out of Burbank Airport, they selected what would become Area 51. It was acquired and a paved runway constructed for the project. The planes were dismantled, loaded onto cargo planes, and flown to the facility for testing. The aircraft was renamed the U-2 in July 1955, the same month the first aircraft, Article 341, was delivered to Groom Lake. The "U" referred to the deliberately vague designation "utility" instead of "R" for "reconnaissance", and the U-1 and U-3 aircraft already existed. The CIA assigned the cryptonym AQUATONE to the project, with the USAF using the name OILSTONE for their support to the CIA. James Baker developed the optics for a large-format camera to be used in the U-2 while working for Perkin-Elmer. The new camera had a resolution of from an altitude of . The aircraft was so crowded that when Baker asked Johnson for of space for a lens with a focal length, Johnson replied "I'd sell my grandmother for six more inches!"; Baker instead used a f/13.85 lens in a format for his final design. Fuel The U-2 has used Jet Propellant Thermally Stable (JPTS) since the aircraft's development in the 1950s. JPTS is a high thermal stability, high altitude fuel, created specifically for the U-2. JPTS has a lower freeze point, higher viscosity, and higher thermal stability than standard USAF fuels. In 1999, the Air Force spent approximately $11.3 million (equivalent to $20.58 million in 2023 dollars) on fuel for the U-2 aircraft and was looking for a lower-cost alternative. JPTS is a specialty fuel and as such has limited worldwide availability and costs over three times the unit volume price of USAF's primary jet fuel, JP-8. Research was carried out to find a cheaper and easier alternative involving additives to generally used jet fuels. A JP-8 based alternative, JP-8+100LT, was being considered in 2001. JP-8+100 has increased thermal stability by over stock JP-8, and is only 0.5 cents per gallon more expensive; low-temperature additives can be blended to this stock to achieve desired cold performance. The small landing gear made a perfect balance in the fuel tanks essential for a safe landing. Similarly to sailplanes, the U-2 had a yaw string on the canopy to detect slip or skid during the approach. A skid during flight with no bank was the hint of an imbalance around the longitudinal axis which could be resolved by moving the