But, the Soviets were aggressive in attacking any aircraft near the country's borders. Their interceptor MiG-7 planes could only fly up to 45,000 feet. It was believed that their radar could track aircraft up to 65,000 feet. So, the US government contracted with Skunk Works to build a plane that could fly at 70,000 feet so that it would be beyond the reach of Soviet fighters and radar.
Since the plane had to climb to 70,000 feet, it had to be light. So the lead engineer at Skunk Works, Kelly Johnson, and his team eliminated the landing gear to make the plane lighter. The plane would take off from a special cart and land on its belly like a glider. Since altimeters at that time could measure up to only 45,000 feet altitude, the team re-calibrated them to measure up to 80,000 feet. Since existing runways were inadequate for landing the plane, they built a longer runway in a classified military facility called Area 51.
The aircraft they designed and built was named U-2 in July 1955. The "U" stood for “utility”, and was meant to be deliberately vague. It was equipped with a camera that could see an object 2.5 feet-wide from an altitude of 60,000 feet. The plane could fly up to 70,000 feet and had a range of 4,000 miles. Later versions of the plane were modified to double the range.
The CIA flew U-2 planes on reconnaissance flights over the Soviet Union during the cold war, Egypt during the Suez crisis, Cuba during the Cuban missile crisis and various other conflicts. It used the cover story that the flights were for high altitude weather research. In May 1960, the Soviet Union used a missile to bring down a U-2 plane. This disproved the invincibility of U-2 planes. Nevertheless, U-2 remains the highest flying single engine plane in service to this day.