The U2 Spy Plane was a plane launched by the U.S. in 1955 and it was first introduced in 1957.
The plane had the capability to fly at high altitudes of 70,000 feet or 21,336 meters, and reach 500 miles an hour which meant they were almost out of vision from any opponents on the ground floor.
The allies' main intentions for using the plane were to take spy shots of Russian military bases throughout the Cold War. Even after the early 60s when the Russians found out about the plane scouting them from radars, there weren't any possibilities to shoot down the plane with missiles or jets obviously because of the altitude the plane flew.
Just a short while later, the Russians had developed a Zenith surface-to-air missile with a much longer range meaning it was able to reach the spy plane and eventually shoot it down. On May 1, the rocket locked on to the spy plane. The only survivor from the crash was Francis Gary Powers who was the pilot and ended up parachuting down right into the enemy base.
After the capture of Powers, President Eisenhower was forced to admit the plan of spying on enemy bases for several years. Powers was planned to be sentenced 10 years in prison but after just 2 years, they let him free in exchange for spying on U.S. instead.