2-up - ETH Zürich

Considering Changes in the Flight Software
MISSION STATUS - 15 July 1997, noon PDT
The team continues to trouble-shoot the
problem by testing all of the sequences
leading up to reset in JPL's Mars Pathfinder
testbed; considering changes in
the flight software that would allow for
immediate recovery if the flight computer
were to reset itself; and modifying
operational activities to minimize data
loss if a reset should occur again. “In a
sense, the reset itself is not harmful
because it brings us back into a safe
state,” said Reeves. “But it does cause a
disruption of the operational activities.”
790
The Task Had Not Been Given High Enough Priority
MISSION STATUS - July 17, 1997, 11 am PDT
Mars Pathfinder engineers... also noted that they have found and are in the
process of fixing a software bug that had caused the lander's computer to
reset itself four times in recent days.
“The resets on the lander computer
were caused by a software task that
was unable to complete the task in the
allotted time,” said Flight Director
Brian Muirhead. “We found that the
task was being cut short because it had
not been given high enough priority to
runthroughtocompletion.Basically,
we just need to add one instruction to
the computer software to raise the
priority of that task.”
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