Main Engine Cut Off

“We have an agreement with SpaceX that they are going to take our launch vehicle configuration and run it through the actual crew-loading timeline to demonstrate consistency,” Lueders said. “It’s for us to get confidence on the crew-loading sequence.”

This means that the static fire and launch of the Demo-1 mission will follow fuel-loading procedures for crew missions, as will the static fire and launch of the in-flight abort mission. The fifth test will come during the static fire test of the Demo-2 flight.