Orbital Sciences Corp launched the first flight of its unmanned Antares rocket Wednesday to the International Space Station, as NASA forges ahead with its plan to privatize US space missions.

The Cygnus capsule, hitched to Orbital Science's Antares rocket, blasted off at 10:58 am (1458 GMT) from NASA's Wallops Flight Facility off Virginia's eastern coast, for a Sunday rendezvous with the ISS.

The first stage functioned a little more than four minutes before separating, after which the second-stage motors functioned for about two minutes and a half.

Cygnus then separated to reach Earth's orbit, marking the success of the launch.

The payload separation was successful, a NASA commentator said on the US space agency's live television feed. Cheers could be heard at mission control.

"That was just a beautiful launch," a NASA commentator said.

Cygnus will ferry about 1,600 pounds (725 kilograms) of food, clothing and cargo for the crew aboard the space station. It will remain docked to the ISS for a month.

"All going very smoothly with the continuing health of the spacecraft," a NASA commentator said, adding that solar rays had been fully deployed to supply power to the spacecraft.

Orbital Sciences has a $1.9-billion contract with NASA that requires the company to deliver freight to the ISS over the course of eight flights by the beginning of 2016.

The company is one of just two private US firms enlisted by NASA to carry payloads to the ISS. The other is California-based Space Exploration Technologies, or SpaceX.

NASA is eager to give private industry the job of carrying cargo and crews, in hopes of cutting costs, now that its space shuttle fleet has been retired.

The US space agency plans to focus its attention on deep-space missions to land probes on asteroids and Mars.

Wednesday's demonstration flight -- the first to the ISS by the Virginia-based Orbital Sciences -- is meant to show that Cygnus can successfully deliver cargo to the space station.

If the test is successful, it could lead to regularly scheduled missions within months. Another Cygnus capsule is set to launch in December.

Orbital first launched its Antares rocket, carrying a dummy payload, on a successful trial flight in April.

Cygnus's docking with the ISS will mark the fourth of a private vessel to the orbiting outpost.

The first was SpaceX's Dragon capsule in May 2012. Dragon later made two more trips to deliver cargo to the ISS.

Unlike the Dragon capsule, Cygnus cannot return to Earth and will be destroyed upon re-entry after its mission is complete.