The Smithsonian Institution's National Air and Space Museum (NASM) maintains the largest collection of historic air and spacecraft in the world. The NASM Archives Division maintains a still picture collection of approximately 1.7 million images, and a motion picture collection of approximately 700,000 feet of film, as well as over 2 million technical drawings.
You can contact the NASM Archives Division by writing them at:
NASM Archives Division
Smithsonian Institution
PO Box 37012
National Air and Space Museum
Room 3100, MRC 322
Washington, DC 20013-7012
General Museum Information: 202-633-1000
Archives Reference Desk (including still images): 202-633-2315
Film Archives: 202-633-2337