Atoll is the NATO code name for a Soviet-era air-to-air missile called the K-13. The Atoll is a Soviet copy of America's AIM-9 Sidewinder missile. An unexploded Sidewinder was acquired by the Communist block in 1958 after a Taiwanese F-86 Sabre engaged a Chinese MiG-17 and fired a Sidewinder. The missile failed to explode but lodged in the Chinese fighter's fuselage. Previous to the Atoll, Soviet missiles were highly complicated affairs. The Sidewinder's modular construction made reverse engineering not only easy but as one Soviet engineer stated:

"The Sidewinder missile was to us a university offering a course in missile construction technology..."

Soviet missile design radically changed after the acquisition of the Sidewinder.

The Atoll was first deployed in 1961, using a passive infra-red homing device. It had a range of about 4 miles. For decades it became the Soviet block's main air-to-air missile.