Just south of Tucson, Arizona, is the Pima Air and Space Museum, the world’s third-largest aircraft collection. Here is a vast collection of aerospace items, some located in specially-built hangers, some sitting out in the desert sun (and weathering occasional sand storms). The 35-year old museum is mind-bogglingly huge, with more than 300 aircraft and 125,000-plus objects and artifacts to pore over, spread across five hangars in an area of some 80 acres (32.4 hectares).