U-2 Dragon Lady
An aircraft that has demonstrated the soundness of its design through over fifty years of flight, the it has many names: CL-282 as its internal name at the Lockheed Skunk Works, U-2 Dragon Lady, usually just called the U-2, and sometimes by its CIA codeword of AQUATONE, or SENIOR YEAR after its Air Force sensor systems. It is a high-altitude reconnaissance aircraft that remains a key U.S. intelligence collection platform. With modifications over the years, it collects imagery intelligence, signals intelligence, and measurement and signature intelligence. Ironically, since the cover story for the first aircraft shot down was "weather research", U-2 aircraft do conduct high-altitude environmental research for the civilian sector.
A 1954 letter from Dr. Edwin Land, chief of Polaroid and a key scientific intelligence advisor, to Director of Central Intelligence Allen Dulles inspired the idea that became the CIA AQUATONE project and the U-2.  Land, chairman of President Dwight Eisenhower’s Technological Capabilities Panel, DCI Dulles, to develop a high-altitude reconnaissance aircraft that could overfly the Soviet Union. Dulles was not enthusiastic.
Essentially, the aircraft has the aerodynamics of a glider, but equipped with a jet engine, the engine and life support systems designed to operate at altitudes over 70,000 feet. The pilot must wear a full-pressure suit comparable to the space suits worn by astronauts. Its most efficient high-altitude flight profile is a delicate balancing of optimizing range and keeping the engine running.
Complex to handle at high altitude, takeoff and landing, if they were not deadly serious, remind many observers of slapstick comedy. The aircraft has two main landing gear in a low bicycle configuration. The low-altitude handling characteristics of the aircraft and bicycle-type landing gear require precise control inputs during landing; forward visibility is also limited due to the extended aircraft nose and "taildragger" configuration. A second U-2 pilot normally "chases" each landing in a high-performance vehicle, assisting the pilot by providing radio inputs for altitude and runway alignment. These characteristics combine to earn the U-2 a widely accepted title as "the most difficult aircraft in the world to fly". 
Designed by Kelly Johnson, a legendary aircraft designer, at the high-security Lockheed facility later to be known as the "Skunk Works", the U-2 added glider wings to the fuselage of Johnson design, the F-104 Starfighter, but with radical changes such as removing traditional landing gear. It was developed within a year of the contract award.
Early deployment and cover story
Its early cover identity was as a research aircraft for NACA, the predecessor of the National Aeronautics and Space Administration (NASA). On 7 May 1956 NACA Director Dr. Hugh L. Dryden announced weather research for NACA, in cooperation with the United States Air Force. It was described as operating from a location in Nevada, later to be known as Area 51. Initial operations were described as domestic, but Dryden announced overseas "research" three weeks later. Even in early 1960, the U.S. Senate was told the U-2 had been carrying out NASA weather missions.
A major overseas operating location was Adana, Turkey (later renamed as Incirlik), where the "2nd Weather Reconnaissance Squadron (Provisional)" was deployed in August 1956. Actual responsibility was split between the Air Force and CIA, with the Air Force providing the base support and the CIA providing civilian pilots and operational planners. No actual weather flights were made from this location; all missions were IMINT and SIGINT. While the Soviet Union was the primary target, overflights were also made over Egypt, Iran, Iraq, Lebanon, the Mediterranean, Saudi Arabia, Syria, and Iraq. The Mediterranean missions monitored British and French shipping during the Suez Crisis of 1956. 
The Incirlik location remained the primary operating base, although there were support facilities in Germany, and forward operating bases ad Lahore and Peshawar, Pakistan. with alternate landing sites including Bødo, Norway. While the Soviets became aware of the flights, they were unable to interfere with the air defenses at hand. Further, for every overflight, there was one or more flights that did not go over the Soviet border, but collected SIGINT along it.
Value and risk of early Soviet overflights
U-2 aircraft were deliberately flown by civilian pilots; there was a conscious decision to separate the national intelligence function from military operations. CIA official Herbert I. Miller wrote "...As a covert intelligence platform, AQUATONE has merely substituted high-altitude vehicles and precision equipment...for more prosaic modes of transportation and the eyes and memory of an agent...AQUATONE operations are not intended to be the counterpart of the targget-spotting function of military reconnaissance which is an immediate prelude to hostilities. 
