The U-2 reconnaissance aircraft played a pivotal role in two of the most famous events of the Cold War. In the mid-1950s, the United States was desperate to know what was going on behind the Iron Curtain. No information had come out of the Soviet Union since the Second World War. In 1957, the USSR launched Sputnik, the world's first artificial satellite. This, along with other advances in Soviet technology, led to concerns that they were becoming technologically superior. The gathering of photographic aerial intelligence was deemed essential.