The aircraft is still in service today, almost fifty years later, as it is less expensive to operate than using satellites and it is more efficient than the SR-71 Blackbird.  The U-2 has also out-lived the SR-71 which was retired after only 25 years of service.  The SR-71 has only recently been re-commissioned for active service.

From the U-2 has been developed the TR-1.  This was being produced openly as a high-altitude tactical surveillance aircraft for the USAF.  Intended primarily for use in Europe, the TR-1 is equipped with an ASARS (Advanced Synthetic Aperture Radar System), all-weather SLAR (Side-Looking Airborne Radar) and extensive ECM (Electronic Counter Measures) equipment.

According to LTC Bowen, and other pilots, the early versions of the U-2 were inherently dangerous.  The early U-2 had structural difficulties and was "very squirrelly" to handle at altitudes of 60,000 - 70,000 feet as the aircraft had a very narrow margin of error in airspeed.    For example, if the aircraft's airspeed fluctuated by more than +/- 2 knots of cruise speed, the aircraft would literally come apart in flight.  The wings could come off and well as the tail assembly. (the tail was held in place by three bolts.)  This margin for error was called the "Coffin's Corner."  There is a myth that the U-2 "cuts" its engine once it reaches altitude.  This is a myth.  The U-2 burns on redline for the duration of its flight.  It has an "unclassified" maximum altitude of 70,000 feet.

Another area where the aircraft was difficult to handle was in the traffic pattern and while landing.  A vast majority all the aircraft destroyed occurred during this phase of flight.  The U-2 and TR-1 have center trucks under the fuselage for landing gear - so it's like a bicycle on takeoff and landing.  There are rollers mounted in the middle of each wing called "pogos" (similar to training wheels on a bicycle.) Once power is engaged on takeoff, the pilot has little time to look at the instruments as he must concentrate on what is happening outside.  With such a large surface area on the wings, the wings start to fly as soon as you accelerate.  When the wings lift, the pogos drop away.  It is not unusual for this to occur within 15-20 feet after the brakes are released.  It takes 2,000 - 3,000 feet to get the U-2 airborne, so from the moment the brakes are released, even though the aircraft is still on the runway, the pilot is flying the aircraft.  The pilot must concentrate on keeping the wings level, using ailerons to compensate for any crosswind.