Revision as of 22:29, 13 November 2005 edit Hektor (talk \| contribs) Autopatrolled, Extended confirmed users 56,662 edits →''MINERVA'' mini-lander		Revision as of 23:59, 13 November 2005 view source 205.246.158.36 (talk) No edit summary
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No profanity, please. --> ~~{\| class="toccolours" style="margin-left: 1em; float:right; width: 20em;"~~ ~~\| colspan="2" style="text-align:center; background: #001000;"\| [[Image:Hayabusa(Muses-C) sampling.jpg\|270px\|Hayabusa collecting asteroid rock sample]]~~ \|- ~~\| colspan="2" style="font-size:smaller; text-align:center;" \| Hayabusa spacecraft~~ \|- ~~\|'''Organization'''\|\|[[JAXA]]~~ \|- Hello this is a try ~~\|'''Launch date'''\|\|[[9 May]] [[2003]]~~ THIS IS AWESOME!!!!! \|- ~~\|'''Mass'''\|\|510 kg (dry 380 kg)~~ \|- ~~\|'''Current destination'''\|\|asteroid [[25143 Itokawa]]~~ \|- ~~\|'''Mission'''\|\|asteroid sample return~~ \|- ~~! colspan="2" style="background: #87CEEB; text-align:center;" \| Instruments~~ ~~\|- style="vertical-align: top;"~~ ~~\|'''AMICA'''\|\|multiband imaging camera~~ ~~\|- style="vertical-align: top;"~~ ~~\|'''LIDAR'''\|\|laser altimeter~~ ~~\|- style="vertical-align: top;"~~ ~~\|'''NIRS'''\|\|near-infrared spectrometer~~ ~~\|- style="vertical-align: top;"~~ ~~\|'''XRS'''\|\|x-ray spectrometer~~ \|} ~~{{otheruses}}~~ '''Hayabusa''' (はやぶさ - [[peregrine falcon]]) is an [[unmanned space mission]] led by the [[Japan Aerospace Exploration Agency]] to collect a sample of material from a small [[near-Earth asteroid]] named [[25143 Itokawa]] (dimensions 540 meters by 310 meters by 250 meters) and return the sample to [[Earth]] for analysis. The Hayabusa spacecraft, formerly known as '''MUSES-C''' (ミューゼスＣ), was launched on [[9 May]][[2003]] and rendezvoused with Itokawa in mid-September [[2005]]. Having arrived at Itokawa, ''Hayabusa'' is studying the asteroid's shape, spin, topography, color, composition, density, and history. As of November [[2005]], it is currently in preparation for one or two brief landings on the asteroid to collect samples, and it will return those samples to Earth by July [[2007]]. ~~The spacecraft also carried a detachable mini-lander but it failed to reach the surface (see [[#Minerva mini-lander\|Minerva mini-lander]] below).~~ ~~==Mission firsts==~~ Other spacecraft, notably [[Galileo spacecraft\|''Galileo'']] and ''[[NEAR Shoemaker]]'', have visited asteroids before, but the ''Hayabusa'' mission, if successful, will mark the first time that an asteroid sample is returned to Earth for analysis. In addition, ''Hayabusa'' has been promoted as 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'' is not a 'lander'; it will simply touch the surface with its sample capturing device and then move away. However, it will be the first craft designed from the onset to make contact with the surface of an asteroid. ~~==Mission profile==~~ The Hayabusa spacecraft was launched on [[9 May]], [[2003]] at 04:29:25 UTC on an [[M-5 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 (two separate units, each with two exhausts) have been operating near-continuously for the last two years, slowly moving Hayabusa toward a September [[2005]] rendezvous with Itokawa. The spacecraft will not go into orbit around the asteroid, but will remain in a station-keeping [[heliocentric]] orbit close by. Hayabusa will initially survey the asteroid surface from a distance of about 20 km, the "gate position". Following this, the spacecraft will then move closer to the surface ("home position"), then for a series of soft landings and collection of samples at two sites. [[Autonomous robot\|Autonomous]] optical navigation will be employed extensively during this period because the long communication delay prohibits Earth-based real-time commanding. Once Hayabusa touches down with its deployable collection horn, the spacecraft will fire a tiny projectile at the surface and then collect the resulting spray. The samples, with a total mass of approximately one gram, will be held inside a separate re-entry capsule. After a few months in close proximity to the asteroid, the spacecraft will fire its engines to begin its cruise back to Earth. The re-entry capsule will be detached from the main spacecraft at a distance of about 300,000 to 400,000 km from the Earth, and the capsule will coast on a ballistic trajectory, re-entering the Earth's atmosphere in July [[2007]]. The capsule will experience peak decelerations of about 25 G and heating rates approximately 30 times those experienced by the [[Apollo spacecraft]]. It will land via parachute near [[Woomera, South Australia\|Woomera]], [[Australia]]. ~~==''MINERVA'' mini-lander==~~ ''Hayabusa'' carried a tiny mini-spacecraft (weighing only 591 g) named ''MINERVA'' (short for MIcro/Nano Experimental Robot Vehicle for Asteroid). Unfortunately, an error during deployment resulted in the craft's failure. This solar-powered, box-shaped vehicle was designed to take advantage of Itokawa's very low gravity by hopping great distances across the surface of the asteroid, relaying images from its cameras to Hayabusa whenever the two spacecraft were in sight of one another.