Economic and programmatic considerations for advanced transportation propulsion technology

Requirements for space transportation will increase after the Space Shuttle becomes operational. Shuttle derivatives and new earth-to-orbit vehicles are compared economically. The addition of both one and two new vehicle types are considered. Programmatic considerations are included in deriving a scenario which appears reasonable and includes the Space Shuttle, a heavy-lift cargo derivative of the Shuttle, a unique dual-fuel orbit transfer vehicle, and a small new earth-to-orbit vehicle in the foreseeable future. Large new orbital transfer and earth-to-orbit vehicles would be added when needed.