This is thought to be the Raptor prototype SpaceX is developing under a USAF contract for a methalox Falcon 9 upper stage concept.[0] Thus it's about the size o

This is thought to be the Raptor prototype SpaceX is developing under a USAF contract for a methalox Falcon 9 upper stage concept.[0] Thus it's about the size of a Merlin 1D-Vac. Nobody is claiming otherwise. [0] http://www.defense.gov/News/Contracts/Contract-View/Article/642983 http://www.defense.gov/News/Contracts/Contract-View/Article/...