On May 1, 1960, the Soviet Union shot down an American U-2 spy plane over its territory. The pilot, Francis Gary Powers, parachuted to the ground, but not precisely to safety -- he was captured by the Soviets. President Eisenhower and the US government didn't know that for a while, however, just that the plane was missing. On the 3rd, NASA issued a statement that the airplane was on a joint NASA-US Air Force "air weather service mission" in Turkey and had apparently gone down in or near Lake Van, Turkey.
Khrushchev then proceeded to use the incident to embarrass Eisenhower's administration, which stuck to the "air weather service mission" story a little too long. The plot, as related by Mount Holyoke College's International Relations Program's web site, got thicker:
"In another long speech to the Supreme Soviet on the next day, May 7, Khrushchev said, among other things, that the pilot was alive and that Soviet authorities had recovered parts of the airplane. He also displayed samples of the developed film allegedly taken by camera equipment installed on the plane and charged that Powers had flown out of Peshawar airfield in Pakistan, which was correct, and not out of Turkey, and his landing destination was Bodo airfield in Norway.
"In response to this speech, the Department of State issued a statement on May 7 admitting that while the inquiry ordered by the President established that 'insofar as the authorities in Washington are concerned there was no authorization for any such flight as described by Mr. Khrushchev,' such a flight over the Soviet Union to gather information was probably undertaken, and it justified such activities as necessary 'given the state of the world today' and the Soviet Government's rejection of the President's 'open skies' proposal in 1955.
"In a statement released to the press on the afternoon of May 9, Secretary [of State Christian] Herter conceded that the President had issued directives authorizing the gathering of intelligence information, although specific missions of unarmed civilian aircraft had not been subject to authorization."
The president was embarrassed, an international conference wrecked, and Powers spent 21 months in the jug. Years after his death in a helicopter crash in 1977, he was his posthumously awarded Prisoner of War Medal, Distinguished Flying Cross and National Defense Service Medal.