DENVER, Colorado - The
hunt is on for the still-silent Mars Global Surveyor, the venerable NASA orbiter that failed to phone home earlier this month.
Now
another Mars orbiter is being primed to image the missing-in-action spacecraft.
NASA will attempt this week to use the Mars Reconnaissance Orbiter to spot the errant Mars Global Surveyor (MGS). If
successfully identified and photographed, engineers might be able to better assess what's ailing the
troubled probe and perhaps take corrective steps.
Spacecraft
engineers remain puzzled as to what occurred onboard the Mars orbiter to
curtail its communications with Earth.
MGS
was last heard from on November 5 after reporting earlier that it had problems
with a solar panel. Since then, repeat tries at regaining contact with MGS
using the Jet Propulsion Laboratory's Deep Space Network of powerful radio
dishes were to no avail.
Deep in troubleshooting
Engineers
here at Lockheed Martin Space Systems--designer and builder of the long-running
MGS--have been busily studying the situation. Navigation, instrument, and
spacecraft teams are deep in troubleshooting what might have happened to the
orbiter.
Without
radio contact the true whereabouts of MGS isn't precisely known.
"Right
now we don't have a great estimate on exactly where MGS is since it has been
out of contact for a while," said Wayne Sidney, the Mars Reconnaissance Orbiter
Flight Engineering Team Lead for Lockheed Martin Space Systems.
MGS
could be in a self-generated safe mode, perhaps making use of its thrusters and
has perturbed its orbit about Mars, Sidney told SPACE.com. By
extrapolating from the last known position of MGS, experts hope to deduce the
coordinates for where the craft should be as it spins around Mars.
Two-step plan
Tasking
the Mars Reconnaissance Orbiter (MRO) which was also designed and built by
Lockheed Martin Space Systems, to image MGS won't be easy. Sidney said that
there's a plus or minus 45 second window of error to deal with in catching sight
of MGS.
A
two-step plan is being implemented, Sidney advised. The strategy calls for
utilizing MRO's High Resolution Imaging Science Experiment (HiRISE) camera on
Wednesday, Sidney said, to take a long-exposure that, it is hoped, grabs a
glimpse of the MGS.
Given
that HiRISE successfully picks up the fast-moving MGS, then more precise and
higher-resolution targeting of the camera system can be done on Friday, Sidney said.
"So
it's two steps...back to back," Sidney noted. "It has been a scramble to try and
figure out how to do it. It's going to take a lot of push ups to get it done
this week, but I think everybody involved is actually pretty excited about it.
Most of us worked both [MGS and MRO] programs."
Photographing
MGS would help mission controllers learn what direction the spacecraft's
mast-mounted, high-gain antenna is pointed. It is used to receive signals from
Earth as well as send transmissions to ground controllers. Also, knowing the
orientation of the spacecraft's solar panels would be a plus, Sydney said.
Lost cause?
As
for calling MGS a lost cause, Sidney stated that there could definitely be a
scenario that brings the mute of a probe back to life. But MGS is the oldest of
six spacecraft now active at the red planet and has been in service longer than
any other spacecraft ever sent to Mars.
Launched
in November 1996, the MGS original mission was to examine Mars for a full
Martian year, roughly two Earth years. Once that period elapsed, NASA extended
the mission repeatedly, most recently on October 1 of this year.
It's
important to recognize that MGS was on its third extended mission, Sidney said. And through all the years of scanning Mars, he added, MGS also supported the
Mars Reconnaissance Orbiter's lengthy aerobraking at the planet by watching for
martian dust storms that influence Mars' upper atmosphere.
There's
a feeling that maybe the well-used MGS felt it was time to sign off.
On
the 10th anniversary of MGS in space--November 7--that's the same day that MRO
cranked up its primary science tasks.
"It
really seems like there's some fate involved in this," Sidney said. "MGS knew
it was time to retire."
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