3 more Nasa Shuttle missions left what next?

[SilverHood]

Thats not going to be a problem for a few hundred thousand years tho so no great rush

Well, assuming we're still here in 100 years and that some loons with nukes haven't wasted us all.

 

[Helme]

I'd like to know where you are keeping this hundreds of thousand years supply of fossil fuel hidden

 

[Jeros]

I'd like to know where you are keeping this hundreds of thousand years supply of fossil fuel hidden

As would those in Geosciences

Current reserves are overstated, its good PR after all.

 

[rynnor]

I'd like to know where you are keeping this hundreds of thousand years supply of fossil fuel hidden

Who said Fossil Fuels? Theres a lot of Nuclear fuel sufficient for hundreds of thousands of years of energy. Theres plenty of seawater we can use for Hydrogen and oxygen if we still use such propellants and of course theres always the sun.

As Silverhood says its unlikely to be a big problem because we are more likely to have ahnillated ourselves before the fuel runs out.

 

[Athan]

Iron from asteroids? Screw that, a real driver for mining the Moon and/or asteroids may be a looming shortage of 'rare earth' metals.

Other than something like this I struggle to think of any justifiable reason for manned space flight beyond LEO. There's plenty of science to be done out in space, but the vast majority can be done via robotic craft. I'm not even sure putting observatories on the far side of the Moon is justified, given the expense and more importantly time it would take to get them up and running. By then you've probably improved on the basic technologies and implemented them back on Earth for a better result (cf artificial 'guide stars' via lasers to measure atmospheric turbulence and correct for it using multi-component mirrors).

If we are going to get Man out beyond LEO permanently we've still got some awfully tricky problems to solve, i.e. radiation shielding, and making much more efficient forms of propulsion (and/or some big advances in energy storage densities).

For a good introduction to just how difficult this stuff is see Atomic Rockets.

 

[Helme]

Well iron isnt the only mineral found in asteroids, the main reason to go for them however is that they are 99.9% useful materials. There's no useless rock there, you don't have to look for specific deposits. Wherever you dig you get something valuable.

And the huge supplies of metals helps alot when it comes to building things in space, because you don't have to ship up the materials from earth which saves HUGE amounts of money.

But yes, the moons resources, especially Hydrogen-3 is very attractive with fusion power just around the corner.

 

[Athan]

The key thing isn't if what's there is useful.

It's if what's there is useful and:

1) We can actually get to it at all
2) That getting to it (and getting it to where we need it, AND processing it) is easier (read gives a larger return) than sourcing it from Earth.

This is all far from "simply" jacking up current rocket technology to be able to reach the asteroids/Moon and return material from them. You also need to be able to then process it and use it in a practical manner. If we're skipping the Moon and just using asteroids then presumably we need a whole in-orbit industry to process said materials, i.e. big-time advances in processing and manufacture in free-fall.

But if there's something out there that we do need and plain can't get any more out of Earth, that will be a real incentive to reach out into the solar system for more than robotic exploration. Until we have that I don't see anyone feeling enough incentive to do it.

I'm also sat here wondering if you can come up with a few good citations for "99.9% useful materials" from asteroids. It's not just a matter of having the right atoms in abundance, but the compounds they're currently in being things we know how to refine. Oh, and fusion power has been 'just around the corner' for decades now.

Yes, I'm a big fat cynic when it comes to all of this. I wish I wasn't, but there's far too much evidence that this kind of thing is incredibly hard to the point of possibly not being worth it even if we do have a dire need for materials available out there. Unless there's some big, step-change, new physics we discover I really can't see us getting usefully out of LEO other than robotic exploration. Ever.

 

[Embattle]

There's quite alot of benefits to spending money in space programs. They're not really that apparent to normal people but we do get alot out of it. Cell phones, GPS etc. all come from space research.

That was indeed the case in the past, the reality is now that private companies spend so much on R&D and that technology moves so fast compared to when the moon missions were that the benefit is less.

