Early insights from investigators examining Friday's failed launch of the first SpaceX Falcon 1 rocket suggest a fuel leak triggered a fire that ultimately brought down the booster, the company's founder said today.

This closeup image shows the Merlin main engine during launch. Credit: Thom Rogers/SpaceX

"The good news is that all vehicle systems, including the main engine, thrust vector control, structures, avionics, software, guidance algorithm, etc. were picture perfect. Falcon's trajectory was within 0.2 degrees of nominal during powered flight," Elon Musk said in a statement posted this morning on his brother's blog.

"However, at T+25s, a fuel leak of currently unknown origin caused a fire around the top of the main engine that cut into the first stage helium pneumatic system. On high resolution imagery, the fire is clearly visible within seconds after liftoff. Once the pneumatic pressure decayed below a critical value, the spring return safety function of the pre-valves forced them closed, shutting down the main engine at T+29s."

The rocket tumbled out of the sky and impacted the ocean about 41 seconds after liftoff.

Initial speculation immediately after Friday's malfunction wondered if a thermal coat wrapped around the first stage liquid oxygen tank that was supposed to separate at liftoff could have contributed to the mishap. Launch video showed the jacket ripping apart as the rocket climbed into the sky.

"It does not appear as though the first stage insulation played a negative role, nor are any other vehicle anomalies apparent from either the telemetry or imaging. Falcon was executing perfectly on all fronts until fire impaired the first stage pneumatic system," Musk said.

"Our plan at this point is to analyze data and debris to be certain that the above preliminary analysis is correct and then isolate and address all possible causes for the fuel leak. In addition, we will do another ground up systems review of the entire vehicle to flush out any other potential issues.

"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. However, I would hope that the next launch occurs in less than six months."

That next mission of Falcon 1 is scheduled to carry the TacSat experimental communications satellite for the U.S. Naval Research Laboratory from Vandenberg Air Force Base in California.

The Falcon 1 rocket lifts off. Credit: Thom Rogers/SpaceX

"It is perhaps worth noting that those launch companies that succeeded also took their lumps along the way. ... 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," Musk said.

Friday's launch was the first for the start-up company. SpaceX developed the small Falcon 1 as a stepping stone to much larger boosters of the future.

"I am very encouraged and grateful that our launch customers took the time to call and express their support of SpaceX when their reaction could easily have been the opposite. We will stand by them as they have stood by us. SpaceX is in this for the long haul and, come hell or high water, we are going to make this work."

Musk added that he "believes in maximum disclosure" and will continue to provide information about the accident.