Those
"never say die" robots on Mars--NASA's Spirit and Opportunity--continue to chalk
up science at their respective exploration sites.
Looming
large for the Opportunity rover at Meridiani Planum is Victoria Crater--a grand
bit of territory that's roughly half a mile (800 meters) in diameter. That's
about six times wider than Endurance Crater, a feature that the rover
previously surveyed for several months in 2004, gathering data on rock layers there
that were affected by water of long, long ago.
"We
are closing in ... we've got only about a kilometer to go now," said Steve Squyres,
lead scientist at Cornell University in Ithaca, New York for the dual Mars
exploration rovers.
"Feel
free to work out your own guess at an estimated time of arrival based on our
recent progress...but I'm not making any predictions! Mars has fooled us too many
times before," Squyres told SPACE.com.
Lay of the land
Pushing
across Meridiani Planum has not been easy for Opportunity. The landscape is one
of rolling ripples
of sand and splashes of outcrop rock.
"We're
pushing as hard as we can with a very old rover," Squyres added. "We'll get
there when and if we get there."
Once there, Squyres
said that the plan is to approach that feature much as they did Endurance
Crater.
"[We'll]
start by taking images from several points along the rim to get the lay of the
land...and then see if there's a place where we can enter the crater safely,"
Squyres said. "There's no guarantee that we'll be able to get in, of course,
but we're not driving all this way just for the view."
Rim shots
Also
anxiously awaiting Opportunity's hoped for wheeling up to Victoria Crater is
William Farrand, a research scientist at the Space Science Institute in Boulder, Colorado. He is a member of the Mars Exploration Rover science team.
"The
rover has been making good progress towards Victoria Crater. So--knock on
wood--it should get there perhaps as early as late July," Farrand told SPACE.com.
"We will be getting just amazing images when we get to the rim of Victoria
Crater."
Farrand
said the views at that feature are sure to be spectacular. But the real payoff,
he added, is to check out the exposures of outcrop that the science team is
expecting to see on the inner walls of Victoria Crater.
"Opportunity's mission has been all about reading the story contained within the layered
rocks that lie just below the surface of Meridiani Planum," Farrand advised.
"We got about 40 to 50 centimeters of outcrop at Eagle Crater [at the start of
its roving] and then 7 meters at Endurance Crater."
However,
at Victoria, it looks like there's a deeper story there.
Images
taken from Mars orbit suggest there might be something like 65 feet (20 meters)
of outcrop exposed within the walls of Victoria Crater, Farrand stated.
It
is still not clear whether rover scientists will be able to get into the crater
to do the type of detailed, on-the-spot analysis that they were able to do within
the inner rim of Endurance Crater.
But
Farrand said that by utilizing Opportunity's Panoramic Camera and Mini-Thermal
Emission Spectrometer, researchers should be able to do some tremendous remote
sensing at that locale.
Spirit: making it through winter
And
on the other side of Mars within Gusev crater, sistership Spirit is devotedly
engaged in gathering science data too. It's in need of a little dental work,
however.
The
robot's grinding teeth have worn away on its arm-mounted rock abrasion tool--but
only after exposing interiors of five time more rock targets than its design
goal of three rocks. The tool still has useful wire bristles for brushing
targets.
"Spirit
has been very busy lately, taking an enormous panorama that we call the McMurdo
Pan," Squyres reported. The robot is doing lots of work with its robot arm--officially
labeled, in mechanical jargon, as the Instrument Deployment Device, or IDD.
Spirit
has been positioned in such a way that its solar panels can help the machine
endure several months of Martian winter.
The
power on Spirit is good, Squyres noted. Projections of the rover's overall
health, he said, suggest the robot will make it through the martian winter and
be able to keep doing science the whole time.
"One
thing about staying in one place for a long time is that it enables lots of
interesting science that just isn't possible when you're always moving. We're
taking advantage of that now with Spirit," Squyres explained.
The "eyes" have it
Both
Spirit and Opportunity are churning out travelogue-like photos of their
respective treks over Mars. The eyes of the robots - their camera systems - are
capturing a wide range of scenery along the way.
"All
of the cameras continue to work remarkably well and are continuing to acquire
beautiful images," said astronomer Jim Bell, the Panoramic camera (Pancam) payload
element lead for the Mars exploration rovers at Cornell University. "They have
proven to be extremely robust to the extreme conditions on the martian surface...large
temperature swings, fine dust everywhere, large cosmic ray flux," he told SPACE.com.
Since
the twin rovers independently landed on Mars in January 2004, Spirit's cameras
have taken about 82,000 pictures. Opportunity has taken about 71,500 pictures -
for a total down-linked image data volume of about 19 gigabytes. Of these,
54,400 and 49,500 are the high-resolution Pancam images, respectively, Bell said.
"At
Meridiani, once we get to Victoria Crater in June or July we are obviously
looking forward to remarkable views of the interior," Bell said, and to help identify
possible routes to explore even deeper exposures of sedimentary outcrop rocks.
"At
Gusev, we are hunkered down for the winter now, obtaining detailed chemical
measurements on reachable rocks and soils and acquiring the gigantic 360°
McMurdo panorama with little or no compression in all [camera] filters from our
winter haven parking spot," Bell said.
Up
there on Mars, Bell concluded, "the missions just keep rocking on!"
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