Lunar Reconnaissance Orbiter

This article or section documents a scheduled or expected spaceflight.
Details may change as the launch date approaches or more information becomes available.

The Lunar Reconnaissance Orbiter (LRO) is a robotic spacecraft which the United States plans to place in orbit around the Moon.^[1] Launch is planned for October 2008 aboard an Atlas V launch vehicle.^[2] LRO will be the first mission implementing the United States Vision for Space Exploration and its objectives are primarily to support that policy, such as surveying lunar resources and identifying possible landing sites for subsequent human exploration of the Moon. The preliminary design review was completed in February 2006 and the critical design review was completed in November of 2006.^[3]

Mission

Under development by NASA's Goddard Space Flight Center, LRO is planned to be a large and sophisticated spacecraft in a polar orbit for a nominal mission of one Earth year. An optional extended phase of the mission (up to 5 years) could provide a communications relay for other future ground lunar missions, such as moon lander or rover.

Areas of investigation will include:^[4]

Selenodetic global topography
Characterization of deep space radiation in Lunar orbit
The lunar polar regions, including possible water ice deposits and the lighting environment
High-resolution mapping (max 0.5 m) to assist in the selection and characterization of future landing sites

Onboard instruments

The orbiter will carry a complement of six instruments and one technology demonstration:

CRaTER - The primary goal of CRaTER is to characterize the global lunar radiation environment and its biological impacts.
DLRE - The Diviner Lunar Radiometer Experiment will measure lunar surface thermal emission to provide essential information for future surface operations and exploration.
LAMP - Reflected Lyman _ sky-glow and starlight produce sufficient signal for even a small UV instrument like LAMP to see in the Moon's permanently shadowed regions.
LEND - LEND - The Lunar Exploration Neutron Detector will provide measurements, create maps, detecting possible near-surface water ice deposits.
LOLA - The Lunar Orbiter Laser Altimeter (LOLA) investigation will provide a precise global lunar topographic model and geodetic grid that will serve as the foundation of this essential understanding.
LROC - The Lunar Reconnaissance Orbiter Camera (LROC) has been designed to address the measurement requirements of landing site certification and polar illumination. LROC comprises a pair of narrow-angle cameras (NAC) and a single wide-angle camera (NAC).
Mini-RF - Demonstrate new lightweight SAR and communications technologies, locate potential water-ice.

LRO's high-resolution mapping will show some of the larger pieces of equipment previously left on the Moon, and will return approximately 70-100TB of image data.

LCROSS

Piggy-backing on the launch of LRO will be the Lunar CRater Observation and Sensing Satellite (LCROSS), which is designed to watch as the launch vehicle's Centaur upper stage impacts a permanently shadowed region near either the north or south pole of the Moon. Spectral analysis of the resulting impact plume will help to confirm preliminary findings by the Clementine mission which hinted that there may be water ice in the permanently shadowed regions. LCROSS will fly through the debris plume, then approximately 10 minutes later will itself impact into a different part of the crater. The two impacts, which should be easily visible to amateur astronomers, will also be monitored by Earth-based observatories and possibly by other orbital assets. The addition of the LCROSS payload came about after NASA changed LRO to a larger rocket from the Delta II. It was chosen from 19 other proposals.^[5] LCROSS is being managed by NASA's Ames Research Center and built by Northrop Grumman. The LCROSS preliminary design review was completed on 2006-09-08. The LCROSS mission passed its Mission Confirmation Review on 2007-02-02^[6]. The LCROSS mission passed its Critical Design Review on 2007-02-22.^[7]

Launch, cis-lunar transfer and lunar orbit insertion

A nominal mission profile includes a launch providing a characteristic energy ( $C_3\,\!$ ) of -1.85 km²s^-2, leading to a cis-lunar transfer time of approximately 4 days, followed by lunar orbit insertion through a series of five implusive maneuvers requiring delta-vs of 11 to 385 meters per second.^[8]

References

^ Lunar Reconnaissance Orbiter. NASA.
^ Lockheed Martin's Atlas V Selected To Launch Lunar Reconnaissance Orbiter. Lockheed Martin (2006-07-28). Retrieved on 2006-08-31.
^ Lunar Reconnaissance Orbiter Successfully Completes Critical Design Review (2006-12-07). Retrieved on 2007-02-06.
^ Savage, Donald; Gretchen Cook-Anderson (2004-12-22). NASA Selects Investigations for Lunar Reconnaissance Orbiter. NASA News. Retrieved on 2006-05-18.
^ Tariq Malik. "NASA Adds Moon Crashing Probes to LRO Mission", 2006-04-10. Retrieved on 2006-04-11.
^ "NASA Moon-Impactor Mission Passes Major Review", 2007-02-02.
^ "Lunar Crater Observation and Sensing Satellite Passes Critical Design Review", 2007-03-02.
^ NASA RLEP - 2008 Lunar Reconnaissance Orbiter. NASA.

External links

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