(WASHINGTON POST)  Christian Davenport — An unmanned SpaceX Falcon 9 rocket bound for the International Space Station exploded a couple of minutes after liftoff Sunday morning. It was the third cargo mission to the space station to be lost in recent months.

Elon Musk, SpaceX’s founder tweeted that “there was an overpressure event in the upper stage liquid oxygen tank.” He added: “That’s all we can say with confidence right now. Will have more to say following a thorough” analysis.

NASA officials said it was not clear what caused the explosion. During an afternoon press conference William Gerstenmaier, NASA’s associate administrator for human exploration and operations, said there was “no negligence here.”

The three failures from three different launch providers show “the challenges facing engineering and the challenges facing space flight in general.”

Source: Elon Musk SpaceX’s rocket just exploded. Here’s why that’s such a big deal. – The Washington Post