Nasa on Friday cut two astronauts from the next crew to make room on the return trip for the two stuck at the International Space Station.
Nasa’s Nick Hague and Russian Aleksandr Gorbunov will launch in September aboard a SpaceX rocket for the orbiting laboratory.
The duo will return with Suni Williams and Butch Wilmore in February.
Nasa decided it is too risky for Ms Williams and Mr Wilmore to fly home in their Boeing Starliner capsule, marred by thruster troubles and helium leaks.
Astronauts Zena Cardman and Stephanie Wilson have been bumped from the SpaceX flight.
Nasa said they could fly on future missions.
The space agency said it took into account spaceflight experience and other factors in making the decision.
After the shuttles retired, the US relied on Russia to ferry crews to the space station until SpaceX began taking astronauts in 2020.
The two countries have continued to trade seats.
Next month, Nasa’s Don Pettit will be launching to the space station while Nasa’s Tracy Dyson will be returning to Earth on Russian capsules.
Nasa turned to private businesses a decade ago, wanting two competing US companies ferrying astronauts in the post-shuttle era.
Ms Williams and Mr Wilmore were Boeing’s first crew, arriving at the space station in June for what was supposed to be a week-long stay.
Their capsule will return empty as early as next Friday, aiming for a touchdown in the New Mexico desert.
