NASA’s twin lunar Gravity Recovery and Interior Laboratory (GRAIL) spacecraft lifted off from Cape Canaveral Air Force Station in Florida at 9:08 a.m. EDT (6:08 a.m. PDT) Saturday, Sept. 10, to study the moon in unprecedented detail. GRAIL-A is scheduled to reach the moon on New Year’s Eve 2011, while GRAIL-B will arrive New Year’s Day 2012. The two solar-powered spacecraft will fly in tandem orbits around the moon to measure its gravity field. GRAIL will answer longstanding questions about the moon and give scientists a better understanding of how Earth and other rocky planets in the solar system formed.
Quoted from NASA Launches Mission to Study Moon From Crust to Core on ScienceDaily: Top News