Science Forums 2

[maddog]

I'm beginning to feel that if your post's get long enough I will give up... Nada!

Originally Posted by Boerseun

Mass Drivers work beautifully in principle, and would work very fine if you wanted to move an asteroid. But it will only work well if you're presented with a homogeneous aggregate of uniform-sized particles. Because what you're doing, in essence, is to use the asteroid for rocket fuel. Bits of it will be launched in the opposite direction of where you're planning on traveling. So imagine your asteroid is composed of one solid piece of iron/nickel. First, you have to cuts bits off which would be launched to supply you with the necessary thrust. I don't know about mining in space, but mining on Earth (essentially cutting pieces of rock out of the Earth) requires immense supporting industries to supply such mundane items as cutting tools, which have a notoriously short lifespan, given what you intend to do with them.

Mining in space will be only a few order of magnitude more complicated. Machines will not need air. Some ability to stay attached to the asteroid in Low-g. People will need
air. Their presence will be to direct/control and/or repair machines. For rocks high in
metal content have the smelting processing right on the asteroid is viable.

Originally Posted by Boerseun

That is clearly not what I've said, if you've read my posts.

What is "clearly not what I've said" ? I've read all your post(s) quite thoroughly. So I'm
not sure what you are referring to.

Originally Posted by Boerseun

NASA does some wonderful work, and the best they've done so far included robotic exploration. Consider the Voyagers, the Pioneers, the sequence of Mars Rovers. Apollo could be included in this list as well, if the prime mover for that particular venture wasn't political, which, sorrily, it was. They wanted to prove to the Russians that they've got superior rocketry, and they did. It was very hard for them to justify sending humans to the moon for any other reason, and once they achieved it, it fizzled out.

All the robotic mission are great, produce great results and does lessen the need for
people in space en mass eventually.

Originally Posted by Boerseun

With "pie-in-the-sky" I mean grandiose ideas that has no justification apart from the fact that it's cool, and has very little practical application.

I interpret you mean by PITS to mean any people in space into the future ? So that
means that the Constellation Program is PITS ???

Originally Posted by Boerseun

I find it ironic that you're willing to flatly dismiss any future advances in recycling technology, stating that there's "no way" for recycling to be the answer, yet you're putting your faith in grand futuristic schemes dependent on fickle public support?

I am not willing to dismiss any innovation into the future. Especially any propulsion
system that could even circumvent gravity itself. Like Solar Power Generation, you will
likely never get 100 % efficiency. To get even close to 40%+ you will need some
draconian 100% enforcement (Mandatory) of Recycling (may happen) as well as some
atomic manipulation of 100% efficiency. Not forseeable today. Maybe in 15-20 years
may be a different thing all together. It is hard for me to see recycling ever rising above
50% efficiency though in the next 100 years. I may be wrong

Originally Posted by Boerseun

Let's say recycling technology achieves a 50-60% recycling rate in the next ten to twenty years. How much of your asteroid are you going to cut off to serve as reaction mass? 50%? 60%? While there's a 50-100km thick layer of perfectly mineable resources right under your feet?

Studies on mass drivers typically put in 8-15% from Asteroid belt to Earth orbit.

Originally Posted by Boerseun

I'm not too sure how big an impact chrome bumpers might have had on the chromium industry, but I will take your word for it. However, I suspect the poisonous nature of chromium hexaflouride had a bigger impact on Stateside production than the mere availability of the ore. As a case in point, in my town, Hernic Ferrochrome (Pty)Ltd is one of the biggest employers, and one of the biggest suppliers of chromium in the world. They have enough chrome to last for many, many years - with vast untapped seams lying in wait for higher commodity prices. Yet, they use hexaflouride in extracting chromium from the ore - which is the very same they would have to use for any chrome-bearing ore coming from space. Unless you want to ship tons of the stuff to Jupiter so that pure chrome can be shipped back to Earth - which seems highly unlikely in the face of high shipping costs. Either way, hexaflouride will be used, on Earth, to process the ore - regardless of where the ore came from.

I would probably agree environmental impact may have been greater than 0 in making
the decision, not all of it. Look for example at the CFC issues of the 80's and 90's. CFCs
were know to be health hazard, yet it was not until that the Ozone layer of the Earth was
in danger that steps were taken to remove the danger.

Originally Posted by Boerseun

Bingo. In my example about all airplanes flying to Antarctica, that would indeed make perfect sense in 1957. Because that would be purely for science. And we've achieved the perfect model for that - with the Mars Rovers. Robotized exploration is the ticket. It's cheap, expendable, scalable, and has vast application on the domestic economy of Earth.

So you agree. If a purpose is found for some advance, it will be used. So all we need
is cheap propulsion to the outer planets and we'll have it.

