This is the J2-X. The liquid-fuel cryogenic rocket engine is the modernized version of the J-2, which NASA used in the late-'60s and early-'70s to thrust humans beyond low Earth orbit. (Click any image below for hi-res.)
You might think NASA's not doing a lot these days, what with the dismantling of the manned space program and everything, but they're still making explosions. Now there's video: the J-2X, which NASA says is our next ticket to space.
After Kennedy announced his crazy Moon idea, NASA scrambled to get rockets powerful enough to achieve that mission. Rocketdyne created the J-2, the 232,250 pounds of force beast that powered the Saturn's second stage. This is the J-2X.