National Aeronautics and Space Administration + NASA Quest
+ Search Quest
 Find it at NASA
 Home mission About the Moon impact
 LCROSS - Lunar CRater Observation and Sensing Spacecraft
 Tech Info observation education news

Lunar CRater Observation and Sensing Satellite (LCROSS)

Lunar Prospector Mission

Lunar ProspectorThe Lunar Prospector mission was a tremendous success. Following a nearly flawless launch, a four-day journey to the Moon, and entry into lunar orbit, the tiny spin-stabilized spacecraft successfully sent valuable data back to Earth. Carrying five scientific instruments, Lunar Prospector was designed to map the Moon’s surface composition and possible deposits of polar ice, measure magnetic and gravity fields, and study lunar outgassing events.

On March 5th, 1998, Lunar Prospector captured the public’s imagination by announcing the discovery of a signal for water ice at both of the lunar poles. The neutron spectrometer instrument onboard Lunar Prospector detected hydrogen, which is assumed to be in the form of water. The data indicated that a large quantity of water ice, possibly as much as 300 million metric tons, was mixed into the regolith at each pole. This was the first direct evidence of the presence of water ice at the Moon's frigid poles.

The mission ended on July 31, 1999 when Lunar Prospector was deliberately targeted to impact a permanently shadowed area of a crater near the lunar South Pole. It was hoped that the impact would release water vapor from the suspected ice deposits and that the plume would be detectable from Earth, but no plume was observed. However, the LCROSS mission will pick up where Lunar Prospector left off…

Visit the Lunar Prospector homepage.

About the Moon
Clementine Mission | Lunar Prospector Mission

Visit the NASA Mission Site @

 FirstGov  NASA

Editor: Brian Day
NASA Official: Daniel Andrews
Last Updated: October 2009