Gallery: SA-2 Surface to Air Missile (SAM)

Developed in the mid-1950s, the V-750 Dvina was the first effective Soviet surface-to-air missile. The Soviets used it to shoot down Gary Powers' U-2 over the USSR in 1960 and Maj. Rudolph Anderson's U-2 over Cuba in 1962. The missile was better known by the NATO designation SA-2 Guideline. The Soviets began exporting it to many countries worldwide in 1960, with many remaining in use into the 21st century.

North Vietnam began receiving SA-2s shortly after the start of Operation Rolling Thunder in the spring of 1965. With Soviet help, they built several well-camouflaged sites, regularly moving SA-2s and their equipment among them. The North Vietnamese also ringed SA-2 sites with anti-aircraft artillery (AAA), making them even more dangerous to attack.

The SA-2 did not operate alone, but as part of a complete system. A typical SA-2 site in North Vietnam had six missiles on launchers, control and support vans, a Spoon Rest acquisition radar, and a Fan Song guidance radar.

The Spoon Rest radar detected incoming aircraft at long range (as far as 70 miles), providing location data to the system computer.

The Fan Song guidance radar performed two functions: target acquisition and missile guidance. It acquired as many as four targets before firing. After launch, it guided up to three SA-2s against one target. (The North Vietnamese sometimes placed the radars away from the missiles to make the site harder to destroy.)

The SA-2 missile had a solid fuel booster rocket that launched and accelerated it, then dropped off after about six seconds. While in boost stage, the missile did not guide. During the second stage, the SA-2 guided, and a liquid-fuel rocket propelled it to the target.