Ivy Mike – The First Thermonuclear Bomb

At 19:15 Zulu time, on October 31, 1952, (That’s 3:15 or so in the afternoon, Eastern Daylight Time) the United States detonated the “Mike shot” of Operation Ivy. This was the first thermonuclear explosion. The Mike device wasn’t designed to be a weapon, as the cryogenic hydrogen isotopes it relied on made it too big. At 80 short tons, (70 metric tons) the Soviet engineers of the day dubbed it the “thermonuclear installation.”

The 10.4 megaton explosion pretty much obliterated Enewetak Atoll. For comparison, consider that it is 450 times greater than the bomb dropped on Nagasaki, Japan. In fact, the trigger for the thermonuclear explosion was a Nagasaki-type bomb. (The video explains how it all works.)

It is estimated that after decades of environmental cleanup, the atoll should be fit for human habitation in another 10 or 20 years. (Half life is your friend, when you are fighting radiation.)

The Castle Bravo detonation in 1954 eliminated the need for cryogenics. And proved that this technology could be a weapon. It also shows the arrogance of scientists. They were sure part of the hydrogen in the mix would be “inert,” so they calculated the expected yield at 6 megatons. That excess hydrogen, wasn’t inert, and the yield was more like 15 megatons. But that is a story for another time.

The Ivy Mike shot (that’s what they were called during the Cold War) ushered in the age of thermonuclear weapons. One atomic bomb destroyed the center of Hiroshima. A Thermonuclear device of this magnitude would have wiped it from the map. But as technology marched on, designers built smaller fission bombs and used them to trigger smaller fusion bombs. The W87 warhead/Mk 21 re-entry vehicle (from the Peacekeeper missile) was 300 kilotons. Small by comparison, but a Peacekeeper missile (now decommissioned) could have 10 independently-targetable warheads. (Anyone remember the video game “Missile Command?”)

It seems that people are forgetting about the Cold War. (Not that folks dwelt on the possibility of destruction when it was looming over us like the Sword of Damocles.) Aside from a few good James Bond movies, did we get anything out of it? Did we learn anything from it? Probably not. And now we have rogue nations with nuclear arms, and the Russians and Chinese making faces at the West. Seems like Cold War 2.0 to me.

You can see the changes the bomb caused in the geography of the atoll at Nuclear Weapons Archive. A side by side comparison of the island before and after the shot can be found at this link.

It isn’t surprising that A Capella Science has a take on nuclear weapons.