 

[Ctuchik]

But yes, the moons resources, especially Hydrogen-3 is very attractive with fusion power just around the corner.

i really don't think fusion power is anywhere near close.

they cant even guarantee that they will get more power out of it them they pump in yet.

and then we have the cost of building the reactors... last i heard anything about it ITER were estimated to cost 5 billion euro, and even that were supposedly very optimistic.

 

[Ch3tan]

5 billion is peanuts.

 

[xane]

i really don't think fusion power is anywhere near close.

Depends how you look at it, the main issue is ignition of the fuel source and the current technology required is a high energy laser.

Of course, laser technology is coming from a military application, the intention is to shoot down missiles, once that is achieved it makes nuclear weapons redundant and solves the energy crisis.

 

[Helme]

This is whats in the near earth asteroids which aren't that far away, and we can bring closer into earths orbit(some of them already are). The major problem is that the infrastructure to process isn't there yet, but the reality is that we either need a space elevator or find a way to launch stuff so that it doesn't cost $5000/kg - or just circumvent the atmosphere alltogether and launch from space.

Neart Earth Asteroids:
Silicates-
Mass Present (10^15 g): 2,500
Per Capita Inventory (g/person): 140,000,000
Population Sustainable (billion people): 17.8

Ferrous Metals-
Mass Present (10^15 g): 300
Per Capita Inventory (g/person): 20,000,000
Population Sustainable (billion people): 30.0

Fe in oxides-
Mass Present (10^15 g): 300
Per Capita Inventory (g/person): -
Population Sustainable (billion people): -

Cement-
Mass Present (10^15 g): 60
Per Capita Inventory (g/person): 10,000,000
Population Sustainable (billion people): 6.0

Industrial CaO-
Mass Present (10^15 g): -
Per Capita Inventory (g/person): 2,000,000
Population Sustainable (billion people): 30.0

Phosphates-
Mass Present (10^15 g): 10
Per Capita Inventory (g/person): 2,000,000
Population Sustainable (billion people): 5.0

Water-
Mass Present (10^15 g): 300
Per Capita Inventory (g/person): 10,000,000
Population Sustainable (billion people): 30.0

Carbon-
Mass Present (10^15 g): 100
Per Capita Inventory (g/person): 1,000,000
Population Sustainable (billion people): 100.0

Nitrogen-
Mass Present (10^15 g): 10
Per Capita Inventory (g/person): 700,000
Population Sustainable (billion people): 14.0

Sulfur-
Mass Present (10^15 g): 60
Per Capita Inventory (g/person): 1,200,000
Population Sustainable (billion people): 50.0

Sulfides-
Mass Present (10^15 g): 150
Per Capita Inventory (g/person): 1,200,000
Population Sustainable (billion people): 125.0

----

Also by my fusion statement, I meant that it's actually doable in a realistic timeline, the question remains how effective it will be however. And as previously mentioned $5 billion is peanuts, the Long Island Nuclear Power plant costed that much 25 years ago.

 

[rynnor]

Well iron isnt the only mineral found in asteroids, the main reason to go for them however is that they are 99.9% useful materials. There's no useless rock there, you don't have to look for specific deposits.

Hmm - theres lots of types of different asteroids which we have analysed from meteorite fragments - your basic nickel iron asteroids but also rocky ones full of silicates.

Now Iron is the most abundant metal to be found on the earth - in many places you can mine iron ore straight from the surface without digging through 'useless rock' like in Australia so this would be effectively junk in space which you would have to process to get to the more valuable materials so the 99.9% usefull materials is extremely misleading.

Lets go back a step - these asteroids are in orbit of the sun - its not like they are parked in space where we just need to saunter over and start mining them - presumably youd time landing your miner till the closest pass to the earth but from that point on its going to be heading away from you and may not have another close pass for a long time.

Next its currently difficult to identify what a given asteroid is made of which is not great for mining.

Then how do you mine them? On earth we use explosives to shatter the rock into pieces we can process but these wont work in a vacuum.

If you could get an explosive to work you would risk shattering the asteroids or changing their orbit unpredictably.

