Tiny Mars rover set to take giant roll for mankind
Mystery glitch that threatened mission fixed
July 5, 1997
Web posted at: 11:08 p.m. EDT (0308 GMT)
PASADENA, California (CNN) -- NASA scientists are getting
ready to send off Pathfinder's tiny rover on its historic
mission to roam the desolate, rock-strewn surface of Mars.
Saturday night, commands were sent to prompt Pathfinder's landing vehicle to lower the ramps that the rover, Sojourner, will use to roll down to the Martian surface. The rover, which has been stored in a compact position, will also rise up to its full size -- only about as big as a microwave oven -- prior to deployment.
The actual descent of the rover is scheduled to come two to three hours after the ramps are lowered. When that happens, it will mark the first time that a mobile spacecraft from Earth has driven over the surface of another planet.
However, at least in the beginning, Sojourner won't wander
very far afield.
"For the first couple of days, we'll really just have a
learner's permit, relative to driving the rover. It will
take us a couple of days to get our sea legs," says rover
system engineer Matt Wallace.
"We'll just drive down the ramp, and we may do a small turn,
but very little other than that," he said. Scientists also
will activate an instrument on the rover, called an X-ray
spectrometer, that can evaluate the chemical composition of
rocks and soil.
Pathfinder project manager Tony Speer also announced Saturday
night that the Pathfinder lander has been named Sagan
Memorial Station in honor of the late astronomer Carl Sagan.
Rover descent would mark end of dramatic day
If the rover deployment goes off as planned, it will be a
welcome end to a day of drama that threatened to cast a cloud
on a space mission that had been exceeding expectations.
Late Friday evening -- hours after a flawless landing on the
red planet's surface -- scientists at NASA's Jet Propulsion
Laboratory in Pasadena, California, discovered that only the
smallest bits of information were getting through from the
rover to the lander. That could have hampered the ability to
move the rover around the Martian surface.
The JPL team labored all day Saturday to correct what they
believed was a software problem in a communications modem.
Just before 7 p.m. EDT Saturday (2300 GMT), they began to
receive data sent from the rover to the lander to Pasadena,
indicating that their efforts had been successful.
Cheers and high-fives erupted in Mission Control, as someone
exclaimed, "We're alive, we're alive."
At a press conference a short time later, NASA scientists
were at a loss to explain what caused the communications
problem -- or what fixed it. The leading theories are that
switching to a backup power supply for the lander's modem or
shutting down the rover's systems for its usual nighttime
hibernation may have been what did the trick.
A computer system on the lander also shut down and reset
itself sometime during the Martian night. Mission manager
Richard Cook said, "We're a little perplexed as to what
happened," but he said it should not have any detrimental
effects on the Pathfinder mission.
Rover is centerpiece of Pathfinder mission
The rover is the "gee whiz" centerpiece of the mission. And
the communication link between it and the lander was an
essential element in its success, because commands to the
rover from Earth are sent through the lander.
If it is cut off from communication with Earth for an
extended period of time, Sojourner has been programmed to
eventually begin rolling on its own, using preset data stored
in its memory. But NASA scientists clearly preferred not to
resort to that backup plan.
"We would prefer to try to command that activity, as opposed
to letting the rover make up its own mind to do this itself,"
said Jacob Matijevic, rover manager.
NASA analyzing Mars images
NASA officials have been busy analyzing the images being sent
back by Pathfinder, which they started receiving about 9:35
p.m. EDT Friday (0135 GMT Saturday). So far, engineers say
they have been able to make several interesting observations:
Officials also said they were perplexed by an object in one
of the photographs.
"The most mysterious thing in this picture is this little
object on the horizon that has been likened to a couch,"
Smith said, pointing to the object. "Somebody suggested there
was a homeless person camped out there."
He said he believed the squiggly object might be one of the
parachutes used to help Pathfinder slow down during entry.
But, he said, geologists believed it was a fascinating rock
that needs to be investigated further.
- NASA gets good news on Pathfinder glitch - July 5, 1997
- CNN: NASA TV live
- NASA gets good news on
Pathfinder glitch - July 5, 1997
- Communications glitch hampers Mars rover - July 5, 1997
- Mars Pathfinder sends first snapshots - July 4, 1997
- NASA: Pathfinder has landed - July 4, 1997
- Pathfinder speeds toward Martian surface - July 4, 1997
- Pathfinder nears its destiny - July 3, 1997
- Scientists giddy as Pathfinder nears Mars - July 1, 1997
- NASA hope third time's the charm for Mars probe launch - December 3, 1996
- Pathfinder to roam Mars in search of possible life - October 1, 1996
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