This is an unflown example of a flight data recorder that has been installed on most modern commercial aircraft in the United States beginning in the 1990s. It uses all solid-state recording, and is designed to withstand the shock of a crash, fire, or submersion under water. ALthough popularly known as the "Black Box," it is in fact painted bright orange to make it easier to locate.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.