A fire fed by a fuel leak caused the failure of a commercial rocket seconds into its maiden launch, the company that built it has confirmed.
Fire caused the loss of Falcon 1 during lift-off
SpaceX's Falcon 1 rocket was lost during lift-off from an island in the Kwajalein Atoll in the Pacific Ocean.
It was carrying a US Air Force Academy research satellite onboard.
The vision of Elon Musk, co-founder of the electronic payment system PayPal, the Falcon was designed to cut the cost of current satellite launches.
The unexplained fuel leak occurred 25 seconds into the launch near the top of the main engine on the rocket's first stage, SpaceX's founder said.
"Falcon was executing perfectly on all fronts until fire impaired the first-stage pneumatic system," Mr Musk explained.
The fire cut a helium pneumatic system, and when pneumatic pressure fell, a safety function within the valves forced them to close, shutting down the main engine 29 seconds into the flight, he added.
The company said it would investigate all possible causes for the leak.
"I cannot predict exactly when the next flight will take place, as that depends on the findings of this investigation, and ensuring that our next customer is comfortable that all reasonable steps have been taken to ensure reliability," Mr Musk said.
"However, I would hope that the next launch occurs in less than six months."
He noted that other rocket developers had also had failures before succeeding.
"Having experienced firsthand how hard it is to reach orbit, I have a lot of respect for those that persevered to produce the vehicles that are mainstays of space launch today," he said.
Falcon 1 is a 21m-long (70-foot-long), two-stage rocket powered by liquid oxygen and kerosene. Its first stage is designed to parachute into the ocean to be recovered and used again. It is intended to be the first in a family of low-cost rockets.
SpaceX had originally planned to launch last November, but the mission was delayed by concerns ranging from problems with the rocket to limitations on the supply of liquid oxygen at the remote Kwajalein Atoll site.
The rocket was carrying FalconSat-2, part of an Air Force Academy satellite programme intended to measure plasma that can interfere with communications in space.