NASA engineers have raised the temperature on a Mars-bound spacecraft to help it weather a bout of space radiation. The induced fever should take care of radiation damage affecting an instrument on the Mars 2001 Odyssey, the space agency said. Mission controllers at the Jet Propulsion Laboratory sent a radio command last week ordering Odyssey to heat up its gamma ray spectrometer detector. The action was designed to erase radiation damage that has occurred naturally during the interplanetary cruise.