An engineer works the switch to power on a Boeing CST-100 Starliner spacecraft inside Boeing's Commercial Crew and Cargo Processing Facility at NASA's Kennedy Space Center in Florida. This was the first time "Spacecraft 1," as the individual Starliner is known, was powered up. It is being assembled for use during a pad abort test that will demonstrate the Starliners' ability to lift astronauts out of danger in the unlikely event of an emergency. Later flight tests will demonstrate Starliners in orbital missions to the station without a crew, and then with astronauts aboard. The flight tests will preview the crew rotation missions future Starliners will perform as they take up to four astronauts at a time to the orbiting laboratory in order to enhance the research taking place there.