Boeing Crew Flight Test: What Happened to Starliner's First Crewed Mission?

Boeing's Crew Flight Test (CFT) was the first crewed launch of the CST-100 Starliner spacecraft, carrying NASA astronauts Butch Wilmore and Suni Williams to the International Space Station on June 5, 2024. What was planned as an eight-day certification mission became a nine-month ordeal after helium leaks and maneuvering thruster failures raised serious safety concerns. NASA ultimately decided the two astronauts would return to Earth in March 2025 aboard a SpaceX Crew Dragon rather than risk a return flight on the Starliner.

What Were the Technical Problems That Grounded Starliner?

Before launch, engineers discovered five helium leaks in Starliner's service module — helium being critical for pressurizing the propulsion system. Mission managers initially accepted the risk and launched anyway. In orbit, five of Starliner's 28 reaction control system (RCS) thrusters failed during the rendezvous approach to the ISS, with four later recovered. The combination of helium leaks and thruster unreliability meant NASA could not certify the spacecraft safe for a crew return. Throughout the summer of 2024, Boeing and NASA ran ground tests and computer simulations, but could not resolve confidence issues before the spacecraft's on-orbit consumables neared their limits. Starliner ultimately undocked uncrewed on September 6, 2024, and landed at White Sands Space Harbor, New Mexico, on September 7, 2024.

Who Are Butch Wilmore and Suni Williams?

Barry 'Butch' Wilmore, a retired U.S. Navy captain and NASA astronaut, served as commander of the CFT mission. Sunita 'Suni' Williams, also a retired Navy officer and veteran of two long-duration ISS expeditions, served as pilot. Both are experienced spaceflight veterans — Williams logged 195 days in space across two prior missions. During their unplanned extended stay, both were formally integrated into ISS Expedition 71 and 72 crews, contributing to station operations and scientific research. Williams was named commander of Expedition 72 in September 2024, making productive use of their time aboard.

How Did the Mission End and What Does It Mean for Boeing?

Wilmore and Williams returned to Earth on March 18, 2025, splashing down aboard SpaceX Crew Dragon Freedom after 286 days in space. The extended mission was a significant blow to Boeing's space ambitions. The Starliner program had already suffered years of delays and a costly uncrewed test failure in 2019. NASA has not yet confirmed whether Boeing will receive a crewed mission certification or additional service orders. SpaceX, by contrast, had completed multiple operational Crew Dragon missions without incident. Boeing has spent over $1.5 billion in cost overruns on the fixed-price Commercial Crew contract, and the CFT outcome deepened investor and agency uncertainty about Starliner's future.