Within days of the 1960 Powers CIA U-2 shoot-down, NASA presented the press with a U-2A aircraft in fictitious NASA markings, to bolster the government's cover story that Powers was on a scientific weather research mission - NASA Photo
Our overt knowledge of the U-2 came crashing into the world's collective consciousness on May 1st 1960, when Francis Gary Powers was shot down in his U-2C over Sverdlovsk, Russia.
Within days of the shoot-down, Dr. Hugh Dryden, director of NASA, reiterated the agency's previous (May 1956) statements that the U-2 aircraft was a new research tool for high-altitude atmospheric and meteorological research, flown with the logistical and technical support of the Air Force.
U-2 Historians have point to these and subsequent statements by NASA and its predecessor agency, the National Advisory Committee for Aeronautics (NACA), as the US government's first "cover story" to mask the true covert operational use of these new U-2 aircraft by the CIA.
The reality, from subsequent declassified government documents now reveals that, at the time Dryden made those proclamations in May 1956, the first U-2 aircraft were just becoming operational with the CIA. Within a month, the CIA conducted their first operational over-flights, conducted over Poland and East Germany. By the 4th of July 1956, the CIA had flown three more over-flights of Eastern Europe, including the very first clandestine over-flight of the Soviet Union.
Its important to note, that the US Air Force would not receive their first five U-2 aircraft until June 1957 and NASA wouldn't finally get their (first) two U-2 aircraft until June 1971.
Looking back to when Dr. Dryden announced the peaceful scientific research purposes of the U-2 to the press in May 1960, after the Powers shoot-down, its now evident that he wasn't actually lying. By that point, Air Force U-2 were conducting peaceful, high-altitude atmospheric and meteorological research flights throughout the world and would continue to do so until 1968.