Miller went on to describe the value of the collected information as immense. A 4 July 1956 mission, for example, covered 5 of the 7 targets of greatest interest to the U.S. One of the revelations of this mission was to throw doubt on the U.S.-perceived "bomber gap", which was an issue in the 1960 Presidential election. While bombers were expected to be present at a minimum of 2 of the 5 bases, no bombers were photographed as any. Miller said the diversity of U-2 coverage make it "capable of studying a culture rather than one solely designed to cover specific targets."
On 1 May 1960, a U-2 aircraft was shot down over the Soviet Union. It is still unclear if the aircraft was hit by a Soviet S-75 Dvina surface-to-air missile at its operating altitude, or if the U-2 had descended to a lower altitude as a result of engine problems. The mission, flown by Francis Gary Powers, launched Peshawar, was to overfly two intercontinental ballistic missile test sites, and land in Norway.
While the U.S. first claimed that a "weather reconnaissance" aircraft was off-course and may have crashed, it was not known that the Soviets were holding a live pilot and recognizable reconnaissance equipment from the aircraft. Premier Nikita Khruschev made much of the intrusion, and cancelled an upcoming summit meeting with the U.S. Norway, Pakistan, and Turkey disavowed knowledge of the purpose of the mission, and the U.S. units in those countries returned home.
Cuban Missile Crisis
In October 1962, a U-2 obtained the first confirmation of Soviet missiles in Cuba, and were active throughout the resulting Cuban Missile Crisis. One U-2 was shot down, killing the Air Force pilot, Rudolf Anderson.
Flown by Nationalist Chinese pilots, U-2 aircraft later overflew the People's Republic of China. U-2 aircraft have participated in operations in Afghanistan, the Balkans, and Iraq.
Apropos of the original cover story, U-2 aircraft have photographed national disasters to help in their assessment, and participated in research on high-altitude flight.
Variants and the future
The U-2R, first flown in 1967, was 40 percent larger and more capable than the original aircraft. A tactical reconnaissance version, the TR-1A, first flew in August 1981 and was structurally identical to the U-2R. The last U-2 and TR-1 aircraft were delivered in October 1989; in 1992 all TR-1s and U-2s were designated as U-2Rs. Since 1994, $1.7 billion has been invested to modernize the U-2 airframe and sensors. These upgrades also included the transition to the GE F118-101 engine which resulted in the re-designation of all Air Force U-2 aircraft to the U-2S. The U-2, for example, carries the only operational spectroscopic MASINT collection system.
U-2s are home based at the 9th Reconnaissance Wing, Beale Air Force Base, California, but are rotated to operational detachments worldwide. U-2 pilots are trained at Beale using five two-seat aircraft designated as TU-2S before deploying for operational missions.  The Wing reports to the Eighth Air Force, with a dual reporting structure to United States Strategic Command and Air Combat Command. Intelligence collected by the U-2 goes to the appropriate Unified Combatant Command being supported, and, as appropriate, IMINT to the National Geospatial-Intelligence Agency, SIGINT to the National Security Agency, and MASINT to the Defense Intelligence Agency.
The Air Force has proposed to retire the U-2, starting in 2007 and completely by 2011. Indeed, the MQ-4 Global Hawk unmanned aerial vehicle has similar flight characteristics and may be a successor for those missions not appropriate for other air and space reconnaissance platforms. Eventually, the airframes of all aircraft wear out. Nevertheless, the U-2 has survived retirement threats before, operating long after its assumed successor, the SR-71 Blackbird. Regardless of the final disposition, it never lose its place in aviation fame, both for its technology when created, and as one of the few military aircraft that has had over a half-century of operational service.
- Other code words were CHALICE and IDEALIST, but AQUATONE is best known
- Edwin Land (November 5, 1954), A Unique Opportunity for Comprehensive Intelligence, Science, Technology and the CIA, National Security Archive Electronic Briefing Book No. 54
- "SENIOR YEAR / AQUATONE / U-2 / TR-1 "Dragon Lady"", Globalsecurity
- Herbert I. Miller (17 July 1957), Suggestions re the Intelligence Value of AQUATONE, Science, Technology and the CIA, National Security Archive Electronic Briefing Book No. 54
- Pentagon To Retire U2 Spy Plane, 5 January 2006