Boeing’s Starliner is ready to lift off and return to Earth on June 22, according to NASA

The Boeing Starliner spacecraft is now scheduled to detach from the International Space Station and return to Earth with its inaugural crew of astronauts on June 22, allowing more time to complete planning for the complex operation, NASA said on Friday.

NASA astronauts Butch Wilmore and Sonny Williams launched aboard the Starliner spacecraft on June 5 and arrived at the International Space Station the next day, after a 24-hour flight during which the spacecraft experienced four helium leaks and five failures in 28 propulsion maneuvers.

“The additional time will allow the team to complete departure planning and operations while keeping the spacecraft clear within flight rules for crew emergency scenarios,” NASA and Boeing said in a statement.

They aim to depart on June 22 at the earliest, giving them another opportunity to extend their time on the ISS. The Starliner is designed for future six-month missions, but could remain docked with the ISS for up to 45 days during the current mission.

The return to Earth is expected to take about six hours and will target a site in the Utah or New Mexico desert or other backup locations, depending on local weather conditions.

The Starliner’s first flight with astronauts is a crucial final test in a long-delayed and over-budget program before NASA can certify the spacecraft for routine astronaut missions and add a second American crew vehicle to its fleet, joining SpaceX’s Crew Dragon.

The spaceship encountered more problems during docking with the International Space Station. A fifth leak of helium — used to pressurize the thrusters in the Starliner’s propulsion system — emerged, and an oxidizer valve was seized separately, NASA said.

These onboard issues come after years of other challenges Boeing has faced with Starliner, including a failed unmanned test in 2019 in which dozens of software bugs, design issues and management issues prevented it from being able to dock with the International Space Station. During a repeat test in 2022, the connection was successful.

If all goes as planned with the return of the two Starliner astronauts to Earth, Boeing faces other challenges before the spaceship is ready to operate and market it to customers other than NASA.