PASADENA, Calif. — Easy pickings is what NASA’s Spirit rover has found on Mars.
Over the weekend, the robot was steered to a select rock at the Gusev Crater landing site, inching up to the target for detailed camera inspection.
That football-sized rock, named "Adirondack," may be the tip of the iceberg, so to speak, with much of the object perhaps buried below the sandy topside surface.
Once the robot wheeled off its landing base last Thursday, the robot parked itself on Mars and began to survey the scene. Rover control here at the Jet Propulsion Laboratory spotted a set of candidate rock types within a short driving distance for up-close scrutiny.
Trek to Adirondack
Scientists identified three rocks as possible driving targets. Two were dubbed "Sushi" and "Sashimi" and sat in an area that was tagged the Wasabi region. The third was the pyramid-shaped rock, Adirondack.
The total drive to Adirondack took 30 minutes, with picture-taking sessions done along the way. A little over 10 feet (2.85 meters) was covered by Spirit from a standing start near the lander.
Driving the rover to Adirondack has provided valuable data for future outings, said Eddie Tunstel, mobility engineer for the Mars rovers at JPL.
Once Spirit eased on up to the rock, it "wiggled" its wheels in the Martian surface. "Basically to get good footing," Tunstel said. Now resting within a foot of Adirondack, that distance is "well enough in reach of the robotic arm," he said.
Gaining solid footing on Mars means that Spirit should be adequately anchored in dirt, good enough to apply the robot’s Rock Abrasion Tool, or RAT — one of four geological instruments mounted on the rover’s outstretched robot arm.
Scientists on the rover team are assessing if the chunk of Mars is an ideal candidate for the RAT, a fast-spinning rock-grinding device.
Spirit’s new jaunt across the Martian landscape placed it in face-to-face position with Adirondack. Over the next few days, the rover is to stay put and gather information about the rock.
Dave Des Marais, a researcher from NASA’s Ames Research Center, said careful appraisal of the rock is planned, including study of its cracked face. Those observations are anticipated to turn Adirondack into a "time capsule" — a way to discern clues about the object’s geological history.
Video: Adirondack in 3-D Late last week, Spirit made first use of its microscopic imager, built to help scientists analyze and understand Martian rocks and soils by taking very high-resolution, close-up images. Spirit also used two spectrometer instruments over the weekend on the same patch of soil examined by the microscope.
A Mössbauer spectrometer singles out types of iron-bearing minerals. The alpha particle X-ray spectrometer identifies the elements in rocks and soils. First results from these spectrometers, both supplying good data, will be explained Tuesday.
At Spirit’s present location, the Mössbauer spectrometer, alpha particle X-ray spectrometer and microscopic imager are to take turns focusing in on Adirondack, both before and after the rock has undergone a RAT session, Des Marais told Space.com.
This before-and-after analysis of the rock, Des Marais explained, should give a handle on processes that have influenced Adirondack’s current geological state.
Opportunity on target
Adler said that Opportunity — the twin to Spirit that is now zipping toward Mars — is on target for its entry, descent and landing on Mars, making a Red Planet touchdown at about 9:05 p.m. PT Saturday (12:05 a.m. ET Sunday).
Opportunity’s trajectory was adjusted late last Friday, putting it on a precise heading for Meridiani Planum, on the opposite site of Mars from where Spirit landed.
"Right now, it doesn’t look like any more trajectory maneuvers are slated for Opportunity," Adler noted.
Adler said that when the orbiting Mars Global Surveyor flies over the Meridiani Planum area, it takes temperature profiles of the atmosphere that Opportunity will cut through as it dives to its landing spot.
Dust storms elsewhere on Mars have altered the atmosphere in the Meridiani Planum region.
"We’ve been getting daily reports … so we’ve got a pretty good idea of how the atmosphere has changed over time," Adler said. "It’s starting to cool off now, meaning the air in which the spacecraft is going to deploy its parachute will be denser."
Engineers here at JPL have been busy reviewing Spirit’s entry, descent and landing on Jan. 3 to ascertain the timing sequence for safely dropping Opportunity onto Mars.
"Overall, I’m not worried about it. We’ve got a ton of margin," Adler told Space.com. Because of the dust storm activity, engineers have decided to deploy Opportunity’s parachute a little bit higher than originally planned, and a few seconds earlier, he said.
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