」...ＪＡＸＡ|url=https://www.yomiuri.co.jp/science/20200913-OYT1T50040/|language=ja|newspaper=The Yomiuri Shimbun|access-date=2020-09-14|archive-date=5 December 2020|archive-url=https://web.archive.org/web/20201205174454/https://www.yomiuri.co.jp/science/20200913-OYT1T50040/|url-status=dead}}</ref><ref name="Mainichi20200915">{{cite news|date=September 15, 2020|title=Japan's Hayabusa2 aims to probe asteroid '1998KY26' in 2031|url=https://mainichi.jp/english/articles/20200915/p2g/00m/0fe/092000c|newspaper=The Mainichi Newspapers|access-date=2020-09-15|archive-date=15 September 2020|archive-url=https://web.archive.org/web/20200915090218/https://mainichi.jp/english/articles/20200915/p2g/00m/0fe/092000c|url-status=dead}}</ref><ref name="Haya220200915">{{Cite web|title=Hayabusa 2 Press conference materials |date=15 September 2020 |publisher=JAXA |url=http://www.hayabusa2.jaxa.jp/enjoy/material/press/Hayabusa2_Press_20200915_ver9_en2.pdf}}</ref> The observation of Torifune will be a high-speed fly-by of an [[S-type asteroid]].<ref>{{cite news |last=Wall |first=Mike |title=Japanese space capsule carrying pristine asteroid samples lands in Australia |url=https://www.space.com/japan-hayabusa2-asteroid-samples-land-australia |access-date=2020-12-11 |date=5 December 2020 |work=[[Space.com]] |archive-url=https://web.archive.org/web/20230925103858/https://www.space.com/japan-hayabusa2-asteroid-samples-land-australia |archive-date=25 September 2023 |url-status=live }}</ref> The fixed camera of ''Hayabusa2'' was not designed for this type of fly-by. The rendezvous with {{mp|1998 KY|26}} will be the first visit of a fast rotating micro-asteroid, with a rotation period of about 10 minutes.<ref name="Haya220200915"/> Between 2021 and 2026, the spacecraft will also conduct [[astronomical transit|transit]] observations of [[exoplanet]]s.<ref name="Haya220200915"/> An option to conduct a [[Venus]] flyby to set up an encounter with {{mpl|2001 AV|43}} was also studied.<ref>{{cite web|url=https://www.jiji.com/jc/article?k=2020010900196|title=はやぶさ２、再び小惑星へ 地球帰還後も任務継続―対象天体を選定へ・ＪＡＸＡ|trans-title=Hayabusa2 will explore another asteroid, continuing mission after returning target sample to Earth|agency=Jiji Press|date=9 January 2020|access-date=9 January 2020|language=ja|archive-date=24 May 2020|archive-url=https://web.archive.org/web/20200524100408/https://www.jiji.com/jc/article?k=2020010900196|url-status=dead}}</ref><ref name="space-20200812">{{cite web|last=Bartels|first=Meghan|url=https://www.space.com/japan-hayabusa2-asteroid-mission-eyes-second-target.html|title=Japan may extend Hayabusa2 asteroid mission to visit 2nd space rock|publisher=Space.com|date=12 August 2020|access-date=13 August 2020}}</ref>

Selected EAEEA (Earth → Asteroid → Earth → Earth → Asteroid) scenario:<ref name="Haya220200915"/>
* December 2020: Extension mission start
* 2021 until July 2026: cruise operation
* July 2026: S-type asteroid [[98943 Torifune]] high-speed fly-by
* December 2027: Earth swing-by
* June 2028: Second Earth swing-by
* July 2031: Target body ({{mpl|1998 KY|26}}) rendezvous

