30 October 1961: Major Andre E. Durnovtsev, aircraft commander of a specially modified Tupolev Tu-95V “Bear A” bomber, dropped a RDS-220 three-stage radiation implosion bomb, weighing 27,000 kilograms, from an altitude of 10,500 meters (34,449 feet) over the Mityushikha Bay test range on Novaya Zemlya. The bomb, variously known as “Big Ivan” or “Tsar Bomba” was retarded by parachute to allow the Bear to escape the blast effects. At 4,000 meters (13,123 feet) above the surface, the bomb detonated.
Major Durnovtsev’s Tu-95 was approximately 45 kilometers (28 miles) away at the time of the explosion. At the same time, a secret United States Air Force KC-135A instrumentation aircraft, Speedlight, had flown closer to gather data about the air burst. It was close enough that its special antiradiation paint was scorched. After the data was analyzed by the Foreign Weapons Evaluation Panel (the “Bethe Panel”) the RDS-220 yield was estimated at 57 megatons. This was the largest nuclear weapon detonation in history. It was also the “cleanest”, with 97% of the energy yield produced by fusion. Relative to its size, very little fallout was produced.
Tsar Bomba fireball over Novaya Zemlya, 30 October 1961. The fireball has reached a diameter of 5 miles (8 kilometers).
All buildings in the town of Severny, 55 kilometers (34.2 miles) from Ground Zero, were destroyed. Wooden buildings as far as 200 kilometers (124 miles) were destroyed or heavily damaged. A visible shock wave in the air was seen at a distance of 700 kilometers (435 miles). The shock wave from the explosion traveled around the world three times.
The RDS-220 was 8 meters (26.25 feet) long, with a diameter of 2.1 meters (6.89 feet). It weighed 27,000 kilograms (59,525 pounds).