The unmanned SpaceX Dragon capsule performed a practice lap around the orbiting lab and checked out its communication and navigation systems.

Officials at the U.S. space agency, NASA, and the SpaceX company said the rendezvous went well, although test results still were being analyzed.

It is the first U.S. vessel to visit the space station since NASA's shuttles retired last summer — and the first private spacecraft to ever attempt a delivery. The Dragon is carrying 1,000 pounds (453 kilograms) of provisions.

The space station astronauts struggled with bad computer monitors and camera trouble as the Dragon zoomed toward them, but the problem did not hold up the operation.

The astronauts successfully turned on Dragon's strobe light by remote control, but could not see it because of the sun glare and distance. The Dragon finally popped into camera view about 10 minutes later, appearing as a bright speck of light against the blackness of space, near the Earth's blue horizon. The two solar wings were clearly visible as the Dragon drew closer.

"Can nicely see the vehicle," Dutch spaceman Andre Kuipers said.

On Friday, two of the space station's six astronauts, Kuipers and Donald Pettit, will use the space station's robotic Canadarm2 to grab the Dragon and attach it to the complex. The crew will have a week to unload the contents before releasing the spacecraft for re-entry. It is the only supply ship designed to return to Earth with experiments and equipment; the others burn up in the atmosphere.

It is the first U.S. vessel to visit the space station since NASA's shuttles retired last summer. The space station astronauts struggled with bad computer monitors and camera trouble as the Dragon zoomed toward them. A NASA spokesman in Cape Canaveral, Fla., said the problem would not hold up the operation.

SpaceX's near-term objective is to help stockpile the space station, joining Russia, Europe and Japan in resupply duties. In three or four more years, however, the California-based company run by the billionaire who co-founded PayPal, Elon Musk, hopes to be launching station astronauts.

It is the cornerstone of President Barack Obama's strategy for NASA: turning over orbital flights to private business so the space agency can concentrate on destinations farther afield, such as asteroids and the planet Mars.

Canadarm2 maker

Obama called Musk on Wednesday, a day after Dragon's flawless launch from Cape Canaveral aboard the company's Falcon 9 rocket.

"The president just called to say congrats. Caller ID was blocked, so at first I thought it was a telemarketer," Musk said via Twitter early Thursday. He ended his tweet with a smiley emoticon.

Musk monitored Thursday's operation from the SpaceX Mission Control in Hawthorne, Calif., where the company is based.

MacDonald, Dettwiler and Associates built the space station's Canadarm2, and vice-president Paul Cooper welcomed the private-sector involvement.

"I think the test flight of SpaceX actually is one of the first steps toward having good old-fashioned competition to create value in space activities," he told.

Cooper stressed the space station, which is the size of a football field, must keep its distance from any remotely controlled vessels that bring up supplies.

Avoid collision

"You wouldn't want to have any opportunity for there to be a collision," he said.

"So the easiest way for that to be avoided is to have a plan in which the approach vehicle actually stops before it even touches the space station."

MDA's Dextre, a two-armed, $200-million robot that is also on the space station, will be hooked up to the robotic arm and its cameras will be used to inspect the capsule.

The space capsule will then be docked to the station and the food and supplies on board will be unloaded.

The space shuttles used to be the primary means of getting things to and from the space station. Discovery is now a museum relic, with Endeavour and Atlantis soon to follow.

Aboard the incoming Dragon — 5.8 metres tall and 3.7 metres across — are food, clothes, batteries and other space station gear.