LOS ANGELESspincasinonodepositbonus, Augspincasinonodepositbonus. 24 (Xinhua) -- NASA has decided to bring Boeing's Starliner back to Earth in September, and the two stranded astronauts, Butch Wilmore and Sunita Williams, will remain at the International Space Station (ISS) until next February, the agency announced on Saturday.

"The uncrewed return allows NASA and Boeing to continue gathering testing data on Starliner during its upcoming flight home, while also not accepting more risk than necessary for its crew," NASA said in a release.

NASA astronauts Wilmore and Williams arrived at the ISS on June 6 aboard the Boeing Starliner. They were meant to return after eight days, but have been stuck in space for more than two months due to technical problems of the spacecraft.

NASA and Boeing identified helium leaks and experienced issues with the spacecraft reaction control thrusters on June 6 as Starliner approached the space station.

Since then, engineering teams have made efforts to review a collection of data, conduct flight and ground tests, host independent reviews with agency propulsion experts, and develop various return contingency plans.

NASA said Wilmore and Williams will continue their work formally through February 2025. They will fly home aboard a SpaceX Dragon spacecraft with two other crew members assigned to the agency's SpaceX Crew-9 mission.

"The uncertainty and lack of expert concurrence does not meet the agency's safety and performance requirements for human spaceflight, thus prompting NASA leadership to move the astronauts to the Crew-9 mission," said NASA.

To ensure a docking port is available at the ISS for the Crew-9 mission, Starliner is expected to make a safe, controlled autonomous re-entry and landing in early September, before the Crew-9 mission's departure, according to NASA.

NASA and Boeing will work together to adjust end-of-mission planning and Starliner's systems to set up for the uncrewed return in the coming weeks.

The Crew-9 mission, originally slated with four crew members, will launch no earlier than Tuesday, Sept. 24.

"Starliner is a very capable spacecraft and, ultimately, this comes down to needing a higher level of certainty to perform a crewed return," said Steve Stich, manager of NASA's Commercial Crew Program.

"The NASA and Boeing teams have completed a tremendous amount of testing and analysis, and this flight test is providing critical information on Starliner's performance in space. Our efforts will help prepare for the uncrewed return and will greatly benefit future corrective actions for the spacecraft," Stich said.■