During the presentation video, he refers to the materials chosen to build it. He says that stainless steel is the paradoxically lighter material they could use. He supports his thesis on the fact that it is a material that can withstand extreme temperatures (high and low), having the melting point at 1500 degrees, when aluminum alloys and carbon fiber yield at 300-500 degrees. With this, they can be allowed to use less heat shield material, since it is not necessary to prevent the temperature from exceeding 500 degrees.