The Commercial Crew Program (CCP) provides commercially operated crew transportation service to and from the International Space Station (ISS) under contract to NASA, conducting crew rotations between the expeditions of the International Space Station program. American space manufacturer SpaceX began providing service in 2020, using the Crew Dragon spacecraft, and NASA plans to add Boeing when its Boeing Starliner spacecraft becomes operational no earlier than 2025. NASA has contracted for six operational missions from Boeing and fourteen from SpaceX, ensuring sufficient support for ISS through 2030.

The Boeing Starliner is a class of partially reusable spacecraft designed to transport crew to the International Space Station (ISS) and other low-Earth-orbit destinations. It is manufactured by Boeing, with the Commercial Crew Program (CCP) of NASA as the anchor customer. The spacecraft consists of a reusable crew capsule and an expendable service module.