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From: starrfie@hydro.la.asu.edu (Sumner Starrfield)
Subject: Latest Mars Observer News- No News is Bad News
Date: Mon, 30 Aug 93 12:05:16 MST
Forwarded from the Mars Observer Project
MARS OBSERVER STATUS REPORT
August 29, 1993
9:00 PM PDT
The 64 hour safemode waiting period, which began with a command to reset
or "cold boot" Standard Control Processor 1, expired at about 8:50 PM PDT this
evening, with no spacecraft transmitter carrier or telemetry received
at the flyby predicted coordinates. The in-orbit position will be scanned
by the DSN (Deep Space Network) antennas after midnight looking for
transmitter carrier. If none is seen, the Flight Team will follow up with
commands to reset the engineering data formatter and power-on the transmitter.
With no acknowledgement from the spacecraft, commands will be sent to
reboot the Standard Control Processor backup and to select it as the primary.
If Standard Control processor 2 remains viable, receipt of the reset
command will invoke safemode and another 64 hour waiting period.
This status will be updated as new information becomes available.
MARS OBSERVER STATUS REPORT
August 30, 1993
8:00 AM PDT
The first fault protection 65 hour safemode waiting period expired Sunday
evening at about 8:20 PM PDT, with no spacecraft transmitter carrier or
telemetry received on the ground. The Flight Team responded by radiating
commands to power-on and select SCP-1 (Standard Control Processor #1),
followed by commands to reset the engineering data formatter and to power-on
transmitter 1. Those commands were sent to both flyby and on orbit
predicted locations. That activity was completed at 4:07 AM PDT this morning.
After two way light time elapsed, no indications of carrier or telemetry were
seen.
The decision to "cold boot" SCP-2 (Standard Control Processor 2) has not been
finalized and should be made this morning. Caution in evaluating potential
effects on other spacecraft telecommunications subsystem components is being
exercised. With the decision to power-on/reset SCP-2, another 65 hour waiting
period will be observed. If the result of the SCP-2 power-on/reset is the same
as those to date, commands will be sent to switch back to SCP-1 and repeat the
steps to restore telecommunications. The result of that activity will dictate
whether commanding will take place to switch radio crystal oscillator from the
backup to the primary and repeating telecommunications subsystem restoration
commanding.
This status will be updated during the day and evening as new information
becomes available.
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