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{{Short description|Japanese probe to asteroid and sample return (2003–2010)}}
{{Other uses}}
{{Use dmy dates|date=May 2020}}
{{Italic title}}
{{Infobox spaceflight
| name                  = ''Hayabusa''
| names_list            = Muses-C (before launch)<!--list of previous names if the spacecraft has been renamed. 
Include the dates applicable if possible, and separate each name with a linebreak. 
Omit if the spacecraft has only ever been known by one name. 
Do not include Harvard, COSPAR/NSSDC or SATCAT/NORAD/NASA designations as alternative names-->

<!--image of the spacecraft/mission-->
| image                 = [[File:Hayabusa hover.jpg|300px]]
| image_caption         = An artist's rendering of ''Hayabusa'' above Itokawa's surface
| image_alt             = <!--image alt text-->
| image_size            = <!--include px/em; defaults to 220px-->

<!--Basic details-->
| mission_type          = [[sample return]]
| operator              = [[JAXA]]
| Harvard_designation   = <!--spacecraft launched 1962 and earlier only (e.g. 1957 Alpha 2)-->
| COSPAR_ID             = 2003-019A
| SATCAT                = 27809
| website               = <!--Homepage of the craft/mission, OFFICIAL PAGES ONLY-->
| mission_duration      = {{age in years, months and days|2003|05|09|2010|06|13}}
| distance_travelled    = <!--How far the spacecraft travelled (if known)-->
| orbits_completed      = <!--number of times the spacecraft orbited the Earth - see below for spacecraft beyond Earth orbit-->
| suborbital_range      = <!--downrange distance reached if spacecraft did not enter orbit-->
| suborbital_apogee     = <!--altitude reached if spacecraft did not enter orbit-->

<!--Spacecraft properties-->
| manufacturer          = <!--company or companies who built the satellite-->
| launch_mass           =510 kg<ref>{{cite web|url=https://solarsystem.nasa.gov/missions/hayabusa/in-depth/ |title=Hayabusa |publisher=NASA's Solar System Exploration website |access-date=November 30, 2022}}</ref>
| dry_mass              = {{convert|380|kg|abbr=on}}
| payload_mass          = <!--Mass of instrumentation-->
| dimensions            = 
| power                 = <!--in watts-->

<!--Launch details-->
| launch_date           = {{start date|2003|05|09|04|29|25|7=Z|df=y}}
| launch_rocket         = [[M-V]]
| launch_site           = [[Uchinoura Space Center]]
| launch_contractor     = <!--organisation(s) that conducted the launch (e.g. United Launch Alliance, Arianespace, etc)-->

<!--end of mission-->
| disposal_type         = '''sample return capsule''': recovered<br>'''spacecraft''': ballistic reentry<br>'''Minerva and rover''': lost contact
| last_contact          = '''Minerva''': 12 November 2005
| recovery_by           = <!--recovered by-->
| recovery_date         = '''sample capsule''': 07:08, 14 June 2010
| decay_date            = '''spacecraft''': 13 June 2010
| landing_date          = '''sample capsule''': {{end date|2010|06|13|df=y}} 14:12 UT<ref>{{Cite web|url=https://www.nasa.gov/connect/ebooks/beyond_earth_detail.html|title=Beyond Earth: A Chronicle of Deep Space Exploration|date=20 September 2018}}</ref>
| landing_site          = near [[Woomera, Australia]]

|interplanetary         =  {{Infobox spaceflight/IP
   |type                = flyby
   |object              = [[Earth]]
   |arrival_date        = 06:23, 19 May 2004
   |departure_date      = <!--Date of leaving orbit for orbiters-->
   |distance            = {{convert|3725|km|abbr=on}}
 }}

 {{Infobox spaceflight/IP
   |type                = rendezvous
   |object              = {{ats|25143|Itokawa}}
   |arrival_date        = 12 September 2005, 1:17 UTC<ref name="arrival" />
   |departure_date      = December 2005
 }}

 {{Infobox spaceflight/IP
   |type                = lander
   |object              = {{ats|25143|Itokawa}}
   |orbits              = <!--number of orbits completed at target body (if applicable and known)-->
   |component           = <!--part of the spacecraft involved, if spacecraft split into multiple components-->
   |arrival_date        = 19 November 2005, 21:30 UTC
   |departure_date      = 19 November 2005, 21:58 UTC
   |location            = <!--landing/impact site, including EOM impacts for atmospheric probes and lunar/asteroid orbiters-->
   |distance            = <!--closest approach distance for flybys, distance travelled on surface for rovers, omit for others-->
 }}

 {{Infobox spaceflight/IP
   |type                = lander
   |object              = {{ats|25143|Itokawa}}
   |orbits              = <!--number of orbits completed at target body (if applicable and known)-->
   |component           = <!--part of the spacecraft involved, if spacecraft split into multiple components-->
   |arrival_date        = 25 November 2005
   |departure_date      = <!--Date of leaving orbit for orbiters, date of launch for landers which took off again-->
   |location            = <!--landing/impact site, including EOM impacts for atmospheric probes and lunar/asteroid orbiters-->
   |distance            = <!--closest approach distance for flybys, distance travelled on surface for rovers, omit for others-->
   |sample_mass         = <1g
 }}

<!--transponder parameters-->
| trans_band            = <!--Transponder frequency bands-->
| trans_frequency       = <!--specific frequencies-->
| trans_bandwidth       = <!--bandwidth-->
| trans_capacity        = <!--capacity of the transponders-->
| trans_coverage        = <!--area covered-->
| trans_TWTA            = <!--TWTA output power-->
| trans_EIRP            = <!--equivalent isotropic power-->
| trans_HPBW            = <!--half-power beam width-->

<!--Only use where a spacecraft/mission is part of a clear programme of sequential missions. 
If in doubt, leave it out-->
| programme             = 
| previous_mission      =
| next_mission          =

<!--mission insignia or patch-->
| insignia              = <!--omit the "file" prefix-->
| insignia_caption      = <!--image caption-->
| insignia_alt          = <!--image alt text-->
| insignia_size         = <!--include px/em; defaults to 180px-->

|instruments_list=
 {{Infobox spaceflight/Instruments
  |acronym1=AMICA
  |acronym2=LIDAR
  |acronym3=NIRS
  |acronym4=XRS
  |name1=Asteroid Multiband Imaging Camera
  |name2=[[LIDAR|Light Detection and Ranging Instrument]]
  |name3=[[Near-infrared spectroscopy|Near-Infrared Spectrometer]]
  |name4=[[X-ray spectroscopy|X-Ray Fluorescence Spectrometer]]
 }}
}}

{{nihongo|'''''Hayabusa'''''|はやぶさ|extra="[[Peregrine falcon]]"|lead=yes}} was a [[robotic spacecraft]] developed by the [[Japan Aerospace Exploration Agency]] (JAXA) to [[Sample return mission|return a sample of material]] from a small [[near-Earth asteroid]] named [[25143 Itokawa]] to [[Earth]] for further analysis.
''Hayabusa'', formerly known as '''MUSES-C''' for '''Mu Space Engineering Spacecraft C''', was launched on 9 May 2003 and [[Space rendezvous|rendezvoused]] with Itokawa in mid-September 2005. After arriving at Itokawa, ''Hayabusa'' studied the asteroid's shape, spin, topography, color, composition, density, and history. In November 2005, it landed on the asteroid and collected samples in the form of tiny grains of asteroidal material, which were returned to Earth aboard the spacecraft on 13 June 2010.

The spacecraft also carried a detachable minilander, ''[[MINERVA (spacecraft)|MINERVA]]'', which failed to reach the surface.

== Mission firsts ==
[[File:D. Moura and J. Kawaguchi IAC 2010.jpg|thumb|Denis J. P. Moura (left) and Junichiro Kawaguchi (right) at the 2010 [[International Astronautical Congress]] (IAC)]]
[[NASA]]'s ''[[Galileo (spacecraft)|Galileo]]'' and ''[[NEAR Shoemaker]]'' spacecraft had visited asteroids before, but the ''Hayabusa'' mission was the first one to return an asteroid sample to [[Earth]] for analysis.<ref>{{cite news |url=https://www.bbc.co.uk/news/10307048 |title=Hayabusa asteroid-sample capsule recovered in Outback |date=14 June 2010 |access-date=15 May 2011 |work=[[BBC News]] |first=Jonathan |last=Amos}}</ref>

''Hayabusa'' was the first spacecraft designed to deliberately land on an asteroid and then take off again (''NEAR Shoemaker'' made a controlled descent to the surface of [[433 Eros]] in 2000, but it was not designed as a lander and was eventually deactivated after it arrived). Technically, ''Hayabusa'' was not designed to "land"; it simply touches the surface with its sample capturing device and then moves away. However, it was the first craft designed from the outset to make physical contact with the surface of an asteroid. Junichiro Kawaguchi of the [[Institute of Space and Astronautical Science]] was appointed to be the leader of the mission.<ref>{{cite web|url=http://www.astrobio.net/pressrelease/458/two-way-asteroid-trip-takes-off|title=Two-Way Asteroid Trip Takes Off|work=Astrobiology Magazine|publisher=[[NASA]]|date=12 May 2003|access-date=16 November 2010 |archive-url=https://web.archive.org/web/20210225062543/https://www.astrobio.net/meteoritescomets-and-asteroids/two-way-asteroid-trip-takes-off/ |archive-date=2021-02-25 |url-status=usurped}}</ref>

Despite its designer's intention for momentary contact, ''Hayabusa'' landed and sat on the asteroid surface for about 30 minutes (see [[#In proximity of Itokawa|below]]).

