practice these maneuvers, special rendezvous and docking simulators were built for the astronauts. Gemini-Titan launches and serial numbers The Gemini-Titan II launch vehicle was adapted by NASA from the U.S. Air Force Titan II ICBM. (Similarly, the Mercury-Atlas launch vehicle had been adapted from the USAF Atlas missile.) The Gemini-Titan II rockets were assigned Air Force serial numbers, which were painted in four places on each Titan II (on opposite sides on each of the first and second stages). USAF crews maintained Launch Complex 19 and prepared and launched all of the Gemini-Titan II launch vehicles. Data and experience operating the Titans was of value to both the U.S. Air Force and NASA. The USAF serial numbers assigned to the Gemini-Titan launch vehicles are given in the tables above. Fifteen Titan IIs were ordered in 1962 so the serial is "62-12XXX", but only "12XXX" is painted on the Titan II. The order for the last three of the 15 launch vehicles was canceled on July 30, 1964, and they were never built. Serial numbers were, however, assigned to them prospectively: 12568 - GLV-13; 12569 - GLV-14; and 12570 - GLV-15. Program cost From 1962 to 1967, Gemini cost $1.3 billion in 1967 dollars ($ in ). In January 1969, a NASA report to the US Congress estimating the costs for Mercury, Gemini, and Apollo (through the first crewed Moon landing) included $1.2834 billion for Gemini: $797.4 million for spacecraft, $409.8 million for launch vehicles, and $76.2 million for support. Current location of hardware Spacecraft Gemini 1: Intentionally disintegrated upon re-entry to the atmosphere Gemini 2: Air Force Space and Missile Museum, Cape Canaveral Air Force Station, Florida Gemini III: Grissom Memorial, Spring Mill State Park, Mitchell, Indiana Gemini IV: National Air and Space Museum, Washington, D.C. Gemini V: Johnson Space Center, NASA, Houston, Texas Gemini VI: Stafford Air & Space Museum, Weatherford, Oklahoma Gemini VII: Steven F. Udvar-Hazy Center, Chantilly, Virginia Gemini VIII: Armstrong Air and Space Museum, Wapakoneta, Ohio Gemini IX: Kennedy Space Center, NASA, Merritt Island, Florida Gemini X: Kansas Cosmosphere and Space Center, Hutchinson, Kansas Gemini XI: California Museum of Science and Industry, Los Angeles, California Gemini XII: Adler Planetarium, Chicago, Illinois Trainers Gemini 3A: St. Louis Science Center, St. Louis, Missouri. Gemini MOL-B: National Museum of the United States Air Force, Wright-Patterson Air Force Base, Dayton, Ohio Gemini Trainer: Discovery Center, Fresno, California Gemini Trainer: U.S.