SAL KHAN: Right, exactly. ELON MUSK: Because for sure failure is one of the possibilities. But, ideally, you want to try to bracket it and say success is in the envelope of outcomes. And I wasn't quite sure if that was the case. I think success on an academic level would have been quite likely, because you can publish some useless paper--

Musk revealed the company’s planned next-generation rocket will make it possible to build a moon base — and the name he picked is just his latest homage to beloved science fiction, in this case, the British cult classic Space: 1999.

The SpaceX landing Thursday evening marked the first time in history that a rocket was used to put a satellite into geostationary orbit and then return to Earth.

SpaceX, the ambitious rocket company headed by Elon Musk, wants to send a couple of tourists around the moon and back to Earth before the end of next year.