The history of the collection from the 1870's, and the development of the Museum from the 1940's to its opening in 1976 are traced. The architecture of the NASM in relationship to light and environmental control and display concepts, monitoring mechanical and audiovisual exhibits, and the computerized control of these functions and security are among the topics discussed. The conservation of artifacts, most of which is done at the museum's Silver Hill, Maryland, complex, deals with several unique problems. The preferential corrosion of alloys has required the conservation staff to find compatible materials that will not be susceptible to the same deterioration. Large pieces of disassembled aircraft must be handled so as not to create destructive stresses. Structural analysis is necessary in order to approximate stress in flight and stress in exhibition hanging. The library and the planetarium of the NASM are described in detail. -- AATA