NASA announced Saturday that it would use Elon Musk’s SpaceX to bring home two astronauts who had been stuck on the International Space Station since early June because their Boeing Starliner spaceship had several problems during the flight.

Butch Wilmore and Suni Williams will not be taking the Boeing spacecraft back to Earth. Instead, they will take a SpaceX Crew Dragon ship. The choice was made after months of public worry, speculation about the astronauts’ well-being, and disagreements between government agencies about the return mission. The first trip was only supposed to last eight days.

“Spaceflight is risky — even at its safest and even at its most routine — and a test flight, by nature, is neither safe nor routine, and so the decision to keep Butch and Suni aboard the International Space Station and bring the Boeing Starliner home uncrewed is a result of a commitment to safety,” NASA Administrator Bill Nelson said Saturday at a news briefing.

“The pair originally lifted off from Florida’s Space Coast in early June but while in orbit and docked to the ISS, engineers discovered helium leaks and issues involving thrusters, which prompted NASA and Boeing to investigate. The investigation included ground tests at the Army’s White Sands Missile Range in New Mexico to recreate the problems, which both NASA and Boeing characterized as mino

NASA management said they would use the spaceship in an emergency. However, research done in the weeks since has made people less sure that the vehicle is a good choice for getting the astronauts back to Earth.

NASA said that Wilmore and Williams will come back to Earth on a future SpaceX trip because they don’t know enough about the spacecraft.

The people on SpaceX Crew 9 will have to be changed because of these changes to the schedule. The launch from Florida’s Space Coast probably won’t happen until September.

The new plan calls for cutting down on the team of four so that there is room for the two astronauts who are stuck on the ISS and will return in February 2025.

Wilmore and Williams will keep doing tests on the space station until they leave. This is because they are still waiting for more supplies and custom suits for their trip back to Earth.

NASA Commercial Crew Program Manager Steve Stich recently said that he saw a “bright future for Starliner,” even with all the problems. However, it is still unknown if the ship will fly again.

Filings with the U.S. Securities and Exchange Commission show that the Boeing program has been held up for years and has lost more than a billion dollars.

The Starliner news comes at a time when the Fortune 500 company was trying to recover from a rough year in which it admitted that its 737 MAX had design flaws, a door plug flew off an airplane in the middle of a flight, top management, including the CEO, was reorganized, and employees told investigators about bad manufacturing practices at some of its facilities.

NASA, on the other hand, has kept up its demand for at least two U.S.-based vehicles that can take humans to the ISS, since there has only been one since 2020.

If the Boeing CST-100 Starliner had been able to take off and land successfully, it would have become the second cleared ship for sending people and supplies to the ISS.

NASA and Boeing were already working on the first flight after certification. It was supposed to send four astronauts to the ISS in August 2025, but both the date and the mission now seem to be in danger.

NASA officials said it was too early to say how this would affect future Starliner trips because they need to check the spacecraft’s safety first, which could take several months.

There are at least two other private U.S. space companies that want to send crews to the International Space Station, but only Elon Musk’s Dragon spaceship has received NASA approval to do so.