All About GRS
The Gamma Ray Spectrometer (GRS) instrument suite is a set of instruments aboard the 2001 Mars odyssey spacecraft 2001 Mars Odyssey.Two of these instruments (the Nuetron Spectrometer and the High Energy Neutron Detector) detect neutrons released from the surface of the planet. The third instrument (the Gamma Ray Spectrometer) detects gamma ray photons coming from the planet.
Together, these instruments help us learn about the composition of the Martian surface. The information collected by GRS will be used to help determine the composition and location of the elements on Mars. This includes production of a global map of water deposits and other elements on Mars; an estimation of the depth of water deposits; and continued study of how seasons affect the polar ice caps. GRS will also contribute to the study of cosmic gamma ray bursts.
GRS is a part of NASA's Mars Exploration Program. The instrument suite contributes to the primary goals of this program: to understand the enviroment and history of Mars; to learn if that enviroment ever supported or could support life, and to determine what resources exist on the planet.
GRS was launched aboard 2001 Mars Odyssey on April 7, 2001 and arrived at Mars on October 23, 2001. This spacecraft is operated by the Jet Propulsion Laboratory. Other instruments included with this mission are THEMIS (Thermal Emission Imaging System) and MARIE (Martian Radiation Enviroment Experiment).
Extra sites to look at also Lunar and Planetary Lab, the Los Alamos National Laboratory, and Russia's Space Research Institute.