January 7, 2012: On December 18th, the last (for the moment) American U-2 mission was flown over Iraq. These missions began in 1990, after the Iraqi invasion of Kuwait, and continued until December, 2011. The last decade has been the busiest for the U-2 in decades. Because of the spy satellite quality sensors carried by U-2s, and a limited number of spy satellites in space, there was always more demand for U-2 sorties than could be provided. Three years ago, for example, two 41 year old U-2s achieved a record 25,000 hours in the air. One of these aircraft had made three belly (landing gear up) landings, requiring extensive rebuilding after each incident.
With a range of over 11,000 kilometers, the 18 ton U-2s typically fly missions 12 hours long. All U-2s have been upgraded to the Block 20 standard, so they can be kept in service until the end of this decade. Or at least until the 13 ton Global Hawk is completely debugged and available in sufficient quantity to replace it. The U-2 has been in service since 1955 and only 103 were built, of which 26 remain in service (plus five two-seat trainers). The current U-2S aircraft were built as TR-1s in the 1980s and later refurbished and renamed U-2S. Fewer than 900 pilots have qualified to fly the U-2 in that time.
The heavy use of the U-2 has been hard on the pilots. Missions can be as long as 12 hours and pilots operate in a cockpit pressurized to conditions found at 10,000 meters (31,000 feet). This puts more strain on the pilot's body. That, and the fact that they breathe pure oxygen while in the cockpit, means they tend to be completely exhausted after returning from a long mission. U-2s fly missions daily over the Middle East, Afghanistan, and Korea.
This wasn't supposed to happen. Six years ago the U.S. Air Force wanted to retire its U-2s and replace them with UAVs like Global Hawk. But Congress refused to allow it, partly for political reasons (jobs would be lost, which is always a live political issue) and because some in Congress (and the air force) did not believe that Global Hawk was ready to completely replace the U-2. This turned out to be correct. New Global Hawks continue to appear but there is so much demand for the kinds of recon work the two aircraft can do that both pilots and robots will coexist for a while. But eventually the old reliable U-2 will be retired.