PFS issue on Venus Express, PFS scanner stuck in its closed position Options

[Rakhir]

Bad news for PFS. I hope they will be able to solve this issue.

The PFS scanner is stuck in its closed position.
Several attempts to move it were made at the time, but the instrument did not respond. Experts suspected a thermal problem by which low temperatures were blocking the rotation of the mechanism.
Another attempt to move the scanner was made on 16 March 2006, in warmer flight conditions. Unfortunately, the scanner remains stuck.

The next opportunity to perform another test on the spacecraft will be end of April, after the Venus Orbit Insertion.

From http://sci.esa.int/science-e/www/object/in...fobjectid=38964

[PhilHorzempa]

I have it, from a Brilliant Reliable Unmanned Craft Expert,
that the PFS on Venus Express may still be "cured."
Since ESA tests indicate that warming the PFS up
seems to help, they may be considering the possibilities of a more intense
thermal shock. This would mean exposing that side of VEX to the Sun in
a major way to heat up the PFS a lot more, but doing careful studies
to make sure that they won't damage the other instruments in the process,
and also making a lot of high-priority science observations with them
before risking this type of maneuver.
They may also try cycling it between strong heat and
strong cold. Sometimes such thermal shock works, as with
MARSIS' antenna, and sometimes it doesn't, as with
the forward plasma-analyzer door on Mariner 10.
The other option would be to try to include a replacement on Japan's Venus
probe.


Another Phil

[stevesliva]

They may also try cycling it between strong heat and strong cold. Sometimes such thermal shock works, as with MARSIS' antenna, and sometimes it doesn't, as with the forward plasma-analyzer door on Mariner 10.

It worked with the Stardust navcam, after outgassing contaminated the lens.