Elon Musk's SpaceX has successfully launched a rocket out of the Earth's atmosphere, heralding the rebirth of American manned spaceflight later this year.

The unmanned crew capsule atop a Falcon 9 rocket was launched from Florida bound for the International Space Station at 7.49am GMT on Saturday.

Nasa and SpaceX successfully launched the new astronaut capsule on a week-long trip to the International Space Station and back - a key step towards resuming manned space flights from US soil after an eight-year break.

This time around, the only occupant on board SpaceX's Crew Dragon capsule is a dummy named Ripley, named after the character in Alien played by Sigourney Weaver.

But if the test goes smoothly, Nasa plans to put two astronauts aboard by the end of the year.