SA 75 "DWINA" (aka SA 2) - used to shoot down Gary Powers and his U-2 in 1960.
Until that time, U-2, flyng at 80,000 feet was considered safe from Soviet fighter planes or anti-aircraft weapons.
U-2 overflights of the Soviet territory provided vital inteligence during the early days of Cold War.
After U-2 became vulnerable to Soviet missiles, it was replaced by SR-71 Blackbird, and ultimately by spy satellites.
Gary Powers, after spending 2 years in Soviet prison, was exchanged for a Soviet spy in 1962 and returned to the United States.
He died in 1977 in a helicopter crash in Los Angeles.