specialized preservation strategies for artifacts. Collections processing unit — a dedicated loading dock and specially designed secure area for initial inspection and analysis of artifacts. A further expansion of the collections center was approved in December 2016. The addition will be made up of three additional storage modules on the south side of the building. Collection The center was opened on December 15, 2003. The Udvar-Hazy Center displays historic aviation and space artifacts, especially items too large for the National Air and Space Museum's building on the National Mall, including: The Enola Gay, the Boeing B-29 Superfortress which dropped the first atomic bomb on Hiroshima, Japan The orbital spacecraft Space Shuttle Space Shuttle Discovery was put on public display in the James S. McDonnell Space Hangar on April 19, 2012, replacing the atmospheric test vehicle, Space Shuttle Enterprise. A first-generation tracking and data relay satellite (TDRS) that hangs directly above Space Shuttle Discovery The Gemini 7 space capsule A Lockheed SR-71 Blackbird reconnaissance aircraft An Air France Concorde supersonic airliner A United States Air Force Lockheed L-1049 Super Constellation, the military version of the Lockheed Constellation ("Connie") airliner The Boeing 367-80 ("Dash-80") jet transport, which was the prototype for the KC-135 tanker and the 707 airliner The only surviving Bell XV-15 experimental tiltrotor craft A PGM-11 Redstone rocket A SAM-N-2 Lark like the one which scored the first successful United States surface-to-air missile interception of a flying target The only surviving Verville-Sperry M-1 Messenger, the USAAS's first messenger aircraft The Langley Aerodrome A, an early attempt at powered flight by Smithsonian Secretary Samuel Pierpont Langley The Northrop N-1 experimental aircraft The only surviving Boeing 307 Stratoliner, the ex-Pan Am Clipper Flying Cloud One of two surviving German Heinkel He 219 Uhu night fighters The only surviving German Dornier Do 335 Pfeil fighter The only surviving German Horten Ho 229 prototype flying wing jet fighter/bomber The only surviving German Arado Ar 234 Blitz jet bomber The only surviving German Horten H.VI flying wing aircraft One of three surviving German Bachem Ba 349 Natter rocket-powered interceptors The only surviving Japanese Nakajima J1N1-S Gekko The only surviving Japanese Aichi M6A1 Seiran The only surviving Japanese Kyushu J7W Shinden One of four surviving Northrop P-61 Black Widow night fighters One of two surviving Boeing P-26 Peashooter fighters A Bede BD-5, single-seat, home-built aircraft that was somewhat popular in the 1970s (5J version is the