== Mission profile ==
{{more citations needed|section|date=June 2017}}
The ''Hayabusa'' spacecraft was launched on 9 May 2003 at 04:29:25 UTC on an [[M-V]] rocket from the [[Uchinoura Space Center]] (still called [[Kagoshima Space Center]] at that time). Following launch, the spacecraft's name was changed from the original MUSES-C to ''Hayabusa'', the Japanese word for [[falcon]]. The spacecraft's xenon [[ion engine]]s (four separate units), operating near-continuously for two years, slowly moved ''Hayabusa'' toward a September 2005 rendezvous with Itokawa. As it arrived, the spacecraft did not go into orbit around the asteroid, but remained in a station-keeping [[heliocentric orbit]] close by.

[[File:Hayabusa IAC 2010.jpg|thumb|left|The half-scale model of ''Hayabusa'' at the IAC in 2010]]
''Hayabusa'' surveyed the asteroid surface from a distance of about {{convert|20|km|mi|abbr=on}}, the "gate position". After this the spacecraft moved closer to the surface (the "home position"), and then approached the asteroid for a series of soft landings and for the collection of samples at a safe site. [[Autonomous robot|Autonomous]] optical navigation was employed extensively during this period because the long communication delay prohibits Earth-based real-time commanding. At the instant ''Hayabusa'' touched down with its deployable collection horn, the spacecraft was programmed to fire tiny projectiles at the surface and then collect the resulting spray. Some tiny specks were collected by the spacecraft for return to Earth and analysis.

After a few months in proximity to the asteroid, the spacecraft was scheduled to fire its engines to begin its cruise back to Earth. This maneuver was delayed due to problems with [[Spacecraft attitude control|attitude control]] (orientation) and the thrusters of the craft. Once it was on its return trajectory, the re-entry capsule was released from the main spacecraft three hours before reentry<!-- at a distance of about 300,000 to 400,000&nbsp;km (186,411 to 248,548 mi) from the Earth -->, and the capsule coasted on a ballistic trajectory, re-entering the Earth's atmosphere at 13:51, 13 June 2010 UTC.  It is estimated that the capsule experienced peak deceleration of about 25 G and heating rates approximately 30 times those experienced by the [[Apollo spacecraft]]. It landed via parachute near [[Woomera, South Australia|Woomera]], Australia.

In relation to the mission profile, JAXA defined the following success criteria and corresponding scores for major milestones in the mission prior to the launch of the ''Hayabusa'' spacecraft.<ref>{{cite web | url = http://www.isas.jaxa.jp/e/enterp/missions/hayabusa/today.shtml | title = Hot Information HAYABUSA: Resumption of return cruise by combining two ion engines | publisher = JAXA | date = 24 November 2009 | access-date = 27 November 2009 | url-status = dead | archive-url = https://web.archive.org/web/20140413142848/http://www.jaxa.jp/pr/jaxas/pdf/jaxatoday002_p.pdf | archive-date = 13 April 2014 }}</ref> As it shows, the ''Hayabusa'' spacecraft is a platform for testing new technology and the primary objective of the ''Hayabusa'' project is the world's first implementation of microwave discharge [[ion engine]]s. Hence 'operation of ion engines for more than 1000 hours' is an achievement that gives a full score of 100 points, and the rest of the milestones are a series of world's first-time experiments built on it.

[[File:Replica of Hayabusa capsule at JAXA i.jpg|thumb|right|The replica of the re-entry capsule exhibited at JAXAi (closed on 28 December 2010)]]
{| class="wikitable"
|-
! Success criteria for ''Hayabusa''
! Points
! Status
|-
| Operation of ion engines
| 50 points
| Success
|-
| Operation of ion engines for more than 1000 hours
| 100 points
| Success
|-
| Earth gravity assist with ion engines
| 150 points
| Success
|-
| Rendezvous with Itokawa with autonomous navigation
| 200 points
| Success
|-
| Scientific observation of Itokawa
| 250 points
| Success
|-
| Touch-down and sample collection
| 275 points
| Success
|-
| Capsule recovered
| 400 points
| Success
|-
| Sample obtained for analysis
| 500 points
| Success
|}

== MINERVA mini-lander ==
{{Main|MINERVA (spacecraft)}}

''Hayabusa'' carried a tiny mini-[[Lander (spacecraft)|lander]] (weighing only {{convert|591|g|abbr=on}}, and approximately {{convert|10|cm|abbr=on}} tall by {{convert|12|cm|abbr=on}} in diameter) named "''MINERVA''" (short for ''MI''cro-''N''ano ''E''xperimental ''R''obot ''V''ehicle for the ''A''steroid). An error during deployment resulted in the craft's failure.

This solar-powered vehicle was designed to take advantage of Itokawa's very low gravity by using an internal flywheel assembly to hop across the surface of the asteroid, relaying images from its cameras to ''Hayabusa'' whenever the two spacecraft were in sight of one another.<ref>{{cite journal|last=T. Yoshimitsu|author2=S. Sasaki |author3=M. Yanagisawa |author4=T. Kubota |date=2004|title=Scientific capability of Minerva rover in Hayabusa asteroid mission|journal=Lunar and Planetary Science|volume=35|pages=1517–1518|url=http://www.lpi.usra.edu/meetings/lpsc2004/pdf/1517.pdf}}</ref>

MINERVA was deployed on 12 November 2005. The lander release command was sent from Earth, but before the command could arrive, ''Hayabusa''<nowiki>'</nowiki>s altimeter measured its distance from Itokawa to be {{convert|44|m|abbr=on}} and thus started an automatic altitude keeping sequence. As a result, when the MINERVA release command arrived, MINERVA was released while the probe was ascending and at a higher altitude than intended, so that it escaped Itokawa's gravitational pull and tumbled into space.<ref>{{cite news|url=http://www.nbcnews.com/id/10013920|archive-url=https://web.archive.org/web/20140813071839/http://www.nbcnews.com/id/10013920/|url-status=dead|archive-date=13 August 2014|title=Asteroid-hopping robot misses its mark|last=Oberg|first=James|date=14 November 2005|publisher=NBC News|access-date=7 March 2009}}</ref><ref>
{{cite web |url=http://www.isas.jaxa.jp/j/snews/2005/1113.shtml |title=分離後の「ミネルバ」が「はやぶさ」を撮影 |date=13 November 2005 |publisher=JAXA |access-date=16 April 2009}}</ref>

Had it been successful, MINERVA would have been the first hopping space rover. The Soviet mission ''[[Phobos 2]]'' also encountered a malfunction while attempting to deploy a hopping rover.

