Last-minute glitch postpones debut of new U.S. rocket Wed Apr 17, 2013 6:26pm EDT (Reuters) - A U.S. company hired by NASA to fly cargo to the International Space Station canceled plans to launch its new Antares rocket on a demonstration mission on Wednesday after a last-minute technical glitch, officials said. The 13-story rocket developed by Orbital Sciences Corp had been slated to lift off from a new commercial spaceport in Virginia at 5 p.m. EDT (2100 GMT) and place a dummy cargo capsule into orbit. The test flight is expected to clear the way for the company's trial cargo run to the International Space Station later this year. If successful, Orbital Sciences would then start working on an eight-flight, $1.9 billion contract to fly supplies to the station for NASA. About 12 minutes before launch from the Mid-Atlantic Regional Spaceport on Wallops Island, Virginia, an umbilical line on the rocket's upper-stage fell away prematurely, prompting a cancellation, said NASA launch commentator Kyle Herring. The next launch attempt is targeted for no earlier than Friday, although weather at the Wallops Island Flight Facility could be a problem. Meteorologists are forecasting high winds and possible thunderstorms. "You learn a little bit from every launch attempt," John Steinmeyer, a senior project manager with Dulles, Virginia-based Orbital Sciences, said during a NASA TV broadcast. We'll take the lessons learned from today and move into another attempt as soon as it's safe to do so. The company is one of two hired by NASA after the space shuttles were retired to fly cargo to the station, a $100 billion project of 15 nations that flies about 250 miles above the Earth. Privately owned Space Exploration Technologies, or SpaceX, completed its test flights in 2010 and has successfully carried out two of 12 planned cargo runs to the station for NASA under a $1.6 billion contract. Reporting by Irene Klotz in Cape Canaveral, Florida; Editing by Kevin Gray and Mohammad Zargham