After spending 12 weeks at the International Space Station, Boeing’s Starliner spacecraft is scheduled to return to Earth on September 6, though it will do so without its two-man crew. The spacecraft is set to undock from the space station around 6 p.m. ET, and will then spend approximately six hours maneuvering toward its landing site in White Sands, New Mexico, arriving around midnight.

The astronauts who arrived on Starliner, Butch Wilmore and Suni Williams, will remain at the space station due to concerns about gas leaks and propulsion system issues with the spacecraft. NASA, after evaluating these risks, decided it was not safe to have the crew return aboard Starliner.

The spacecraft will return autonomously, with flight controllers in Houston and Boeing’s Mission Control Center in Florida overseeing the mission. They can remotely command the spacecraft if necessary to ensure a safe undocking, re-entry, and parachute-assisted landing.

The success of this uncrewed return is vital for Boeing’s Starliner program. Any mishap during the return or a negative assessment from NASA could further damage Boeing’s reputation, which has already suffered due to issues with the Starliner program. The company has incurred around $1.5 billion in losses, and any additional testing or redesigns could be costly.

Ken Bowersox, NASA’s associate administrator for Space Operations, expressed disappointment that the mission could not be completed with crew but emphasized that decisions should be based on safety rather than disappointment. Even if the uncrewed return goes smoothly, NASA will still need to decide whether to grant Starliner human spaceflight certification, despite the incomplete mission.

In the meantime, astronauts Williams and Wilmore will return to Earth on a SpaceX Crew Dragon capsule, with the earliest possible return slated for February. The Crew Dragon, which has been certified for crewed missions for about four years and completed around a dozen such trips, will bring them back home.