Thursday, May 13, 2010

Stupid Nuke Tricks, Continued

This is a continuation of a list I made a few months ago. I got to thinking about it the other day, and realized that I'd left some interesting projects out. And, in the interests of full disclosure, there is ... well, a bit of a confession to make.

Operation Plowshare: Alfred Nobel, the inventor of dynamite, never intended his invention to be used for warfare. In a weird reversal, the Atomic Energy Commission got the idea of trying to find peaceful uses for atomic explosions. Of what possible use could atomic explosions be in the non-city-destroying sector of the economy, you ask? Well, they use dynamite in mining, don't they? You can move a whole lot of earth with a bucket o' sunshine. The first few tests were mainly along the lines of proving how big a hole you could dig. The Sedan shot in 1962 dug a hole 300 feet deep and 1,200 feet wide. This was the second test of the series. The moratorium on above-ground explosions put paid to some of the more ambitious plans, such as using nukes to dig out a harbor, but even up to the end of the program in 1974 there were plans to use atomic explosions to stimulate natural gas recovery. The gas companies didn't like the plan much. They had two main objections. First, even over 25 years of gas recovery they might only recoup less than half of the cost; and second, customers would probably take umbrage at the delivery of slightly radioactive product. After 1974, the AEC gave it up as a bad idea.

Program #7: Given that the Soviets never really had to sell their government programs to their legislators or to the public, they kind of mailed it in when it came to project names. This program was also referred to as "Nuclear Explosions for the National Economy", but the program could just as easily have been called "Anything the Americans Can Do, We Can Do Bigger." And yes, it was bigger ... and even more useless, if such a thing were even possible. They tried to create an artificial lake. And they did ... but the artificial lake was radioactive, having been dug out by a nuclear explosion. They tried to open up a new diamond mine. And they did ... which produced radioactive diamonds. They conducted 115 detonations over the 24 years between 1965 and 1989, when Mikhail Gorbachev asked, "Why in the world are we still doing this?" No one had a really good answer to this question. For that matter, no one could remember why anyone ever thought it was a good idea to begin with. So, they just kind of gave up.

Spot the Asteroid: Earth-crossing asteroids are a serious threat. We're doing a better job these days of finding them before closest approach, but back in the day, we only found out about them when one of three things happened: (1) it had already zipped by and was going away, (2) it clipped Earth's atmosphere and someone saw the streak as it passed, or (3) WHAM! No one wanted to open Door #3. So, the question was, how do we find them? Well, Sir Arthur Clarke had an idea once. He claimed that an atomic explosion in outer space would allow us to detect every Earth-crossing asteroid in the inner Solar System by using the bomb like the biggest flash bulb in the known Universe. On the one hand, I have a lot of respect for Sir Arthur's capability. But on the other, I'm not really sure how this would have worked in practice. No one else was, either, which is probably why it was never tried.

Deflect the Asteroid: Spotting the asteroid is one thing, doing something about it is another thing entirely. For most of history, men threw their hands up in the air and appealed to the good Lord's mercy, because really, what else can you do? Starting in 1967, people started figuring out what their choices were. There was a brief scare earlier that year about the impending close approach of the asteroid Icarus. MIT Professor Paul Sandorff took that as inspiration, and directed his senior-level system engineering class that spring to find a way to push Icarus out of the way should it come too close. The result of that class project was published as Project Icarus, the only senior thesis ever to become a major motion picture. Basically, they would hijack the Apollo program to use their Saturn V boosters to deliver a series of nuclear warheads to explode near Icarus, pushing its trajectory away from Earth. That was the last word in asteroid defense for quite some time, until Johndale C. Solem of the Los Alamos National Laboratory started crunching the numbers to figure out exactly what a nuclear explosion would do to an asteroid. His report found its way into some conference proceedings, and that was that.

This is more or less where I came in.

Shoemaker-Levy 9 scared the Hell out of me. I really started worrying about what we could do in the event that we were treated to a duck's-eye view of a shotgun blast. I was a doctoral candidate in Aerospace Engineering at the time, and my research advisor gave me considerable latitude when it came to side projects, so I decided that I'd find out. A brief search led me to Dr. Solem's paper, and I was off to the races. So, here's the situation: we spot an asteroid in-bound with only weeks to a couple of months of lead time. What sort of last-ditch defense could we pull off? Well, just about the only thing we can do is pelt it with ICBMs and hope it goes away. Putting together some information on the ranges of our ICBM force, and some knowledge about ballistic trajectories, and Dr. Solem's formulas, I was able to calculate that you wouldn't be able to shift the trajectory enough to make it worthwhile. You can move the impact point by a crater's diameter, and that's about it. But, you can pulverize it. If you can bust it up into pieces 35 meters or smaller, the fragments will burn up in the atmosphere on the way in... And a time-on-target salvo of four Peacekeeper ICBMs can blast a half-mile-wide asteroid into pea gravel. I presented the paper at the 1997 AAS/AIAA Space Flight Mechanics conference. The reception was, as they say, mixed. A small group of Air Force officers in the front row was very interested ... and if there's a top-secret point-defense office in the Pentagon these days, odds are that's probably my fault. Everyone else basically said I was mad. Mad! And I can't really argue with them. I never thought it was a particularly good idea, just possibly the least bad one. It's a plan born of desperation, not of foresight. But if you spot a mountain falling on you with only eight weeks' notice, your options start at horrible and gurgle noisily down the toilet from there.

Still. It's gratifying to know that I earned my "Mad Scientist" title fair and square.

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