Hayabusa
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| Missing image Hayabusa(Muses-C)_sampling.jpg Hayabusa collecting asteroid rock sample | |
| Hayabusa spacecraft | |
| Organization | JAXA |
| Launch date | 9 May 2003 |
| Mass | 500 kg |
| Current destination | asteroid 25143 Itokawa |
| Mission | asteroid sample return |
| Instruments | |
|---|---|
| AMICA | multiband imaging camera |
| LIDAR | laser altimeter |
| NIRS | near-infrared spectrometer |
| XRS | x-ray spectrometer |
- For other uses, see Hayabusa (disambiguation).
Hayabusa (はやぶさ) is a Japanese-led unmanned space mission designed to collect a sample of material from an asteroid named 25143 Itokawa 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 May2003 and is currently on course to rendezvous with asteroid Itokawa in September 2005. While at asteroid Itokawa, the Hayabusa spacecraft and its detachable mini-lander (see Minerva mini-lander below) will study the asteroid's shape, spin, topography, color, composition, density, and history. By November 2005, the Hayabusa spacecraft will briefly land on the asteroid to collect a small sample, and will return this sample to Earth by July 2007.
While other spacecraft, notably Galileo and NEAR Shoemaker, have visited asteroids before, the Hayabusa mission marks the first time that an asteroid sample will be returned to Earth for analysis.
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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 four xenon-fuel ion engines have been operating near-continuously for the last two years, slowly moving Hayabusa toward a September 2005 rendezvous with 25143 Itokawa, a 0.3 x 0.7 km near-Earth object. 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. Following this, the spacecraft will then move close to the surface for a series of soft landings and collection of samples at three sites. On-board optical navigation will be employed extensively during this period because the long communication delay prohibits Earth-based real-time commanding. Once Hayabusa touches down, the spacecraft will fire a tiny projectile at the surface and then collect the resulting spray. Once collected, 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, Australia.
Minerva mini-lander
While at asteroid Itokawa, the Hayabusa spacecraft will deploy a tiny mini-spacecraft named Minerva. Taking advantage of the very low gravity at Itokawa, this solar-powered, box-shaped vehicle will hop along the surface of the asteroid, relaying images from its cameras to Hayabusa whenever the two spacecraft are in sight of each other.
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, 25143 Itokawa. Accordingly, Hayabusa "will bridge the gap between ground observation data of asteroids and laboratory anlaysis of meteorite and cosmic dust collections," says mission scientist Hajime Yano. 1
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.
External links
- NASA page on mission (http://nssdc.gsfc.nasa.gov/database/MasterCatalog?sc=2003-019A)
- JAXA page on mission (http://www.isas.jaxa.jp/e/enterp/missions/hayabusa/index.shtml)
- MSNBC article, "Japan shoots for a piece of an asteroid" (http://www.msnbc.msn.com/id/8131678/)
Notes
- Note 1: Source: June 2005 issue of Sky and Telescope, pp. 34-37, "Japan's asteroid archaeologist"de:Hayabusa