The Orbital Sciences Corporation Antares rocket is seen as it launches from Pad-0A of the Mid-Atlantic Regional Spaceport (MARS) at the NASA Wallops Flight Facility in Virginia, April 21, 2013. [Photo/Agencies]

WASHINGTON - Orbital Sciences Corp., one of two private companies that currently hold a contract with US space agency NASA to fly unmanned cargo missions to the International Space Station, completed a successful test launch of its new Antares rocket on Sunday.

The newest medium-class space launch vehicle in the US lift off at 5 pm EDT (2100 GMT) from NASA's Wallops Flight Facility on Wallops Island, Virginia, followed by payload separation approximately 10 minutes later and mission completion at about 18 minutes after launch.

"The test flight demonstrated all operational aspects of the new Antares launcher, including the ascent to space and accurate delivery of a simulated payload to a target orbit of approximately 150 miles (about 250 kilometers)," said Virginia-based Orbital in a statement.

John Holdren, assistant to the president for science and technology, said that the flight "demonstrates an additional private space-launch capability for the United States and lays the groundwork for the first Antares cargo mission to the International Space Station later this year."

"With NASA focusing on the challenging and exciting task of sending humans deeper into space than ever before, private companies will be crucial in taking the baton for American cargo and crew launches into low-Earth orbit,"  said Holdren in a statement.

Orbital said it will now move forward toward completing a full flight demonstration mission of its new Antares system and Cygnus cargo delivery system to resupply the Space Station around mid-year.

Orbital signed a $1.9 billion deal with NASA to fly eight unmanned supply missions using the Antares and Cygnus cargo delivery system.

Another US company, California-based SpaceX, made history when its Dragon spacecraft became the first commercial vehicle in history to successfully attach to the space station in a May 2012 test flight.

Dragon has already made three trips to the space station and it still needs to complete another ten to fulfill its $1.6 billion contract with NASA. The next SpaceX cargo run is scheduled for September.