Serious Screen Issues Developing with Phoenix Lander
“What we found was that although we had an awful lot of dirt on that screen, almost none of it made it down into the oven,” said TEGA co-investigator William Boynton, of the University of Arizona.
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After such a successful trip and landing on Mars, it would seem that the NASA Mars Phoenix Mission would be a complete success, with its latest technology the forerunner of the next Orion manned spacecraft. But a few clumps of dirt may be changing all of that, with the efforts to jiggle the soil samples into a main TEGA instrument failing due to the heavy clumpy soil which will not go through the mesh screen.
The first sample of Martian soil was delivered last Saturday to the Phoenix TEGA, which is to analyze the vapor composition that comes off the baked dirt. The only problem was the clumpy dirt never went through the screen, according to the relayed images and instrument detectors. There are several reasons but a real biggie is the presence of salts that bind the material together, or moisture in the soil from the landing which cemented the particles together. A real puzzle with nothing definite, mission controllers commanded the Phoenix to use its attached vibrator to loosen the soil—some did but enough to take a measurement.
When the plans were drawn up for the Phoenix, Boynton said the scientists were worried about not getting enough dirt when in actuality they loaded too much that would not sift down. Unlike our last article, this article goes into more detail of the “sprinkling” effect the NASA engineers are using. The second sample has been prepared, using this one for the sprinkle test—first over the Phoenix’s dumping zone, and then over the MECA (Microscope, Electrochemistry and Conductivity Analyzer areas). The scoop at the end of the Robotic Arm will be lowered until it is level, then the arm’s rasp will be powered up to vibrate the scoop—originally intended to scrap up samples of water ice.
This entire process is to “hopefully” knock out the larger clumps which are preventing the sifting process of the Martian regolith, attempting to force out enough of a sample onto the MECA for further analyzing. Once the images come back in, the next sample should be done on Wednesday, and if it shows success then the sample will be tried onto the TEGA.
This entry was posted on Tuesday, June 10th, 2008 at 8:38 am and is filed under Mission Objectives, Space Agency News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
