Two astronauts stranded in space for 49 days – 41 days longer than their planned mission – because of big problems with their Boeing-built ride home, will have to spend at least a few more weeks aboard the International Space Station, officials said Thursday. 

Astronauts Butch Wilmore and Suni Williams soared into space on the Starliner on June 5 and were only supposed to remain at the ISS for nine days — but issues with their ship have left their return date up in the air, and NASA is furiously trying to help solve the problem.

Once in space, astronauts found a series of concerning helium leaks and also problems with the manuevering thrusters, and they have been testing whether the ship can be used to return them to Earth.

Now, they’re expected to stay in orbit until sometime in August, Steve Stich, NASA’s Commercial Crew Program manager, told reporters.

Before the astronauts can come home, NASA and Boeing experts said they need to complete a final set of tests for Starliner’s thrusters scheduled for this weekend.

Engineers have been testing a Starliner model at a New Mexico site to understand why Starliner’s thrusters unexpectedly shut down, and whether there would be any risk in turning them back on for the departure from the ISS.   

The weekend’s test will see Starliner firing 27 of its thrusters while docked on the space station.

Should the thruster tests prove successful and the helium leaks continue to remain stable, then NASA would schedule an agency review next week, which would then set an official date for Wilmore and Williams’ return. 

“The prime intent is still to return Butch and Suni aboard Starliner,” Stich added.  

Mark Nappi, the manager of Boeing Starliner program, said that the company ultimately regrets announcing that Wilmore and Williams’ mission would last eight days, as the delays have garnered backlash against the troubled aerospace giant. 

“My regret is that we didn’t say we would stay up there until the mission is complete, but I’m very confident we have a good vehicle to bring the crew back,” Nappi said.  

Stich added that there are no current concerns about supplies dwindling aboard the ISS with two additional astronauts aboard, noting that Wilmore and Williams have remained positive and continue to enjoy their extended stay in space.   

NASA has previously indicated that Starliner can stay up in space for a maximum of 90 days.

NASA noted that should anything go wrong with the weekend tests and Starliner proves too big of a risk for a return trip, then the agency has other backup methods to getting the astronauts home. 

The easiest method, Stich said, was for Willmore and Williams to hitch a ride on SpaceX’s Crew Dragon spaceship. 

The Boeing rival, which recently ferried four astronauts to the ISS in March, is capable of carrying two to four passengers at a time, but it can fit additional occupants if needed. 

“The beauty of having Dragon and Starliner is that we have two different systems of transportation to the ISS,” Stich said. “Someday Starliner could be a backup to a Dragon mission.”  

SpaceX has served as the sole commercial company approved to transport astronauts and cargo to the space station since 2020.

The last time a NASA astronaut needed help returning to Earth was in 2022, when Russia’s Soyuz capsule sprang a leak with American Frank Rubio on board.

While NASA had considered tapping SpaceX for help, Rubio eventually returned aboard an empty Soyuz capsule that Russia launched.