Every time there’s a test of a scramjet, there’s associated overhype about how great it will be for space access. The upcoming X-51 flight is no exception:
Ms. Waldman said in her report that as scramjet technology is developed testers believe that in the near future it could be used to aid warfighters as a weapons delivery system. She said officials believe that in the future the scramjet technology will make space access easier.
“The application really is all about space lift,” Mr. Brink agreed, and said, “This is the one, I think, in the Air Force Research Lab we’re most excited about.”
Mr. Brink pointed out that they currently transport payload into space with the shuttle, which has to carry all of its oxidizers for the propulsion concept. He said the shuttle is a pure rocket system and said if they can incorporate scramjet engine technology into the space lift systems, they wouldn’t have to carry the oxidizers and could carry more payload instead.
Yeah, if there’s any payload left after you count the weight of the engines, which have terrible T/W compared to rockets, and all of the extra drag you incur staying in the atmosphere to collect the oxygen. I’ve discussed this more than once in the past. I’ve never seen a hypersonic airbreathing conceptual vehicle design that was an improvement in performance over a rocket for a space transport, at least if there was any analysis more serious than the above performed on it. Scramjets have plenty of utility for military applications. I wish that people selling the program didn’t always feel the need to oversell it. And if we had a smarter space media, they’d get called on it.