JPL: Mars Polar Lander Mission Status

From: Brian D Williams (
Date: Wed Jan 26 2000 - 07:47:03 MST


               Mars Polar Lander Mission Status
                       January 25, 2000

     Mission managers have decided to send another set of
commands to Mars to investigate the possibility that a signal
detected by a radio dish at California's Stanford University
came from Mars Polar Lander.

     The commands were sent at 10 a.m. PST today. They will
instruct the lander, if it is operating, to send a signal
directly to Earth to the antenna at Stanford on Wednesday,
January 26, at approximately 1 p.m. PST. The Stanford receiving
station will listen again during the window on Wednesday to see
if it picks up a signal that could originate from Mars. The
results of this test will not be immediate and it will take the
team several days to process the data.

     Mission managers sent commands several times in December and
January instructing Polar Lander to send a radio signal to the
45-meter (150-foot) antenna at Stanford. Although no signal was
detected in real-time, the team in charge of the Stanford antenna
says that after additional processing of the data they may have
detected a signal that could have come from Mars during tests
on December 18 and January 4. Because the signal was so weak,
it took several weeks for the Stanford team to process their
data and reach this conclusion.

     "This week's test is a real long-shot, and I wouldn't want
to get anyone too excited about it," said Richard Cook, Polar
Lander project manager at NASA's Jet Propulsion Laboratory,
Pasadena, CA. "The signal that the Stanford team detected is
definitely artificial, but there are any one of a number of
places it could have originated on or near Earth. Still, we need
to conduct this test to rule out the possibility that the signal
could be coming from Polar Lander."

     If in fact the signal were from Polar Lander, two failures
would have had to occur. First, the lander's X-band radio that
it would use to transmit directly to Earth would have to be broken.
Second, there would have to be a problem somewhere in the relay
with Mars Global Surveyor that prevented the signal from being
picked up and relayed by the orbiter. It is unlikely that a broken
transmitter on the lander could be fixed, and unclear whether a
problem with the relay could be resolved.

     Although the Stanford data from the previous tests took
several weeks to process, the team expects to have results within
several days now that they know what they are looking for.

     Even if the signal were coming from the lander, there is
little hope that any science could be returned. However, it would
give the team a few more clues in trying to eliminate possible
failure modes.

     Mars Polar Lander is managed by the Jet Propulsion
Laboratory for NASA's Office of Space Science, Washington, DC.
Lockheed Martin Astronautics Inc., Denver, CO, is the agency's
industrial partner for development and operation of the
spacecraft. JPL is a division of the California Institute of
Technology, Pasadena, CA.


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