Four astronauts from four different countries have blasted off for the International Space Station.

They should reach the orbiting lab in their SpaceX capsule on Sunday, replacing four astronauts who have been living up there since March.

A US Nasa astronaut was joined on the pre-dawn lift-off from the Kennedy Space Centre at Cape Canaveral in Florida by colleagues from Denmark, Japan and Russia.

It is the first US launch where every spacecraft seat was occupied by a different country – until now, Nasa had always included two or three of its own on its SpaceX taxi flights. A fluke in timing led to the assignments, officials said.

Nasa’s Jasmin Moghbeli, a Marine pilot serving as commander, said her crew’s make-up demonstrates “what we can do when we work together in harmony”.

With her on the six-month mission are the European Space Agency’s Andreas Mogensen, Japan’s Satoshi Furukawa and Russia’s Konstantin Borisov.

SpaceX Crew Launch
The crew is expected to reach the International Space Station by Sunday (AP)

“To explore space, we need to do it together,” the European Space Agency’s director general, Josef Aschbacher, said minutes before lift-off. “Space is really global, and international co-operation is key.”

The astronauts’ paths to space could not be more different.

Ms Moghbeli’s parents fled Iran during the 1979 revolution. Born in Germany and raised on New York’s Long Island, she joined the Marines and flew attack helicopters in Afghanistan.

The first-time space traveller hopes to show Iranian girls that they, too, can aim high. “Belief in yourself is something really powerful,” she said before the flight.

Mr Mogensen worked on oil rigs off the West African coast after getting an engineering degree. He told people puzzled by his job choice that “in the future we would need drillers in space”, like Bruce Willis’ character in the asteroid film Armageddon.

He is convinced the rig experience led to his selection as Denmark’s first astronaut.

Japanese astronaut
Japanese astronaut Satoshi Furukawa is one of four astronauts from four different countries making the journey (Nasa/AP)

Mr Furukawa spent a decade as a surgeon before making Japan’s astronaut cut. Like Mogensen, he has visited the station before.

Mr Borisov, a space rookie, turned to engineering after studying business. He runs a freediving school in Moscow and judges the sport, in which divers shun oxygen tanks and hold their breath underwater.

One of the perks of an international crew, they noted, is the food. Among the delicacies soaring into space with them are Persian herbed stew, Danish chocolate and Japanese mackerel.

SpaceX Crew
The crew hail from Denmark, Japan, Russia and the US (Nasa/AP)

Lift-off was delayed a day because of extra data reviews for the capsule’s life-support system.

Another Nasa astronaut will launch to the station from Kazakhstan in mid-September under a barter agreement, along with two Russians.

SpaceX has now launched eight crews for Nasa. Boeing was hired at the same time nearly a decade ago, but has yet to fly astronauts.

Its crew capsule is grounded until 2024 by parachute and other issues.