The SpaceLiner Concept and its Aerothermodynamic Challenges

This paper outlines the technical concept of a high-speed intercontinental passenger transport using rocket based, suborbital launchers. The paper gives an overview on the recent conceptual design status of the DLR SpaceLiner presenting geometrical size and mass data and describing results of trajectory simulations. 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 otherwise advantageous skipping trajectory is generating very high heat loads in critical areas which could be successfully addressed by advanced ceramic materials with active cooling. DLR is preparing a fundamental research test campaign on active leading edge transpiration cooling in high enthalpy flow. DLR's arc heated, high enthalpy facility foreseen for the experiments is described in the paper. The advanced C/C-structures, the selection of the cooling fluid, and the design of the experimental models are briefly discussed. Supported by the results of the technical study, some programmatic issues concerning space flight are 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.