[Drawing of Lunar Prospector]

Lunar Prospector

Launch Date: 7 January 1998 UT 02:28:44 (6 January 9:28:44 p.m. EST)
Launch Vehicle: Athena II
Launch Site: Kennedy Space Center
Launch Mass 296 kg (fully fueled), 158 kg (dry)
Power System: Body Mounted 202 W Solar Cells and 4.8 amp-hr NiCd Battery

No water was detected from the July 31 crash of Lunar Prospector into the Moon.

The Lunar Prospector is designed for a low polar orbit investigation of the Moon, including mapping of surface composition and possible polar ice deposits, measurements of magnetic and gravity fields, and study of lunar outgassing events. Data from the 19 month mission will allow construction of a detailed map of the surface composition of the Moon, and will improve our understanding of the origin, evolution, current state, and resources of the Moon. The spacecraft is a graphite-epoxy drum, 1.37 meters in diameter and 1.28 meters high with three radial instrument booms. It is spin-stabilized and controlled by 6 hydrazine monopropellant 22-Newton thrusters. Communications are through two S-band transponders and a slotted, phased-array medium gain antenna and omnidirectional low-gain antenna. There is no on-board computer, ground command is through a 3.6 kbps telemetry link. Total mission cost is about $63 million. After launch, the Lunar Prospector had a 105 hour cruise to the Moon, followed by insertion into a near-circular 100 km altitude lunar polar orbit with a period of 118 minutes. In December 1998 the orbit was lowered to 40 km. The nominal mission ended after one year, at which time the orbit was lowered to 30 km. On 31 July 1999 at 9:52:02 UT (5:52:02 EDT) Lunar Prospector impacted the Moon near the south pole in a controlled crash to look for evidence of water ice - none was observed.

More Detailed Information on the Mission and Spacecraft

Scientific Investigations

Gamma Ray Spectrometer (GRS) - G. Scott Hubbard, NASA Ames
Neutron Spectrometer (NS) - William Feldman, Los Alamos
The GRS and NS will return global data on elemental abundances, which will be used to help understand the evolution of the lunar highland crust and the duration and extent of basaltic volcanism, and to assess lunar resources. The NS will also locate any significant quantities of water ice which may exist in the permanently shadowed areas near the lunar poles.

Magnetometer (MAG) - Mario Acuna, NASA Goddard; Lon Hood, Univ. of Arizona LPL
Electron Reflectometer (ER) - Robert Lin, UC Berkeley SSL
The MAG/ER experiments will return data on the lunar crustal magnetic field and the lunar induced magnetic dipole. These data will help provide an understanding of the origin of lunar paleomagnetism and the degree to which impacts can produce paleomagnetism, and allow constraints on the size and composition of the (possible) lunar core.

Alpha Particle Spectrometer (APS) - Alan Binder, Lockheed
The APS instrument will be used to find radon outgassing events on the lunar surface by detecting alpha particles from the radon gas itself and its decay product, polonium. Observations of the frequency and locations of the gas release events will help characterize one possible source of the tenuous lunar atmosphere. Determination of the relationship of outgassing sites with crater age and tectonic features may be possible. This may in turn be used to characterize the current level of lunar tectonic activity.

Doppler Gravity Experiment (DGE) - Alex Konopliv, NASA JPL
This investigation will use Doppler tracking of S-Band radio signals to characterize the spacecraft orbit and determine the lunar gravity field. This data will provide information on the lunar interior and, combined with lunar topographic data, will allow modelling of the global crustal asymmetry, crustal structure, and subsurface basin structure. It can also used for planning future lunar missions.

Lunar Prospector Project Management

Principal Investigator - Alan Binder, Lockheed
Mission Manager - G. Scott Hubbard, NASA Ames
Assistant Mission Manager - Sylvia Cox
Project Manager - Thomas A. Dougherty

The Lunar Prospector mission has been selected by NASA for full development and construction as part of NASA's Discovery program.

Related Information

Experiment and Engineering Raw Data on CD-WO
More detailed information on the spacecraft and mission - from the NSSDCA Master Catalog
Summary of current science results
Ice on the Moon - Details on the discovery

No Water Detected from Lunar Impact - NASA Press Release, 13 October 1999
More on the Lunar Impact - Space Science News
Lunar Impact Page - University of Texas
Articles on scientific results - Science magazine
Creative impact experiment to mark end of Lunar Prospector - NASA Press Release, 28 July 1999
Lunar Prospector may deliberately impact Moon - NASA Press Release, 02 June 1999
Data indicate small lunar core - NASA Press Release, 16 March 1999
Ice on the Moon press releases - 3 September 1998 and 5 March 1998
Post-launch press conference - NASA Press Release, 12 January 1998
Launch Delayed to January 1998 - NASA Press Release, 22 October 1997
Launch Delayed to November - NASA Press Release, 10 September 1997

Spacecraft construction complete - NASA Press Release, 12 March 1997

Discovery Mission announcement (Lunar Prospector, Venus Multi-Probe, Suess-Urey, Stardust)
More information on the Moon
Lunar Data at NSSDCA
Clementine - The most recent lunar mission
NASA's Discovery Program

Lunar Prospector Home Page - NASA Ames
Lunar Prospector Spectrometers - Los Alamos National Laboratory
Lunar Prospector Preliminary Gravity Data

NSSDCA Planetary Home Page
Dr. David R. Williams, dave.williams@nasa.gov
NSSDCA, Mail Code 690.1
NASA Goddard Space Flight Center
Greenbelt, MD 20771

NASA Official: Dr. David R. Williams, david.r.williams@nasa.gov
Last Updated: 26 January 2005, DRW