"The Crew-1 mission has lifted off on a Falcon 9 rocket from @NASAKennedy at 7:27pm ET [00:27 GMT on Monday, November 16] and is en route to the @Space_Station," NASA said on Twitter, where a live broadcast is underway.

Later, NASA said that the rocket’s Stage 1 had separated and that the Crew Dragon space vehicle was "on its way."

The launch of the first ever operational commercial crew mission follows the SpaceX Demo-2 mission that took NASA astronauts Bob Behnken and Doug Hurley to the ISS in May this year.

The SpaceX Crew-1 mission is carrying US astronauts Mike Hopkins, Victor Glover and Shannon Walker and Soichi Noguchi from Japan for a six-month stay on the ISS.

According to NASA Administrator Jim Bridenstine, the first stage of the Falcon 9 rocket will be reused for the SpaceX Crew-2 mission that is expected to be launched in March 2021.