== Scientific and engineering importance of the mission ==
Scientists' understanding of asteroids depends greatly on meteorite samples, but it is very difficult to match up meteorite samples with the exact asteroids from which they came. ''Hayabusa'' helped solve this problem by bringing back pristine samples from a specific, well-characterized asteroid. ''Hayabusa'' bridged the gap between ground observation data of asteroids and laboratory analysis of meteorite and [[cosmic dust]] collections.<ref>"Japan's asteroid archaeologist", [[Sky and Telescope]], June 2005, pp. 34–37</ref> Also comparing the data from the onboard instruments of the ''Hayabusa'' with the data from the [[NEAR Shoemaker|''NEAR Shoemaker'' mission]] will put the knowledge on a wider level.{{Citation needed|date=July 2015}}

The ''Hayabusa'' mission has a very deep engineering importance for JAXA, too. It allowed JAXA to further test its technologies in the fields of [[ion engine]]s, autonomous and optical navigation, deep space communication, and close movement on objects with low gravity among others. Second, since it was the first-ever preplanned soft contact with the surface of an asteroid (the ''NEAR Shoemaker'' landing on 433 Eros was not preplanned) it has enormous influence on further asteroid missions.{{Citation needed|date=January 2014}}

== Changes in mission plan ==
The ''Hayabusa'' mission profile was modified several times, both before and after launch.
* The spacecraft was originally intended to launch in July 2002 to the asteroid [[4660 Nereus]] (the asteroid [[(10302) 1989 ML]] was considered as an alternative target). However, a July 2000 failure of Japan's [[M-5 rocket]] forced a delay in the launch, putting both Nereus and 1989 ML out of reach. As a result, the target asteroid was changed to [[25143 Itokawa|{{mp|1998 SF|36}}]], which was soon thereafter named for Japanese rocket pioneer [[Hideo Itokawa]].<ref>{{cite web|url=http://www.planetary.org/news/2004/0520_Japans_Hayabusa_MUSESC_Swings_By.html |title=Japan's Hayabusa [MUSES-C&#93; Swings By Earth on Way to Asteroid Itokawa – Planetary News &#124; The Planetary Society |publisher=Planetary.org |date=20 May 2004 |access-date=14 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20101128123442/http://planetary.org/news/2004/0520_Japans_Hayabusa_MUSESC_Swings_By.html |archive-date=28 November 2010 }}</ref>
* ''Hayabusa'' was to deploy a small rover supplied by [[NASA]] and developed by [[JPL]], called Muses-CN, onto the surface of the asteroid, but the rover was canceled by NASA in November 2000 due to budget constraints.
* In 2002, launch was postponed from December 2002 to May 2003 to recheck the [[O-ring]]s of its [[reaction control system]] since one of them had been found to be using a different material than specified.<ref name="isasnews20020925">{{cite journal |url=http://www.isas.jaxa.jp/ISASnews/No.259/isas.html#muses-c |title=MUSES-C 打ち上げ延期 |author=Kuninori Uesugi |publisher=ISAS |date=October 2010 |issue=259 |journal=ISAS News |access-date=14 June 2010}}</ref>
* In 2003, while ''Hayabusa'' was en route to Itokawa, the largest [[solar flare]] recorded in history<ref>[http://www.planetary.org/blogs/emily-lakdawalla/2018/0219-10-times-sample-collection.html Ten times the solar system reminded us sample collection is hard]. Emily Lakdawalla, ''The Planetary Society''. 24 February 2018.</ref> damaged the [[solar cell]]s aboard the spacecraft. This reduction in electrical power reduced the efficiency of the ion engines, thus delaying the arrival at Itokawa from June to September 2005. Since orbital mechanics dictated that the spacecraft still had to leave the asteroid by November 2005, the amount of time it was able to spend at Itokawa was greatly reduced and the number of landings on the asteroid was reduced from three to two.
* In 2005, two [[reaction wheel]]s that govern the attitude movement of ''Hayabusa'' failed; the X-axis wheel failed on 31 July, and the Y-axis on 2 October. After the latter failure, the spacecraft was still able to turn on its X and Y axes with its thrusters. JAXA claimed that since global mapping of Itokawa had been completed, this was not a major problem, but the mission plan was altered. The failed reaction wheels were manufactured by Ithaco Space Systems, Inc, New York, which was later acquired by [[Goodrich Company]].
* The 4 November 2005, 'rehearsal' landing on Itokawa failed, and was rescheduled.
* The original decision to sample two different sites on the asteroid was changed when one of the sites, Woomera Desert, was found to be too rocky for a safe landing.
* The 12 November 2005, release of the MINERVA miniprobe ended in failure.

== Mission timeline ==

=== Up to the launch ===
The asteroid exploration mission by the [[Institute of Space and Astronautical Science]] (ISAS) originated in 1986–1987 when the scientists investigated the feasibility of a sample return mission to [[1943 Anteros|Anteros]] and concluded that the technology was not yet developed.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/special/2003/kawaguchi/index.shtml |title=HAYABUSA: Research in the Asteroid 'Sample & Return' Explorer, "HAYABUSA" / Special Feature |publisher=ISAS |date=9 May 2003 |access-date=14 June 2010}}</ref> Between 1987 and 1994, joint ISAS / NASA group studied several missions: an asteroid rendezvous mission later became [[NEAR Shoemaker|NEAR]], and a comet sample return mission later became [[Stardust (spacecraft)|Stardust]].<ref>{{cite web|url=http://stardust.jpl.nasa.gov/science/details.html#histinvest |title=Stardust &#124; JPL &#124; NASA |publisher=Stardust.jpl.nasa.gov |date=21 October 1994 |access-date=14 June 2010}}</ref>

In 1995, ISAS selected asteroid sample return as an engineering demonstration mission, MUSES-C, and the MUSES-C project started in fiscal year 1996. Asteroid Nereus was the first choice of target, [[(10302) 1989 ML|1989 ML]] was the secondary choice. In early development phase, Nereus was considered out of reach and 1989 ML became the primary target.<ref>{{cite journal |url=http://www.minorbody.org/yuseijin/interview/interview04.html |archive-url=https://web.archive.org/web/20110727084411/http://www.minorbody.org/yuseijin/interview/interview04.html |url-status=usurped |archive-date=27 July 2011 |title=MUSES-Cの大いなる挑戦〜世界初の小惑星サンプルリターンへ向けて〜 |trans-title=Great Challenges in MUSES-C: The World's first sample-return mission from an asteroid |language=ja |journal=Planetary People |publisher=Japanese Society for Planetary Sciences |volume=11 |issue=2 |date=2002 }}</ref> A launch failure of [[M-V]] in July 2000 forced MUSES-C's launch to be delayed from July 2002 to November/December, putting both Nereus and 1989 ML out of reach. As a result, the target asteroid was changed to [[25143 Itokawa|{{mp|1998 SF|36}}]].<ref>{{cite web|url=http://www.isas.jaxa.jp/ISASnews/No.234/m-v.html |title=M-V事情 2000.9 No.234 |publisher=Isas.jaxa.jp |access-date=14 June 2010}}</ref> In 2002, launch was postponed from December 2002 to May 2003 to recheck [[O-ring]]s of [[reaction control system]] since one of it was found using different material than specified.<ref name="isasnews20020925"/> On 9 May 2003 04:29:25 UTC, MUSES-C was launched by an M-V rocket, and the probe was named "''Hayabusa''".

=== Cruising ===
Ion thruster checkout started on 27 May 2003. Full power operation started on 25 June.

Asteroids are named by their discoverer. ISAS asked [[Lincoln Near-Earth Asteroid Research|LINEAR]], the discoverer of {{mp|1998 SF|36}}, to offer the name after [[Hideo Itokawa]], and on 6 August, [[Minor Planet Circular]] reported that the target asteroid {{mp|1998 SF|36}} was named ''Itokawa''.<ref>{{cite web |url=http://web.mit.edu/newsoffice/2003/asteroids2.html |title=MIT's LINEAR asteroid named for Japan's 'Dr. Rocket' |publisher=MIT |date=29 September 2003 |access-date=19 June 2010}}</ref><ref>{{cite report|url=http://www.minorplanetcenter.org/iau/ECS/MPCArchive/2003/MPC_20030806.pdf |archive-url=https://web.archive.org/web/20110725081240/http://www.minorplanetcenter.org/iau/ECS/MPCArchive/2003/MPC_20030806.pdf |url-status=dead |archive-date=25 July 2011 |title=The Minor Planet Circulars/Minor Planets and Comets |publisher=Minor Planet Center |issn=0736-6884 |date=6 August 2003 |access-date=27 November 2009 }}</ref>

In October 2003, ISAS and two other national aerospace agencies in Japan were merged to form [[JAXA]].