Originally Posted by Boerseun

But imagine if the purpose of all flight was just to land in Antarctica? There's no market, any resources to be found there can be found much cheaper anywhere else on the planet (there's vast storehouses of coal in Antarctica, yet there's not a single coal mine to be found - international treaties notwithstanding). I think the logic should be pretty clear.

Still would have worked in 1957...
There is expected of 350 years (maybe more counting what hasn't been discovered and
not counting Antarctica) of coal reserves around the world. So we would have to wait
till then to see if someone wants to and mine Antarctica (assuming that mining coal is
even desired in 350 years).

Originally Posted by Boerseun

You can't reason based on the assumption that this will happen within 100 years.

I don't believe I am reasoning that way. Forgive me, that is only IMHO that this will likely
be done w/i 100 years.

Originally Posted by Boerseun

Please read my previous posts where I explain the difficulty of getting viable trade up and running between planets. It will take centuries of committed effort just to get population levels up to the levels required for a self-sustaining economy worthwhile trading with. Remember, trade is a two-way street. A bar of gold costing $1,000 might have made one-way trade worthwhile in the 1600's, when a ship costing $50,000 could carry $1,000,000 worth of the stuff. But what the ship cost $100,000,000,000 and that same bar of gold still cost $1,000? Won't it be more economical to simply get it from Earth? There are plenty, and I mean plenty, of gold-bearing seams that have been shut down because of low prices. Once the prices make it worthwhile, goldmines will spring up around known deposits like fleas on a dog, for many, many years still to come.

This is think that the last 500 years will be like the next 500. Not likely. Anyone who has
ever watched trends. They appear to happen in a nonlinear fashion. What will populate
the solar system with 1 million+ people in the next 100 years will be some innovation in
propulsion that we can not now fathom.

Originally Posted by Boerseun

My mind is not closed to the idea, far from it. Yet, all I hear is dreamy speculation of "what if" and the inevitability of it. I am yet to hear a single "proper convincing argument" in support of colonising other planets. I would really love to, however. So bring it on.

You would have to concede that you don't know what the next innovation in propulsion in
space is gonna' be. I am not willing to say I have the crystal ball.

Originally Posted by Boerseun

With that, I agree fully. I see the technological progress towards something like interplanetary or even interstellar human spaceflight as being the offshoots of research done for quite different purposes. For instance, a concept like "hibernation" to make centuries (or even millenia) long spaceflight possible, might very well be the result of medical research in how to make hibernation possible for humans who have to wait for organs to become available, for instance. Research can then be very well justified due to the immediate application it will have on Earth, and it will pay for itself.

Though I would like to see Interstellar flight in my lifetime, I don't envision it. Again,
maybe I will. Who knows.

Originally Posted by Boerseun

Where exploration is the cake and the spoils the frosting, I see it very much in the light of robotic exploration being the cake (we get to explore the solar system for a pittance, relatively speaking), and human interplanetary flight might be the frosting when rocketry and propulsion have developed to the point (in support of expediting robotic exploration) that it might become appliccable to establishing a human presence beyond low Earth orbit.

Cake or Frosting aside, I agree with you we will eventually get both.

Originally Posted by Boerseun

With that, I agree fully, too. And that should serve as an indication of where our priorities should lie for the next few centuries. (my bold)

I would accept some form of World Peace/World Government -- Solidarity before contemplating
any form of Interstellar travel. We are definitely not there yet. Not even close.

Originally Posted by Boerseun

There might be many reasons and justifications for colonizing the solar system, but overpopulation on Earth is not one of them. Some 300,000 more babies are born than people die, each and every day. Yes, Earth's population grows by a million by the morning of every fourth day. So we'll have to launch 300,000 people every day, and that will only maintain the population at the same level. Overpopulation on Earth is a local problem (planetary speaking), which will have to be solved locally.

Population is just a time bomb waiting to go off. I have seen a lot of studies (don't even
know if legitimate value even exists) of a maximum viable population for the Earth.
We are quickly approaching 7 billion. At the current rate of growth, we will acheive
14 billion within 25 years. Now either we figure out how slow down pop-growth, have
a massive war and kill half the population or more, horrible infectious disease to kill off
98% maybe. Current rate of increasing growth is not sustainable. Period.

Originally Posted by Boerseun

Granted. Fast straight-to-Earth orbits will take enormous amounts of fuel, slow orbits will take much less. But with easy, slow orbits, you're talking years of your resource payload slowly spiraling towards the sun, to be intercepted by Earth. Not to sound too much like a grouch, but commodity supply and demand doesn't quite support that scenario. People want stuff now. A company would rather invest in a mining operation somewhere in Africa that could show a return in a year or two than invest billions in the project you're proposing, which will only deliver a few decades from now.

