Space shuttle Discovery has performed its terminal initiation burn. The shuttle’s engines fired at 1:06 a.m. EDT for its approach to the International Space Station. At 2:43 a.m. Discovery will perform a back flip about 600 feet beneath the station. This maneuver will allow Expedition 23 Commander Oleg Kotov and Flight Engineer Soichi Noguchi to photograph the shuttle’s heat shield for analysis by ground specialists. Finally, Discovery and the seven-member STS-131 crew will dock to the space station’s Harmony Node at 3:44 a.m.