SpaceX has solved the mystery of Falcon 9's explosion

Elon Musk thinks they have finally solved the mystery of their September's Falcon 9 explosion. Speaking with CNBC, he stated that the explosion was caused by a "really surprising problem that's never been encountered before in the history of rocketry."

Just last week, Musk said that the cause of the explosion is one of the toughest puzzles the company has ever had to solve.

The explosion caused complications for NASA since SpaceX was supposed to transfer cargo to International Space Station. However, Orbital ATK stepped in and performed their first successful launch since October 2014 when the rocket failed, and the vehicle and payload were destroyed causing $15 million in damage.

Musk now believes they have found the cause of the accident which he claims is "a combination of liquid helium, advanced carbon fiber composites, and solid oxygen."

New York Times reports that the liquid oxygen fuel froze as it was flowing into rocket's second stage. That triggered the chain of the explosion.

Musk hopes that SpaceX will launch their next Falcon 9 rocket in December this year.