[http://www.unmannedspaceflight.com/index.php?act=Attach&type=post&id=1418] ''MINERVA'' was deployed on [[November 12]], [[2005]]. The lander release command was sent from Earth, but before the command could arrive, ''Hayabusa'''s altimeter measured its distance from Itokawa to be 44m 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. Early inspection of data suggests that mission control is in contact with MINERVA but that it was not successfully dropped onto the asteroid's surface. Instead, it escaped Itokawa's gravitational pull and tumbled into space. [http://asia.news.yahoo.com/051112/kyodo/d8dr004g1.html] [http://www.msnbc.msn.com/id/10013920/] [http://www.isas.jaxa.jp/j/snews/2005/1113_minerva.pdf] It is leaving Itokawa at a speed of 8.3 cm/s, but the sun radiation pressure is slowing it down and would nullify its speed within a week. If so, Minerva could come back to Itokawa and collide with in on [(November 25]]. It is unclear whether or not it will still be powered at that time. Had it been successful, ''MINERVA'' would have been the first 'space hopper' to see action. Instead, it joins ranks with the hoppers carried on the failed [[Phobos program\|Soviet Phobos missions]], which also never saw use. The United States space agency [[NASA]] had originally planned to build a miniature rover as part of the ''Hayabusa'' mission, but the project, developed by [[JPL]] and called Muses-CN, was cancelled in November, 2000, for budgeting reasons. ~~==Scientific importance of the mission==~~ Scientists' current 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 will solve this problem by bringing back pristine samples from a specific, well-characterized asteroid. Accordingly, Hayabusa "will bridge the gap between ground observation data of asteroids and laboratory analysis of meteorite and cosmic dust collections," says mission scientist Hajime Yano. <sup id="fn_1_back">[[#fn_1\|1]]</sup> ~~==Changes in mission plan==~~ ~~The ''Hayabusa'' mission profile has been modified several times, both before and after launch.~~ The spacecraft was originally planned to launch in July [[2002]] to the asteroid [[4660 Nereus]]. However, a July [[2000]] failure of Japan's [[M-5 rocket]] forced a delay in the launch, putting asteroid Nereus out of reach. As a result, the target asteroid was changed from Nereus to Itokawa. ''Hayabusa'' was also to deploy a small rover supplied by [[NASA]], called Muses-CN, onto the surface of the asteroid, but the rover was cancelled by [[NASA]] in November [[2000]] due to budget constraints. In [[2003]], while Hayabusa was en-route to Itokawa, a large [[solar flare]] damaged the solar-cells 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 dictate that the spacecraft still must leave the asteroid by November, the amount of the time the spacecraft will be able to spend at Itokawa has been greatly reduced and the number of landings on the asteroid was reduced from three to two. Two [[reaction wheel]]s that govern the attitude movement of ''Hayabusa'' failed in [[2005]]; the X-axis wheel failed on [[July 31]], and the Y-axis on [[October 2]]. After the latter failure, the spacecraft is now being turned on the X and Y axes with its thusters. JAXA claims that since global mapping of Itokawa has been completed, this is not a major problem, but an updated new mission plan is being developed. The November 4 'rehearsal' landing on Itokawa failed, and has had to be rescheduled. The November 12 release of the ''MINERVA'' mini-probe ended in failure. ~~==Recent events==~~ On [[July 31]], [[2005]], the X-axis reaction wheel failed. On [[August 14]], ''Hayabusa'' '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. [http://www.isas.jaxa.jp/e/snews/2005/0815_hayabusa.shtml] Other images were taken from [[August 22]] to [[August 24]]. [http://www.isas.jaxa.jp/e/snews/2005/0826.shtml] On [[August 28]], the orbit maneuver of ''Hayabusa'' was handed over from the [[ion]] engines to the bi-propellant thrusters. From [[September 4]], Hayabusa's cameras were able to confirm Itokawa's