Communications glitch hampers Mars rover
Pathfinder transmits dramatic images
July 5, 1997
Web posted at: 3:47 p.m. EDT (1947 GMT)
PASADENA, California (CNN) -- NASA scientists scrambled
Saturday to fix a communications problem with Pathfinder's
star performer: the little rover that is to journey onto the
If the problem is not corrected, engineers may not be able to
drive the six-wheeled Sojourner on Mars via remote control,
rover manager Jacob Matijevic said.
"The great galactic ghoul had to get us somewhere and
apparently the ghoul has decided to pick on the rover," said
Donna Shirley, the Mars exploration program manager at NASA's
Jet Propulsion Laboratory.
NASA has hoped the rover will record chemical information
about rocks and soil on Mars that could provide valuable
clues as to whether life could ever have existed on the
The communications problem between Pathfinder and Sojourner
emerged late Friday, hours after a flawless and dramatic
landing on the red planet after a seven-month journey of 309
It also came as Pathfinder beamed back historic photographs
of Mars' desolate, rock-strewn surface.
But as the photographs poured in, engineers discovered one of
the air bags that cushioned Pathfinder's landing had not
fully retracted, blocking the rover's pioneering roll to
'The great galactic ghoul had to get us somewhere.'
Donna Shirley, Mars exploration program manager
Engineers managed to clear at least one of two routes for
Sojourner to reach the surface and its treasure trove of
rocks. But commands sent to deploy one of two ramps and
unlatch the rover were not confirmed before transmissions
ceased Friday night.
At the earliest, the rover could get moving by 10:30
p.m. EDT Saturday, Matijevic said. Sojourner originally had
been scheduled to roll at midnight EDT (0400 GMT) Friday,
about an hour and a half before the daylight period on Mars
'We have confidence we'll be able to find a way to fix and
resolve this problem.'
rover manager Jacob Matijevic
Matijevic said computers on board Pathfinder and the rover
were not communicating properly. He said small "chunks" of
data were going through, but "large chunks" were not.
"We have confidence we'll be able to find a way to fix and
resolve this problem," Matijevic said.
The communication is an essential element of the mission
because commands to the rover are sent through the mother
"We need to get this communication problem, basically,
fixed," said deputy project manager Brian Muirhead.
Matijevic added that if the rover has not heard from NASA
engineers within about two days, it will automatically begin
its historic roll, using pre-set data stored in memory.
"We would prefer to try to command that activity, as opposed
to letting the rover make up its own mind to do this itself,"
Analyzing the images
The first full-color views of the planet from Pathfinder,
perched on the rocky Martian floor, were released by NASA
about 9:35 p.m. EDT (0135 GMT) -- less than nine hours after
the spacecraft made a landing that one NASA scientist
described as "way beyond our expectations."
The first stream of black-and-white pictures, a series of
shots taken around the edges of the spacecraft, started
coming into NASA's Jet Propulsion Laboratory in Pasadena,
California, about 7:35 p.m. EDT (2335 GMT).
Since then, officials have been analyzing the images for new
clues about Mars. So far, engineers said, they've uncovered
several interesting observations:
- The rocks in the photographs slant toward the northwest,
indicating that a flood could have oriented them in that
direction. The pictures were taken in a flood plain.
- The soil contains more than one color, meaning "there's
definitely two types of soil here," according to Peter Smith,
the principal manager for the Pathfinder imager.
Officials said they were perplexed by an object in one
of the photographs. Smith said he believed the squiggly
object might be a Pathfinder parachute. But, he said,
geologists believed it was a fascinating rock that needs to
be investigated further.
"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."
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