The Vulcan has launched on its second-ever national security spaceflight in what will be the biggest test yet for ULA's powerful rocket.

NASA and SpaceX are set to launch the Crew-12 mission early Friday morning from Cape Canaveral Space Force Station. After a weather delay on Tuesday, the launch iss scheduled for 5:15 a.m. Friday. The crew of four will travel to the International Space Station.

Update for 7 a.m. ET: SpaceX successfully launched four astronauts to the International Space Station on the Crew-12 mission.