Washington - Orbital Sciences, one of two private US firms chosen by Nasa to shuttle cargo to the International Space Station, delayed a bid late on Saturday to launch a first test flight of its Antares rocket.
Launch was rescheduled for Sunday at 17:00 (21:00 GMT) from the Wallops Flight Facility on Virginia state's Eastern Shore.
"Excessive wind levels have caused mission managers to delay the launch attempt today of Orbital Sciences' Antares rocket," Nasa said on its website.
"The high-altitude wind speeds exceed range safety restrictions."
The Antares rocket, a two-stage launch vehicle 40 metres tall, is set to hit an orbit of 249km about 10 minutes after take-off.
A $1.9bn contract requires Orbital Sciences to deliver freight to the ISS over the course of eight flights by the beginning of 2016.