60 years of 'Tsar Bomba', history's most powerful nuke

This post was originally published on October 31, 2018. I republished it once in 2020 after Rosatom, the Russian nuclear energy corporation, released 40 minutes of previously classified footage of RDS-220's explosion on August 28, 2020 (embedded below). Watch this minute-long excerpt by Reuters of the explosion. I'm republishing it again, today, following the publication of a new report that examines the US's reaction to the bomb.

Fifty-seven years ago, on October 30, 1961, the Soviets detonated the most powerful nuclear weapon in the history of nukes. The device was called the RDS-220 by the Soviet Union and nicknamed Tsar Bomba – 'King of Bombs' – by the US. It had a blast yield of 50 megatonnes (MT) of TNT, making it 1,500-times more powerful than the Hiroshima and Nagasaki bombs combined.

The detonation was conducted off the island of Novaya Zemlya, four km above ground. The Soviets had built the bomb to one-up the US and followed Nikita Khrushchev's challenge on the floor of the UN General Assembly a year earlier, promising to teach the US a lesson. The B41 nuke used by the US in the early 1960s had a yield of half as much.

But despite its intimidating features and the political context, the RDS-220 yielded one of the cleanest nuclear explosions ever – and was never tested again. The Soviets had originally intended for the RDS-220 to have a yield equivalent to 100 MT of TNT, but decided against it for two reasons.

First: it was a three-stage nuke, weighed 27 tonnes and was only a little smaller than a school bus – too big to be delivered using an intercontinental ballistic missile. Maj. Andrei Durnovtsev, a decorated soldier in the Soviet Air Force, modified a Tu-95V bomber to carry the bomb and also flew it on the day of the test.

The bomb had been fit with a parachute (whose manufacture disrupted the domestic nylon hosiery industry) so that between releasing the bomb and its detonation, the Tu-95V would have enough time to fly 45 km away from the test site. But even then, the bomb's 100 MT yield would have meant Durnovtsev and his crew would have nearly certainly been killed.