Tuesday, March 03, 2009

Starfish Prime: A 1962 Nuclear Experiment with new relevance for contemporary technology

"Starfish Prime" was an American nuclear test explosion high up in space:

The nuclear explosion in space, as seen from Honolulu

A missile carrying a 1.44 megaton nuclear bomb was launched into space and exploded above the earth's atmosphere, to see what the effects would be. From Wikipedia:

Starfish Prime
Starfish Prime was a high-altitude nuclear test conducted by the United States of America on July 9, 1962, a joint effort of the Defense Atomic Support Agency (DASA) and the Atomic Energy Commission (AEC). Launched via a Thor rocket and carrying a W49 thermonuclear warhead (manufactured by Los Alamos Scientific Laboratory) and a Mk. 4 reentry vehicle, the explosion took place 400 kilometers (250 miles) above Johnston Island in the Pacific Ocean. It was one of five tests conducted by the USA in outer space as defined by the FAI. It produced a yield of 1.4 megatons of TNT.


Because there is almost no air at an altitude of 400 kilometers, no fireball formation occurred, although there were many other notable effects. About 1500 kilometers (930 statute miles) away in Hawaii, the electromagnetic pulse (EMP) created by the explosion was felt as three hundred street lights failed, television sets and radios malfunctioned, burglar alarms went off and power lines fused. On Kauai, the EMP shut down telephone calls to the other islands by burning out the equipment used in a microwave link. Also, the sky in the Pacific region was illuminated by an artificial aurora for more than seven minutes. In part, these effects were predicted by Nicholas Christofilos, a scientist who had earlier worked on the Operation Argus high-altitude nuclear shots.

According to U.S. atomic veteran Cecil R. Coale, some hotels in Hawaii offered "rainbow bomb" parties on their roofs for Starfish Prime, contradicting some reports that the artificial aurora was unexpected. According to the U.S. Department of Energy's (DOE) Office of Scientific and Technical Information (OSTI), the aurora was also visible and recorded on film from the Samoan Islands, about 3200 kilometers (2000 statute miles) from Johnston Island. [...]

The damage caused by the tests EMP was much more widespread than anticipated. I've read reports that claim electrical damage was also experienced in New Zealand as well. And a radiation belt was left in space that destroyed and disabled a number of low-orbit satellites:

[...] While some of the energetic beta particles followed the earth's magnetic field and illuminated the sky, other high-energy electrons became trapped and formed radiation belts around the earth. There was much uncertainty and debate about the composition, magnitude and potential adverse effects from this trapped radiation after the detonation. The weaponeers became quite worried when three satellites in low earth orbit were disabled. These man-made radiation belts eventually crippled one-third of all satellites in low orbit. Seven satellites were destroyed as radiation knocked out their solar arrays or electronics, including the first commercial relay communication satellite ever, Telstar.[3] Detectors on Telstar, TRAAC, Injun, and Ariel 1 were used to measure distribution of the radiation produced by the tests.[4]

In 1963, Brown et al. reported in the Journal of Geophysical Research that Starfish Prime had created a belt of MeV electrons, and Bill Hess reported in 1968 that some Starfish electrons remained for five years. Others reported that radioactive particles from Starfish Prime descended to earth seasonally and accumulated in terrestrial organisms such as fungi and lichens. [...]

There is more about the Starfish Prime test and the electrical damage it caused, from the Wikipedia page about Electromagnetic Pulses:

Electromagnetic pulse
[...] The EMP damage of the Starfish Prime test was quickly repaired because of the ruggedness (compared to today) of the electrical and electronic infrastructure of Hawaii in 1962. Realization of the potential impacts of EMP became more apparent to some scientists and engineers during the 1970s as more sensitive solid-state electronics began to come into widespread use.

The larger scientific community became aware of the significance of the EMP problem after a series of three articles were published about nuclear electromagnetic pulse in 1981 by William J. Broad in the weekly publication Science.[1][3][4]

The relatively small magnitude of the Starfish Prime EMP in Hawaii (about 5,600 volts/meter) and the relatively small amount of damage done (for example, only 1 to 3 percent of streetlights extinguished)[5] led some scientists to believe, in the early days of EMP research, that the problem might not be as significant as was later realized. Newer calculations[6] showed that if the Starfish Prime warhead had been detonated over the northern continental United States, the magnitude of the EMP would have been much larger (22,000 to 30,000 volts/meter) because of the greater strength of the earth's magnetic field over the United States, as well as the different orientation of the earth's magnetic field at high latitudes. These new calculations, combined with the accelerating reliance on EMP-sensitive microelectronics, heightened awareness that the EMP threat could be a very significant problem.

In 1962, the Soviet Union also performed a series of three EMP-producing nuclear tests in space over Kazakhstan called "The K Project".[7] Although these weapons were much smaller (300 kilotons) than the Starfish Prime test, since those tests were done over a populated large land mass (and also at a location where the earth's magnetic field was greater), the damage caused by the resulting EMP was reportedly much greater than in the Starfish Prime nuclear test. The geomagnetic storm-like E3 pulse even induced an electrical current surge in a long underground power line that caused a fire in the power plant in the city of Karagandy. After the collapse of the Soviet Union, the level of this damage was communicated informally to scientists in the United States.[8] Formal documentation of some of the EMP damage in Kazakhstan exists[9] but is still sparse in the open scientific literature. [...]

We've used to thinking about nuclear attack, in terms of bombs being dropped on us. But the EMP effects caused from a bomb or bombs exploded high above us would destroy our electrical infrastructure, disabling and disarming us without rendering the land uninhabitable. The bomb doesn't need to be as powerful as the warheads of the Soviet era, and it doesn't even have to hit a target, but instead explodes many miles away above the target.

It's not hard to see how all these factors have become increasing relevant in discussions about missile defense systems. Currently only military superpowers have the capability to launch such weapons at high altitudes, but rouge nations like North Korea and Iran are working on improving their nuclear and missile weapons systems, and could do a great deal of damage, even if they were deployed on a smaller scale than Starfish Prime.

I will do another post later about the contemporary threat of EMP weapons.


UPDATE, here is my related posted about EMPs:

EMP Vulnerability: Could Advanced Electronics be the Achilles' Heel of our Western Civilization?

Scary stuff, but informative. It has some good YouTube videos at the end.

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