The nickname of the extended mission is '''“Hayabusa2♯”''' (read '''“Hayabusa2 Sharp”'''). The character '''“♯” ''' is a musical symbol which raises an adjacent note by a semitone. It is also an acronym for “Small Hazardous Asteroid Reconnaissance Probe,” as the mission is set to investigate potentially dangerous small asteroids that may collide with the Earth in the future. The word “sharp” also highlights the challenging nature of the mission, which is reflected in the musical meaning of raising the note by a semitone, suggesting a raised rank of the mission.<ref>{{Cite conference |last1=Hirabayashi |first1=Masatoshi |last2=Yoshikawa |first2=Makoto |last3=Mimasu |first3=Yuya |last4=Tanaka |first4=Satoshi |last5=Saiki |first5=Takanao |last6=Nakazawa |first6=Satoru |last7=Tsuda |first7=Yuichi |last8=Tatsumi |first8=Eri |last9=Popescu |first9=Marcel |last10=Pravec |first10=Petr |last11=Urakawa |first11=Seitaro |last12=Yoshida |first12=Fumi |last13=Hirata |first13=Naru |last14=Kamata |first14=Shunichi |last15=Kitazato |first15=Kohei |date=2023-02-15 |title=Hayabusa2#'s Exploration to Asteroids 2001 CC21 and 1998 KY26 Provides Key Insights Into Planetary Defense |url=https://ntrs.nasa.gov/citations/20230002153 |conference=8th IAA Planetary Defense Conference |location=Vienna, Austria |archive-url=https://web.archive.org/web/20240123201919/https://ntrs.nasa.gov/citations/20230002153 |archive-date=23 January 2024 |url-status=live }}</ref><ref>{{Cite web |title=2022/06/29 What's new |url=http://www.hayabusa2.jaxa.jp/en/topics/20220629_logo_e/index.html/ |access-date=2023-09-24 |website=JAXA Hayabusa2 porject |language=ja}}</ref>

== See also ==
{{Portal|Spaceflight}}
* [[Abiogenesis]]
* {{annotated link|Hayabusa Mk2}}
* [[OSIRIS-REx]] – NASA asteroid sample return mission to [[101955 Bennu]] (operational at the same time as ''Hayabusa2'')
* [[Panspermia]]

=== Japanese minor body probes ===
* {{annotated link|Hiten (spacecraft)}}
* {{annotated link|Martian Moons Exploration}}
* {{annotated link|OKEANOS}}
* [[Suisei (spacecraft)|''Suisei'']] spacecraft

== Notes ==
{{Reflist|group=Note}}

== References ==
{{Reflist}}

== External links ==
{{Commons category|Hayabusa2}}
* [http://www.hayabusa2.jaxa.jp/en/ ''Hayabusa2'' project website]
* [https://global.jaxa.jp/projects/sas/hayabusa2/ JAXA ''Hayabusa2'' website]
* [http://www.darts.isas.jaxa.jp/planet/project/hayabusa2/ ''Hayabusa2'' Science Data Archives] hosted by the DARTS archive (ISAS)
* [http://europlanet.dlr.de/Hayabusa2/MASCOT/index.html MASCOT related publications by the Institute of Planetary Research] {{Webarchive|url=https://web.archive.org/web/20201130081901/http://europlanet.dlr.de/Hayabusa2/MASCOT/index.html |date=30 November 2020 }} hosted by Europlanet
* [http://pub.haya2.sys.t.u-tokyo.ac.jp/ ''Hayabusa2'' images scientific commentary] {{Webarchive|url=https://web.archive.org/web/20201028191844/http://pub.haya2.sys.t.u-tokyo.ac.jp/ |date=28 October 2020 }}, University of Tokyo
* [https://jpn.nec.com/ad/cosmos/hayabusa2/index.html Asteroid Explorer ''Hayabusa2''], NEC
* [http://www.asahi.com/special/rocket/hayabusa2_3d/ ''Hayabusa2'' 3D model], Asahi Shinbun

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{{Exoplanet search projects}}
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{{2021 in space}}

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[[Category:Sample return missions]]
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