It was formed as the Northern Air Defence Corps in 1957 and was assigned the designation "21st" three years later.

[1] The corps included an anti-aircraft missile regiment with a headquarters in Murmansk (the only military unit in this city), the 5th Radio Technical Brigade with headquarters in Severomorsk, and fighter air regiments based at the Klip-yavr, Afrikanda and Monchegorsk airfields.

[1] In April 1978, corps commander Vladimir Tsarkov ordered an Su-15 pilot to shoot down Korean Air Lines Flight 902 after the plane failed to respond to repeated orders to land, and approached the Soviet border with Finland.

The Su-15 opened fire, forcing the plane to descend, and killing two of the 109 passengers and crew members aboard Flight 902.

The plane made an emergency landing on the frozen Korpijärvi Lake [ru] near the Finnish border.