SpaceX: Cause of Falcon 9 failure still unknown

Air Force safety officers sent commands to destroy SpaceX's failing Falcon 9 rocket after its launch from Cape Canaveral on Sunday morning, but long after a malfunction had already caused the rocket to break apart, officials confirmed Monday.

That action was not responsible for the explosion that ended the company's attempt to launch more than 5,000 pounds of supplies to the International Space Station for NASA, more than two minutes after a 10:21 a.m. liftoff from Cape Canaveral Air Force Station.

Destruct signals sent about 70 seconds after an apparent failure by the rocket's upper stage followed safety procedures, and might have helped burn up toxic fuel that could mingle with debris in the Atlantic Ocean.

"Following the breakup of the Falcon 9 vehicle, 45th Space Wing Mission Flight Control Officers sent command destruct functions in accordance with Air Force policy and procedures to ensure public safety," the Air Force said in a statement.

SpaceX CEO Elon Musk reported Monday that engineers had found no quick answer to what caused the 208-foot rocket to explode, its first failure in 19 flights.

"Cause still unknown after several thousand engineering-hours of review," Musk said on Twitter. "Now parsing data with a hex editor to recover final milliseconds."

Musk said immediately after the launch that too much pressure built up in the Falcon 9's upper stage oxidizer tank, but it was not clear why.

Teams were studying more than 3,000 channels of data recovered from the rocket and its Dragon capsule, which separated from the rocket and continued to transmit telemetry for a period of time after the rocket disintegrated.

There was no indication, however, that the Dragon or its contents might have survived a fall from at least 28 miles up, when the rocket was flying faster than 3,000 mph.

NASA considers it a loss.

The Dragon is equipped with parachutes for its return to Earth, when it typically splashes down in the Pacific Ocean, but it was unclear if they could be deployed during a launch.

Earlier this year at Cape Canaveral, SpaceX successfully tested an abort system designed to save astronauts in a Dragon from a launch pad emergency, part of preparations to fly NASA crews to the ISS as soon as 2017.

A future test is planned to test the same escape system during a launch. If it worked as planned, astronauts would have survived the type of explosion seen Sunday, or a more powerful one.

"The launch escape system would have been enormously helpful here for the astronauts," SpaceX President Gwynne Shotwell said in a press conference Sunday.

Assisted by the Coast Guard, SpaceX teams on Monday continued to search the ocean for rocket debris.

The Coast Guard said the debris was more than 150 miles offshore and was unlikely to wash up on Florida beaches.

SpaceX soon plans to be meeting daily with NASA and the Air Force as the investigation it is leading proceeds under Federal Aviation Administration oversight.

U.S. Sen. Bill Nelson on Monday visited Kennedy Space Center for a briefing on the mishap with NASA and SpaceX representatives.

Speaking to reporters afterward, he expressed confidence that SpaceX would rebound from the failure, and in the NASA strategy that includes SpaceX as one of two companies with contracts to launch astronauts on privately operated rockets and capsules by 2017, along with Boeing.

Nelson, the top Democrat on the Senate committee that sets NASA policy, said a string of failures since last October by three different cargo suppliers proved the need for multiple U.S. options to fly astronauts.

He said Congress should give NASA the $1.2 billion it requested next year for the Commercial Crew Program to ensure those flights are safe, and that delays don't prolong reliance on Russia for transportation up and down from the ISS.

Senate and House proposals are now anywhere from $225 million to $325 million short of that request.

"Of all times, now is not the time to cut the appropriations for Commercial Crew," said Nelson. "If we want to get Americans on American rockets back into space as soon as possible, which is exactly what the American people want, then we better pour the juice and fulfill this president's request on this Commercial Crew appropriation."

Nelson said "a bunch of folks who don't understand what they're doing" in Congress represented the biggest threat to flying astronauts from U.S. soil again by 2017, and warned those missions could be delayed by as much as two years.

Nelson said mishaps like SpaceX's on Sunday are to be expected in the risky business of spaceflight, and SpaceX would continue to provide important support to NASA and eventually launch military satellites.

"SpaceX has had phenomenal success and it will continue," he said. "I think what was shocking to everybody is that SpaceX has had such phenomenal success so quickly that folks didn't anticipate, and thus it was all the more a surprise that this phenomenal success suddenly had a hiccup."

Contact Dean at 321-242-3668 or jdean@floridatoday.com. Follow him on Twitter at @flatoday_jdean and on Facebook at facebook.com/jamesdeanspace.