Four astronauts are about to board a rocket to leave the planet. Update for 7:50 pm ET: SpaceX called off its planned launch of the Crew-10 astronaut mission for NASA due to a hydraulics issue with a clamp device on ground equipment securing the crew's Falcon 9 rocket to the launch pad.

The rocket that will launch NASA's Crew-10 is on the pad. This comes after a spacecraft swap and Falcon 9 incidents required additional testing.