Phoenix Lander Collects Icy Soil But Needs to Work on Delivery

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This view from the Surface Stereo Imager on NASA's Phoenix Mars Lander on the mission's 60th Martian day, or sol, (July 26, 2008) was taken after the lander's scoop sprinkled a soil sample over Thermal and Evolved-Gas Analyzer (TEGA). The upper part of the picture shows the robotic arm scoop parked open-face down above the TEGA after delivery. The TEGA doors farthest to the right were open to receive the sample into one of TEGA's eight ovens. Not enough material reached the oven to allow an analysis to begin. Some of the soil sample can be seen at the bottom of the adjacent pair of doors. This view is presented in false color, which makes the reddish color of the soil-sample material easy to see. (NASA/JPL-Caltech/University of Arizona /Texas A&M University)

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July 26, 2008) to penetrate a hard layer at the bottom of a trench informally called "Snow White." This view, taken by the lander's Surface Stereo Imager and presented in approximately true color, shows the trench later the same sol. Most of the 16 holes left by a four-by-four array of rasp placements are visible in the central area of the image. A total 3 cubic centimeters, or about half a teaspoon, of material was collected in the scoop. Material in the scoop was collected both by the turning rasp, which threw material into the scoop through an opening at the back of the scoop, and by the scoop's front blade, which was run over the rasped area to pick up more shavings. (NASA/JPL-Caltech/University of Arizona /Texas A&M University)

By University Communications July 26, 2008

Most of the icy sample apparently stuck to the back of the scoop.

NASA's Phoenix Mars Lander’s robotic arm collected a more than adequate amount of icy soil for baking in one of the lander’s ovens but will need to adjust how it delivers samples.

Engineers determined the rasping and scraping activity collected a total of 3 cubic centimeters of icy soil, more than enough to fill the tiny oven cell of the Thermal and Evolved-Gas Analyzer, or TEGA. However, images returned from the lander Saturday morning show that much of the soil remained lodged in the robotic arm's scoop after the attempt to deliver the sample to the TEGA.

“Very little of the icy sample made it into the oven,” said Barry Goldstein, Phoenix project manager from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We believe that the material that was intended for the targeted cell is the material that adhered to the back of the scoop.”

Once the sample had been collected, the robotic arm tilted its scoop and ran the rasp motor several times in an attempt to sprinkle the sample into the oven whose doors were wide open. The final step was inverting the scoop directly over the doors. A screened opening over the oven measures about 10 centimeters (4 inches) long by 3 centimeters (1.5 inches) wide. The oven itself is roughly the size of an ink cartridge in a ballpoint pen.

The delivery sequence also included vibrating the screen several times, which would have aided delivery. TEGA detected that not enough sample was recorded as being in its oven, so the oven doors did not close.

The TEGA activities did not cause any short circuits with the equipment.

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

Prior to the sample delivery, Phoenix’s robotic arm made 16 holes in the hard ground with its motorized rasp tool and the scoop collected the rasped material and shavings left on the surface from the rasping action.

The lander conducted these activities overnight Friday to Saturday, Pacific Time, during Martian morning hours of the mission's 60th Martian day, or sol. The Phoenix team planned Saturday to send the spacecraft commands to take images on Sunday, the mission's Sol 61, of areas around and under the TEGA instrument. The images by the Robotic Arm Camera would be a way to check for additional material that might have been released by the scoop on Sol 60.

The Phoenix mission is led by Peter Smith of the University of Arizona with project management at JPL and development partnership at Lockheed Martin, Denver. International contributions come from the Canadian Space Agency; the University of Neuchatel; the universities of Copenhagen and Aarhus, Denmark; Max Planck Institute, Germany; and the Finnish Meteorological Institute. For more about Phoenix, visit: http://www.nasa.gov/phoenix and http://phoenix.lpl.arizona.edu.

Et Cetera