After about six months in space and several delayed departures, two Americans, a Russian, and a Japanese astronaut left the International Space Station (ISS) on board a capsule from Elon Musk's private space flight company SpaceX, NASA said on Saturday.

The four space travelers had undocked from the ISS, the US space agency said, and were scheduled to arrive on Earth on Sunday night.

The departure of the "Crew-5" – consisting of NASA astronaut Nicole Aunapu Mann and her colleague Josh Cassada as well as the Japanese astronaut Koichi Wakata and the Russian cosmonaut Anna Kikina – had been repeatedly postponed due to weather conditions. They were initially scheduled to depart a few days ago.

Crew-5 was launched in October from Cape Canaveral Cosmodrome – the first joint launch of NASA astronauts and a Russian cosmonaut from US soil since the beginning of Russia's war against Ukraine more than a year ago.

Still on board the ISS are the Russian cosmonauts Sergey Prokopyev and Dmitri Petelin as well as NASA astronaut Frank Rubio and "Crew-6," which arrived just a few days ago.

That crew consists of Americans Stephen Bowen and Warren Hoburg, the Russian Andrey Fedyaev, and the Emirati Sultan al-Niyadi.