Starliner

CST-100

Mission Profile

Starliner (CST-100, Boeing Crew Space Transportation-100) is Boeing's commercial crew transportation spacecraft, developed under NASA's Commercial Crew Program to carry astronauts to the International Space Station. The capsule first flew uncrewed in December 2019 on Orbital Flight Test-1, which suffered a software timing error preventing ISS docking. A crewed test flight in May 2024 carrying Butch Wilmore and Suni Williams docked with the ISS but revealed propulsion system anomalies that led NASA to return the spacecraft without its crew, with the astronauts remaining aboard the ISS until early 2025. Despite its development challenges, Starliner provides a second commercial crew transportation option alongside SpaceX's Dragon 2 once certification is achieved.