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Comment Re:Not so fast (Score 1) 226

> Their tech works and they built it.

LOL, I don't think so.

This is the tech that keeps lithobraking and exploding when it's supposed to be landing on a barge. They've been trying to pin a landing since the first flight of Falcon 1. They're currently on Falcon 9.

Maybe they'll succeed one day, but the very high performance rockets they build are obviously *very* fragile.

And that's the problem with their approach, pure rocket reusables have to be super lightly built, and then it's very difficult to make it back down to the ground.

Comment Re:the interesting part (Score 1) 63

> Even the most devoutly religious would not actively wager money to put their faith to the test.

People do this kind of stuff all the time.

Many people wager their lives on their belief in a God, and... usually die.

George R. Price famously gave all his possessions to the poor; got evicted, fell into depression and then killed himself.

Comment Re:Not so fast (Score 1) 226

Actually, I once did a computer model of SpaceX-style reusability, and that's actually what my model showed me, that it would be extremely hard for SpaceX to get it to work.

But my modelling shows that Skylon ought to make orbit, and return and land safety with comparative ease, Their design is very insensitive to weight growth; and they actually have spare mass built into their design in case things are harder than they look.

But yeah, I do agree with you pretty much on the economics, that's the worst part of their design. But compared to the economics of the Space Shuttle... ;)

Comment Re:Not so fast (Score 1) 226

> Sure, at this stage of any project it's easy to be "looking at" very low costs. They haven't done anything yet. The nature of these kinds of projects is there are a whole bunch of costs, technical an regulatory, that aren't apparent until you actually start building something.

I don't agree. For example, the Space Shuttle estimates were about on the money. As in they said, the cost estimate is $X, but we'll need $1.2 X, to allow for obvious contingencies. President Nixon went: we don't budget contingencies, we'll give you X and then fund the overrun later. NASA: OK boss.

So actually, it cost what they said, but it looked to the rest of the world like an overrun.

And the Space Shuttle main engine was about as complicated as SABRE looks like it will be, maybe more so, it was an unreasonably complicated design.

And Reaction Engines actually have a careful design, with computer modelling of everything. That bodes well for a relatively straightforward detailed design and build. The X-33 had none of that, and when they got around to it, they found the horizontal stabilisation was total shit.

And the engine is particularly clever in that it works almost the same at all speeds; the precooler means that it doesn't care whether it's at ground level or Mach 5, the air behind the cooler is at the same temperature. That means, like a rocket engine, they can do almost complete testing when stationary. And the precooler also, they've already tested the precooler; it works fine. And the precooler was the most challenging bit of the whole system; it's something like half a gigawatt per tonne of cooling.

The take-home message is not that it's not a clever design, it's that most of the clever bits are easy to ground test. About the only bit they can't totally test on the ground is the aerodynamics of the aeroshell- but that was basically the same problem that the Space Shuttle faced and dealt with.

Comment Re:Not so fast (Score 3, Informative) 226

Actually, the Skylon group predicted that the X--33 wouldn't work. They said that the X-33 was too tail heavy. And fixing it would mess up the payload fraction. And they were right.

It's difficult to get your head around just how far ahead these guys have been for about 20 years.

The ultimate reason is that they built a computer model of launch vehicles, which they fiddled with until they got a plausible vehicle. Then they did a back-back comparison with a pure-rocket vehicle, and found that there was no big advantage. Then they fiddled around more, and out popped Skylon, and then they found it *seriously* beats pure-rocket vehicles; it's not even close.

Skylon is looking at costs starting around $500/kg and then going lower. SpaceX won't be able to get down to that.

Comment Re:Green Movement opposition to Nuclear (Score 2) 173

Brownouts aren't likely; but grids of all and any design do sometimes brown or black out.

Up to about 20-30% wind/solar, brownouts are largely a non issue- the backup power already built into the network is enough to fill in the extra power.

Going forward, as the existing generating plant wears out, much of the coal plant on many networks is being converted to gas, which has a lower carbon footprint, and is somewhat more flexible, the plant is otherwise mostly paid-off, and hence cheap. It's still wearing out, but it will run less because the wind and solar will fill in, but the grid will have to run on even gas less and less because of climate change.

Past about 2017, brownouts are looking like they will gradually become non issues, because grid-level storage is looking like it will become ridiculously cheap, and because more and more solar and wind will be coming on line; they are both growing exponentially, and are likely to continue for the foreseeable future.

I see no major role for nuclear power, and the amount of power generated from nuclear will reduce over time. This is a combination of its inherent relatively high cost, the fact that people don't trust it, its reliance on (mostly fresh) water, and the long lead times that new reactors require.

Comment Re:Green Movement opposition to Nuclear (Score 2) 173

Wind and solar are far from ineffective. They're growing exponentially, year on year, and costs are coming down rapidly, they're already far below nuclear power's costs in many places.

Nuclear... isn't effective. It's expensive, inflexible, and *dangerous* technology.

Sure, few people usually die from nuclear accidents like meltdowns... but only because people leave, in large numbers. Saying it's not dangerous is like saying fire isn't dangerous if you leave immediately, and don't let it burn you, and then you won't be hurt. Like, duh. And even then economic disruption is *immense*.

The planning procedures for nuclear are long and drawn out- but for good reasons. Fukushima is what happens when they're not long enough. If they had done the leg work correctly, there wouldn't have been any meltdown. Meltdowns happen when people fuck up. Humans fucking up is not going stop any time soon. And Fukushima wasn't the worst case accident; it didn't dump fallout over Tokyo, that would have been enormously worse. Try to imagine.

Organic flow batteries are coming out in 2017. They're looking to be seriously cheap storage (less than a penny average cost per kilowatt hour). If that works as well as it looks it will, nuclear power should be virtually dead, more agile, widely distributed, economically safer, renewables will eat its lunch.

Comment Re:But we're already relying on artificial scarcit (Score 1) 563

Yes, so in the Culture, it wasn't about having money, it was just about asking the Minds to do what you want.

Want a diamond, big as your fist? The Mind will do it for you if it has the resources; or schedule to make it for you later when it has collected them.

Want to make a big cable car system, no problem; it will make it for you. etc.

But obviously some things you might ask for the Mind it couldn't do for ethical or resource issues; and then the Mind would presumably not do it.

Comment Re:Econ 101 (Score 1) 554

Charging money doesn't always work. If you've paid money for something it becomes 'yours', and you 'deserve' it. You 'own' the charging point.

For example in kindergarten they started fining parents for picking up their children late. Although it was intended as a penalty, the parents started leaving their children more; after all, why not, they'd paid for it.

To do two things at once is to do neither. -- Publilius Syrus