Mars lander has trouble getting sample in oven

[July 28, 2008]  PASADENA, Calif. (AP) -- A sample of icy soil collected by the robotic arm of NASA's Phoenix Mars lander is apparently stuck in its scoop, foiling efforts to analyze it.

The arm picked up 3 cubic centimeters of material Friday night and lifted it over an oven designed to heat samples for analysis, mission officials said Saturday. The arm tilted its scoop, ran a tool motor to try to sprinkle the sample into the oven, and finally inverted the scoop directly over the oven's open doors.

But the science instrument, called the Thermal and Evolved-Gas Analyzer, detected that not enough material fell inside and so the oven doors did not close.

The lander then transmitted images Saturday morning showing soil stuck in the scoop.

"We believe that the material that was intended for the targeted cell is the material that adhered to the back of the scoop," Phoenix project manager Barry Goldstein, of NASA's Jet Propulsion Laboratory in Pasadena, said in a statement.

A short-circuit occurred weeks ago when shaking was used to try to get a previous sample into another of Phoenix's eight tiny test ovens and there had been concern that the vibrating action might cause a short-circuit again this time, but that did not occur.

"The good news here is TEGA is functioning nominally, and we will adjust our sample drop-off strategy to run this again," Goldstein said.

Mission officials planned to command the lander to take pictures on Sunday to determine if any more of the soil fell out of the scoop later on.

Saturday marked the lander's 60th Martian day, known as a sol, on the Red Planet's northern arctic plain.

The $420 million mission hopes to find out whether the icy Martian soil contains the chemical ingredients necessary for life. The results from the heating test that was carried out several weeks ago showed water vapor and carbon dioxide, but no signs of carbon.

JPL is managing the Phoenix Mars project. The mission is being led by chief scientist Peter Smith of the University of Arizona in Tucson.

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On the Net:

http://www.nasa.gov/phoenix/

http://phoenix.lpl.arizona.edu/

[Associated Press]

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