SpaceX on Friday became the first commercial outfit to dock its own cargo capsule at the International Space Station, marking a new era for private spaceflight.

The California-based SpaceX is owned by Internet entrepreneur Elon Musk.

With no humans on board, the capsule is delivering about a half tonne of supplies and science experiments for the ISS, and aims to return a slightly larger load of gear to the Earth on May 31.

“It looks like we got us a Dragon by the tail,” said U.S. astronaut Don Pettit, who was operating the Canadian-built robotic arm from the space station as it reached out and hooked on to the unmanned SpaceX capsule at 9.56 a.m. (1356 GMT).

The two spacecraft were travelling about 250 miles (402 km) above northwest Australia at the time of the grab, NASA said.

“Dragon captured by the International Space Station! Just awesome,” wrote SpaceX chief executive Musk on Twitter.

“Everything has gone very smoothly,” said a NASA commentator, adding that the six member ISS crew would soon start working on equalising pressure between the two spacecraft.