This is the protective aluminum case for the HiRISE camera CCD (Charge-Coupled Device). Like your own personal digital camera, a spacecraft camera records images using a CCD--an array of tiny detectors whose combined measurements of light form a picture. This CCD is identical to the one used by the Mars Reconnaissance Orbiter's HiRISE (High Resolution Imaging Science Experiment) camera, flown at the beginning of the twenty-first century.
The Ball Aerospace and Technologies Corporation and the University of Arizona donated this artifact to the Museum in 2010.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.