Spirit Lowers Front Wheels, Looks Around in Infrared
January 9, 2004
NASA's Spirit, the first of two Mars Exploration Rovers on the
martian surface, has stood up and extended its front wheels while
continuing to delight its human partners with new information about
its neighborhood within Mars' Gusev Crater.
Traces of carbonate minerals showed up in the rover's first survey
of the site with its infrared sensing instrument, called the
miniature thermal emission spectrometer or Mini-TES. Carbonates
form in the presence of water, but it's too early to tell whether
the amounts detected come from interaction with water vapor in Mars'
atmosphere or are evidence of a watery local environment in the
past, scientists emphasized.
"We came looking for carbonates. We have them. We're going to
chase them," said Dr. Phil Christensen of Arizona State University,
Tempe, leader of the Mini-TES team. Previous infrared readings from
Mars orbit have revealed a low concentration of carbonates
distributed globally. Christensen has interpreted that as the
result of dust interaction with atmospheric water. First
indications are that the carbonate concentration near Spirit may be
higher than the Mars global average.
After the rover drives off its lander platform, infrared
measurements it takes as it explores the area may allow scientists
to judge whether the water indicated by the nearby carbonates was in
the air or in a suspected ancient lake.
"The beauty is we know how to find out," said Dr. Steve Squyres of
Cornell University, Ithaca, N.Y., principal investigator for the
mission. "Is the carbonate concentrated in fluffy dust? That might
favor the atmospheric hypothesis. Is it concentrated in coarser
material? That might favor the water hypothesis."
Spirit accomplished a key step late Thursday in preparing for
rolling off the lander. In anticipation, the flight team at NASA
Jet Propulsion Laboratory in Pasadena, Calif., played Bob Marley's
"Get Up, Stand Up" as wake-up music for the sixth morning on Mars,
said JPL's Matt Wallace, mission manager. In the following hours,
the rover was raised by a lift mechanism under its belly, and its
front wheels were fully extended. Then the rover was set back down,
raised again and set down again to check whether suspension
mechanisms had latched properly.
Pictures returned from the rover's navigation camera and front
hazard-identification camera, plus other data, confirmed success.
"We are very, very, very pleased to see the rover complete the most
critical part of the stand-up process," Wallace said. Next steps
include retracting the lift mechanism and extending the rear wheels.
A tug on airbag tendons by the airbag retraction motor Thursday
evening did not lower puffed up portions of airbag material that are
a potential obstacle to driving the rover straight forward to exit
the lander. The most likely path for driving off will be to turn 120
degrees to the right before rolling off. "This is something we have
practiced many times. We are very comfortable doing it," Wallace
said.
The earliest scenario for getting the rover off the lander, if all
goes smoothly, is Spirit's 13th or 14th day on Mars, Jan. 16 or 17.
"We're proceeding in a measured, temperate way," said JPL's Peter
Theisinger, project manager for the Mars Exploration Rover project.
"This is a priceless asset. It is fully functioning. It is sitting
in a beautiful scientific target. We're not going to take any
inappropriate risks."
While preparing to learn more about what Mars rocks are made of,
Christensen announced an educational project to involve school
children and other people in getting rocks from all over Earth for
comparison. "Send me your rocks and we'll see if there are rocks in
your back yard that are similar to what we're seeing on Mars," he
said. Information about how to send rocks to Arizona State
University is on the rovers' Web site at
http://marsrovers.jpl.nasa.gov.
Spirit's twin Mars Exploration Rover, Opportunity, will reach Mars
on Jan. 25 (Universal Time and EST; Jan. 24 PST). The rovers' main
task is to spend three months exploring for clues in rocks and soil
about whether past environments near the landing sites were ever
watery and possibly suitable to sustain life.
JPL, a division of the California Institute of Technology,
manages the Mars Exploration Rover project for NASA's Office of
Space Science, Washington.
