LCROSS Mission

NASA's Lunar Crater Observation and Sensing Satellite (LCROSS) investigated water and other volatiles in permanently shadowed terrain near the Moon's south pole. Launched with Lunar Reconnaissance Orbiter in June 2009, it remained attached to the spent Centaur stage during a looping Earth-orbit campaign before separating for the final impacts. On October 9, 2009 the Centaur struck Cabeus crater and excavated buried material. The following shepherding spacecraft observed and flew through the debris plume with cameras, spectrometers, and a photometer, transmitting measurements before its own planned impact. Analysis confirmed water in the excavated material and revealed additional volatile substances. The mission sampled the impact plume remotely and in flight; it returned measurements rather than a physical lunar sample to Earth.