In September, a SpaceX rocket exploded—and nobody could figure out why. Founder Elon Musk called it the toughest problem his company has ever had to solve.
Well, it’s finally been solved, according to the company’s engineers, and SpaceX rocket launches are slated to resume by the end of the year.
“I think we’ve gotten to the bottom of the problem,” Musk said in a CNBC interview. “A really surprising problem that’s never been encountered before in the history of rocketry.”
The September explosion occurred during a routine fueling. The propellant was apparently so cold that as it flowed into a tank on the second stage it froze solid, triggering a domino effect which destroyed the rocket through a series of fireballs.
In 2015 SpaceX switched to a rocket design that uses super-cooled liquid oxygen 40 degrees Celisus colder than what is normally used to propel.