Originally Posted by NASA
"LCROSS launched with the Lunar Reconnaissance Orbiter (LRO) aboard an Atlas V rocket from Cape Canaveral, Fla., on June 18, 2009 at 2:32 p.m. PDT. The LCROSS shepherding spacecraft and the Atlas V’s Centaur upper stage rocket executed a fly-by of the moon on June 23, 2009 (LCROSS lunar swingby video stream coverage) and entered into an elongated Earth orbit to position LCROSS for impact on a lunar pole. On final approach, the shepherding spacecraft and Centaur will separate. The Centaur will act as a heavy impactor to create a debris plume that will rise above the lunar surface. Projected impact at the lunar South Pole is currently: Oct 9, 2009 at 4:30 a.m. PDT. Following four minutes behind, the shepherding spacecraft will fly through the debris plume, collecting and relaying data back to Earth before impacting the lunar surface and creating a second debris plume.
As the ejecta rises above the target crater’s rim and is exposed to sunlight, any water-ice, hydrocarbons or organics will vaporize and break down into their basic components. These components primarily will be monitored by the visible and infrared spectrometers. The near-infrared and mid-infrared cameras will determine the total amount and distribution of water in the debris plume. The spacecraft’s visible camera will track the impact location and the behavior of the debris plume while the visible radiometer will measure the flash created by the Centaur impact."