This is a sample thermal blanket like those covering most of the Space Shuttle fuselage, upper wings, and vertical tail. A standard blanket is a square, but this is one of the many irregular shapes needed to fit various parts of the vehicle's surface. Quilted blankets replaced most of the white tiles originally applied to the topside of the vehicle because they are lighter weight, more durable, and easier to make and install. NASA released a few of these Advanced Flexible Reusable Surface Insulation (AFRSI) blankets, no longer usable and marked scrap, to the Museum in 2006.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.