Encyclopedia Astronautica
Lunar Prospector



lunprosp.jpg
Lunar Prospector
Credit: NASA
American lunar orbiter. One launch, 1998.01.07.

Lunar Prospector was a robotic moon orbiter designed to determine the origin, evolution, and current state of resources of the Moon via low-altitude mapping of its surface composition, magnetic fields, gravity fields, and gas release events. The mission provided a new map that showed in unprecedented detail the chemical composition and the magnetic and gravity fields of the Moon.

Lunar Prospector was the third of NASA's Discovery missions. The mission was led by Lockheed and NASA's Ames Research Centre and the entire cost, including launch vehicle, was less than $63M. 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. The nominal mission duration was one year. A two year extended mission following this was possible, during which the orbit was to be lowered to 50 km and then 10 km altitude to obtain higher resolution measurements.

The spacecraft's launch mass was 295 kg (fully fueled), 126 kg (dry). The spacecraft was a graphite-epoxy drum, 1.4 meters in diameter and 1.22 meters high with three 2.5 meter radial instrument booms. It was spin-stabilized and used with Sun and limb sensors for attitude determination. It was controlled by 6 hydrazine monopropellant 22-Newton thrusters providing 1430 m/s of delta-V. . Communications were through two S-band transponders and a slotted, phased-array medium gain antenna and omnidirectional low-gain antenna. There was no on-board computer; ground command was through a 3.6 kbps telemetry link. Body mounted solar cells provided 206 W and recharged 15 amp-hr NiH batteries.

The payload included :

Scientific Investigations

Gamma Ray Spectrometer (GRS) - Neutron Spectrometer (NS) - The GRS and NS returned global data on elemental abundances, to 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 also located significant quantities of water ice which existed in the permanently shadowed areas near the lunar poles.

Magnetometer (MAG) - Electron Reflectometer (ER) - The MAG/ER experiments would return data on the lunar crustal magnetic field and the lunar induced magnetic dipole. These data would help provide an understanding of the origin of lunar paleomagnetism and the degree to which impacts could produce paleomagnetism, and allow constraints on the size and composition of the (possible) lunar core.

Alpha Particle Spectrometer (APS) - The APS instrument would 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 would 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) - This investigation would use Doppler tracking of S-Band radio signals to characterize the spacecraft orbit and determine the lunar gravity field. This data would provide information on the lunar interior and, combined with lunar topographic data, would allow modeling of the global crustal asymmetry, crustal structure, and subsurface basin structure. It could also used for planning future lunar missions.

Gross mass: 295 kg (650 lb).
Unfuelled mass: 125 kg (275 lb).
Height: 1.22 m (4.00 ft).
First Launch: 1998.01.07.
Number: 1 .

More... - Chronology...


Associated Countries
See also
  • Athena Privately funded family of solid propellant satellite launch vehicles. Originally known as LMLV (Lockheed-Martin Launch Vehicle); LLV (Lockheed Launch Vehicle). Sales did not develop as hoped by the company after the MEO-satellite bubble burst in the 1990's. More...

Associated Launch Vehicles
  • Athena American orbital launch vehicle. Privately funded family of solid propellant satellite launch vehicles. Originally known as LMLV (Lockheed-Martin Launch Vehicle); LLV (Lockheed Launch Vehicle). Sales did not develop as hoped by the company after the MEO-satellite bubble burst in the 1990's. More...
  • Athena-2 American all-solid orbital launch vehicle. The Athena-2 version featured a Castor 120 first stage, Castor 120 second stage, Orbus third stage, and OAM Orbital Adjustment Module. More...

Associated Manufacturers and Agencies
  • NASA American agency overseeing development of rockets and spacecraft. National Aeronautics and Space Administration, USA, USA. More...
  • Lockheed American manufacturer of rockets, spacecraft, and rocket engines. Lockheed Martin, Sunnyvale, CA, USA. More...

Associated Programs
  • Discovery The Discovery program was begun by NASA in the early 1990s as the planetary counterpart to the Explorer program. More...

Bibliography
  • McDowell, Jonathan, Jonathan's Space Home Page (launch records), Harvard University, 1997-present. Web Address when accessed: here.
  • McDowell, Jonathan, Jonathan's Space Report (Internet Newsletter), Harvard University, Weekly, 1989 to Present. Web Address when accessed: here.
  • National Space Science Center Planetary Page, As of 19 February 1999.. Web Address when accessed: here.

Associated Launch Sites
  • Cape Canaveral America's largest launch center, used for all manned launches. Today only six of the 40 launch complexes built here remain in use. Located at or near Cape Canaveral are the Kennedy Space Center on Merritt Island, used by NASA for Saturn V and Space Shuttle launches; Patrick AFB on Cape Canaveral itself, operated the US Department of Defense and handling most other launches; the commercial Spaceport Florida; the air-launched launch vehicle and missile Drop Zone off Mayport, Florida, located at 29.00 N 79.00 W, and an offshore submarine-launched ballistic missile launch area. All of these take advantage of the extensive down-range tracking facilities that once extended from the Cape, through the Caribbean, South Atlantic, and to South Africa and the Indian Ocean. More...
  • Cape Canaveral LC46 Trident, Athena launch complex. This complex was built as part of the U.S. Navy's Trident II ballistic missile effort at the Cape. Construction was underway in February 1984, and the complex was ordnance-certified in November 1986. Complex 46 supported the Cape's first Trident II test missile launch on 15 January 1987. Eighteen more Trident IIs were launched from the site between 17 March 1987 and 27 January 1989. As Trident launch operations moved out to sea later in 1989, the complex was placed on standby status awaiting special Trident II test requirements. No new requirements surfaced in the 1990s, but the Spaceport Florida Authority (SFA) won $4,890,000 in Air Force grants to redesign Complex 46 to handle small commercial space launch operations (e.g., Lockheed Martin's new LMLV-2 space launch vehicle). More...

Lunar Prospector Chronology


1998 January 7 - . 02:28 GMT - . Launch Site: Cape Canaveral. Launch Complex: Cape Canaveral LC46. Launch Pad: SLC46. LV Family: Athena. Launch Vehicle: Athena-2. LV Configuration: Athena-2 LM-004.
  • Lunar Prospector - . Payload: Discovery 3. Nation: USA. Agency: NASA Ames. Manufacturer: Lockheed. Program: Discovery. Class: Moon. Type: Lunar probe. Spacecraft: Lunar Prospector. Decay Date: 1999-07-31 . USAF Sat Cat: 25131 . COSPAR: 1998-001A. The Lunar Prospector was 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 1 to 3 year mission will allow construction of a detailed map of the surface composition of the Moon, and will improve understanding of the origin, evolution, current state, and resources of the Moon. 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. The nominal mission duration was one year.

1999 July 31 - .
  • Lunar Prospector, Moon Impact - . Nation: USA. Spacecraft: Lunar Prospector. A two year extended mission following the original one-year mission was possible, during which the orbit was to be lowered to 50 km and then 10 km altitude to obtain higher resolution measurements. However this was not funded, and the spacecraft was commanded to crash into the moon.

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