Lunar Prospector - Mission Profile

Mission Profile

Following launch on January 7, 1998 UT (6 January EST) aboard a four-stage Athena II rocket, the 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 cis-lunar 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 (57 mi) x 153 km (95 mi) preliminary mapping orbit, and then on 16 January 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 a 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 28 January to a 15 km (9.3 mi) x 45 km (28 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 deliberately targeted to impact 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 construction 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).