SpaceX struggles with rocket explosion probe

The probe into the spectacular launch pad explosion that destroyed an Israeli satellite and a SpaceX rocket is proving to be the “most difficult and complex” in the company’s 14-year history, the company’s founder, Elon Musk, has said.

Mr Musk, writing on Twitter, added that the investigation had not ruled out the possibility a foreign object hit the rocket and sparked a fireball.

The entrepreneur, who also heads electric carmaker Tesla Motors, was writing just over a week after the incident, in which a fireball consumed a Falcon 9 rocket as it was being prepared for a “static fire” test on its engine.

The struggle to understand the incident could puncture hopes expressed immediately after the explosion that flights could resume quickly, because the failure had not involved an actual launch.

“Still working on the Falcon fireball investigation,” Mr Musk wrote. “Turning out to be the most difficult and complex failure we have ever had in 14 years.”

The incident has put on hold plans by Spacecom, owner of the destroyed satellite, to sell itself to a Chinese company.

Mr Musk went on to scotch speculation that the explosion — which started around the oxygen tank for the rocket’s smaller, upper stage — could have resulted from premature ignition of the rocket’s engines. He said the vehicle was still being filled with fuel when it blew up.

“Important to note that this happened during a routine filling operation,” Mr Musk wrote. “Engines were not on and there was no apparent heat source.”

While explosions during or shortly after rocket launches continue to be a recognised risk of the space launch business, a launch pad explosion separate from a launch is unprecedented in the US space industry’s recent history.

The only hint as to a possible cause for the incident was that Mr Musk wrote the company was “particularly trying to understand” a quieter bang, heard on videos of the explosion just before the fireball ignited.

“May come from rocket or something else,” he wrote.

When another Twitter user put it to Mr Musk that some internet videos were claiming something might have hit the rocket, he replied: “We have not ruled that out.”

Mr Musk wrote that he was grateful for help with the investigation from Nasa, the US space agency, the Federal Aviation Administration and the US Air Force, which owns the pad where the explosion took place.

While the explosion destroyed a commercial satellite intended partly for the use of Facebook, the social media company, the explosion is of critical importance to the US government. SpaceX, along with United Launch Alliance, is one of two companies entrusted with launching the US’s most sensitive spy satellites. It also has one of two contracts for future missions carrying US astronauts to the International Space Station.