Aerodynamic reentry problems in wind tunnel facilities at low densities and high energy

Spacecraft reentry problems are discussed. Mean free path, viscosity, particle density, deceleration, and aerodynamic heating aspects are dealt with. The reentry process is discussed. The wind tunnel facilities available at Cologne-Porz and the measuring techniques employed there are described. A number of specific investigations and possibilities of further application are discussed. A summary of the investigations concerning this topic performed in the "Low Density, High Enthalpy Branch" of the Institute is given.