Rocket Burn Sets Stage for Dynamic Moon Duos' Lunar Impact

"NASA wanted to rule out any possibility of our twins hitting the surface anywhere near any of the historic lunar exploration sites like the Apollo landing sites or where the Russian Luna probes touched down," said David Lehman, GRAIL project manager at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

The lunar twins of NASA's Gravity Recovery and Interior Laboratory (GRAIL) mission have each completed a rocket burn that has sealed their fate. The burns modified the orbit of the formation-flying spacecraft. Over the next three days, this new orbit will carry the twins lower and lower over the moon's surface.

On Monday afternoon, Dec. 17, at about 2:28 p.m. PST (5:28 p.m. EST), their moon-skimming will conclude when a portion of the lunar surface - an unnamed mountain near the natural satellite's north pole - rises higher than their orbital altitude.

http://www.moondaily.com/reports/Rocket_Burn_Sets_Stage_for_Dynamic_Moon_Duos_Lunar_Impact_999.html