A SpaceX capsule delivered four astronauts to the International Space Station early on Sunday in a NASA crew-swap mission that will allow a pair of stuck astronauts, Butch Wilmore and Suni Williams, to return home after nine months on the orbiting lab.

Butch Wilmore and Suni Williams originally planned to go to space for just eight days but got stuck on the station after their Boeing Starliner spacecraft experienced problems.

Reaching orbit from NASA’s Kennedy Space Center, the newest crew includes NASA’s Anne McClain and Nichole Ayers, both military pilots; and Japan’s Takuya Onishi and Russia’s Kirill Peskov, both former airline pilots. They will spend the next six months at the space station, considered the normal stint, after springing Wilmore and Williams free.

The two American astronauts stranded aboard the International Space Station for nine months may have been stuck there because of the presidential election, one of their fellow spacemen thinks.

SpaceX will launch a crewed NASA mission on Friday to return two astronauts from the International Space Station, after technical issues with Boeing’s spacecraft extended their stay for nine months, leading SpaceX CEO Elon Musk and President Donald Trump to suggest they were stranded for “political reasons.

Butch Wilmore and Suni Williams need SpaceX to get a relief team to the space station before they can check out. Arrival is set for late Saturday night.

A SpaceX Falcon 9 surged up through blue skies to send a crew on its way to International Space Station where the pair of NASA astronauts who flew up last summer on Boeing’s Starliner have

The four newcomers — representing the US, Japan and Russia — will spend the next few days learning the station's ins and outs from Butch Wilmore and Indian-American Sunita Williams.