The Lunar Precursor Robotic Program (LPRP) is a completed program of robotic spacecraft missions which NASA has used to prepare for future human spaceflight missions to the Moon by 2010. Two LPRP missions, the Lunar Reconnaissance Orbiter (LRO) and the Lunar Crater Observation and Sensing Satellite (LCROSS), were launched in June 2009. The lift off above Cape Canaveral Air Force Station in Florida was successful on June 18, 2009. The unmanned Atlas V rocket launched the two space probes towards the Moon, where they will provide a 3-D map and search for water in conjunction with the Hubble Space Telescope. The launch date, originally planned for October 2008, was shifted to Thursday from Wednesday (June 17) due to a postponement of the Saturday (June 13) launch of the Space Shuttle Endeavour, resulting from a hydrogen fuel leak. This lunar program marks the first United States mission to the Moon in over ten years.Neil Armstrong's first step on the Moon occurred July 20, 1969, and this launch was just 32 days shy of the 40th anniversary. The actual journey to the Moon will take about four days, at which time the LRO will enter a low orbit around the Moon, while the LCROSS mission will perform a "swing-by" to enter a much different orbit to set up for a collision with the Moon's surface several months later. Projected lunar impact of the Centaur and LCROSS spacecraft is on October 9, 2009 at 11:30 UT (7:30 a.m. EDT, 4:30 a.m. PDT), ± 30 minutes. The plume from the Centaur impact may be visible through telescopes with apertures as small as 10 to 12 inches (300 mm).
Initially, the LPRP program was a part of the Science Mission Directorate of NASA (SMD) and was called the Robotic Lunar Exploration Program (RLEP). Management of the RLEP program was assigned to Goddard Space Flight Center (GSFC) in February, 2004. At that time, the Program's goal was to "...initiate a series of robotic missions to the Moon to prepare for and support future human exploration activities." In 2005, responsibility for RLEP was moved to NASA's Exploration Systems Mission Directorate (ESMD) and management assigned to the Ames Research Center (ARC). In 2006, the program was renamed to the Lunar Precursor Robotic Program and management responsibility reassigned to the Marshall Space Flight Center (MSFC). The US$583 million space mission comes equipped with a $504 million state of the art 4,200 pounds (1,900 kg) LRO space probe and a $79 million LCROSS satellite.