Excessive high-altitude winds over the new launch pad at the Mid-Atlantic Regional Spaceport on Wallops Island, Va., forced another scrub in the inaugural flight of the Orbital Sciences Corp. Antares medium-lift launch vehicle.
Another attempt is scheduled for 5 p.m. EDT Sunday, April 21, when wind conditions are forecast to be better.
Orbital Sciences developed the kerosene-fueled Antares under NASA's Commercial Orbital Transportation Services (COTS) program, which provided seed money to private companies developing new vehicles to take cargo to the International Space Station.
The Antares awaiting its first flight carries an instrumented dummy version of Orbital Sciences' Cygnus cargo vehicle. An operational Cygnus is packed with station supplies and ready to launch to the ISS this summer if the inaugural flight goes as planned.
NASA's other COTS partner, SpaceX, already has delivered cargo to the station with its COTS-funded Falcon 9/Dragon combination.