The whole things a nonsense - you still havent demonstrated the reason to be up there mining.

 

[DaGaffer]

Hmm - theres lots of types of different asteroids which we have analysed from meteorite fragments - your basic nickel iron asteroids but also rocky ones full of silicates.

Now Iron is the most abundant metal to be found on the earth - in many places you can mine iron ore straight from the surface without digging through 'useless rock' like in Australia so this would be effectively junk in space which you would have to process to get to the more valuable materials so the 99.9% usefull materials is extremely misleading.

Lets go back a step - these asteroids are in orbit of the sun - its not like they are parked in space where we just need to saunter over and start mining them - presumably youd time landing your miner till the closest pass to the earth but from that point on its going to be heading away from you and may not have another close pass for a long time.

Next its currently difficult to identify what a given asteroid is made of which is not great for mining.

Then how do you mine them? On earth we use explosives to shatter the rock into pieces we can process but these wont work in a vacuum.

If you could get an explosive to work you would risk shattering the asteroids or changing their orbit unpredictably.

The whole things a nonsense - you still havent demonstrated the reason to be up there mining.

Read "A step further out" by Jerry Pournelle. A lot of the mechanics of asteroid mining has been worked out for at least 30 years by places like JPL. Oh, and iron wouldn't necessarily be useless, you can use it to protect yourself from radiation and as reaction mass.

One of the big advantages of mining out there is precisely that you're not doing it down here, so no pollution (and attendant cost worries) and the other is that once you're actually out there, the economics of refining drop through the floor (thanks to a big free energy source called the Sun) and transportation into a gravity well is several orders of magnitude cheaper than transportation out of it.

The trick is to take the first step and actually construct your infrastructure from the materials out there; once you've done that the economics are game-changing; which is the problem; energy and mining companies have no interest in changing the status quo because their businesses rely on scarcity; once you're out of the gravity well, you spent a huge amount getting there, but the resources are not scarce and your commodity cost falls through the floor (unless you can maintain a monopoly of supply, which you probably can't once enough people are at the top of the gravity well). This is where capitalism in its current form fails, too short-term and fundamentally built around models of scarcity (which is also why capitalism struggles with ideas like digital media, but I digress).

 

[Athan]

Go read the stuff about delta-v on that Atomic Rockets page I linked. It's really the biggest factor in any of this. It doesn't matter how much stuff there is out there that's potentially useful if you can't supply enough delta-v to get it where you want it. Also, unless you're planning on simply dropping stuff into the Pacific as a cheap way of braking, you DO need as much delta-v to bring it usefully to us as it takes to get (the same mass) out to the asteroids. The big difference between going up and coming down is going up you're fighting against air resistance some of the way, but coming down we currently make use of that so as to require next to no fuel to brake down into the gravity well. If you're not even talking about bringing stuff down from LEO then you have *ALL* the delta-v problem still.

Oh, and as is often said about many aspects of the requisite technology to explore and exploit space... if what's proposed is dropping great big chunks of rock from asteroids down through LEO onto the surface of the Earth... you've not just got a means of transporting useful materials down to Earth... you've got a mucking great big weapon of mass destruction too.

So in the asteroid mining scenario you need a target that comes close enough to us *and* where the delta-v requirement to 'catch' it is low enough. Then you need the ability to mine it quickly enough (in this case just breaking off bits and storing them for now), *and* then you need to be able to apply enough delta-v to your original ship *and* what you've mined to bring it back to where you can process it.

An alternative would be finding a sufficient population of asteroids in approximately the same orbit and building the whole refining/processing infrastructure there to minimise the delta-v requirement (why boost all of the ore down to LEO if you only need some smaller %age of the mass as final product?). Just boost/brake stuff towards LEO when the positioning is optimal. But then you're talking more delta-v to set that up in the first place, not to mention probably having to supply it with consumables (unless we've advanced closed-system technology to the point where we don't need to ship any extra oxygen/water/food, and/or can pull the basics out of the asteroids as well).

