[meteorite-list] Mars Rover Rises From Crater For New Trek

[Ron Baalke]

http://msnbc.msn.com/id/6708091/

Mars rover rises from crater for new trek

After studying Endurance Crater, Opportunity sets its sights for
heat shield impact site and beyond

[Image]
The Opportunity rover's heat shield shows up as a white speck in the
distance, in an image that was captured by the rover's panoramic camera
after rising out of Endurance Crater. Martian bedrock is visible in the
foreground.

By James Oberg
NBC News space analyst
Special to MSNBC
December 13, 2004

After six months of exploring the inside of a stadium-sized Martian
crater, the seemingly never-ending story of NASA's Opportunity rover
continues with a trek across the Martian plains. New goals and new
discoveries are already in sight.

Photographs released on Sunday show new views of the Martian plains,
taken by the robot as it cleared the rim. One of the latest images shows
a white object, the goal of Opportunity's next traverse.

This artificial structure is not some alien monument, but the probe's
own heat shield, released moments before its landing almost a year ago.
Scientists are eager to examine both the shield and the deep hole it
gouged into the ground.

How it got this far

Opportunity landed on Mars on Jan. 24, bouncing across Meridiani Planum
and coming to rest within a 20-meter-wide (65-foot-wide) crater.
Designed for a 90-day primary mission, the rover rolled across a
cratered plain, examining rocks and small craters.

On June 10,
long after its 90-day "warranty" had lapsed, Opportunity stood on the
edge of a crater whose walls were lined with sedimentary rocks that
promised to contain secrets of the early eons of Mars. After weighing
the risks and potential payoffs, scientists sent the wheeled robot over
the edge and into the crater.

Over the months that followed, Opportunity defied the depths of the
Martian winter, a communications gap when Mars passed behind the sun,
the minor aches and pains of aging hardware, and a growing burden of
choking dust that slowly strangled the flow of electrical power from its
solar energy panels. It drilled holes, sampled rocks and dust, and sent
back pictures ranging from microscopic-scale detail shots to stunning
panoramas.

Controllers at NASA's Jet Propulsion Laboratory faced steep, slippery
slopes and crumbly soil where the six wheels turned as uselessly as auto
wheels spinning in snow and ice. Planners also had to keep the rover's
top edged to the north to maximize the sunlight falling on the solar panels.

"The rover was pushed to its traverse limits, but continued to perform
all that was asked of it," mission planners said in a recent status
report. "Opportunity remains in excellent health," they said, adding
that "solar power is nearly as high now as it was at the beginning of
the mission." Somehow the dust was not accumulating as fast as hoped, or
was being shaken off by the rover's frantic motions.

The crashed flying saucer

The rover mission's principal investigator, Steven Squyres of Cornell
University, described the team's plans in a recent interview with
Astrobiology magazine

"We've got a lot of things ahead of us," he explained. "The first thing
we're going to do is get to the heat shield. We've been itching to go to
this thing for months now."

The disk-shaped shield hit the ground at about 200 miles per hour. "It's
going to look like a crashed flying saucer out in the desert," Squyres
joked.

"We want to look down into whatever hole it dug," he said. "It's
probably deeper than any hole that we can dig with our wheels.

Examining the shield itself will also help design future Mars probes, he
added. This is important, he explained, because "no one's ever been able
to examine a heat shield that's gone through the Martian atmosphere."
The rover will use its microscope to document the effects of the heat
shield's fiery passage through the atmosphere - and the data could help
designers craft thinner, lighter, more efficient shielding.

Squyres estimated that the heat shield was about 500 feet (150 meters) away.

Over the horizon

A few specific local science experiments will also now be possible.
"There are a few cobbles - little fist-sized rocks scattered about the
plains - and we've never looked at one," Squyres told Astrobiology
magazine. "So we're going to find out what those rocks are made of."

The probe will then roll south, probably for the rest of its life. About
a mile and a half (2.5 kilometers) away begins a region of what is
called "etched terrain," broad striped regions that are thought to
represent different levels of sediments. Analyzing those layers could
provide further insights about Mars' geological history.

About 2 miles (3.2 kilometers) even farther away is Victoria Crater, six
times bigger than Endurance Crater. That may prove to be "one crater too
far" -  unreachable in any reasonable rover lifetime. But Opportunity and
its twin rover Spirit, on the other side of the planet, already have
shown surprising endurance, and there may be more surprises yet to come.