The spacecraft rolled out May 4 from the back of Boeing’s Commercial Crew and Cargo Processing Facility at NASA’s Kennedy Space Center in Florida on a transport vehicle and then left the parking lot at about 11:00 a.m. EDT. Starliner made a carefully orchestrated trek to United Launch Alliance’s Vertical Integration Facility (VIF) at Cape Canaveral Space Force Station.
After about an hour-long journey, Starliner was hoisted and mated to the Atlas V rocket that will launch the uncrewed spacecraft to orbit. With the two vehicles now connected, the teams will perform integrated testing to ensure they’re properly communicating with one another prior to launch.
The return to the launch site comes after diligent testing and analysis work by the Starliner team, which became necessary when propulsion system valves did not open as designed during prelaunch system checks last year. The completed spacecraft that returned to the launch complex included the same reusable crew module attached to a brand-new service module.
Teams integrated a new direct purge system into the service module in order to protect the valves from ambient moisture at Boeing’s spacecraft factory, on the roll out to the VIF and while Starliner is at the VIF. The purge system will prevent moisture from entering the valves by flowing dry nitrogen gas directly to oxidizer valves in the service module and surrounding them with a dry environment.
An additional vehicle conditioning purge system, provided by ULA and part of standard prelaunch operational procedures, will give the spacecraft ideal environmental conditions from the load onto the transport vehicle through L-8 hours. Just prior to cryogenic propellant loading, Starliner will begin receiving a dry atmosphere through the launch vehicle’s gaseous nitrogen purge system.
The purge system will be monitored and the valves cycled frequently until launch, which is targeted for May 19 at 6:54 p.m. EDT.