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Missile Defense

Technology has always found its greatest consumer in a nation's war and defense efforts. Since the last attempts at a "Star Wars" defense system, has technology changed considerably enough to make the latest Missile Defense initiatives more successful? Can such an application of science be successful? Is a militarized space inevitable, necessary or impossible?

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rshow55 - 04:44pm Jun 30, 2003 EST (# 12767 of 12770)
Can we do a better job of finding truth? YES. Click "rshow55" for some things Lchic and I have done and worked for on this thread.

Gisterme then raises points where the answers depend a lot on the question "are you buying or selling" - or, alternatively - are you in favor of change or against it?

gisterme: " Naturally the hydrogen would have to be liquified to be transported efficiently...would that be by hydrogen supertankers? Sounds expensive.

It would be expensive. The question is whether it would be worth doing.

Current energy production is 27 billion barrels per year. Suppose that tranportation of that much energy equivalent in hydrogen took 200 ships - - which might be surface vessels or submersibles - each transporting the equivalent of 135 million barrels/year. If a capital charge of 1$/barrel moved was charged - and the ships were to be amortized in five years - each of the ships would have to be constructable for 675 million dollars. If a 2$/barrel capital charge was used - each of the ships would have to be constructable for 1.35 billion dollars.

A lot of money could reasonably be spent to engineer these ships well. And would have to be.

A lot of money could reasonably be spent to engineer storage and distribution facilities - and would also have to be.

"Worth doing" would depend on who owned the assets. For a company or nation with a big stake in current oil reserves and current energy industry arrangements - the gain might be partly offset by losses in their old petroleum businesses. For a company or nation with a smaller stake in the old arrangements - the same investment might be relatively more attractive.

rshow55 - 04:45pm Jun 30, 2003 EST (# 12768 of 12770)
Can we do a better job of finding truth? YES. Click "rshow55" for some things Lchic and I have done and worked for on this thread.

gisterme: " How much energy is required to cool a ton of hydrogen to liquid temperature and maintain it there? Is that taken into account in your array size calculation?

The thermodynamic limit cost of doing the refrigeration job is a tiny fraction of the energy value of the hydrogen. I haven't estimated that cost - though I've glanced at things involved. My guess is that for these stakes the industrially achieved cost of doing the refrigeration is likely to be under 1$/barrel after extensive engineering.

gisterme: " I wonder how large an explosion a hundred thousand tons of liquid hudrogen would make if a suicide bomber set itself off aboard a liquid hydrogen super tanker or at a large land storage facility? Who would want one of those in their harbor? Gotta wonder. Way safer nuclear powerplants have been pretty much rejected here in the state for fear of what might happen if things go wrong."

You ask an experimental question about fires from liquid hydrogen in the event of an explosion - and draw some conclusions that depend on engineering details. The idea that nuclear plants are "way safer" depends on numbers that neither you nor I have. It is true that if hydrogen and air mix, the mixture is explosive. But mixing rates are far from instantaneous - an explosion set by sabotage on a hydrogen transporting vessel or at a storage tank would produce a very nasty fire - but probably little blast - if engineers gave reasonable thought to mixing issues when designing these installations for safety. My guess is that vulnerability to sabotage for well designed hydrogen storage would be of the same order as vulnerabilities in oil and gas installations now - and that these risks could be controlled well for a charge of pennies per barrell energy equivalent - costs not very different from costs incurred today for the same energy input.

jorian319 - 04:49pm Jun 30, 2003 EST (# 12769 of 12770)

Hydrogen's lighter-than-air characteristic makes for a surprising "explosion" profile. In open air, it seeks to rapidly disperse upward and outward, and a goodly fireball can result. But since it is already rising, damage on the ground beneath it is minimal. This is unlike propane or other gasses that can "pool".

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