STS-135: The final shuttle launch

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.

SpaceX test-fired a Falcon 9 rocket Saturday at Cape Canaveral, two days before a scheduled launch Monday with 60 Starlink broadband relay stations that will make SpaceX the owner of the world’s largest fleet of commercial satellites.

Follow the key events of the Falcon 9 rocket’s ascent to orbit with 60 satellites for SpaceX’s Starlink broadband network.