Washington - Orbital Sciences launched the first flight of its unmanned Cygnus cargo ship on 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 (14:58 GMT) from Nasa's Wallops Flight Facility off Virginia's eastern coast, for a Sunday rendezvous with the ISS.
Cygnus separated from the rocket's second stage about 10 minutes after blast-off to reach Earth's orbit, marking the success of the launch. It later deployed both of its solar arrays, which will supply power to the spacecraft.
The payload separation was successful, a Nasa commentator said on the US space agency's live television feed. Clapping could be heard at mission control.
"That was just a beautiful launch," a Nasa commentator said.
"All going very smoothly with the continuing health of the spacecraft."
Cygnus will ferry about 590kg of food, clothing and other cargo for the crew aboard the space station, which it is scheduled to reach at 11:30 GMT Sunday.
The spacecraft, which was orbiting Earth at a speed of 28 160km/h, will remain docked at the ISS for a month.
"Today marks a milestone in our new era of exploration as we expand the capability for making cargo launches to the International Space Station from American shores," Nasa Administrator Charles Bolden said in a statement.
"Orbital's extraordinary efforts are helping us fulfil the promise of American innovation to maintain our nation's leadership in space."
Cygnus contains two basic components: the Service Module, produced by Orbital Sciences, and the Pressurized Cargo Module made by an affiliate of French group Thales and Italy's Finmeccanica.
Orbital Sciences has a $1.9bn 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 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.
"Today's launch is the culmination of more than five years' work between the Nasa and Orbital teams," said Alan Lindenmoyer, Nasa's programme manager for commercial crew and cargo.
"Everyone involved should be extremely proud, and we are looking forward to a successful series of checkouts between now and when Cygnus reaches the space station this weekend."
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.