Lunar CRater Observation and Sensing Satellite (LCROSS)

The Lunar CRater Observation and Sensing Satellite (LCROSS) is a robotic spacecraft operated by NASA, which is currently orbiting the Earth and is targeted for impact on the Moon early October 2009.^[2] LCROSS is designed to watch as the launch vehicle's spent Centaur upper stage, with a nominal impact mass of 2,305 kg (5,081 lb), strikes the Cabeus A crater^[3] near the south pole of the Moon (projected impact at the lunar South Pole is currently: Oct 9, 2009 at 11:30 UTC). LCROSS was launched on June 18, 2009, together with the Lunar Reconnaissance Orbiter as part of the shared Lunar Precursor Robotic Program, the first American mission to the Moon in over ten years. Together, LCROSS and LRO form the vanguard of NASA's return to the Moon.^[4]

Early in the morning on August 22, 2009, LCROSS ground controllers discovered an anomaly due to a sensor issue, the spacecraft burned through 309 pounds of fuel, resulting in more than half of remaining fuel at the time burned up. According to Dan Andrews, the LCROSS project manager, "Our estimates now are if we pretty much baseline the mission, meaning just accomplish the things that we have to (do) to get the job done with full mission success, we're still in the black on propellant, but not by a lot."^[5]

LCROSS is a fast-track, low-cost companion mission to the LRO. The LCROSS payload was added after NASA moved the LRO from the Delta IIto a larger launch vehicle. It was chosen from 19 other proposals.^[6]

LCROSS launched with the LRO aboard an Atlas V rocket from Cape Canaveral, Florida, on June 18, 2009, at 21:32 UTC (17:32 EDT). On June 23, four and a half days after launch, LCROSS and its attached Centaur booster rocket successfully completed a lunar swingby and entered into polar Earth orbit with a period of 37 days, positioning LCROSS for impact on a lunar pole.^[7][8]

LCROSS suffered a malfunction on August 22, depleting half of its fuel and leaving very little fuel margin in the spacecraft^[9].

Lunar impact, after approximately three orbits, is projected for October 9, 2009, at 11:30 UTC, ± 30 minutes. The mission team announced that Cabeus A will be the target crater for the LCROSS dual impacts scheduled for 11:30 UTC on October 9, 2009. ^[10]

On final approach, the shepherding spacecraft and Centaur will separate and the Centaur upper stage will act as a heavy impactor to create a debris plume that will rise above the lunar surface. Following four minutes after impact of the Centaur upper stage, the shepherding spacecraft will fly through this debris plume, collecting and relaying data back to Earth before impacting the lunar surface and creating a second debris plume. NASA expects the impact velocity will be over 9,000 km/h (5,600 mph). The ejecta plume will be in the order of 317 tonnes (350 tons) and rise 9.6 km (6 mi) from the surface.^[11][12]

It is hoped that spectral analysis of the resulting impact plume will help to confirm preliminary findings by the Clementine and Lunar Prospectormissions which hinted that there may be water ice in the permanently shadowed regions. LCROSS will fly through the debris plume and will then crash itself into a different part of the crater approximately four minutes after the Centaur impact. Mission scientists estimate that the Centaur impact plume may be visible through amateur-class telescopes with apertures as small as 25 to 30 cm (10 to 12 inches).^[13] Both impacts will also be monitored by Earth-based observatories and possibly by other orbital assets.

Research and Compiled by : Futuristic Space Resources