This stainless steel model of the sharp-edged spacecraft SHEFEX II (Sharp Edged Flight Experiment) measures about 70 centimetres in length. A porous heat tile is located on the surface. Nitrogen flows through and out of the tile as the spacecraft re-enters Earth’s atmosphere. As the gas flows out, it clings like a film to the outer surface of the flight experiment, creating a buffer layer between the spacecraft and the hot surrounding air.