Boeing’s (NYSE:BA) Starliner spacecraft, with its inaugural astronaut crew aboard, is now scheduled to undock from the International Space Station and return to Earth on June 22, NASA announced on Friday. This extended timeline provides more time to finalize planning for the complex process.

NASA astronauts Butch Wilmore and Suni Williams were launched aboard Starliner on June 5 and arrived at the ISS the following day. During the 24-hour flight, the spacecraft encountered four helium leaks and five failures of its 28 maneuvering thrusters.

“The extra time allows the team to finalize departure planning and operations while the spacecraft remains cleared for crew emergency return scenarios within the flight rules,” NASA and Boeing said in a joint statement.

The target departure date is no earlier than June 22, with the possibility of further extensions of time at the ISS. Although Starliner is designed for future six-month missions, it can stay docked to the ISS for a maximum of 45 days during its current mission.

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

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

During its time docked to the ISS, the spacecraft has encountered additional problems. A fifth leak of helium, used to pressurize Starliner’s propulsion system thrusters, has been detected, and separately, an oxidizer valve has been stuck, according to NASA.

These in-flight problems follow years of other challenges Boeing has faced with Starliner, including a 2019 uncrewed test failure where numerous software glitches, design problems, and management issues prevented its ability to dock to the ISS. A repeat uncrewed test in 2022 succeeded in docking.

If all goes as planned with Starliner’s return of two astronauts back to Earth, Boeing still faces other challenges before making the spacecraft operational and bringing it to market for other non-NASA customers.