The Tsar Bomba was the most powerful nuclear weapon ever created. On 30 October 1961 the Soviet Union experimentally detonated the bomb after dropping it from a plane above Nova Zembla. A second plane was nearby to gather data on the explosion.


According to this article from the bbc:

In order to give the two planes a chance to survive – and this was calculated as no more than a 50% chance – Tsar Bomba was deployed by a giant parachute weighing nearly a tonne.

A similar thing is mentioned on the English article on the Tsar Bomba from wikipedia:

Both aircraft were painted with the special reflective paint to minimize heat damage. Despite this effort, Durnovtsev and his crew were given only a 50% chance of surviving the test.

My Skepticism

This 50% chance seems a bit suspicious to me, because it is a conveniently round number, it is quite a low survival rate for an experiment (even for a high profile military experiment during the cold war), and it is not clear to me why it should be so dangerous.

Wikipedia lists the CTBTO website as the source for this claim. While the CTBTO is a respectable organisation, the webpage is not a primary source and does not fully convince me.

There is no mention of the 50% chance on the Russian version of the wikipedia page (using google translate).

This document claims that:

even if the parachute system had failed during the test, the bomber's crew would not have been endangered, as the bomb contained a special mechanism which triggered its detonation only after the plane had reached a safe distance

Which directly contradicts the 50% claim.


Does a primary source exist for the 50% number? Or is there any evidence suggesting that the Soviets either did or did not think beforehand that there was a significant chance of the crew not surviving the experiment?

  • 7
    I will note that the Tsar Bomba is reported to have had a yield on the order of 50 megatons, while the Hiroshima bomb was only around 15 kilotons. Which is to say that the Tsar Bomba was around 3000 times more powerful. May 22, 2020 at 20:56
  • 3
    Re as the bomb contained a special mechanism which triggered its detonation only after the plane had reached a safe distance -- I have a harder time accepting that claim compared to the USSR sending planes where the only protection was flying away before the bomb goes off. The former would require a high degree of sophistication, one that Russia does not use to this day on its rocket launches. Russian rockets do not have a flight termination system. If the launch fails and the rocket lands on some remote village, so be it. May 23, 2020 at 17:27
  • 1
    Can't this be answered by some speed/ distance calculations? How long does it take for the bomb to fall to the ground, how far do the planes fly in this time, how big is the lethal range of the bomb? First 2 should be easy and hopefully give a number so that a rough estimate for the 3 will suffice.
    – quarague
    May 24, 2020 at 14:03
  • 1
    "Conveniently" round numbers also happen when you have very imprecise numbers. May 25, 2020 at 0:26
  • 4
    @DavidHammen Nonsense. This "high degree of sphistication" trigger could be as simple as a switch activated from radio by the plane's pilot once he knows he's far away enough. This was a prototype after all, they didn't need any hard-tested all-weather all-time failsafe device.
    – Rekesoft
    May 28, 2020 at 9:38


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