Gamma Ray Spectrometer (2001 Mars Odyssey)
The Gamma Ray Spectrometer (GRS) is a gamma-ray spectrometer on the 2001 Mars Odyssey spacecraft, a space probe orbiting the planet Mars since 2001. Part of NASA's Mars Surveyor 2001 program, it returns geological data about Mars's surface such as identifying elements and the location of water. It is maintained by the Lunar and Planetary Laboratory at the University of Arizona in the United States. This instrument has mapped the distribution surface hydrogen, thought to trace water in the surface layer of Martian soil.<ref>Template:Cite web</ref>
GRS specifications
The Gamma Ray Spectrometer weighs Template:Convert and uses 32 watts of power. Along with its cooler, it measures Template:Convert. The detector is a photodiode made of a Template:Convert germanium crystal, reverse biased to about 3 kilovolts, mounted at the end of a Template:Convert boom to minimize interferences from the gamma radiation produced by the spacecraft itself. Its spatial resolution is about Template:Convert.<ref>Template:Cite journal</ref><ref>Template:Cite web</ref>
The neutron spectrometer is Template:Convert.
The high-energy neutron detector measures Template:Convert. The instrument's central electronics box is Template:Convert.