Konstantin Borisov (left), Andreas Mogensen, Jasmin Moghbeli and Satoshi Furukawa wave as they prepare to board the SpaceX Dragon spacecraft. AFP

NASA and SpaceX's Dragon spacecraft blasted off on Saturday carrying four astronauts to the International Space Station.

The Crew-7 mission is commanded by American Jasmin Moghbeli and includes Andreas Mogensen of Denmark, Satoshi Furukawa of Japan and Konstantin Borisov of Russia. Crew-7 will join the seven people already aboard the ISS, before members of Crew-6 including Emirati astronaut Sultan Al Neyadi leave for Earth a few days later.

The crew will spend six months aboard the ISS, where they will carry out science experiments including collecting samples during a spacewalk to determine whether the station releases microorganisms through its life-support system vents.

The goal is to understand if microorganisms can survive and reproduce in space.

Another experiment will aim to assess the physiological differences between sleep on Earth and in space.

The Dragon spacecraft carried by a Falcon 9 rocket lifted off at 3:27am (0727 GMT) from Launch Complex 39A at NASA's Kennedy Space Center in Florida, in front of around 10,000 people who gathered to watch the launch.

"We have liftoff!" NASA said on X, formerly known as Twitter.

The SpaceX Crew Dragon spacecraft blasts off at Cape Canaveral, Florida on Saturday. Reuters

Cheers could be heard in the mission control room soon after the Dragon craft separated from the Falcon 9 rocket with the crew in orbit.

A united team with a common mission

"We may have four crew members on board from four different nations... but we're a united team with a common mission," Moghbeli said after the separation.

The launch was pushed back to Saturday to give engineers an extra day to review a component of the Crew Dragon capsule's environmental control and life support system, NASA said in a blog post.

It is the first space mission for both Moghbeli and Borisov.

"This is something I've wanted to do for as long as I can remember," said Moghbeli, a Naval test pilot, during a media call last month.

"One of the things I'm most excited about is looking back at our beautiful planet," added the 40-year-old American.

"Everyone who I've talked to who has flown already has said that was a life-changing perspective – and also floating around in space, it seems really fun."

Crew-7 is set to be the seventh routine mission to the orbital platform for Elon Musk's SpaceX, with the first coming in 2020.

NASA pays SpaceX for the taxi service as part of a commercial crew programme that it put in place to reduce dependency on Russian rockets for astronaut transport after the space shuttle programme ended in 2011.

Boeing is the other contracted private partner, but its programme remains mired in delays and technical difficulties. It has not yet flown any crew.

Borisov will be the third Russian to fly on a SpaceX Crew Dragon capsule, fixed atop a Falcon 9 rocket.

Space remains a rare area of cooperation between the United States and Russia despite Moscow's invasion of Ukraine, with Americans also continuing to fly aboard Russian Soyuz rockets that launch from Kazakhstan.

"I'm looking forward to coping with all the tasks. This is a very interesting profession: you are preparing for something that you haven't tried yet, and you really want to do it well," said Borisov.

The first segment of the ISS was launched in 1998, and it has been continuously inhabited by an international crew since 2001.

Its operations are set to continue until at least 2030, after which it will be decommissioned and crash into the ocean. Several private companies are working on commercial space stations to replace it.

Agence France-Presse