A SPACEX CREW capsule has arrived at the International Space Station, delivering the replacements for Nasa’s two stuck astronauts.

The four newcomers – from the US, Japan and Russia – will spend the next few days learning the station’s ins and outs from Butch Wilmore and Suni Williams, who will then strap into their own SpaceX capsule later this week to end an unexpected extended mission that began last June.

The pair expected to be away for just a week when they launched on Boeing’s first astronaut flight but they hit the nine-month mark earlier this month.

Wilmore swung open the space station’s hatch and then rang the ship’s bell as the new arrivals floated in one by one on Sunday and were greeted with hugs and handshakes.

“It was a wonderful day,” Williams told mission control. “Great to see our friends arrive.”

There are now 11 people on board the ISS. AP AP

The Boeing Starliner capsule encountered so many problems that Nasa insisted it returned to Earth empty, leaving its test pilots behind to wait for a SpaceX lift.

Their ride arrived in late September with a downsized crew of two and two empty seats reserved for the leg back. But more delays resulted when their replacements’ new capsule needed extensive battery repairs.

Weather permitting, the SpaceX capsule carrying Wilmore, Williams and two other astronauts will undock from the space station no earlier than Wednesday and splash down off Florida’s coast.

Until then, there will be 11 aboard the orbiting lab, representing the US, Russia and Japan.