SpaceX test fires Raptor engine for rocket that might one day take people to Mars

Elon Musk said SpaceX successfully tested its Raptor rocket engine that might one day be used to transport people to Mars. SpaceX "achieved first firing of the Raptor interplanetary transport engine," Musk said Sunday night on Twitter. The engine is powered by methane and liquid oxygen. The disclosure came on the eve of Musk's scheduled appearance Tuesday at the International Astronautical Congress in Guadalajara, Mexico, where he is expected to discuss SpaceX's efforts toward eventually reaching Mars. Musk is chief executive of Hawthorne-based SpaceX, a privately held company whose full name is Space Exploration Technologies Corp.