And, yes, in space the Sun can provide a lot of free energy, but that also bites you in the ass with cooling problems. One of the things that went up on this current Shuttle mission is a fresh tank of ammonia, used for cooling the station.

 

[rynnor]

One of the big advantages of mining out there is precisely that you're not doing it down here, so no pollution (and attendant cost worries) and the other is that once you're actually out there, the economics of refining drop through the floor (thanks to a big free energy source called the Sun) and transportation into a gravity well is several orders of magnitude cheaper than transportation out of it.

So your not only going to send up a mining robot but also a refiner? What are you going to use for propellant to get the mined material back to earth?

Do you have any idea how expensive it is to get 1Kg of material just into orbit - theres pretty much nothing you could mine that would allow you to break even let alone make any profit.

You also have to take into account the high risks of failure in everything that involves space - some of your payloads will never make orbit let alone reach an asteroid.

In the absence of a really cheap way of reaching orbit the whole thing is currently a fantasy.

 

[DaGaffer]

So your not only going to send up a mining robot but also a refiner? What are you going to use for propellant to get the mined material back to earth?

Do you have any idea how expensive it is to get 1Kg of material just into orbit - theres pretty much nothing you could mine that would allow you to break even let alone make any profit.

You also have to take into account the high risks of failure in everything that involves space - some of your payloads will never make orbit let alone reach an asteroid.

In the absence of a really cheap way of reaching orbit the whole thing is currently a fantasy.

Did you actually read anything I said? You have to build your infrastructure in space, from materials you find up there. If you're hauling every kilo to set up a mining operation in space from Earth, it will never make sense. You have to haul up the tools to build the tools, but after that the cost drops.

The worries about atomic rockets and delta-v shortages are surmountable as well; think ion drives etc. You don't need speed, once the refined materials are flowing its like the old days of tea clippers; a futures market (which also accomodates unreliability and ship failures).

 

[Athan]

The worries about atomic rockets and delta-v shortages are surmountable as well; think ion drives etc. You don't need speed, once the refined materials are flowing its like the old days of tea clippers; a futures market (which also accomodates unreliability and ship failures).

delta-v is not specific impulse. You *NEED* to change your velocity by a certain amount to change from your current orbit to your desired one (and in most cases you'll do this twice, once to get into a transfer orbit, and again at destination to get into the target orbit). Sure we've sent a couple of orbiters to the Moon using ION engines, but it took weeks to months. That doesn't cut it for humans who will be consuming oxygen and food all the way there and back. (Remember necessary fuel for given delta-v varies by the CUBE of the mass you want to get there due to more mass meaning more fuel, meaning even more fuel needed).

But, yes, sending back materials can be done with low specific impulse means of propulsion. However you still need to set up all that infrastructure, either utilising hypothetical advances in AI and robotics (so that you can use the 'slow' methods as transit time doesn't matter so much), or requiring high specific impulse propulsion to get humans there and back (sufficiently quickly so they don't run out of oxygen, food, other supplies, or get fried by prolonged radiation exposure).

This is a VERY HARD problem, and I'm not convinced it's possible to solve it adequately. It just looks too much like even with some form of nuclear propulsion, or even anti-matter, you can't get the energy density necessary to get *humans* around the solar system quickly enough to not run out of supplies and/or get fried by radiation. Robotic exploration/operations are entirely different as they don't have the same time constraints. Time will tell of course.

 

[rynnor]

Did you actually read anything I said? You have to build your infrastructure in space, from materials you find up there. If you're hauling every kilo to set up a mining operation in space from Earth, it will never make sense. You have to haul up the tools to build the tools, but after that the cost drops.

Thats one of the many huge flaws in your idea though - this may work if you have a massive infrastructure in space but you'll never get there.

Do you have any conception of how much youd need to haul up to have enough to be self sufficient and be able to make your own miners all the while shielding everything from solar flares and constantly repairing it?

And who repairs the robot that repairs the robot that repairs the waldoes?

Its a lovely theory but its not gonna happen in this reality unless we advance considerably in multiple sciences.

