Video replay: Parker Solar Probe launches atop Delta 4-Heavy

SpaceX’s third Falcon Heavy rocket is set for liftoff from NASA’s Kennedy Space Center in Florida, and the heavy-lift launcher will head on an easterly course over the Atlantic Ocean atop more than 5 million pounds of thrust.

The revised Atlas 5 rocket firing order includes two national security missions this summer before launching NASA’s daring asteroid sampler mission in September as originally planned.

More testing will be done on both the thrusters on the spacecraft’s aft section. The Starliner crew will also repeat some previously conducted test activities, like the ‘safe haven’ protocol.