PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109. TELEPHONE (818) 354-5011
http://www.jpl.nasa.gov
Mars Pathfinder Mission Status
July 10, 1997
2 p.m. Pacific Daylight Time
Seven days into surface activities on the Mars Pathfinder
mission, all spacecraft systems and instruments are continuing to
perform well. The rover remains in excellent health and appears
to be driving a little bit faster when left to its own devices
than when it receives instructions from Earth.
"Basically the rover overshot its target rock, Yogi, by a
little bit last night," explained Dr. Justin Maki, of the
University of Arizona, who is a member of the Imager for Mars
Pathfinder (IMP) team. Maki showed a movie of Sojourner as it
approached the large boulder and began to climb up its side with
one wheel. In this type of dead reckoning, the rover performed
just as it should have, which was to back off the rock once it
knew the rock was in the way, then turn and move away from the
object. Although the rover travels about 1 centimeter per second
(about 2 feet per minute), it appeared to be moving a little bit
faster on its own.
The science team targeted the left side of Yogi for alpha
proton X-ray spectrometer study because it appears to be dark and
free of Martian dust. However, that side turned out to be tricky
for the rover because of the rock's uneven contours and the
slight depression in the soil beneath the rock. The rover team
will instruct Sojourner to attempt instrument placement again
tonight. Multiple attempts to position the science instrument
were anticipated, making this repeat attempt nothing out of the
usual.
The navigation team also announced the Ares Vallis landing
site coordinates today as 19.33 degrees north latitude, 33.55
degrees west longitude.
Dr. Carol Stoker of NASA Ames Research Center showed some of
the virtual reality products that her team is beginning to
produce from the Pathfinder data during today's press briefing.
Data from the lander camera's stereo images are overlain with
terrain models to create the three-dimensional perspective, which
can then be rotated in any direction on any plane on a computer
screen. The 3-D perspective will be very useful to the science
team in planning rover traverses and in analyzing data.
Dr. Julio Magalhaes, also of NASA Ames Research Center, a
member of the atmospheric structure instrument/meteorology
package (ASI/MET) on board the Pathfinder lander, reported that
upper atmospheric temperatures are
extremely cold. Temperatures at an
altitude of 80 kilometers (50 miles) above the surface were
171 Celsius (minus 275 degrees Fahrenheit). In the lower
atmosphere, between 60 km to 13 km (37 to 8 miles) above the surface, the
temperatures are warmer and very close to those recorded by the
Viking landers of the mid-1970s.
The next scheduled press briefing will be held at 12:00 Noon
Pacific Daylight Time on July 11 in JPL's von Karman Auditorium.
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