page_title: Lunar Prospector
section_title: Mission profile
hierarchical_section_title: Lunar Prospector / Mission profile
caption_attribution_description: English: Path of the Lunar Prospector spaceprobe Source: NASA
context_page_description: Lunar Prospector was the third mission selected by NASA for full development and construction as part of the Discovery Program. At a cost of $62.8 million, the 19-month mission was designed for a low polar orbit investigation of the Moon, including mapping of surface composition including polar ice deposits, measurements of magnetic and gravity fields, and study of lunar outgassing events. The mission ended July 31, 1999, when the orbiter was deliberately crashed into a crater near the lunar south pole, after the presence of water ice was successfully detected.
  Data from the mission allowed the construction of a detailed map of the surface composition of the Moon, and helped to improve understanding of the origin, evolution, current state, and resources of the Moon. Several articles on the scientific results were published in the journal Science.
  Lunar Prospector was managed by NASA Ames Research Center with the prime contractor Lockheed Martin. The Principal Investigator for the mission was Alan Binder. His personal account of the mission, Lunar Prospector: Against all Odds, is highly critical of the bureaucracy of NASA overall, and of its contractors.
context_section_description: Following launch on January 7, 1998 UT (January 6 EST) aboard a four-stage Athena II rocket, Lunar Prospector had a 105-hour cruise to the Moon. During the cruise, the three instrument booms were deployed. The MAG and APS collected calibration data, while the GRS, NS, and ER outgassed for one day, after which they also collected calibration data in cislunar space. The craft was inserted into an 11.6-hour period capture orbit about the Moon at the end of the cruise phase. After 24 hours Lunar Prospector was inserted into a 3.5-hour period intermediate orbit, followed 24 hours later (on January 13, 1998) by transfer into a 92 km × 153 km (57 mi × 95 mi) preliminary mapping orbit, and then on January 16 by insertion into the near-circular 100 km (62 mi) altitude nominal lunar polar mapping orbit with an inclination of 90 degrees and a period of 118 minutes. Lunar calibration data was collected during the 11.6- and 3.5-hour orbits. Lunar mapping data collection started shortly after the 118 minute orbit was achieved. The data collection was periodically interrupted during the mission as planned for orbital maintenance burns, which took place to recircularize the orbit whenever the periselene or aposelene was more than 20 km (12 mi) to 25 km (16 mi) from the 100 km nominal orbit; this occurred about once per month. On December 19, 1998, a maneuver lowered the orbit to 40 km (25 mi) to perform higher resolution studies. The orbit was altered again on January 28 to a 15 km × 45 km (9.3 mi × 28.0 mi) orbit, ending the one year primary mission and beginning the extended mission.
  The mission ended on July 31, 1999 at 9:52:02 UT (5:52:02 EDT) when Lunar Prospector was steered into a deliberate collision in a permanently shadowed area of the Shoemaker crater near the lunar south pole. It was hoped that the impact would liberate water vapor from the suspected ice deposits in the crater and that the plume would be detectable from Earth; however, no such plume was observed.
  The Lunar Prospector mission was the third mission selected by NASA for full development and launch as part of NASA's Discovery Program. Total cost for the mission was $63 million including development ($34 million), launch vehicle (~$25 million) and operations (~$4 million).
caption: Path of Lunar Prospector space probe
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