Live coverage: International Space Station crew lands in Kazakhstan

SpaceX’s Falcon 9 rocket and Crew Dragon spacecraft emerged from the company’s hangar at the Kennedy Space Center early Thursday for the quarter-mile trip up the ramp to historic Launch Complex 39A, ready for final testing before liftoff on the first U.S. mission to carry astronauts into orbit in nearly nine years.

A Falcon 9 rocket lifted off from Vandenberg Air Force Base at 4:39 a.m. PDT (7:39 a.m. EDT; 1139 GMT) Wednesday, and SpaceX successfully landed the rocket’s first stage on a drone ship in the Pacific Ocean. The mission’s primary objective is the deployment of 10 Iridium Next communications satellites into low Earth orbit.

The launch of a United Launch Alliance Delta 4-Heavy rocket from Cape Canaveral was aborted three seconds before a planned liftoff at 3:28 a.m. EDT (0728 GMT). The rocket was set to loft a classified payload for the National Reconnaissance Office, the U.S. government’s spy satellite agency.