This is the status quo given no new innovation in propulsion.

Originally Posted by Boerseun

As far as I can recall, you said that atmospheric braking is to be employed. And the reason that decelerating space craft don't hit people's houses with any regularity, is that their reentry is usually controlled by thousands of humans working in concert around the globe to plan, track, command, steer and manage the whole operation. And that is just for a single item coming down from orbit like, say, the Space Shuttle. But what you're proposing is more like Columbia's fatal re-entry, continuously, all around the globe, for chunks of rock big enough so as to not completely ablate during entry. And then there is to be a complete mining industry devoted to picking up the pieces as they scatter and fall all over the world. Two-thirds of your ore will be practically inacessable, seeing as they would fall into the ocean. They would merely serve to pollute the atmosphere, and be gone. I simply cannot see any sense behind it.

I was thinking of nothing of the kind. Near Earth Orbit only.

Originally Posted by Boerseun

The first caveman to pick up a piece of flint and chipped it into a knife, was the first miner, or the first to "rape the planet's surface". Mining is nothing new, nor strange. The pollution and destruction that you allude to regarding mining, is an artefact of technology. As technology improves, so too does the pollution and destruction go down. Compare, for instance, an 18th century coal mine in England to a modern day colliery.
Besides, what, pray tell, might be the difference between "raping" the surface of the Earth, and "raping" an asteroid? If I understand your proposal correctly, there might be somebody living on that asteroid, after all?

Maybe little. Though Asteroids are already hazardous environment. So no beautification
project will necessary for reclamation.

Originally Posted by Boerseun

They were cheap, and paid for by the Wrights themselves. The analogy is not applicable, because what you're proposing in colonising the solar system is dependent on public money. Vast streams of public money, continuously, for centuries. And all of that when we suddenly have to bail out gigantic corporations because something fundamental is broken in our understanding of economics. And that economy will be the underpinning of any succesfull interplanetary venture. If the technology reaches the level where crazy billionaires like Richard Branson can build a colony on Europa using off-the-shelf items, when it becomes private and out of the public domain, when private individuals can fund it (like the Dutch East India Company in the 1600's) then I'd be all for it. And then invoking the Wrights as an argument in favour, might hold water. But using public money, the Wrights simply don't feature.

I can see that within 50-60 years. Of course they will then be Multi-Trillionaires.

Originally Posted by Boerseun

Rocketry was brougth to perfection by Werner von Braun, who built the V2 for Hitler to bomb London with. Von Braun later helped NASA land on the moon, using in a big way his V2 experience. I think Armstrong & co. should have at least planted a Britsh flag alongside the US flag, for the poor Brits who died serving as a testing range for moon rocket technology. But that's besides the point.

Feeling slighted are we ???

Originally Posted by Boerseun

And I think I've debunked them all. But for brevity, I will sum up:

No, you debunked nothing to nobody (except for maybe what lies in your head)...

Originally Posted by Boerseun

1) Resources:
Nada. Every conceivable resource you can find on any asteroid, can be found on Earth, much cheaper, much safer, without the danger of destroying domestic markets as a 1,000 ton lump of pure gold falling out of the sky might do.

Once up front Nonrecurring Cost (NRC) are paid, Asteriod mining will be cheaper.

Originally Posted by Boerseun

2) Colonies:
Colonies would imply that there is something for people to do out there. They can either gather resources, which even if economically viable, can be better, safer, and cheaper, be done by machines.

Need someone to manage/fix the machines. Some people will be needed. Thus colonies.

Originally Posted by Boerseun

Or, they can gather knowledge, which:
3) Knowledge:
Space-based telescopes, Mars Rovers, the Huygens probe, Voyagers 1&2, the Pioneers, the Venera landers, all of these have returned reams and reams of perfectly usable data without a single human on board. If we land a buggy on Mars and we later whish that the thing had a certain capability we haven't though of, that capability can be included in the next rover. The technology improves. If there's a big budget cut, we can safely shut down the system without any loss of life. Science is pure. Science is the interpretation of data; the gathering can be done by anybody or anything.

This does not lessen any science data gathered by robotic means. All well and good.

Originally Posted by Boerseun

Once again, I'm sorry for appearing overly negative. But I haven't heard a single compelling argument in favour of human space flight and/or colonisation beyond low earth orbit. Don't get me wrong, however. I think it will be awesomely and amazingly cool. I think to be a citizen of some far-off planet will be rockingly awesome. But there must be a very valid and solid reason for blowing tons of public money, when we're battling with such issues as falling educational standards etc., for which there might be much better application of said tax monies than to chase resources that is uneconomical, unrealistic, and found right under your feet on Earth, in any case.

Very much so. It is because of this negativity you exude is why you can not even hear
any statement to the contrary as being viable.

maddog