Instrument on Mars-bound probe falters

A drawing of the Mars Odyssey spacecraft.

By Richard Stenger
CNN

(CNN) -- A radiation detector on a spacecraft bound for Mars failed during a recent test and scientists remain unsure why, NASA said this week.

Observations from the Mars Odyssey instrument could prove useful for human exploration of the red planet. The $300 million robot ship is scheduled to begin orbiting Mars in late October.

Mission engineers shut off the martian radiation environment experiment after the detector did not respond during communications with the spacecraft last week, according to NASA's Jet Propulsion Laboratory (JPL), which manages the mission.

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After flight controllers tried to no avail to reset the instrument, project scientists put together a team to rescue the detector on Odyssey, which should reach Mars orbit on October 23.

"We have limited information on the nature of the problem with the radiation experiment. The investigative team will develop a fault tree containing a list of potential causes for the behavior," said mission manager David Spencer in a statement.

Mars Odyssey is scheduled to arrive at the red planet in October.

Other instruments seem to be working well on the orbiter, including a gamma-ray spectrometer, a visible camera and an imaging system to observe infrared heat emissions, according to JPL scientists.

In June, mission controllers commanded Odyssey to heat up the gamma-ray spectrometer to erase radiation damage that had occurred naturally during the interplanetary cruise.

Launched in April, Odyssey needs to cover an additional 11.5 million miles (18.5 million kilometers) before concluding a journey of 286 million miles (460 million kilometers).

The 1.7-ton ship is slated to search for mineralogical evidence of water on Mars and measure radiation levels around the planet, according to NASA.

The probe will be the first to visit Mars since two NASA spacecraft disappeared near the planet's surface in late 1999.