This volume offers an introduction into the technology programs and international projects of reusable orbital transport systems. Besides the technological requirements, meteorological and air chemical aspects in regard to the environmental compatibility of future transport systems are the most important topics. The aim of the symposium was to investigate the classical disciplines and methods of aeronautics and astro- nautics in connection with meteorological and air chemical methods and models. For this purpose an attempt was made to identify technological optimization parameters in respect to the air chemical environmental compatibility of future orbital transport systems.