From: Jan Wee <jwee@mail.arc.nasa.gov>
Subject: Mars Pathfinder Mission Status - 24 January 1997 (resend)
Date: Mon, 27 Jan 1997 21:20:18 -0600
Dear discuss-lfm members,
I encourage you to visit the Mars Pathfinder web site often as you
can tap into excellent resources updating you on the Pathfinder Mission.
Same goes for the Mars Global Surveyor! There are some wonderful Mars Watch
images provided by amateur and professional astronomy groups as well
as a Mission Status email service. The report below is a sample of
the latest report. You can sign up online via the Pathfinder Mission
web site.
One of the reflector sites for Mars Pathfinder is at:
http://wwwmpf.arc.nasa.gov
MARS PATHFINDER MISSION STATUS
24 January 1997
The spacecraft continues to function well and is currently 14 million kilometers
from Earth. The major activity for last week was starting the performance
testing of the K=15 R=1/6 convolutional code. Early tests results indicate that
the Block III MCD is operating as expected and that the expected telecom link
improvements match predicts.
The project is investigating some minor anomalies which occurred this week
involving the spacecraft Command Detector Unit. The most serious of these
occurred on Monday, January 20 when the CDU transitioned to a lock state during
a period when we were not uplinking to the spacecraft. The CDU lost lock as
expected when we transmitted an uplink signal, but this "self-lock" behavior is
not expected. In addition, we experienced two other episodes where commands were
rejected by the spacecraft uplink hardware for unexplained reasons. The project
has started a tiger team activity to further investigate these problems and
determine potential causes. The possibility of solar flare induced SEUs is being
assessed, but we are not ruling out other potential causes.
The flight team is also investigating an attitude control fault that we
experienced on Sunday, January 19. This fault occurred when estimates of the
attitude covariance matrix inexplicably jumped by several orders of magnitude.
The resulting fault response reinitialized attitude control flight software and
turned off the Propulsion Drive Electronics. Analysis of telemetry before and
after the fault did not show a definitive cause. We are currently planning to
perform additional diagnostic tests to assess memory and software integrity in
case SEUs or numerical divergence problems may have caused this problem.
Continuing EDL and surface operations planning. The Rover team completed a
successful Rover Operations Readiness Test, and planning is nearly complete for
the first full team Surface Operations Readiness Test on January 27-28.
Jan Wee, discuss-lfm moderator
Jan Wee, Education Outreach Coordinator
Passport to Knowledge
Voice: 608-786-2767 (8am-4pm Central time)
Fax: 608-786-1819 (anytime)
Check our web resources:
Live From Mars
http://quest.arc.nasa.gov/mars
(Nov.'96- Nov'97)
Live From Antarctica 2
http://quest.arc.nasa.gov/antarctica2
(January-March '97)