Comparative Study on Options for High-Speed Intercontinental Passenger Transports: Air-Breathing- vs. Rocket-Propelled

This paper investigates the technical options for high-speed intercontinental passenger transports on a preliminary basis. Horizontal take-off hypersonic air-breathing airliners are assessed as well as vertical take-off, rocket powered stages, capable of a safe atmospheric reentry. The study includes a preliminary sizing and performance assessment of all investigated vehicles and compares characteristic technical and passenger environment data. The aerodynamic shape of the air-breathing hypersonic airliners is defined to fulfill the L/D and range requirements. The propulsion system including air-intake and nozzle is integrated into the preliminary design. The rockets are based on an advanced but technically conservative approach not relying on exotic technologies. The two stage, fully reusable vehicle is designed as an “exceedingly reliable” system to overcome the safety deficits of current state-of-the-art launchers. An engine-out capability is integrated for example. The analysis critically assesses the technical options, technology demands, and tries to evaluate the available options on a sound basis. Supported by the results of the technical study, some programmatic issues concerning space flight are finally discussed. A preliminary cost analysis of the rocket powered vehicle gives an indication on the economic feasibility and its impact on launch vehicle production. The development of very high speed intercontinental passenger transport might enable, as a byproduct, to considerably reduce the cost of space transportation to orbit