Force, Wright-Patterson Air Force Base, Dayton, Ohio. B-14/20 AF Ser. No. 61–2768 at the Stafford Museum, Oklahoma. B-44/16 AF Ser. No. 62–0025 at the National Museum of Nuclear Science & History adjacent to Kirtland Air Force Base, Albuquerque, New Mexico. B-104 AF Ser. No 66–4315 at the Spaceport USA Rocket Garden, Kennedy Space Center, Florida. B-108 AF Ser. No. 66-4319 (23G-10 the spare for the 23G program) at the Evergreen Aviation and Space Museum in McMinnville, Oregon. Titan II launch vehicle The Titan II space-launch vehicles were purpose-built as space launchers or are decommissioned ICBMs that have been refurbished and equipped with hardware required for use as space launch vehicles. All twelve Gemini capsules, including ten crewed, were launched by Titan II launchers. The Titan II space launch vehicle is a two-stage liquid fueled booster, designed to provide a small-to-medium weight class capability. It is able to lift approximately into a circular polar low-Earth orbit. The first stage consists of one ground ignited Aerojet LR-87 liquid propellant rocket engine (with two combustion chambers and nozzles but a single turbopump system), while the second stage consists of an Aerojet LR91 Liquid-propellant engine. By the mid-1980s, with the stock of refurbished Atlas E/F missiles finally starting to run out, the Air Force decided to reuse decommissioned Titan IIs for space launches. The Martin Marietta Astronautics Group was awarded a contract in January 1986 to refurbish, integrate, and launch fourteen Titan II ICBMs for government space launch requirements. These were designated Titan 23G. The Air Force successfully launched the first Titan 23G space launch vehicle from Vandenberg Air Force Base 5 September 1988. NASA's Clementine spacecraft was launched aboard a Titan 23G in January 1994. All Titan 23G missions were launched from Space Launch Complex 4 West (SLC-4W) on Vandenberg Air Force Base, under the operational command of the 6595th Aerospace Test Group and its follow-on organizations of the 4th Space Launch Squadron and 2nd Space Launch Squadron. The Titan 23G ended up being less of a cost-saving measure than anticipated as the expense of refurbishing the missiles for space launches turned out to be more than the cost of flying a brand-new Delta booster. Unlike refurbished Atlas missiles, which were completely torn down and rebuilt from the ground up, the Titan 23G had relatively few changes aside from replacing the warhead interface and adding range safety and telemetry packages. The engines were