Asteroid-punching probe back on track November 11, 2005Posted by jtintle in Hayabusa, Itokawa, Space News.
NewScientist.com news service
Japan’s Hayabusa spacecraft successfully completed a practice approach to asteroid Itokawa on Wednesday after a previous â€śdress rehearsalâ€? failed on 4 November. Mission managers have now set dates for three more rendezvous with the space rock in an effort to return the first-ever asteroid samples to Earth in 2007.
On 4 November, mission officials called off the first rehearsal descent with the probe still 700 metres away from the asteroid because it had trouble identifying its landing site. The rehearsal was meant to test autonomous landing technologies in advance of two sample-collecting touchdowns and release a robot called Minerva that will hop around the asteroid, snapping images and measuring temperatures.
But mission officials say they have now identified the problem and successfully descended to within 70 metres of the 600-metre-long asteroid on Wednesday. They will retry the rehearsal descent â€“ and release Minerva â€“ on 12 November, then attempt sample collection landings on 19 and 25 November.
No specific information has been released concerning the problem or its solution, but on 7 November Hayabusa’s project manager Jun’ichiro Kawaguchi told New Scientist: “We had difficulty accurately guiding the spacecraft.”
He said the problem was “deeply related” to the loss of two of its three stabilising reaction wheels in July and October 2005. Since then, the craft has been using its single remaining wheel and onboard hydrazine fuel thrusters to keep itself oriented.
Source: New Scientist SpaceÂ