On 31 March 2004, ion thruster operation was stopped to prepare for the Earth swing-by.<ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0420.shtml |title=はやぶさの現状と今後の予定 / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref> Last maneuver operation before swing-by on 12 May.<ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0512.shtml |title=「はやぶさ」地球スウィングバイに向けた軌道微調整終了 / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref> On 19 May, ''Hayabusa'' performed Earth swing-by.<ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0518.shtml |title=「はやぶさ」地球と月の撮影に成功！ / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0519.shtml |title=「はやぶさ」地球撮影。大西洋中心にくっきり！ / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0519_gif.shtml |title=「はやぶさ」が撮影した地球（アニメーション） / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0520.shtml |title=「はやぶさ」の地球スウィングバイ（CGアニメーション） / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0520_3.shtml |title=地球最接近直前の「はやぶさ」が撮影した日本上空付近の画像 / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0520_2.shtml |title=地球スイングバイ後の「はやぶさ」から撮影した地球 / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0524.shtml |title=「はやぶさ」地球スウィングバイ成功確認！ / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref> On 27 May, ion thruster operation was started again.<ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2004/0621.shtml |title=「はやぶさ」イオンエンジン本格的に再稼動 / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref>

On 18 February 2005, ''Hayabusa'' passed aphelion at 1.7 AU.<ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/snews/2005/0309.shtml |title=「はやぶさ」遠日点通過！〜太陽から史上最も離れた電気推進ロケット〜 / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref> On 31 July, the X-axis reaction wheel failed. On 14 August, ''Hayabusa''<nowiki>'</nowiki>s first image of Itokawa was released. The picture was taken by the star tracker and shows a point of light, believed to be the asteroid, moving across the starfield.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2005/0815_hayabusa.shtml |title=Hayabusa performed the Star Tracker imaging of Itokawa! / Topics |publisher=ISAS |date=15 August 2005 |access-date=14 June 2010}}</ref> Other images were taken from 22 to 24 August.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2005/0826.shtml |title=Hayabusa's navigation camera photographed the "Itokawa" / Topics |publisher=ISAS |date=26 August 2005 |access-date=14 June 2010}}</ref> On 28 August, ''Hayabusa'' was switched over from the [[ion engine]]s to the bi-propellant thrusters for orbital maneuvering. From 4 September, ''Hayabusa''<nowiki>'</nowiki>s cameras were able to confirm Itokawa's elongated shape.<ref>{{cite web |author=Japan Aerospace Exploration Agency |url=http://www.isas.ac.jp/e/snews/2005/0905.shtml |title=Hayabusa successfully captured Itokawa Shape for the first time in Space / Topics |publisher=ISAS |date=5 September 2005 |access-date=14 June 2010 |archive-date=13 June 2011 |archive-url=https://web.archive.org/web/20110613040345/http://www.isas.ac.jp/e/snews/2005/0905.shtml |url-status=dead }}</ref> From 11 September, individual hills were discerned on the asteroid.<ref>{{cite web |author=Japan Aerospace Exploration Agency |url=http://www.isas.ac.jp/e/snews/2005/0911.shtml |title=Itokawa Image on September 10 / Topics |publisher=ISAS |date=11 September 2005 |access-date=14 June 2010 |archive-date=13 June 2011 |archive-url=https://web.archive.org/web/20110613040351/http://www.isas.ac.jp/e/snews/2005/0911.shtml |url-status=dead }}</ref> On 12 September, ''Hayabusa'' was {{convert|20|km|abbr=on}} from Itokawa and JAXA scientists announced that ''Hayabusa'' had officially "arrived".<ref name="arrival">{{cite web |author=Japan Aerospace Exploration Agency |url=http://www.isas.ac.jp/e/snews/2005/0912.shtml |title=Hayabusa arrives Itokawa / Topics |publisher=ISAS |date=12 September 2005 |access-date=14 June 2010 |archive-date=15 May 2011 |archive-url=https://web.archive.org/web/20110515154002/http://www.isas.ac.jp/e/snews/2005/0912.shtml |url-status=dead }}</ref>

=== In proximity of Itokawa ===
On 15 September 2005, a 'color' image of the asteroid was released (which is, however, grey in coloring).<ref>{{cite web |author=Japan Aerospace Exploration Agency |url=http://www.isas.ac.jp/e/snews/2005/0914.shtml |title=The synthesized pseudo-color image of Itokawa which took by Hayabusa / Topics |publisher=ISAS |date=14 September 2005 |access-date=14 June 2010 |archive-date=13 June 2011 |archive-url=https://web.archive.org/web/20110613040426/http://www.isas.ac.jp/e/snews/2005/0914.shtml |url-status=dead }}</ref> On 4 October, JAXA announced that the spacecraft had successfully moved to its 'Home Position' 7&nbsp;km from Itokawa. Closeup pictures were released. It was also announced that the spacecraft's second reaction wheel, governing the Y-axis, had failed, and that the craft was now being pointed by its rotation thrusters.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2005/1004.shtml |title=Hayabusa arrives at Home Position, and Current Status of Hayabusa Spacecraft / Topics |publisher=ISAS |date=4 October 2005 |access-date=14 June 2010}}</ref> On 3 November, ''Hayabusa'' took station 3.0&nbsp;km from Itokawa. It then began its descent, planned to include delivery of a target marker, and release of the Minerva minilander. The descent went well initially, and navigation images with wide-angle cameras were obtained. However, at 01:50&nbsp;[[Coordinated Universal Time|UTC]] ({{Nowrap|10:50 am}} [[Japan Standard Time|JST]]) on 4 November, it was announced that due to a detection of an anomalous signal at the Go/NoGo decision, the descent, including release of Minerva and the target marker had been canceled. The project manager, Junichiro Kawaguchi, explained that the optical navigation system was not tracking the asteroid very well, probably caused by the complex shape of Itokawa. A delay of a few days was required to evaluate the situation and reschedule.<ref>{{cite web|author=in はやぶさリンク, 宇宙開発 |url=http://smatsu.air-nifty.com/lbyd/2005/11/114_7a7a.html |title=「はやぶさリンク」：11/4降下リハーサル中止の記者会見: 松浦晋也のL/D |publisher=Smatsu.air-nifty.com |access-date=14 June 2010}}</ref><ref>{{cite web |url=http://www.planetary.org/news/2005/1108_Hayabusa_JAXA_Regrouping_for.html |title=Hayabusa: JAXA Regrouping for Touch-Down Landings on Asteroid – Planetary News &#124; The Planetary Society |publisher=Planetary.org |access-date=14 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20111121004649/http://www.planetary.org/news/2005/1108_Hayabusa_JAXA_Regrouping_for.html |archive-date=21 November 2011 }}</ref>

On 7 November, ''Hayabusa'' was 7.5&nbsp;km from Itokawa. On 9 November, ''Hayabusa'' performed a descent to {{Nowrap|70 m}} to test the landing navigation and the laser altimeter. After that, ''Hayabusa'' backed off to a higher position, then descended again to {{Nowrap|500 m}} and released one of the target markers into space to test the craft's ability to track it (this was confirmed). From analysis of the closeup images, the Woomera Desert site (Point B) was found to be too rocky to be suitable for landing. The Muses Sea site (Point A) was selected as the landing site, for both first and, if possible, second landings.<ref>{{cite web|url=http://www.jaxa.jp/press/2005/11/20051110_hayabusa_j.html |title=JAXA｜「はやぶさ」のリハーサル降下再試験について |publisher=Jaxa.jp |access-date=14 June 2010}}</ref>

On 12 November, ''Hayabusa'' closed in to {{Nowrap|55 m}} from the asteroid's surface. MINERVA was released but due to an error failed to reach the surface. On 19 November, ''Hayabusa'' landed on the asteroid. There was considerable confusion during and after the maneuver about precisely what had happened, because the high-gain antenna of the probe could not be used during final phase of touch-down, as well as the blackout during handover of ground station antenna from [[Deep Space Network|DSN]] to Usuda station. It was initially reported that ''Hayabusa'' had stopped at approximately 10 meters from the surface, hovering for 30 minutes for unknown reasons. Ground control sent a command to abort and ascend, and by the time the communication was regained, the probe had moved 100&nbsp;km away from the asteroid. The probe had entered into a [[Safe mode (spacecraft)|safe mode]], slowly spinning to stabilize [[Spacecraft attitude control|attitude control]].<ref>{{cite web|url=http://planetary.org/news/2005/1121_Hayabusa_Does_Not_Land_on_Asteroid_in.html |title=Hayabusa Does Not Land on Asteroid in First Attempt, But Successfully Delivers Target Marker – Planetary News &#124; The Planetary Society |publisher=Planetary.org |access-date=14 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110621231644/http://planetary.org/news/2005/1121_Hayabusa_Does_Not_Land_on_Asteroid_in.html |archive-date=21 June 2011 }}</ref><ref>{{cite web|author=2005.11.20 in Hayabusa |url=http://5thstar.air-nifty.com/blog/2005/11/fate_of_hayabus.html |title=Fate of Hayabusa: 5thstar_管理人_日記 |publisher=5thstar.air-nifty.com |date=20 November 2005 |access-date=14 June 2010}}</ref> However, after regaining control and communication with the probe, the data from the landing attempt were downloaded and analyzed, and on 23 November, JAXA announced that the probe had indeed landed on the asteroid's surface.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2005/1124_hayabusa.shtml |title=Hayabusa Landed on and Took Off from Itokawa successfully – Detailed Analysis Revealed / Topics |publisher=ISAS |access-date=14 June 2010}}</ref> Unfortunately, the sampling sequence was not triggered since a sensor detected an obstacle during descent; the probe tried to abort the landing, but since its orientation was not appropriate for ascent, it chose instead a safe descent mode. This mode did not permit a sample to be taken, but there is a high probability that some dust may have whirled up into the sampling horn when it touched the asteroid, so the sample canister attached to the sampling horn was sealed.

