Sunita Williams to remain in space till...: NASA

National Aeronautics and Space Administration (NASA) has said it's 'too risky' to bring the two astronauts, Sunita Williams and Butch Wilmore, back to earth currently, because of which Boeing's Starliner capsule will return without the two astronauts.

Wilmore and Williams will continue their work formally as part of the expedition and will return only in February 25.

This means what would have been a week-long test flight will now extend to around 8 months.

'Wilmore and Williams will continue their work formally as part of the Expedition 71/72 crew through February 2025. They will fly home aboard a Dragon spacecraft with two other crew members assigned to the agency's SpaceX Crew-9 mission. Starliner is expected to depart from the space station and make a safe, controlled autonomous re-entry and landing in early September,' NASA said in a statement.

The uncrewed return of capsule will allow NASA and Boeing to continue gathering testing data on the Starliner during its upcoming flight home, while also not accepting more risk than necessary for its crew.

Wilmore and Williams, who flew to the International Space Station in June aboard NASA's Boeing Crew Flight Test, have been supporting station research, maintenance, and Starliner system testing and data analysis, among other activities.

NASA Administrator Bill Nelson said the spaceflight is 'risky' and the decision to keep the two astronauts in space and bring the Starliner unscrewed is because of 'commitment to safety'.

"Spaceflight is risky, even at its safest and most routine. A test flight, by nature, is neither safe, nor routine. The decision to keep Butch and Sunita aboard the International Space Station and bring Boeing's Starliner home uncrewed is the result of our commitment to safety: our core value and our North Star," Nelson said.

"I'm grateful to both the NASA and Boeing teams for all their incredible and detailed work."

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

Since then, engineering teams have completed a significant amount of work, including reviewing a collection of data, conducting flight and ground testing, hosting independent reviews with agency propulsion experts, and developing various return contingency plans.

The uncertainty and lack of expert concurrence do 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.