Roughly 48 hours after a first launch attempt was scrubbed, four astronauts are set to climb aboard a SpaceX rocket again on Friday to launch to the International Space Station.

NASA astronauts Anne McClain and Nichole Ayers, Japanese astronaut Takuya Onishi and Russian cosmonaut Kirill Peskov are set to lift off at 7:03 p.m. ET from NASA’s Kennedy Space Center in Florida.

The flight, a mission known as Crew-10, is part of NASA’s regular rotation of crew members to and from the space station. But it has attracted more attention than usual because it means NASA astronauts Suni Williams and Butch Wilmore are finally closing in on their long-awaited flight back to Earth.

Williams and Wilmore have been in the spotlight for months because of the unusual circumstances of their time in orbit. The pair was expected to stay at the space station 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 at the orbiting outpost.

The new crew will relieve Williams, Wilmore and two others — NASA astronaut Nick Hague and Russian cosmonaut Aleksandr Gorbunov — who are wrapping up a roughly six-month stint at the space station.

The Crew-10 astronauts will ride into orbit atop a SpaceX Falcon 9 rocket, and NASA will broadcast the event live on NASA TV beginning at 3 p.m. ET.

Assuming the launch happens as planned, the incoming crew members are expected to arrive at the space station on Saturday. After that, the outgoing crew could depart as early as Wednesday, March 19, according to NASA.

The scrubbed launch attempt this week added to the drama of the situation. It was called off on Wednesday with just over 40 minutes remaining in the countdown clock, because of an issue with one of the ground systems at the launch pad. The four astronauts were already strapped inside the Dragon capsule when the decision was made.

The Crew-10 mission is made up of a mix of veterans and first timers. Both McClain and Onishi will be visiting the space station for the second time, while Ayers and Peskov will be embarking on their first spaceflight. All four astronauts share a common background as pilots.

Their arrival in orbit will kick off a handover period that typically lasts a couple days to allow the new crew members to get trained and up to speed on science experiments, maintenance work and other projects at the station.

After that, Williams, Wilmore, Hague and Gorbunov will travel home in the SpaceX Dragon capsule that Hague and Gorbunov flew to the space station in September. Two seats were purposefully kept empty so that their colleagues could later hitch a ride back to Earth.

The Starliner spacecraft that Williams and Wilmore flew to space encountered several issues in June as it docked with the orbiting lab. After months of investigation and tests, NASA decided to bring the Starliner craft back to Earth with no one aboard and have the astronaut duo wait for a ride on a SpaceX vehicle instead.

Their unexpectedly long stay in low-Earth orbit has recently become a political talking point. SpaceX CEO Elon Musk and President Donald Trump have both made unsubstantiated claims that the Biden administration held up the flight back to Earth for political reasons. Trump also said recently that he had tasked Musk with bringing the astronauts home. However, NASA has planned to use a SpaceX vehicle for their return journey since it was announced in August.