The Boeing Starliner Crewed Flight Test (CFT), intended as the final verification before regular crewed service to the International Space Station (ISS), became an unexpected turning point for Boeing and NASA's Commercial Crew Program. Launched on June 5, 2024, from Cape Canaveral, Florida, the spacecraft carried NASA astronauts Butch Wilmore and Suni Williams with the goal of a week-long stay at the ISS. However, despite a successful launch and docking on June 6, the mission encountered severe technical challenges that ultimately led to an uncrewed return and an extended stay for the astronauts.
Mission Timeline and Objectives
The CFT mission was envisioned as the critical final step for Starliner before entering regular crew rotation service. Astronauts Wilmore and Williams were tasked with conducting various tests aboard the ISS while ground crews analyzed data from the launch and docking sequence. The capsule was scheduled to undock after approximately eight days and land in the American Southwest, marking a successful demonstration of Boeing’s long-awaited crewed capabilities.
However, the mission did not proceed as planned. During the docking sequence, multiple technical failures surfaced, including performance degradation in the reaction control system (RCS) thrusters. The spacecraft software deemed five of the thrusters damaged and unusable. Additionally, Boeing and NASA engineers detected five separate helium leaks within the service module, which compromised the spacecraft's safety and attitude control.
Safety Concerns and Uncrewed Return
The technical failures prompted weeks of joint testing and analysis. Despite exhaustive troubleshooting, NASA and Boeing could not definitively determine the root cause of the thruster malfunctions, deeming it too risky to attempt a crewed return. On September 6, 2024, the decision was made to bring Starliner back to Earth uncrewed. The spacecraft undocked from the ISS at 6:04 p.m. Eastern time and safely landed at White Sands Space Harbor in New Mexico at 10:01 p.m. MDT.
During reentry, Starliner faced additional, unrelated issues, including a brief glitch in its navigation system and a failure of one of the 12 thrusters used to orient the capsule during atmospheric re-entry. Despite these anomalies, the landing was completed without incident.
Astronauts' Extended Stay on ISS
Wilmore and Williams, originally expected to return within ten days of launch, ultimately remained on the ISS for approximately 290 days. NASA prioritized safety by keeping them onboard the station, where they joined the Expedition 71/72 crew. The astronauts finally returned to Earth aboard a SpaceX Crew Dragon as part of the Crew-9 mission in March 2025, following the launch of Crew-10 to replace them.
Political and Public Reactions
The extended stay became a topic of political debate, with former President Trump accusing the Biden administration of abandoning the astronauts. Both Wilmore and Williams publicly dismissed such narratives, emphasizing their commitment to the mission and clarifying that they did not feel stranded or abandoned. Wilmore stated, "We don't feel abandoned, we don't feel stuck, we don't feel stranded... Let's change the narrative to 'prepared' and 'committed.'"
The Future of Boeing Starliner
The setbacks faced by Starliner have cast uncertainty over its future. Boeing and NASA are conducting a thorough review of the mission data to understand the root causes and make improvements before attempting another crewed mission. Boeing CEO Kelly Ortberg has expressed the company’s commitment to resolving the issues and moving forward with the program, while NASA Administrator Bill Nelson has reiterated the importance of learning from these challenges.
While SpaceX's Crew Dragon continues to fulfill NASA’s crew rotation needs, Boeing’s Starliner remains grounded as engineers address the identified problems. As the Commercial Crew Program evolves, the lessons learned from Starliner's troubled CFT mission will shape the future of human spaceflight safety and engineering excellence.
Conclusion
The Boeing Starliner CFT mission underscores the inherent complexities of human spaceflight and the necessity of rigorous testing and safety protocols. Though the mission faced unprecedented challenges, both Boeing and NASA have vowed to apply the lessons learned to future missions. The safe return of the astronauts aboard SpaceX’s Crew Dragon not only marked the end of this turbulent chapter but also served as a reminder of the importance of collaboration and adaptability in space exploration.