There's a thread about this here, but I though it was too old to be of relevance. I didn't know about this ESA-funded project's existence until just now. With the results from the preliminary tests today ESA approved the completion of its first full prototype. http://www.theregister.co.uk/2012/11/29/esa_sabre_clearance/ I don't know how feasible is this, or if it is a good approach, and my gut tells me to rely on good ol' rockets, but this just looks amazing. Looking at the spacecraft proposed design as well as the engine schematics, it resembles exactly what I'd make up as my dream spacecraft engine and spacecraft. Besides, it should be our goal to explore all possibilities for reaching space, so even if this turns out to be less promising than it looks, this is still great news for space flight research. https://en.wikipedia.org/wiki/Skylon_(spacecraft) https://en.wikipedia.org/wiki/SABRE_(rocket_engine) Yay!