Space & Rocket Center, Huntsville, Alabama Gemini Trainer: Kentucky Science Center, Louisville, Kentucky Gemini Trainer: Texas Air Museum, Slaton, Texas 6165, GATV: National Air and Space Museum, Washington, D.C. (not on display) El Kabong: Kalamazoo Air Museum, Kalamazoo, Michigan Gemini Trainer: Kalamazoo Air Museum, Kalamazoo, Michigan TTV-2: National Space Centre, Leicester, UK Trainer: Pate Museum of Transportation, Fort Worth, Texas MSC 313: Private residence, San Jose, California Rogallo Test Vehicle: White Sands Space Harbor, White Sands, New Mexico TTV-1: Steven F. Udvar-Hazy Center, Chantilly, Virginia unnamed: Air Force Space and Missile Museum, Cape Canaveral Air Force Station, Florida unnamed: Air Force Space and Missile Museum, Cape Canaveral Air Force Station, Florida Ingress/Egress Trainer: U.S. Space & Rocket Center, Huntsville, Alabama MSC-307: USS Hornet Museum, former NAS Alameda, Alameda, California Proposed extensions and applications Advanced Gemini McDonnell Aircraft, the main contractor for Mercury and Gemini, was also one of the original bidders on the prime contract for Apollo, but lost out to North American Aviation. McDonnell later sought to extend the Gemini program by proposing a derivative which could be used to fly a cislunar mission and even achieve a crewed lunar landing earlier and at less cost than Apollo, but these proposals were rejected by NASA. A range of applications were considered for Advanced Gemini missions, including military flights, space station crew and logistics delivery, and lunar flights. The Lunar proposals ranged from reusing the docking systems developed for the Agena Target Vehicle on more powerful upper stages such as the Centaur, which could propel the spacecraft to the Moon, to complete modifications of the Gemini to enable it to land on the lunar surface. Its applications would have ranged from crewed lunar flybys before Apollo was ready, to providing emergency shelters or rescue for stranded Apollo crews, or even replacing the Apollo program. Some of the Advanced Gemini proposals used "off-the-shelf" Gemini spacecraft, unmodified from the original program, while others featured modifications to allow the spacecraft to carry more crew, dock with space stations, visit the Moon, and perform other mission objectives. Other modifications considered included the addition of wings or a parasail to the spacecraft, in order to enable it to make a horizontal landing. Big Gemini Big Gemini (or "Big G") was another proposal by McDonnell Douglas made in August 1969. It was intended to provide large-capacity, all-purpose access to space, including missions that ultimately used Apollo