The Canadarm 2 reaches out to grapple the SpaceX Dragon cargo spacecraft and prepare it to be pulled into its port on the International Space Station on April 17, 2015. Photo: VCG

A SpaceX capsule carrying four astronauts back to Earth after a busy six months on the International Space Station (ISS) landed Monday off the coast of Florida, a NASA live broadcast showed.

Slowed by the Earth's atmosphere, as well as four huge parachutes, the Dragon capsule was able to withstand the dizzying descent thanks to its heat shield.

It landed in the Gulf of Mexico at 10:33 pm (0333 GMT Tuesday), marking the end of the "Crew-2" mission.

A boat will retrieve the capsule, and the astronauts on board will be brought back to land via helicopter.

Since arriving on April 24, the crew of two Americans, a Frenchman and one Japanese astronaut conducted hundreds of experiments and helped upgrade the station's solar panels.

They boarded their Dragon, dubbed Endeavour, and undocked from the ISS at 2:05 pm (1905 GMT), NASA announced.

Endeavour then looped around the ISS for around an hour and a half to take photographs, the first such mission since a Russian Soyuz spaceship performed a similar maneuver in 2018.

The Dragon, which flew mostly autonomously, has a small circular window at the top of its forward hatch through which the astronauts can point their cameras.

"Proud to have represented France once again in space! Next stop, the Moon?" tweeted Thomas Pesquet from the European Space Agency.

Their activities have included documenting the planet's surface to record human-caused changes and natural events, growing Hatch chile peppers and studying worms to better understand human health changes in space.

Crew-2's departure was delayed a day by high winds. 

Bad weather and what NASA called a "minor medical issue" have also pushed back the launch of the next set of astronauts, on the Crew-3 mission, which is now set to launch Wednesday.

Until then, the ISS will be inhabited by only three astronauts - two Russians and one American.

SpaceX began providing astronauts a taxi service to the ISS in 2020, ending nine years of US reliance on Russian rockets for the journey following the end of the Space Shuttle program.

AFP