Snapshots from Atlas 5 launch

United Launch Alliance said Monday it did not submit a proposal in a competition to launch a U.S. Air Force GPS navigation satellite, apparently relinquishing the contract to rival SpaceX, the only other company certified to launch the mission.

A United Launch Atlas 5 rocket is set to launch the U.S. Air Force’s fifth Advanced Extremely High Frequency communications satellite from Cape Canaveral. This timeline shows the major mission events planned over a nearly six-hour flight to an optimized geostationary transfer orbit.

The United Launch Alliance Atlas 5 rocket, standing 197 feet tall and and weighing 1.2 million pounds, unleashes 2.4 million pounds of thrust from its main engine and four side-mounted solid boosters to launch the secret NROL-42 payload for the U.S. National Reconnaissance Office from Vandenberg Air Force Base, California.