The basic concept of the Reusable Launch Vehicle (RLV) for CATS is still valid and remains untested. The Space Shuttle with its expendable External Tank represented the worst of both worlds between the Expendable Launch Vehicle (ELV) and the RLV. This was recognized almost on the day the Space Shuttle was designed. However the cost caps of the Space Shuttle's development prohibited a true RLV and set the stage for disaster. Developing a true RLV from Saturn V technology would have been like developing a Boeing 747 directly from the Ford Trimotor without all the intermediate government subsidized steps, i.e. the B-29, the F-86 Sabre Jet, the Boeing 707 subdized by the USAF and the C-5 design competition between Boeing and Lockheed. If the Space Shuttle had been a true fully reusable RLV with a robust hot metal thermal protection system then we probably would now have RLV access to LEO at $1000/kg and be well on our way towards colonizing Mars. Instead the Space Program is currently in the toilet with the Apollo Command Module slated to come back as the CEV with more lunar Flags and Footprints on the horizon. Being in this situation is clear evidence that the Space Shuttle was a disaster for the Space Program.

Gary