[meteorite-list] Re: Touchdown!

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 09:41:09 2004
Message-ID: <200102130239.SAA27226_at_zagami.jpl.nasa.gov>

>
> Ron-
> I'm sure I can speak for everyone in saying thank you for the daily photos and
> details of this incredible mission. It has been appreciated and will be
> missed.

Thanks. Another update, it looks like the spacecraft landed a little earlier than
expected, and was in the middle of its final burn when it made contact with the asteroid.
Since safing was turned off, it would have continued to fire its thrusters and try to
maintain its orientation.
One estimate I've heard was that the thrusters fired for an additional 90 seconds after
touchdown. So it probably thrusted itself off the surface, and came back down again, and
then ended up on its side. The spacecraft was also in the middle
of transmitting its final image, so when it made contact, the tranmission to Earth
was interrupted, and the bottom 25% of the final image did not get through. When the
carrier signal was detected, it was a little weaker than before, but since the signal
was through the high gain antenna, that means the antenna was pointed in the general
direction of the Earth. We haven't received any telemetry data yet, and that is the next
step, to reestablish full communications with the spacecraft.

Ron Baalke
Received on Mon 12 Feb 2001 09:39:48 PM PST