LCROSS used a spacecraft to crash into the Moon to search for water ice in 2009.
NASA launched the Lunar Crater Observation and Sensing Satellite, or LCROSS, together with the Lunar Reconnaissance Orbiter on June 18, 2009. LCROSS sent its spent Centaur rocket stage into Cabeus crater near the lunar south pole on October 9.
The impact created a plume of debris that the following LCROSS spacecraft observed with cameras and spectrometers. Scientists identified water and other volatile compounds in the ejected material.
LCROSS was designed around a deliberate impact rather than a soft landing. Its results supported the idea that permanently shadowed polar craters preserve water ice because sunlight never reaches their floors.