On 25 November, a second touchdown attempt was performed. It was initially thought that this time, the sampling device was activated;<ref>{{cite web|url=http://www.spacedaily.com/2005/051126064812.zgtr2p1v.html |title=Japan probe 'almost certainly' collected first-ever asteroid samples |publisher=Spacedaily.com |date=26 November 2005 |access-date=14 June 2010}}</ref> however, later analysis decided that this was probably another failure and that no pellets were fired.<ref>{{cite web|url=http://www.newscientistspace.com/article.ns?id=dn8868&feedId=online-news_rss20|archive-url=https://archive.today/20090418001916/http://www.newscientistspace.com/article.ns?id=dn8868&feedId=online-news_rss20|url-status=dead|archive-date=18 April 2009|title=Space news and outer space articles from New Scientist – New Scientist Space – New Scientist |publisher=New Scientist Space |access-date=14 June 2010}}</ref> Due to a leak in the thruster system, the probe was put in a "safe hold mode".<ref>{{cite web|author=in はやぶさリンク |url=http://smatsu.air-nifty.com/lbyd/2005/11/hayabusa_link_t_1.html |title=[HAYABUSA link&#93; The press conference at 16:00 JST 26th: 松浦晋也のL/D |publisher=Smatsu.air-nifty.com |access-date=14 June 2010}}</ref>

On 27 November, the probe experienced a power outage when trying to reorient the spacecraft, probably due to a fuel leakage. On 30 November, JAXA announced that control and communication with ''Hayabusa'' had been restored, but a problem remained with the craft's [[reaction control system]], perhaps involving a frozen pipe. Mission control was working to resolve the problem before the craft's upcoming [[launch window]] for return to Earth.<ref>{{cite web |url=http://www.planetary.org/news/2005/1130_Hayabusa_Team_ReEstablishes_Command.html |title=Hayabusa: Team Re-Establishes Command and Works to Bring its Falcon Home – Planetary News &#124; The Planetary Society |publisher=Planetary.org |access-date=14 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100430075456/http://www.planetary.org/news/2005/1130_Hayabusa_Team_ReEstablishes_Command.html |archive-date=30 April 2010 }}</ref> On 2 December, an attitude (orientation) correction was attempted, but the thruster did not generate enough force. On 3 December, the probe's Z-axis was found to be 20 to 30 degrees from the Sun direction and increasing. On 4 December, as an emergency measure, xenon propellant from the ion engines was blown to correct the spin, and it was confirmed successful. On 5 December, [[Spacecraft attitude control|attitude control]] was corrected enough to regain communication through the medium gain antenna. Telemetry was obtained and analyzed. As the result of telemetry analysis, it was found that there was a strong possibility that the sampler projectile had not penetrated when it landed on 25 November. Due to the power outage, the [[telemetry]] log data was faulty. On 6 December, ''Hayabusa'' was 550&nbsp;km from Itokawa. JAXA held a press conference about the situation so far.<ref>{{cite web |author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.ac.jp/j/snews/2005/1207.shtml |title=「はやぶさ」探査機の状況について / トピックス |publisher=ISAS |access-date=14 June 2010 |archive-date=31 March 2010 |archive-url=https://web.archive.org/web/20100331094638/http://www.isas.ac.jp/j/snews/2005/1207.shtml |url-status=dead }}</ref><ref>{{cite web|author=in はやぶさリンク |url=http://smatsu.air-nifty.com/lbyd/2005/12/hayabusa_link_p.html |title=[HAYABUSA link&#93;: Press Conference at 16:50 on 7th Dec. JST: 松浦晋也のL/D |publisher=Smatsu.air-nifty.com |access-date=14 June 2010}}</ref>

On 8 December, a sudden orientation change was observed, and communication with ''Hayabusa'' was lost. It was thought likely that the turbulence was caused by evaporation of 8 or 10[[Cubic metre#Multiples and submultiples|cc]] of leaked fuel. This forced a wait of a month or two for ''Hayabusa'' to stabilize by conversion of [[precession]] to pure rotation, after which the rotation axis needed to be directed toward the Sun and Earth within a specific angular range. The probability of achieving this was estimated at 60% by December 2006, 70% by spring 2007.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2005/1214.shtml |title=Status of the Hayabusa / Topics |publisher=ISAS |date=14 December 2005 |access-date=14 June 2010}}</ref><ref>{{cite web|author=in はやぶさリンク |url=http://smatsu.air-nifty.com/lbyd/2005/12/press_conferenc.html |title=[Hayabusa link&#93;: Press Conference on 14th Dec.: 松浦晋也のL/D |publisher=Smatsu.air-nifty.com |access-date=14 June 2010}}</ref>

=== Recovery and return to Earth ===
[[File:Animation of Hayabusa trajectory returning from Itokawa to Earth.gif |thumb |right |Animation of ''Hayabusa''{{'s}} trajectory returning from [[25143 Itokawa|Itokawa]] to [[Earth]].<br>{{legend2|magenta| Hayabusa}}{{legend2|Cyan| [[25143 Itokawa|Itokawa]]}}{{·}}{{legend2| RoyalBlue |[[Earth]]}}{{·}}{{legend2| Yellow|[[Sun]]}}]]
On 7 March 2006, JAXA announced<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2006/0308.shtml |title=Current Status of Hayabusa Spacecraft – Communication and Operation Resumption / Topics |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web|author=in はやぶさリンク |url=http://smatsu.air-nifty.com/lbyd/2006/03/7_8c16.html |title=本日午後7時からの記者会見: 松浦晋也のL/D |publisher=Smatsu.air-nifty.com |access-date=14 June 2010}}</ref> that communication with ''Hayabusa'' had been recovered in the following stages: On 23 January, the beacon signal from the probe was detected. On 26 January, the probe responded to commands from ground control by changing the beacon signal. On 6 February, an ejection of xenon propellant was commanded for attitude control to improve communication. The spin axis change rate was about two degrees per day. On 25 February, telemetry data was obtained through the low-gain antenna. On 4 March, telemetry data was obtained through the medium-gain antenna. On 6 March, ''Hayabusa'''s position was established at about 13,000&nbsp;km ahead of Itokawa in its orbit with a relative speed of {{Nowrap|3 m}} per second.

On 1 June, ''Hayabusa'' project manager Junichiro Kawaguchi reported<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/snews/2006/0601.shtml |title=Recent Status of Hayabusa spacecraft as of the end of May, 2006 / Topics |publisher=ISAS |date=1 June 2006 |access-date=14 June 2010}}</ref> that they confirmed two out of four ion engines were working normally, which would have been sufficient for the return journey. On 30 January 2007, JAXA reported that 7 out of 11 batteries were working and the return capsule was sealed.<ref>{{cite journal |url=http://www.isas.jaxa.jp/ISASnews/No.313/ISASnews313.pdf |author=Jun'ichiro Kawaguchi |title=「はやぶさ」の現状 |trans-title=Status of Hayabusa |issue=314 |date=2007 |journal=ISAS News |publisher=JAXA |issn=0285-2861}}</ref> On 25 April, JAXA reported that ''Hayabusa'' started the return journey.<ref>{{cite web|author=宇宙航空研究開発機構（JAXA）宇宙科学研究所 |url=http://www.isas.jaxa.jp/j/topics/topics/2007/0425.shtml |title=「はやぶさ」地球帰還に向けた本格巡航運転開始! / トピックス |publisher=ISAS |access-date=14 June 2010}}</ref><ref>{{cite web |url=http://www.isas.jaxa.jp/e/topics/2007/0501.shtml |title=Hayabusa leaves for Earth |publisher=JAXA |date=1 May 2007 |access-date=14 June 2010}}</ref> On 29 August, it was announced that Ion Engine C onboard Hayabusa, in addition to B and D, had been successfully re-ignited.<ref>{{cite web |url=http://www.hayabusa.isas.jaxa.jp/e/index_54.html |title=Hayabusa project top |publisher=Hayabusa.isas.jaxa.jp |date=28 July 2007 |access-date=14 June 2010 |archive-url=https://web.archive.org/web/20110517050315/http://www.hayabusa.isas.jaxa.jp/e/index_54.html |archive-date=17 May 2011 |url-status=dead }}</ref> On 29 October, JAXA reported that the first phase of trajectory maneuver operation had finished and the spacecraft was now put in a spin-stabilized state.<ref>{{cite web |url=http://www.isas.jaxa.jp/e/topics/2007/1029.shtml |title=Hayabusa Finished First Leg of Orbit Maneuver toward Earth |date=29 October 2007 |access-date=14 June 2010}}</ref> On 4 February 2009, JAXA reported success in reignition of the ion engines and starting the second phase of the trajectory correction maneuver to return to Earth.<ref>{{cite web|author=Japan Aerospace Exploration Agency |url=http://www.isas.jaxa.jp/e/topics/2009/0204.shtml |title=HAYABUSA: Firing ion engine and starting second phase orbit maneuver to return to Earth / Topics |publisher=ISAS |date=4 February 2009 |access-date=14 June 2010}}</ref> On 4 November 2009, the ion engine D automatically stopped working due to an anomaly from degradation.<ref>{{cite press release |url=http://www.jaxa.jp/press/2009/11/20091109_hayabusa_e.html |title=Asteroid Explorer "HAYABUSA" Ion Engine Anomaly |publisher=JAXA |date=9 November 2009 |access-date=23 November 2009 |archive-date=23 November 2009 |archive-url=https://web.archive.org/web/20091123184649/http://www.jaxa.jp/press/2009/11/20091109_hayabusa_e.html |url-status=dead }}</ref>

