This is a black HRSI (high-temperature reusable surface insulation) tile from the Space Shuttle's first flight. Tiles were an integral component of the Space Shuttle orbiter's thermal protection system. This system shielded the vehicle from the destructively searing heat of re-entry into the atmosphere and also provided passive thermal control in orbit. About 23,000 black tiles shielded the entire underside of the orbiter, as well as portions of the vertical tail, wings, and forward and aft fuselage where temperatures reach 1,200-2,300 degrees F (650-1,260 degrees C).
This tile was removed from the aft fuselage body flap after being damaged on the first flight of Columbia in 1981. NASA transferred a number of such tiles to the Museum after the STS-1 mission.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.