The Falcon 1 rocket stands atop the launch pad built on Omelek Island in the Central Pacific. Credit: Thom Rogers/SpaceX

The setback came during the second countdown for this debut launch for Space Exploration Technologies. The initial launch try November 26 was thwarted by what the company described as an incorrectly set vent valve that allowed liquid oxygen to escape from a ground storage tank.

Monday's shot at launching the 70-foot rocket to place an Air Force Academy cadet-built space plasma probe into orbit was targeting a 2 p.m. EST (1900 GMT) liftoff. But strong winds ripping across Omelek Island, a small isle in the Kwajalein Atoll of the Central Pacific, forced countdown clocks to stop at T-minus 15 minutes. SpaceX reported winds upwards of 28 knots, violating the launch time limit of 24 knots.

"Due to high winds, we placed the countdown on hold and began draining the fuel tank," SpaceX CEO Elon Musk wrote in a candid status report issued late Monday.

"As we drained fuel from the first stage tank, a faulty pressurization valve caused a vacuum condition in the tank. This caused a fuel tank barrel section to deform and suck inward."

The first stage, which uses a highly refined kerosene fuel and liquid oxygen, was built to be reusable. It is equipped with parachutes and locator devices for recovery from the ocean.

"It is important to note that the root cause is an electrical fault with a valve, not structural design," Musk added.

The rocket was being lowered off the pad late Monday for transport on its mobile trailer to the nearby hangar on the island to undergo more-detailed inspections by engineers.

"At this point, it appears that no other damage was sustained to the vehicle or the satellite," Musk wrote.

When SpaceX can try again to launch is unknown. It isn't clear whether the damage can be repaired at the remote launch site, about 5,000 miles from the U.S. mainland, or if the first stage must be replaced completely.

SpaceX officials told reporters last month that the second Falcon rocket was nearing completion in the company's Los Angeles manufacturing factory, and the third was being constructed.

The Falcon 1 booster is SpaceX's first rocket -- one capable of hauling small payloads into space. But it serves as the foundation for the company's development of significantly larger vehicles for lofting heftier cargos.

Musk has invested a large stake of his own money in creating the Falcon family that promises to dramatically reduce launch costs and improve reliability over existing rockets. The native of South Africa amassed his fortune as co-founder of PayPal, the online payment system, and earlier the Zip2 software company.

The Falcon 1 is being sold for $6.7 million, a Falcon 5 for $18 million, and the Falcon 9 varies from $27 million for medium-lift to $78 million for the heavy-class rocket. The prices appear substantially cheaper than existing U.S. rockets on the market today.

SpaceX has a mixture of government and commercial orders for a half-dozen Falcon 1 missions, two Falcon 9 vehicles and a $100 million launch services deal with the Air Force.

The company expects to conduct three Falcon 1 launches during the next 12 months.