Boeing Starliner undocks from ISS without Sunita Williams, Butch Wilmore; Here’s why

On September 6, 2024, Boeing‘s Starliner spacecraft undocked from the International Space Station (ISS) and began its return journey to Earth. The undocking occurred at 6:04 p.m. EST and was streamed live on NASA‘s website. This mission was particularly notable because the spacecraft returned without the astronauts it had initially carried into space.
NASA astronauts Barry “Butch” Wilmore and Sunita “Suni” Williams were part of the first crewed test flight of the Starliner, which launched on June 5, 2024, from Cape Canaveral Space Force Station in Florida.

The mission was intended to last about a week, but several issues with the spacecraft extended their stay on the ISS. Problems included helium leaks and malfunctioning thrusters, which led NASA to decide that the spacecraft was too risky to carry the crew back to Earth.

The decision to return the Starliner without its crew was made on August 24, 2024. NASA and Boeing officials expressed confidence in the spacecraft’s ability to return safely, despite the issues encountered. Steve Stich, program manager for NASA’s Commercial Crew Program, stated, “We have confidence in the vehicle… We’ve had two good landings so far and we’re expecting another one on Friday.”
The Starliner is part of NASA’s Commercial Crew Program, which aims to certify spacecraft for routine missions to and from the ISS. The spacecraft’s return journey was targeted for a landing at White Sands Space Harbor in New Mexico at approximately 12:03 a.m. EST on September 7, 2024. This landing site has been used for previous Starliner missions and is well-equipped to handle the spacecraft’s return.
Wilmore and Williams prepared the Starliner for its departure by reconfiguring the spacecraft’s seats for an uncrewed landing and packing cargo inside for ground crews to retrieve. They also returned standard visiting vehicle emergency hardware stowed inside the Starliner back to the ISS for future mission operations.

The Starliner had faced challenges even before its launch. The flight test was initially scheduled for May 6, 2024, but was delayed due to a problem with an oxygen valve on a rocket from United Launch Alliance (ULA). A new launch date was set for May 25, 2024, but a small helium leak in the service module caused another delay. Despite these setbacks, the spacecraft successfully launched on June 5, 2024.
During its time docked at the ISS, the Starliner experienced several issues that required extensive troubleshooting. Engineers discovered that parts of the propulsion system were likely getting too hot or exposed to propellant vapor, causing some materials to bulge or corrode. These findings led to the decision to return the spacecraft without its crew.
The safe return of the Starliner is vital for the overall Boeing Starliner program. NASA and Boeing continue to gather testing data to ensure the spacecraft can perform routine missions to and from the ISS. The next crewed mission for the Starliner is planned for February 2025, when Wilmore and Williams are expected to return to Earth aboard SpaceX‘s Crew-9 Dragon spacecraft.
The successful undocking and return of the Starliner mark a significant milestone in NASA’s efforts to certify new spacecraft for human spaceflight. Despite the challenges faced, the mission demonstrates the resilience and adaptability of both the spacecraft and the teams involved in its development and operation.