On 19 November 2009, JAXA announced that they managed to combine the ion generator of ion engine B and the neutralizer of ion engine A.<ref>{{cite press release |url=http://www.jaxa.jp/press/2009/11/20091119_hayabusa_e.html |title=Restoration of Asteroid Explorer, HAYABUSA's Return Cruise |publisher=JAXA |date=19 November 2009 |access-date=23 November 2009 |archive-date=23 November 2009 |archive-url=https://web.archive.org/web/20091123100227/http://www.jaxa.jp/press/2009/11/20091119_hayabusa_e.html |url-status=dead }}</ref> It was suboptimal but expected to be sufficient to generate the necessary [[delta-v]]. Out of {{Nowrap|2,200 m/s}} delta-v necessary to return to the Earth, about {{Nowrap|2,000 m/s}} had been performed already, and about {{Nowrap|200 m/s}} were still necessary.<ref>{{cite web |url=http://smatsu.air-nifty.com/lbyd/2009/11/post-1cd1.html |title=はやぶさリンク：はやぶさ、帰還に向けてイオンエンジン再起動 |author=Shinya Matsuura |date=19 November 2009 |access-date=23 November 2009}}</ref> On 5 March 2010, ''Hayabusa'' was on a trajectory that would have passed within the lunar orbit. Ion engine operation was suspended to measure the precise trajectory in preparation to perform Trajectory Correction Maneuver 1 to the Earth-rim trajectory.<ref>{{cite web |url=http://www.jspec.jaxa.jp/activity/hayabusa.html |script-title=ja:小惑星探査機「はやぶさ」 |date=10 March 2010 |access-date=12 March 2010 |language=ja |url-status=dead |archive-url=https://web.archive.org/web/20100316200104/http://www.jspec.jaxa.jp/activity/hayabusa.html |archive-date=16 March 2010 }}</ref><ref>{{cite web |url=http://www.isas.jaxa.jp/j/enterp/missions/hayabusa/trj.shtml |script-title=ja:軌道情報 |language=ja |date=5 March 2010 |access-date=26 March 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110616022704/http://www.isas.jaxa.jp/j/enterp/missions/hayabusa/trj.shtml |archive-date=16 June 2011 }}</ref> On 27 March, 06:17 UTC, ''Hayabusa'' was on a trajectory which would pass 20,000&nbsp;km from Earth center, completing the orbit transfer operation from Itokawa to Earth.<ref>{{cite web |url=http://www.jaxa.jp/press/2010/03/20100327_hayabusa_j.html |script-title=ja:小惑星探査機「はやぶさ」搭載イオンエンジンの連続運転による軌道制御の終了について |publisher=JAXA |language=ja |date=27 March 2010 |access-date=27 March 2010}}</ref> By 6 April, the first stage of Trajectory Correction Maneuver (TCM-0) which led to a rough Earth rim trajectory was completed. It was planned to be 60 days until reentry.<ref name=jaxa20100421>{{cite web |url=http://www.jaxa.jp/press/2010/04/20100421_hayabusa_j.html |script-title=ja:小惑星探査機「はやぶさ」搭載カプセルの地球帰還について |trans-title=Regarding the Arrival of Return Capsule of the Asteroid Probe "Hayabusa" |language=ja |publisher=JAXA |date=21 April 2010 |access-date=21 April 2010}}</ref><ref>{{cite web |url=http://www.isas.ac.jp/j/enterp/missions/hayabusa/today.shtml |script-title=ja:軌道情報 |language=ja |date=12 April 2010 |access-date=12 April 2010 |author=Jun'ichiro Kawaguchi |publisher=JAXA |url-status=dead |archive-url=https://web.archive.org/web/20100327142721/http://www.isas.ac.jp/j/enterp/missions/hayabusa/today.shtml |archive-date=27 March 2010 }}</ref><ref>{{cite web |url=http://ameblo.jp/hayakawa-moon/entry-10501923176.html |script-title=ja:本日より |language=ja |date=6 April 2010 |access-date=7 April 2010}}</ref><ref name=20100331_sac_hayabusa>{{cite web |url=http://www.jaxa.jp/press/2010/03/20100331_sac_hayabusa.pdf |script-title=ja:「はやぶさ」試料回収カプセルの再突入に係る計画について |language=ja |author=JAXA Space Exploration Center |date=31 March 2010 |access-date=31 March 2010}}</ref> By 4 May, the probe completed its TCM-1 maneuver to align precisely to the Earth rim trajectory.<ref>{{cite web |url=http://www.isas.jaxa.jp/home/hayabusa-live/?itemid=413 |title=TCM-1 operation was successfully completed |date=4 May 2010 |access-date=4 May 2010}}</ref> On 22 May, TCM-2 started, continued for about 92.5 hours, and finished on 26 May.<ref>{{cite web |url=http://www.isas.jaxa.jp/home/hayabusa-live/?blogid=6&archive=2010-05 |title=Hayabusa Live Archive |access-date=27 May 2010}}</ref> It was followed by TCM-3 from 3 through 5 June to change the trajectory from the Earth rim to [[Woomera, South Australia]],<ref>{{cite web |url=http://www.isas.jaxa.jp/home/hayabusa-live/?itemid=533 |title=TCM-3 operation started, shift the target from Earth's outer rim to WPA |date=3 June 2010 |access-date=3 June 2010}}</ref><ref>{{cite web |url=http://www.isas.jaxa.jp/home/hayabusa-live/?itemid=548 |title=TCM-3 operation completed, shift the target from Earth's outer rim to WPA |date=5 June 2010 |access-date=5 June 2010}}</ref> TCM-4 was performed on 9 June for about 2.5 hours for a precision descent to [[Woomera Prohibited Area]].<ref>{{cite web |url=http://www.isas.jaxa.jp/home/hayabusa-live/?itemid=563 |title=TCM-4 operation completed, precise guidance to WPA |date=9 June 2010 |access-date=9 June 2010}}</ref>

The reentry capsule was released at 10:51 UTC on 13 June.

=== Reentry and capsule retrieval ===
[[File:Hayabusa reentry from Ames Research 2010-06-13 25seconds.png|thumb|right|The glowing return capsule is seen forward of and below the parent ''Hayabusa'' probe bus as the latter breaks up.]]

