WASHINGTON (BLOOMBERG) - SpaceX won formal Nasa approval to carry astronauts to the International Space Station, reaching a milestone for a commercial space vehicle three months after completing a crewed test mission.

The certification enables SpaceX's Dragon capsule and Falcon 9 rocket to begin regular crew rotations to the orbiting lab, with the next flight planned for Nov 14 with four astronauts. Nasa granted final approval after a two-day flight readiness review that concluded Tuesday, making the SpaceX vehicles the first that the US agency has rated for humans since the Space Shuttle.

"This is a great honour that inspires confidence in our endeavor to return to the Moon, travel to Mars, and ultimately help humanity become multi-planetary," Elon Musk, founder of Space Exploration Technologies Corp, said in a statement.

SpaceX's first operational flight for the National Aeronautics and Space Administration is scheduled for 7.49pm Eastern time on Saturday (Nov 14), with docking at the station expected eight and a half hours later. A backup launch attempt would be at 7.27pm on Sunday. A second mission is set for March 2021 with a third in September or October.

Boeing Co is also a participant in Nasa's Commercial Crew Programme to fly astronauts to the station, but the company has suffered delays following a botched uncrewed test flight of its Starliner vehicle in December 2019. Boeing plans a second test, also without crew, in the first quarter of 2021, said Steve Stich, Nasa's commercial crew manager.