elongated shape. [http://www.isas.ac.jp/e/snews/2005/0905.shtml] From [[September 11]], individual hills could be discerned on the asteroid. [http://www.isas.ac.jp/e/snews/2005/0911.shtml] On [[September 12]], ''Hayabusa'' was 20 km from Itokawa and JAXA scientists announced that Hayabusa had officially 'arrived'. [http://www.isas.ac.jp/e/snews/2005/0912.shtml] On [[September 15]], a 'colour' image of the asteroid was released (which is, however, grey in colouring) [http://www.isas.ac.jp/e/snews/2005/0914.shtml] On [[October 4]], JAXA announced that the spacecraft had successfully moved to its 'Home Position' 7 km from Itokawa. Closeup pictures were released. However, it was also announced that the spacecraft's second reaction wheel, governing the Y-axis, had failed, and that it is now being pointed by the craft's rotation thrusters.[http://www.isas.jaxa.jp/e/snews/2005/1004.shtml] On [[November 2]], JAXA held a press conference about scientific and engineering achievements during proximity operations around Itokawa. [http://www.isas.jaxa.jp/e/snews/2005/1102.shtml] On [[November 3]], ''Hayabusa'' was 3.0 km from Itokawa. On [[November 3]], ''Hayabusa'' began its descent which was to have included delivery of a target marker, and release of the Minerva mini-lander. The descent went well initially, and navigation images with wide-angle cameras were been obtained. However, at 1:50 am [[Coordinated Universal Time\|UTC]] (10:50 am [[Japan Standard Time\|JST]]) on [[November 4]], 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. [http://jaxa.tv] The project manager, Jun-ichiro Kawaguchi, explained that the optical navigation system found a larger than permissible range, an error probably caused by the complex shape of Itokawa. It will take a few days to evaluate the situation and set new schedule. [http://smatsu.air-nifty.com/lbyd/2005/11/114_7a7a.html] [http://www.planetary.org/news/2005/1108_Hayabusa_JAXA_Regrouping_for.html] On [[November 7]], ''Hayabusa'' was 7.5 km from Itokawa. On [[November 9]], ''Hayabusa'' performed a descent to 70m to test the landing navigation and the laser altimeter. After that, ''Hayabusa'' backed off to a higher position, then descended again to 500m 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 so that a landing will now be performed only at the Muses Sea site (Point A) even if the landing is to be performed twice. [http://www.jaxa.jp/press/2005/11/20051110_hayabusa_j.html] On [[November 12]], ''Hayabusa'' closed in to 55m from the asteroid's surface. ''MINERVA'' was released but due to an error failed to reach the surface (see above). ~~==Timeline of future events==~~ '''November 19, 2005''': Hayabusa will land briefly on Itokawa, and collect one [[gram]] of dust, and return to its parking orbit. '''November 25, 2005''': Hayabusa will land and collect the sample again. Whether to perform this second landing or not will be decided upon the result of first landing. '''Early December 2005''': ''Hayabusa'' will begin its return to Earth. '''June 2007''': ''Hayabusa'' will release its samples to return to Earth in a re-entry capsule. ~~==External links==~~ [http://www.jaxa.jp/news_topics/vision_missions/solar/pages/hayabusa3_e.html JAXA detailed website on Hayabusa] [http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=2003-019A NASA page on mission] [http://www.isas.jaxa.jp/e/enterp/missions/hayabusa/index.shtml JAXA page on mission] [http://www.isas.jaxa.jp/e/enterp/missions/hayabusa/today.shtml JAXA Hayabusa Today (live updates of the craft's position)] [http://news.bbc.co.uk/2/hi/science/nature/4291258.stm Probe set for asteroid touch down] [http://www.msnbc.msn.com/id/8131678/ MSNBC article, "Japan shoots for a piece of an asteroid"] [http://www.spaceflightnow.com/news/n0508/22hayabusa/ ''Ambitious mission hopes to return bits of asteroid''] Comprehensive article by [http://www.spaceflightnow.com Spaceflight Now] [http://www.jpl.nasa.gov/news/fact_sheets/muses.pdf PDF document about cancelled Muses CN Rover] [http://www.hayabusa.isas.jaxa.jp/e/index.html JAXA: Latest news from Hayabusa] [http://www.isas.jaxa.jp/e/snews/2005/1102.shtml High-resolution images of Itokawa] ~~==Notes==~~ *<cite id="fn_1">[[#fn_1_back\|Note 1:]] Source: June 2005 issue of [[Sky and Telescope]], pp. 34-37, "Japan's asteroid archaeologist"</cite> ~~[[Category:Japanese probes]]~~ ~~[[Category:Japanese space program]]~~ ~~[[de:Hayabusa]]~~ ~~[[fr:Hayabusa]]~~ ~~[[he:היאבוסה]]~~ ~~[[id:Hayabusa]]~~ ~~[[ja:はやぶさ (探査機)]]~~ ~~[[pl:Hayabusa]]~~ ~~[[ru:Хаябуса (КА)]]~~ ~~[[zh:隼鸟号]]~~

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