The reentry capsule and the spacecraft reentered Earth's atmosphere on 13 June 2010 at 13:51 UTC (23:21 local).<ref>[http://indyposted.com/27014/mission-accomplished-for-japans-asteroid-explorer-hayabusa/ Mission Accomplished For Japan's Asteroid Explorer Hayabusa] {{webarchive|url=https://web.archive.org/web/20100616232222/http://indyposted.com/27014/mission-accomplished-for-japans-asteroid-explorer-hayabusa/ |date=16 June 2010 }}</ref> The [[heat shield|heat-shielded]] capsule made a parachute landing in the South [[Outback|Australian outback]] while the spacecraft broke up and incinerated in a large fireball.<ref>{{cite news |url=http://www.space.com/missionlaunches/hayabusa-asteroid-probe-landing-preview-100613.html |title=Space Probe, Perhaps with a Chunk of Asteroid, Returns to Earth Sunday |work=[[Space.com]] |date=13 June 2010 |access-date=13 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20100616062115/http://www.space.com/missionlaunches/hayabusa-asteroid-probe-landing-preview-100613.html |archive-date=16 June 2010 }}</ref>

An international team of scientists observed the 12.2&nbsp;km/s entry of the capsule from {{convert|11.9|km|ft|abbr=off}} on board NASA's DC-8 airborne laboratory, using a wide array of imaging and spectrographic cameras to measure the physical conditions during [[atmospheric reentry]] in a mission led by NASA's [[Ames Research Center]], with [[Peter Jenniskens]] of the [[SETI Institute]] as the project scientist.<ref>{{cite web | title=Hayabusa Re-Entry airborne observing campaign | url=http://airborne.seti.org/hayabusa/ | publisher=The SETI Institute | access-date=10 May 2010 | url-status=dead | archive-url=https://web.archive.org/web/20100628145257/http://airborne.seti.org/hayabusa/ | archive-date=28 June 2010 }}</ref><ref>{{cite news|url=https://www.youtube.com/watch?v=gfYA4f-AIL0|title=NASA Team Captures Hayabusa Spacecraft Reentry|publisher=NASA|date=14 June 2010|access-date=14 June 2010}}</ref>

Since the reaction control system no longer functioned, the {{convert|510|kg|lb}} space probe re-entered the Earth's atmosphere similar to the approach of an [[asteroid]] along with the sample re-entry capsule, and, as mission scientists expected, the majority of the spacecraft disintegrated upon entry.<ref>{{cite magazine
 | last =  Ryall
 | first = Julian
 | title = Asteroid Probe Set to "Collide" With Earth
 | magazine = National Geographic
 | date = 11 June 2009
 | url = http://news.nationalgeographic.com/news/2009/06/090611-asteroid-collision-hayabusa.html
 | archive-url = https://web.archive.org/web/20090614040332/http://news.nationalgeographic.com/news/2009/06/090611-asteroid-collision-hayabusa.html
 | url-status = dead
 | archive-date = 14 June 2009
 | access-date = 12 June 2010}}
</ref>

[[File:Hayabusa Re-Entery.jpg|thumb|left|The re-entry seen from the [[Woomera Test Range]]]]
The return capsule was predicted to land in a {{Nowrap|20 km}} by {{Nowrap|200 km}} area in the [[Woomera Prohibited Area]], [[South Australia]]. Four ground teams surrounded this area and located the re-entry capsule by optical observation and a radio beacon. Then a team on board a helicopter was dispatched. They located the capsule and recorded its position with GPS. The capsule was successfully retrieved at 07:08 UTC (16:38 local) of 14 June 2010.<ref>{{cite web | title=Retrieving the Capsule completed | url=http://www.jaxa.jp/press/2010/06/20100614_hayabusa5_e.html | publisher=JAXA | access-date=14 June 2010}}</ref> The two parts of the heat shield, which were jettisoned during the descent, were also found.<ref name="bbcnews10307048">{{cite news |url=https://www.bbc.co.uk/news/10307048  |title=Hayabusa asteroid-sample capsule recovered in Outback |author= Jonathan Amos |work=BBC News  |date=14 June 2010 |access-date=14 June 2010}}</ref>

[[File:Hayabusa reentry from Ames Research 2010-06-13.ogv|thumb|''Hayabusa'' re-entry filmed by a camera onboard NASA's DC-8 Airborne Laboratory. The glowing return capsule is seen forward of and below the main ''Hayabusa'' probe bus as the latter breaks up. The [[heat shield|heat-shield]]ed capsule continues leaving a wake after the main bus fragments have faded. ([[:File:Hayabusa atmospheric reentry (close-up).ogv|Close-up video]])]]
After confirming that the explosive devices used for parachute deployment were safe, the capsule was packed inside a double layer of plastic bags filled with pure nitrogen gas to reduce the risk of contamination. The soil at the landing site was also sampled for reference in case of contamination. Then the capsule was put inside a cargo container which had air suspension to keep the capsule below 1.5 G shock during transportation.<ref>{{cite web |url=http://www.mrd-matsuda.co.jp/jaxa.html |script-title=ja:はやぶさ回収ボックス |language=ja |publisher=Matsuda R&D Co. |access-date=16 June 2010 |archive-date=7 July 2017 |archive-url=https://web.archive.org/web/20170707174451/http://mrd-matsuda.co.jp/jaxa.html |url-status=dead }}</ref>  The capsule and its heat shield parts were transported to Japan by a chartered plane and arrived at the curation facility at the JAXA/ISAS [[Sagamihara Campus]] on 18 June.<ref>{{cite web |url=http://www.jaxa.jp/press/2010/06/20100618_hayabusa_e.html |title=HAYABUSA Capsule Arrived at JAXA Sagamihara Campus |publisher =JAXA |access-date=18 June 2010}}</ref>

A [[Tokyo Metropolitan Government]] adviser and former lieutenant general, Toshiyuki Shikata, claimed that part of the rationale for the reentry and landing part of the mission was to demonstrate "that Japan's ballistic missile capability is credible."<ref>{{cite news |url=https://www.wsj.com/articles/SB10001424052970203658804576638392537430156 |title=In Japan, Provocative Case for Staying Nuclear |author=Chester Dawson |newspaper=Wall Street Journal |date=28 October 2011 |access-date=13 November 2011}}</ref>

==Scientific study of samples==
Before the capsule was extracted from the protecting plastic bag, it was inspected using [[X-ray computed tomography|X-ray CT]] to determine its condition. Then the sample canister was extracted from the reentry capsule. The surface of the canister was cleaned using pure nitrogen gas and carbon dioxide; it was then placed in the canister opening device. The internal pressure of the canister was determined by a slight deformation of the canister as the pressure of the environment nitrogen gas in the clean chamber was varied. The nitrogen gas pressure was then adjusted to match the internal canister pressure to prevent the escape of any gas from the sample upon the opening of the canister.<ref>{{cite web|url=http://www.jaxa.jp/pr/jaxas/pdf/jaxas032.pdf |title=JAXA's 032 |language=ja |publisher=JAXA |access-date=16 June 2010 |url-status=dead |archive-url=https://web.archive.org/web/20110617054922/http://www.jaxa.jp/pr/jaxas/pdf/jaxas032.pdf |archive-date=17 June 2011 }}</ref>

===Confirmation of asteroid particles===
On 16 November 2010, JAXA confirmed that most of the particles found in one of two compartments inside the ''Hayabusa'' sample return capsule came from Itokawa.<ref>{{cite web|url=http://www.jaxa.jp/press/2010/11/20101116_hayabusa_e.html| title=Identification of origin of particles brought back by Hayabusa | publisher=JAXA |date=16 November 2010 |access-date=16 November 2010}}</ref> Analysis with a scanning electron microscope identified about 1,500 grains of rocky particles, according to the JAXA press release.<ref>{{cite web|url=http://www.spaceflightnow.com/news/n1011/16hayabusa/|title=Japan says Hayabusa brought back asteroid grains|author=Stephen Clark|publisher=Spaceflight Now|date=17 November 2010|access-date=17 November 2010}}</ref> After further studying the analysis results and comparison of mineral compositions, most of them were judged to be of extraterrestrial origin, and definitely from the asteroid Itokawa.<ref>{{cite web |url=http://news.sciencemag.org/sciencenow/2010/11/spacecraft-successfully-returns-.html |title=Spacecraft Successfully Returns Asteroid Dust |author=Dennis Normile |publisher=Science |date=16 November 2010 |access-date=20 November 2010 |url-status=dead |archive-url=https://web.archive.org/web/20101120041501/http://news.sciencemag.org/sciencenow/2010/11/spacecraft-successfully-returns-.html |archive-date=20 November 2010 }}</ref>

According to Japanese scientists, the composition of ''Hayabusa''<nowiki>'</nowiki>s samples was more similar to [[meteorite]]s than known rocks from Earth. Their size is mostly less than 10 micrometers.<ref>{{cite web|url=http://www.space.com/scienceastronomy/asteroid-dust-collected-by-japan-space-probe-101116.html|title=Asteroid Dust Successfully Returned by Japanese Space Probe |author=Tariq Malik|date=16 November 2010|access-date=17 November 2010|publisher=SPACE.com}}</ref> The material matches chemical maps of Itokawa from ''Hayabusa'''s remote sensing instruments. The researchers found concentrations of [[olivine]] and [[pyroxene]] in the ''Hayabusa'' samples.

Further study of the samples had to wait until 2011 because researchers were still developing special handling procedures to avoid contaminating the particles during the next phase of research.

