It is 50 years since the first flight of the U-2, the iconic US spy plane which gained notoriety during the Cold War. The BBC's Nick Childs reviews its career.
The U-2 flies at very high altitude to escape most air defences
The U-2 - in a heavily modified form - is still very much with us today, continuing to gather intelligence for the United States around the world.
But it was above all a Cold War espionage tool, the epitome of that much overused phrase, "the spy plane", with its pencil-like long fuselage and wide, glider-like wings.
Developed in great secrecy, it was designed to fly at very high altitude - over 15 miles (25km) up - to evade most air defences.
And the Americans initially used it mainly to fly secret spy missions over the Soviet Union's most sensitive missile sites and other installations.
But it hit the headlines when, on May Day 1960, the Soviets managed to shoot one down.
Initially, the Americans put out an innocent cover story, but then Moscow produced the pilot, who had survived. His name was Gary Powers.
The incident scuppered an East-West summit and put US-Soviet relations into the deep-freeze.
A U-2 was shot down over Russia in May 1960 with its pilot Gary Powers
It was also a U-2 that uncovered the Soviet military preparations in Cuba that led to the Cuban missile crisis in 1962.
Again, another U-2 was shot down then, raising tensions for a while.
The basic design of this single-seat, single-engined plane may have been overtaken by the latest stealth technology, but its ability to fly so high, and its latest high-powered cameras and special, all-weather radar, still offer US intelligence a unique surveillance capability.
Satellites may offer some advantages, but the U-2 is more flexible.
And it still retains its aura of mystery from the Cold War.