[meteorite-list] Hayabusa's Practice Descent (Rehearsal) on November 4th

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Nov 7 00:09:02 2005
Message-ID: <200511070507.jA757dx25933_at_zagami.jpl.nasa.gov>

http://www.isas.ac.jp/e/snews/2005/1104.shtml

Hayabusa's Practice Descent (Rehearsal) on November 4th
Japan Aerospace Exploration Agency (JAXA)
November 4, 2005

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 Hayabusa's 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 JAXA's Usuda station, the radio
communication to the spacecraft, the attitude control were all in order
and the instruments aboard were all functioning normally.

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 strategy stiffer.

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.
Received on Mon 07 Nov 2005 12:07:38 AM PST