[meteorite-list] Deep Impact Spacecraft Is Spinning Out of Control

[Ron Baalke]

http://blogs.nature.com/news/

NASA's Deep Impact spacecraft is spinning out of control
Eric Hand
Posted on behalf of Ron Cowen
Nature News Blog
September 5, 2013

NASA's Deep Impact spacecraft is in deep trouble. The craft, famous for 
blasting a projectile into the Comet Tempel 1 in 2005, lost contact with 
Earth sometime between 11 August and 14 August. Recent commands to put 
the craft in hibernation, or safe mode, were unsuccessful, and Deep Impact 
is now spinning out of control, says principal investigator Michael A'Hearn 
of the University of Maryland in College Park. The mission was renamed 
Epoxi when it was extended to observe comets and stars with transiting 
exoplanets.

Engineers have traced the problem to a software-communications glitch 
that reset the craft's computer. They are now working on commands that 
could bring Deep Impact back into operation. They may try to communicate 
with the spacecraft this weekend, but the team first has to figure out 
its most likely orientation and whether to broadcast signals to the 
vehicle's high-gain or low-gain antenna.

Mission scientists are racing against the clock because the craft's batteries 
rely on power provided by Deep Impact's solar panels. If the panels on 
the wayward craft happen to be pointing in a direction where they receive 
partial sunlight, the batteries could last for a few months. But if the 
panels are pointed away from the Sun, the batteries would die in just 
a few days. Once the batteries are gone, Deep Impact can no longer be 
revived, A'Hearn says.

One casualty of the mishap is that scientists have not received any of 
the expected images the craft was scheduled to take in August of Comet 
ISON, the icy space rock that could make a spectacle in the inner Solar 
System this fall before diving into the Sun, A'Hearn says.