Phoenix Suffers Unknown Problem with Sample Analysis Oven

by Ian O'Neill on June 7, 2008

Mars dirt doesn\'t make it to the oven for testing (NASA/UA)
The first sample for scientific analysis dug from the surface of the Mars has failed to make it to the onboard oven used to test for organic compounds and water. Mission scientists have been overviewing a picture taken by the lander after Phoenix’s 8-foot long robotic arm dropped the sample on-target, but a sensor inside the chamber has reported seeing nothing falling into the oven. The regolith sample can be clearly seen scattered over the oven doors (pictured), and the vibration plate appears to be functioning. Mission control is currently trying to understand what went wrong, so sample analysis has been postponed, possibly for a few days…

Everything was looking fine as the robotic arm reached out and dug into the Martian top layer of regolith on Sol 11 (June 5th) of the Phoenix Mars Mission. The Martian dirt was excavated from a little patch known as “Baby Bear” and then lifted above the open doors of the Thermal and Evolved-Gas Analyzer (TEGA – a hi-tech oven used to bake the samples and analyze the gases emitted). The robotic arm then released the sample on to the vibrator above the open TEGA hatch. The vibrating plate, used to shake the sample into the oven chamber, was registered as working as it should. It all seemed fine, even the picture taken of the dropped regolith on the top deck of Phoenix fell in the right place. Unfortunately, the electronic “eye” inside the chamber did not detect any falling grains of dirt.

University of Arizona mission scientists are understandably concerned about this complication. “We think everything is working correctly, although we don’t really know for sure,” William Boynton, UA Tucson researcher who is overlooking the oven experiments, said in a news briefing today (Saturday). “We’re a little bit concerned about this but we have some other things to check out.

If the regolith was dropped in the right place, and the vibrating plate appears to be working as it should, why have no particles been registered as entering the open chamber? The problem could lie in the screen at the top of the TEGA. The screen will only allow small particles into the chamber for analysis. If the regolith is too compacted, or is composed of larger-than-expected particles, none may be able to enter the oven. On the other hand, the instrument readings from the vibrator are in fact wrong, meaning it is not working and particles are not being fed into the chamber.

But do not be alarmed. If the oven is broken, Phoenix has come prepared. This oven is one of eight on board, so whilst scientists try to understand the problem, at least they know they have another seven ovens to take over the mission’s primary objectives. In the mean time, mission control will send commands to the lander to analyse the area it excavated with its robotic arm and cameras.

Source: Associated Press


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Hello! My name is Ian O'Neill and I've been writing for the Universe Today since December 2007. I am a solar physics doctor, but my space interests are wide-ranging. Since becoming a science writer I have been drawn to the more extreme astrophysics concepts (like black hole dynamics), high energy physics (getting excited about the LHC!) and general space colonization efforts. I am also heavily involved with the Mars Homestead project (run by the Mars Foundation), an international organization to advance our settlement concepts on Mars. I also run my own space physics blog:, be sure to check it out!

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