Apollo 10's lunar module, designated as Snoopy, separated from the lunar orbiter with USAF Colonel Tom Stafford and U.S. Navy Commander Gene Cernan firing the descent engines to make the closest approach up to that time to the Moon, coming within 15400 meters (about 9.6 miles) of the Moon's surface, reaching its lowest altitude at 2130:43 UTC (4:30 in the afternoon EST). [