Hayabusa currently hovering around a near Earth asteroid Itokawa commenced its
descent at 19:17 GMT on November 3rd commanded from the ground, when the altitude
to the surface was about 3.5 km. It took an aim at calibrating its proximity laser range
finders, visibility calibration and image processing of a target marker as well as deploying a
hopping robot MINERVA.
Down to about 700 meters in attitude, both attitude and trajectory control had been
performed via Hayabusafs proprietary autonomous guidance and navigation capability as
planned. However, the onboard navigation computer detected anomalous information that
did not satisfy the requirement, the abort command was transmitted from the ground at
03:30 GMT on November 4th. The subsequent events were all canceled and the
spacecraft fired its chemical engines and started ascent.
When the operation ended from JAXAfs Usuda station, the radio communication to the
spacecraft, the attitude control were all in order and the instruments aboard were all
Despite the interruption, the project team thinks that it obtained very important
information through this practice descent flight, and that this practice does make the
The project intends to perform another practice descent again. As of today, the
rehearsal schedule together with those for two touching-down and sampling have not
been decided yet. What caused the interruption and how it is coped with are presently
under investigation and the details will be released after it has been identified.