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Lunar Crater Observation and Sensing Satellite (LCROSS)



The Lunar Crater Observation and Sensing Satellite (LCROSS) is designed to search for water ice on the Moon's surface by directing a 2000 kg Centaur upper stage into an impact with the Moon while observing the collision from behind. The objective is to observe the resulting ejecta plume and look for evidence of exhumed water or hydrated materials that would indicate water ice is present at or near the surface at the lunar poles.

Mission Profile

LCROSS launched along with the Lunar Reconnaissance Orbiter (LRO) spacecraft, on an Atlas 5 401 at 21:32 UT (5:32 p.m. EDT) on 18 June 2009. LCROSS separated from LRO at 22:16:43 UT. LCROSS passed the Moon on 23 June at 10:30:33 UT at a distance of 3200 km, receiving a gravity assist and going into Earth orbit. The mission consists of a Shepherding Spacecraft (S-S/C) attached to the Centaur upper stage. The S-S/C will guide the Centaur after orbital insertion through two highly eccentric 40-day Earth orbits. The S-S/C then guided the Centaur into a trajectory which caused it to impact in Cabeus, a 98 km diameter crater centered at 84.9 S, 324.5 E near the lunar south pole, chosen for its likelihood of containing water ice. Centaur impact took place on 9 October 2009 at 11:31:19.5 UT at 84.678 S lon., 311.275 E approximately -3825 meters lunar altitude The Centaur impacted the lunar surface at a velocity of approximately 2.5 km/sec and an angle of roughly 75 degrees, throwing up debris, possibly including water, hydrocarbons, and/or hydrated material. The S-S/C separated from the Centaur at 01:50 UT on 9 October and performed a delay burn of 50 m/s to follow a few minutes behind. The S-S/C took images and collected other data on the impact and cloud of ejecta for approximately four minutes as it flew through it before also striking the Moon, at 11:35:36.1 UT at 84.72 S lat., 310.38 E lon. at a lunar altitude of approximately -3809 meters.

Spacecraft and Subsystems

The S-S/C is built on an EELV Secondary Payload Adaptor (ESPA) 158 cm diameter ring with a dry mass of 534 kg and 300 kg of hydrazine propellant. Peak power for the system of 372 W is supplied by a 600 W solar array charging a 40A-h Li-Ion battery. Propulsion is through two 8-thruster pods supplied by a mono-propellant fuel tank mounted inside the ring. Communications will be via an S-band transponder and two omnidirectional and two medium-gain horn antennas. Attitude control is achieved through a system of star trackers, 10 sun sensors, and an inertial measurement unit controlling an N2H4 reaction control system. Outer radiator panels, heat pipes, and multilayer insulation are used for thermal control. The S-S/C is equipped with two visible cameras, three infrared cameras, three spectrometers, and a photometer for observations.

Alternate Names

  • 35316
  • urn:nasa:pds:context:instrument_host:spacecraft.lcross

Facts in Brief

Launch Date: 2009-06-18
Launch Vehicle: Atlas V 401
Launch Site: Cape Canaveral, United States
Mass: 534 kg
Nominal Power: 372 W

Funding Agency

  • National Aeronautics and Space Administration (United States)


  • Planetary Science

Additional Information

Questions and comments about this spacecraft can be directed to: Dr. David R. Williams



NameRoleOriginal AffiliationE-mail
Dr. Daniel R. AndrewsProject ManagerNASA Ames Research
Dr. Anthony ColapreteMission Principal InvestigatorNASA Ames Research

Selected References

  • Colaprete A., et al., Detection of water in the LCROSS ejecta plume, Science, 330, No. 6003, 463-468, Oct. 2010.
  • Schultz, P. H., et al., LCROSS cratering experiment, Science, 330, No. 6003, 468-472, Oct. 2010.
  • Colaprete, A., et al., An Overview of the Lunar Crater Observation and Sensing Satellite (LCROSS), Space Sci. Rev., 167, No. 1-4, 3-22, doi:10.1007/s11214-012-9880-6, May 2012.
  • Ennico, K., et al., The Lunar Crater Observation and Sensing Satellite (LCROSS) payload development and performance in flight, Space Sci. Rev., 167, No. 1-4, 23-69, doi:10.1007/s11214-011-9753-4, May 2012.
  • Marshall, W., et al., Locating the LCROSS impact craters, Space Sci. Rev., 167, No. 1-4, 71-92, doi:10.1007/s11214-011-9765-0, May 2012.
  • Heldmann, J. L., et al., LCROSS (Lunar Crater Observation and Sensing Satellite) observation campaign: Strategies, implementation, and lessons learned, Space Sci. Rev., 167, No. 1-4, 93-140, doi:10.1007/s11214-011-9759-y, May 2012.
[LCROSS payload]
[LCROSS payload]
[Cabeus LCROSS impact site]
LCROSS Impact Site - Cabeus

Lunar Reconnaissance Orbiter (LRO) - NSSDC

LCROSS Impact Data Indicates Water on Moon - 13 November 2009 Ames Press Release
NASA Spacecraft Impacts Lunar Crater in Search for Water Ice - 9 October 2009 NASA Press Release
NASA'S LCROSS Mission Changes Impact Crater - 28 September 2009 Press Release
NASA'S LCROSS Reveals Target Crater for Lunar South Pole Impacts - 11 September 2009 NASA Press Release
NASA Returning to the Moon with First Lunar Launch in a Decade - 18 June 2009 NASA Press Release
NASA set to launch LRO in 2008 - 18 May 2006 NASA Press Release
NASA chooses new spacecraft to search for water on Moon - 10 April 2006 NASA Press Release

Moon Page
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