After
surviving near fatal dust storms on Mars, NASA's Opportunity rover is gearing
up for its long-awaited trek inside an expansive crater on the red planet's
surface.
Opportunity could begin descending down into Mars'
giant Victoria Crater by Sept. 11 after spending two months hunkered down to wait
out sunlight-blotting storms that nearly starved
the solar-powered rover and its robotic twin, Spirit. The rover spent this
week rolling ever closer to entry point into Victoria Crater.
"Opportunity
might be ready for that first 'toe dip' into the crater as early as next
week," said John Callas, project manager for the Mars rover mission at the Jet
Propulsion Laboratory in Pasadena,
Calif., in a Friday
statement.
Victoria is
the largest crater visited by Opportunity during a 43-month trek across its Meridiani
Planum landing site. A bright layer of exposed rock inside the 2,400-foot wide
(730-meter wide) crater may yield tantalizing clues of interactions between
Mars' surface and atmosphere millions of years ago, mission researchers said.
To prepare
for the descent into Victoria Crater, Opportunity's handlers will send the rover
to
an entry point that will allow clear access to the bright band of rock
about 40 feet (12 meters) blow the depression's rim. The rover will then back
out a bit to check how much it may slip during the descent.
"We
chose a point that gives us a straight path down, instead of driving
cross-slope from our current location," said JPL rover driver Paolo
Bellutta. "The rock surface on which Opportunity will be driving will provide good traction and control of its path into
the crater."
Spirit,
meanwhile, climbed atop a rock plateau dubbed "Home Plate' on Wednesday.
The plateau had been a long-time destination for Spirit as the rover explores
its Gusev Crater landing site.
Health
checks planned
But before
Opportunity can begin its crater descent, scientists on Earth will check the
health of two vital instruments to ensure the months-long martian dust storms
haven't crippled their ability to collect data.
If the dust
storms have not impacted a microscope-like camera on Opportunity's robotic arm,
mission managers will use it to inspect a crucial mast-mounted mirror.
The mirror
reflects infrared light into the rover's Miniature Thermal Emission
Spectrometer (Mini-TES), allowing scientists to determine the minerals present
on the martian surface. Some data from the spectrometer's last use hinted that
the mirror, which can also swivel to cover a mast opening as a dust guard, may
not be moving properly.
"It
would be the first permanent loss of an instrument on either rover," said
rover science principal investigator Steven Squyres, of Cornell University in
Ithaca, N.Y. "But we'll see."
The dust woes of Opportunity and Spirit began in late June, when astronomers spotted
growing dust storms on the red planet's surface. The storms swelled to blot
out much of the sunlight on the planet's surface, leading some mission managers
to worry that the solar-powered rovers could starve from lack adequate energy
supplies.
By late
August, the storms had subsided enough
to allow Opportunity and Spirit to once more explore Mars. Opportunity, which weathered
the storms while perched on the rim of Victoria, resumed preparations to enter
the crater.
All-weather
rovers
Originally
slated to spend three Earth months exploring Mars, Spirit and Opportunity are
now in their fourth year of red planet roving. The two robots have uncovered
evidence of the planet's ancient watery past, scaled hills and studied a
martian meteorite among their many
scientific exploits.
While dust
is still settling from Mars' recent storms, wind gusts have been aiding
Opportunity's recovery by blowing away dust particles from its solar arrays
almost as fast as they are deposited, mission managers said.
"These
rovers are tough," said Alan Stern, NASA's associate administrator for
science missions, in a Friday statement. "They faced dusty winds, power
starvation and other challenges--and survived."
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