In 2013 JAXA announced that 1500 extraterrestrial grains had been recovered, comprising the minerals [[olivine]], [[pyroxene]], [[plagioclase]] and [[iron sulfide]]. The grains were about 10 micrometers in size.<ref>[http://physicsworld.com/cws/article/news/2014/dec/03/japan-launches-second-asteroid-mission Japan launches second asteroid mission (Physicsworld.com, Dec 3, 2014)]</ref> JAXA performed detailed analyses of the samples by splitting particles and examining their crystal structure at [[SPring-8]].<ref>{{cite news|url=http://mdn.mainichi.jp/mdnnews/news/20101007p2a00m0na010000c.html |title=Dust in Hayabusa asteroid probe capsule could be extraterrestrial |newspaper=[[Mainichi Shimbun]] |date=7 October 2010 |access-date=6 November 2010 |url-status=dead |archive-url=https://web.archive.org/web/20101009234832/http://mdn.mainichi.jp/mdnnews/news/20101007p2a00m0na010000c.html |archive-date=9 October 2010 }}</ref>

===Results===
The 26 August 2011 issue of [[Science (journal)|''Science'']] devoted six articles to findings based on dust collected by ''Hayabusa''.<ref name=nyt25aug>{{cite news|title=Asteroid Dust Confirms Meteorite Origins|url=https://www.nytimes.com/2011/08/30/science/30obmeteor.html|access-date=26 August 2011|newspaper=New York Times|date=25 August 2011}}</ref> Scientists' analysis of the dust from Itokawa suggested that it had probably originally been part of a larger asteroid. Dust collected from the asteroid surface was believed to have been exposed there for about eight million years.<ref name=nyt25aug/>

Dust from Itokawa was found to be "identical to material that makes up meteorites."<ref name=nyt25aug/> Itokawa is an [[S-type asteroid]] whose composition matches that of an [[LL chondrite]].<ref name=latimes26aug>{{cite news|title=Most Earth meteorites linked to single asteroid|url=http://www.latimes.com/news/science/la-sci-asteroid-meteorites-20110826,0,4632492.story|access-date=26 August 2011|newspaper=Los Angeles Times|date=26 August 2011}}</ref>

==In popular culture==
In Japan, rival film companies announced the production of three different feature length theatrical films based on the story of ''Hayabusa'', one of which, ''[[Hayabusa: Harukanaru Kikan]]'' (2012), starred [[Ken Watanabe]].<ref>{{cite news|last=Nishida|first=Kensaku|script-title=ja:映画「はやぶさ」３社競う 足踏み日本、自信回復の願い|trans-title=Film 'Hayabusa', 3 companies compete...|url=http://www.asahi.com/showbiz/movie/TKY201107120311.html|access-date=28 August 2011|language=ja|newspaper=Asahi shinbun|date=12 July 2011}}</ref><ref>Shoji, Kaori, "[https://www.japantimes.co.jp/culture/2011/09/23/films/in-a-galaxy-not-so-far-away/#.XTWFXehKjIU In a galaxy not so far away....]", ''[[Japan Times]]'', 23 September 2011, p. 20.</ref>

The [[Lego]] construction toy company released a model of ''Hayabusa'' through their Cuusoo website.<ref>{{cite web|title=The Second LEGO CUUSOO Product : Hayabusa|url=http://legocuusoo.posterous.com/the-second-lego-cuusoo-product-hayabusa|archive-url=https://web.archive.org/web/20130329145523/http://legocuusoo.posterous.com/the-second-lego-cuusoo-product-hayabusa|url-status=dead|archive-date=2013-03-29}}</ref>

Many references to ''Hayabusa'' appear in the Japanese series ''[[Kamen Rider Fourze]]'', a space-themed [[tokusatsu]] series.

==See also==
{{Portal|Spaceflight}}
* {{annotated link|Hayabusa2}}
* {{annotated link|OSIRIS-REx}} 
* {{annotated link|Timeline of Solar System exploration}}

==References ==
{{Reflist|30em}}

==Further reading==
* {{cite journal|author=Fujiwara, A.|display-authors=etal|title=Hayabusa at Asteroid Itokawa (Special Issue)|date=2006|pages=1327–1353|volume=312|pmid=16741105|issue=5778|journal=Science|doi=10.1126/science.312.5778.1327|doi-access=free}}
* {{cite journal|last1=Hiroi|first1=T.|last2=Abe.|first2=M.|last3=Kitazato|first3=K.|last4=Abe|first4=S.|last5=Clark|first5=B.E.|last6=Sasaki|first6=S. |last7=Ishiguro|first7=M.|last8=Barnouin-Jha|first8=O.S.|title=Developing space weathering on the asteroid 25143 Itokawa|date=2006|volume=443|pages=56–58|journal=Nature|doi=10.1038/nature05073|pmid=16957724|issue=7107|bibcode=2006Natur.443...56H|s2cid=4353389|url=https://zenodo.org/record/889820}}
* {{cite journal|title=Spunky Hayabusa Heads Home With Possible Payload|journal=Science|page=565|volume=328|date=30 April 2010|pmid=20430991|doi=10.1126/science.328.5978.565|issue=5978|bibcode=2010Sci...328..565N|last1=Normile|first1=D.}}

== External links ==
{{Commons category}}
* [https://web.archive.org/web/20140413142848/http://www.jaxa.jp/pr/jaxas/pdf/jaxatoday002_p.pdf ISAS/JAXA page on the mission]
* [https://web.archive.org/web/20051125064403/http://www.isas.ac.jp/e/enterp/missions/hayabusa/movie.shtml ISAS/JAXA ''Hayabusa'' mission movie]
* [https://www.youtube.com/watch?v=0nHxCQYA2PU The Great Challenges of ''Hayabusa'' – World's first asteroid sample return mission] – Official JAXA YouTube Channel
* [https://web.archive.org/web/20140413142848/http://www.jaxa.jp/pr/jaxas/pdf/jaxatoday002_p.pdf ISAS/JAXA ''Hayabusa'' Today (live updates of the craft's position)]
* [http://www.isas.jaxa.jp/e/snews/2005/1102.shtml ''Hayabusa''{{'}}s Scientific and Engineering Achievements during Proximity Operations around Itokawa] (JAXA press release on 2 November 2005)
* [http://www.lpi.usra.edu/meetings/lpsc2006/ The 37th Lunar and Planetary Science Conference] has Special Session on  [ftp://ftp.lpi.usra.edu/pub/outgoing/lpsc2006/full702.pdf Results of the ''Hayabusa'' Mission]{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}}, and a poster session [ftp://ftp.lpi.usra.edu/pub/outgoing/lpsc2006/full623.pdf Results of the ''Hayabusa'' Mission]{{dead link|date=May 2025|bot=medic}}{{cbignore|bot=medic}}
* The 42nd Lunar and Planetary Science Conference has Special Session on [http://www.lpi.usra.edu/meetings/lpsc2011/pdf/sess503.pdf Results from ''Hayabusa'']
* [http://www.isas.jaxa.jp/e/snews/2006/0602.shtml Initial Scientific Results of ''Hayabusa''{{'}}s Investigation on Itokawa ~Summary of the Special Issue of ''Science'' Magazine~] (ISAS/JAXA press release)
* [https://darts.isas.jaxa.jp/planet/project/hayabusa/ ''Hayabusa'' Project Science Data Archive]
* {{YouTube|id=HpuU1hd_xeY|title=NASA AMES video of ''Hayabusa'' spacecraft's re-entry}}
* [http://www.nasa.gov/multimedia/videogallery/index.html?media_id=15112814 NASA Team Captures ''Hayabusa'' Spacecraft Reentry] at [[NASA]]
* [https://www.flickr.com/photos/aussmc/sets/72157624258750654/ JAXA ''Hayabusa'' mission] re-entry capsule photos and videos by [[Australian Science Media Centre]]
*{{cite web |url=http://www.jaxa.jp/pr/jaxas/pdf/jaxatoday002_p.pdf |title=JAXA Today August 2010|access-date=7 September 2010 |url-status=dead |archive-url=https://web.archive.org/web/20140413142848/http://www.jaxa.jp/pr/jaxas/pdf/jaxatoday002_p.pdf |archive-date=13 April 2014 }}
* [https://pdssbn.astro.umd.edu/data_sb/missions/hayabusa/index.shtml ''Hayabusa Mission Archive''] at the NASA Planetary Data System, Small Bodies Node

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[[Category:Missions to near-Earth asteroids]]
[[Category:Japanese space probes]]
[[Category:Sample return missions]]
[[Category:Space probes launched in 2003]]
[[Category:Spacecraft which reentered in 2010]]
[[Category:Destroyed space probes]]
[[Category:Articles containing video clips]]
[[Category:Hopping spacecraft]] <!--MINERVA-->