[meteorite-list] Spirit Gets A Dust Devil Once-Over

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Mon Mar 21 13:24:56 2005
Message-ID: <200503140647.j2E6lCN28924_at_zagami.jpl.nasa.gov>

http://space.com/missionlaunches/spirit_dust_050312.html

Spirit Gets A Dust Devil Once-Over
By Leonard David
space.com
12 March 2005

Mars scientists and engineers are elated about a dust-busting blast that
has struck the Spirit rover at its Gusev crater exploration site.

Turns out that a martian whirlwind - dubbed a dust devil - likely zoomed
over the robot high up in the Columbia Hills. That fleeting flyby
effectively cleaned Spirit's solar arrays, giving the robot a new lease
on life.

Engineers report that the rover's power reading quickly shot up to
almost as high as when the rover landed on Mars over a year ago.

Gusev: Alive with dust devils

Rover scientists suspected something was up at the Gusev site when
Spirit's wheel tracks were disappearing. Onboard cameras could look down
and see the tracks vanishing. Rover team members assumed that the site
was experiencing a heavy dust loading in the atmosphere.

Indeed, the rover's energy quickly dropped. Seeing the robot's
decreasing power level, controllers started to consider cutting back on
rover Mars work.

"Gusev was alive with dust devils," explained one scientist familiar
with rover operations.

But suddenly Spirit's available energy rocketed to a high level. The
plus-up in power, team members believe, was due to a whirlwind passing
right over the robot, removing the dust that had collected on its solar
cells.

Martian squeegee men

The impact of the devilish dust-off was significant.

"The noon solar output from the panels went from a 40 percent loss to
just 7 percent," said rover science team member, Larry Crumpler, a
research curator in volcanology and space sciences at the New Mexico
Museum of Natural History and Science in Albuquerque.

Images of the panels taken later showed "beautiful dark panels,"
Crumpler explained. "And all the wires and edges on the [rover] deck
have little dust tails. I think it might have been the Martian squeegee
men. Either that or one heck of a buffeting by a dust devil," he said.

Spirit has been busy wrapping up a spectacular panorama from the vantage
point of "Larry's Lookout."

Miracle cleaning event

Earlier this month, lead investigator for the Mars Exploration Rover
mission, Steve Squyres of Cornell University, noted that Spirit's
depleted power was reducing the number of hours per day available to
snap photos.

Squyres couldn't gauge the chance of what he called a "miracle cleaning
event" - akin to what occurred months ago on Opportunity, its sister
robot on the other side of Mars. "If it happens, I'll take it!"

"We have to assume the worst - that the solar panels are going to stay
dirty and just get dirtier," Squyres told SPACE.com at the time.

As to what caused Opportunity's solar panels at Meridiani Planum to
become cleaned is a puzzle, Squyres said. "Wind has to be involved at
some level you figure. Frost might have helped. A frost build-up on
arrays could coagulate the dust - but the fact is that we don't understand
it very well. But I'll take it."
Received on Mon 14 Mar 2005 01:47:12 AM PST