It's definitely not sabotaged. SpaceX CEO Elon Musk said investigators might have figured out the cause of the Falcon 9 explosion last Sept. 1 and it has something to do with oxygen fuel being too cold.

Last Sept. 1, a SpaceX Falcon 9 rocket supposed to carry Facebook's Internet satellite to space exploded while being fuelled at the Cape Canaveral Air Force base launch pad. The explosion caused a stir in the commercial space flight industry. SpaceX considered it as the 'most difficult' anomaly they had faced, but a closure is seen on the horizon as more information about the blast was gathered.

In a recent interview, Elon Musk said they must have gotten to the bottom of the problem. And with the discovery, Musk expects SpaceX to resume flights this December.

"It basically involves liquid helium, advanced carbon fiber composites, and solid oxygen," SpaceX CEO Elon Musk said in an interview. "Oxygen so cold that it actually enters solid phase," Musk added.

Various reports pointed out that Musk believes the extra cool oxygen is likely the cause of the explosion. The supercooled liquid oxygen is used by SpaceX as its main propellant and that it has gotten too cold that might have caused the explosion.

The liquid oxygen turning into solid is not supposed to happen. This might have triggered the blast that caused a multimillion rocket and an Israeli-made Facebook satellite. The solid oxygen could have reacted with another hardware, the rocket's helium pressure vessels. The rocket is designed in such a way that the three vessels sit atop the oxygen tank where liquid oxygen is stored.

The rocket also has carbon fiber composite material that experts fear might have caused the ignition. But aside from that, SpaceX hasn't revealed much information about the findings. Musk also refused to give additional details when asked.

NASA recently expressed its thoughts on SpaceX and its fuelling system in a recent article. The agency thinks that fueling a rocket 30 minutes before take off is worrisome.