The countdown clock is stopped at a three-hour built in hold as a SpaceX Falcon 9 rocket, with the company's Crew Dragon capsule attached, sits on the launch pad at Launch Complex 39A Sunday, Nov. 15, 2020, at the Kennedy Space Center in Cape Canaveral, Fla. Four astronauts will fly on the SpaceX Crew-1 mission to the International Space Station scheduled for launch on later today. (AP Photo/Chris O'Meara)