Video: SpaceX test-fires Falcon 9 rocket at pad 40 (members only)

The mission was the second of potentially three Falcon 9 flights set to take place this week. Liftoff from pad 40 at Cape Canaveral Space Force Station happened at 10:35 p.m. EDT (0235 UTC).

Eric Boe, one of three astronauts assigned to the first piloted test flight of a Boeing CST-100 Starliner commercial crew ship later this year has been removed from the mission due to unspecified medical issues, NASA announced Tuesday. He will be replaced by veteran astronaut Mike Fincke.

SpaceX technicians at Cape Canaveral are readying for the first launch of an upgraded Falcon 9 rocket configuration next week, a mission that will debut changes to make the launcher safer for astronauts and make it easier — and less expensive — for the company to reuse first stage boosters.