Four astronauts will have to wait a bit longer for their journey to the International Space Station.
Mission controllers called off a planned launch Wednesday because of an issue with one of the clamp arms that holds the SpaceX rocket in place on the launch pad.
NASA has yet to announce a new launch date and time.
The routine launch attempt was closely watched because it would have kicked off a series of events culminating in the long-awaited flight back to Earth for NASA astronauts Suni Williams and Butch Wilmore.
Williams and Wilmore were expected to stay on the ISS for just a week as part of the first crewed test flight of Boeing’s Starliner spacecraft in June, but problems with the vehicle forced them to remain in orbit, where they’ve now been for nine months.
Wednesday’s launch, a mission known as Crew-10, was scrubbed with about 43 minutes left in the countdown clock. Liftoff was scheduled for 7:48 p.m. ET from NASA’s Kennedy Space Center in Florida aboard a Falcon 9 rocket.
The four crew members — NASA astronauts Anne McClain and Nichole Ayers, Japanese astronaut Takuya Onishi and Russian cosmonaut Kirill Peskov — were already strapped inside their space capsule.
NASA officials said that there are additional opportunities for the launch this week — at 7:26 p.m. ET Thursday and at 7:03 p.m. ET Friday — but that the decision will depend on whether the hydraulics issue with the clamp arm can be resolved in time.
Whenever the members of Crew-10 do arrive at the space station, they will take over for Williams, Wilmore and two fellow crew members onboard. Then preparations will be underway for the astronauts to finally return home.
The Boeing capsule on which Williams and Wilmore launched encountered several issues during its docking process at the ISS, including malfunctioning thrusters. Because of those problems, NASA decided to bring the Starliner craft back to Earth with no one onboard, leaving the pair to wait for a ride back to Earth.
The two will travel home in a SpaceX Dragon capsule that arrived at the space station in September, carrying NASA astronaut Nick Hague, Russian cosmonaut Aleksandr Gorbunov and two empty seats for their colleagues.
Hague and Gorbunov will return to Earth with Wilmore and Williams, capping their monthslong mission at the ISS.
The unusual situation became a political talking point for SpaceX CEO Elon Musk and President Donald Trump, who have made unsubstantiated claims that the Biden administration held up the flight back to Earth for political reasons. Trump said recently that he had tasked Musk with bringing the astronauts home, but NASA’s plan to use a SpaceX vehicle for their return journey has remained the same since it was announced in August.