CAPE CANAVERAL, Fla. — The world’s first private supply ship drew close to the International Space Station on Thursday in a critical fly-by-without-stopping test in advance of the actual docking.

The SpaceX Dragon capsule was directed to stay at least 1 1/2 miles away from the orbiting lab as it got started on a practice lap and checkout of its communication and navigation systems.

The historic linkup is scheduled for Friday, assuming success on Thursday.

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 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, like asteroids and Mars.

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.

On Friday, two of the space station’s six astronauts Donald Pettit and Andre Kuipers, will use the space station’s robot arm 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.

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 — 19 feet tall and 12 feet across — is food, clothes, batteries and other space station gear.