The SpaceX company’s Falcon 9 rocket took flight from Cape Canaveral, Florida, at 3.44am local time today, launching a new era of spaceflight.
It was carrying a capsule named Dragon that is packed with 1,000lb (454kg) of space station provisions.
It is the first time a private business has launched a vessel to the space station. Until now it has been something only major governments have done.
The real test will come on Thursday when the Dragon gets close to the space station. It will undergo practice manoeuvres from more than a mile (1.6km) out. If all goes well, docking will take place on Friday.
Nasa and SpaceX have stressed that this is a demonstration flight.
SpaceX’s billionaire founder, Elon Musk, hailed the launch.
He said on Twitter: “Falcon flew perfectly!! Dragon in orbit ... Feels like a giant weight just came off my back.”
In December 2010, SpaceX became the first private company to launch a spacecraft into orbit and retrieve it. That test flight of a Dragon capsule paved the way for this mission, which also is meant to culminate with a splashdown of the capsule in the Pacific.
This newest capsule is supposed to remain at the space station for a week before bringing back experiments and equipment. None of the other types of current cargo ships can return safely; they burn up on the way down.