The mission will send the first full batch of 27 operational satellites into low Earth orbit. United Launch Alliance will launch its Atlas 5 551 rocket from pad 41 at Cape Canaveral Space Force Station on April 9 during a three-hour window that opens at 12 p.m. EDT (1600 UTC).
The United States Space Force 51 (USSF-51) mission was the 58th and final time an Atlas 5 rocket launches a national security payload. Liftoff happened at Tuesday, July 30, during a three-hour window that opens at 6:45 a.m. EDT (1045 UTC).
The 200th Atlas-Centaur rocket, history some 52 years in the making, will blast off Tuesday from Cape Canaveral to deliver a U.S. Navy mobile communications satellite into orbit.