Powered by nine oxygen and kerosene-burning engines, the 48m-tall rocket, built by Space Exploration Technologies (SpaceX), lifted off from its seaside launch pad at Cape Canaveral Air Force Station at 9.35am yesterday.

The billionaire founder and CEO of SpaceX is Pretoria-born IT expert Elon Musk. He said the rocket had put its Dragon payload into its intended orbit.

The Falcon booster, flying for the fourth time, streaked through balmy, partly cloudy skies as it headed east over the Atlantic Ocean towards the station's orbit, about 400km up.

The Dragon capsule will reach the $100-billion space station - a project of 15 nations - tomorrow.

SpaceX made a successful practice run to the station in May, clearing the way for it to begin working off a $1.6-billion, 12-flight contract to deliver cargo for Nasa.

With the retirement of the US space shuttles last year, Nasa turned to the private sector to develop and fly freight to the station and wants to do the same for crew transportation.

Dragon is designed to return to Earth intact so it can bring back research and equipment from the station.

That return capability has been missing since the shuttle's retirement.

Dragon is to leave the station on October 28 and will splash down in the Pacific Ocean, off the coast of California.