A privately bankrolled spacecraft is getting ever closer to the International Space Station for a historic docking Friday.

The SpaceX Dragon capsule contains a half-ton of supplies. The station's crew will use a robot arm to snare the Dragon.

On Thursday, the unmanned capsule came within 1 1/2 miles of the space station in a practice fly-by. Early Friday, it returned to the neighborhood.

This is the first time a private company has launched a vessel to the space station, joining a small, elite group of governments. President Barack Obama is pushing commercial ventures in orbit so NASA can concentrate on grander destinations like asteroids and Mars.

The California-based SpaceX is run by Paypal's billionaire creator, Elon Musk.