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More Bounce to the Ounce

mceglowski.substack.com

51–60 of 66 posts

Re: More Bounce to the Ounce

#52

Earlier quoted context omitted.

Anathem was so chock full of interesting ideas, too bad the last parts of it were so rushed (or at least felt that way to me).

That's most of Stephenson's books. 90% world building and then 10% story at the end.

This worked for Snow Crash - felt like I went on a theme park ride, got to the end of it, and hopped off still buzzing. Doesn't work so well for something less tongue in cheek.

Re: More Bounce to the Ounce

#53
post #25

Earlier quoted context omitted.

> This is among the reason I've thought nuclear waste should be disposed of in space. Send the stuff onto the moon Congrats; you have come up with a way to make nuclear waste disposal 100x more dangerous and 1000x more expensive!

You need to think more clearly about this. Reprocessing is very expensive; $1000/kg and up. Launch to space will likely become much cheaper than this as fully reusable launch vehicles become available. Even if the spent fuel must be armored against accident the cost of launching it to LEO, and then to the moon, is likely to become much cheaper than the cost of reprocessing it here on Earth. Space disposal has the pos…

That $1000/kg figure is reprocessing something like 10kg of material to get 1kg of enriched material.

Current costs to launch a kg to orbit are something like $2,000-$6,000.

If we're comparing it to you enriched amount, you'd have to launch 10kg, which means you'd have to hit $100/kg launch costs to break even. I'm not convinced that will ever be possible; that's on the order of a first class arline ticket for a 50kg person.

This also doesn't consider what you're getting for launching it into orbit. If the 100 year risk of a casket leaking is (say) x mrads into the environment, you're going to have to consider what the equivalent of vaporizing all of it into the atmosphere in the event of a failed launch is. the fallout (hah) from a failed launch of nuclear waste seems magnitudes more catastrophic than having the same stuff slowly leaking in the middle of a desert cave.

Re: More Bounce to the Ounce

#55
post #47
post #4

This is a really enjoyable read. Majiec is a great writer and speaker. A breath of fresh air compared much of modern blog/essay content.

I know you didn’t mean anything by it, but this is the funniest misspelling of the name “Maciej” that I’ve ever seen.

Oh! I actually thought I tried to be really careful to get that right and somehow still didn't see I'd transposed the j and c. Definitely no harm intended!

Re: More Bounce to the Ounce

#58
post #25

Earlier quoted context omitted.

You need to think more clearly about this. Reprocessing is very expensive; $1000/kg and up. Launch to space will likely become much cheaper than this as fully reusable launch vehicles become available. Even if the spent fuel must be armored against accident the cost of launching it to LEO, and then to the moon, is likely to become much cheaper than the cost of reprocessing it here on Earth. Space disposal has the pos…

That $1000/kg figure is reprocessing something like 10kg of material to get 1kg of enriched material. Current costs to launch a kg to orbit are something like $2,000-$6,000. If we're comparing it to you enriched amount, you'd have to launch 10kg, which means you'd have to hit $100/kg launch costs to break even. I'm not convinced that will ever be possible; that's on the order of a first class arline ticket for a 50kg…

> Current costs to launch a kg to orbit are something like $2,000-$6,000.

This is false. Launch on Falcon 9 is under $1K/kg.

Moreover, current launch costs are just a milestone toward future launch costs, which promise to me much lower. Ultimately launch will be a few times the cost of propellant (just like air travel), so $10/kg is a reasonable expectation.

> vaporizing in the atmosphere

How does this happen? Launch explosion? That doesn't vaporize an armored container. Entry from near-orbital speed? Also survivable passively.

The result of an accident will be tracking down the armored canister(s), cleaning up any local impact fragments, and prepared the stuff for another launch.

The armored canister doesn't have to be sent beyond LEO, so it could be reused, and doesn't impose a mass penalty on that beyond-LEO transport system.

Re: More Bounce to the Ounce

#60
post #19

Earlier quoted context omitted.

It is more similar to the Medusa method. Lots of ideas have been proposed. One problem is getting the nukes prepositioned (and they won't easily stay in one spot!) with chemical rockets is quite challenging (rather than carrying them and launching them along the way) and also they would actually need to be set in groups of 3 to provide balanced forces along an axis, or alternately along a parabolic helix to compensat…

Would they? Why not just shape your ship like a big torus so as you fly the bombs go right through your central axis?

I think there were big reflectors in the book, but it's been years since I read it. It's the sail that would need to be toroidal and huge. I guess the better point is that, if you can always maneuver the bombs at EXACTLY the right point relative to the sail and they are are perfectly uniformly spherical, and you can orient the sail perfectly before hand, then you can balance on top of the nuclear pin and don't need a stabilizing concentric force.
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