[X] My Assistant

[PhilHorzempa]

My purpose in starting this new thread is to review what we know
about the demise of the Mars Observer. As most know, the Coffey
review board concluded that vapor migration in the propellant
lines led to explosive mixing whenthe system was pressurized.
However, several other possible scenarios for the mishap were
possible, and in my opinion, perhaps, more likely than vapor migration.

My 'favorite' alternate model for MO's end concerns the pyro valves on
the Mars Observer. As I recall, they were similar to ones on Landsat 6.
I have not been able to find a final report for the demise of Landsat 6 on
the Internet. However, if my memory is correct, it was concluded that
the pyros in the Landsat 6 attitude control system ruptured the propellant
lines during the launch process. The Landsat 6 was launched on a Titan 2
and depended on an SRM for the final kick to orbit.

Landsat 6's ACS was to control attitude during the solid rocket burn.
However, the rupture in the prop lines caused all prop to bleed away.
Therefore, the satellite tumbled during the SRM burn, causing it to fall
short of orbital velocity.

I think that something similar may have happened to the Mars Observer.


Another Phil