 

[DaGaffer]

Thats one of the many huge flaws in your idea though - this may work if you have a massive infrastructure in space but you'll never get there.

Do you have any conception of how much youd need to haul up to have enough to be self sufficient and be able to make your own miners all the while shielding everything from solar flares and constantly repairing it?

And who repairs the robot that repairs the robot that repairs the waldoes?

Its a lovely theory but its not gonna happen in this reality unless we advance considerably in multiple sciences.

To paraphrase a very famous speech:

We choose to go to the moon in this decade and do the other things, not because they are easy, but because they are hard, because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one which we intend to win, and the others, too.

Ultimately we live in a finite resource environment; unless we want to strip-mine our own planet (tricky when we also want to live on it), then we're going to have to do these things. We went to the Moon with 1960s tech and the goal itself advanced multiple sciences. If we don't think we can do better than we did in the 1960s, we may as well kill ourselves now, because we won't have a future anyway in the long run.

 

[Athan]

Political hyperbole doesn't over-ride the realities of the physical Universe. I'm personally quite certain that the USA 1960s Moon program had more to do with the Cold War than any real scientific/exploration endeavour, even if it did contribute to the latter.

That 1960s tech. was good for getting a very minimal mass to the Moon including supporting 3 humans, only 2 of which went down, and spent only a few hours out on the surface, to then return a fraction of the mass back to Moon orbit and ultimately even less of it to the surface of the Earth. It is a far far far cry from the kinds of technology you are saying are possible (with literally no evidence to back you up).

Personally I think the fact we live in a finite resource environment means that we need to halt our population growth and then slowly reverse it down to a sensible level. Something around a 1 billion cap seems a reasonable ballpark figure (you can go lower if you literally don't care about scientific advance, as that does require quite a lot of supporting population). Yes, eventually the Sun is set go grow into a Red Giant and anyone still living on Earth is fucked and it would be nice to have colonies elsewhere by then. But just because "we need to do this" doesn't mean it is possible.

Again I state I am aware I'm a big cynic on this. I actually want to be wrong, I just can't see how this stuff is possible given current scientific knowledge. And note that the scientific limitations I keep alluding to aren't of the "we're just ignorant and cowering in our fear not even wanting to try" type, these are hard scientific limits based on well-tested theories. (i.e. you can't come back with "yeah, but people thought we'd never be able to go faster than sound", it's irrelevant).

 

[Ch3tan]

BBC News - Obama sets Mars goal for America

There you go, Barak has told us there will be yanks on the Mars, but not until 2030.

 

[Athan]

Not quite. He's said humans orbiting Mars by mid 2030s, and landing sometime after that. Of course this is all comfortably far into the future that if it does happen most people will have forgotten he had anything to do with it (and more importantly politically it's far after he'll have ended a possible 2nd term so any future failure won't be set at his feet).

Still, we'll see. At least this is an improvement on his prior announcements that seemed to pretty much kill USA manned space flight dead. Oh, and I note he's pretty much explicitly said "that old 1960s tech? crap for this, we need new stuff". So, uh, cross your fingers we can develop the necessary new propulsion technologies.

 

[Ch3tan]

Not quite. He's said humans orbiting Mars by mid 2030s, and landing sometime after that. Of course this is all comfortably far into the future that if it does happen most people will have forgotten he had anything to do with it (and more importantly politically it's far after he'll have ended a possible 2nd term so any future failure won't be set at his feet).

Still, we'll see. At least this is an improvement on his prior announcements that seemed to pretty much kill USA manned space flight dead. Oh, and I note he's pretty much explicitly said "that old 1960s tech? crap for this, we need new stuff". So, uh, cross your fingers we can develop the necessary new propulsion technologies.

Yeah I know, I was taking the piss.

What he has said on the whole is positive, and as you pointed out is without risk to him.

 

[rynnor]

Thought this was the appropriate place for - BBC News - X-37B military spaceplane launches from Cape Canaveral

Is this just so they can still launch all those secret military sattelites?

 

[Athan]

That's part of it, yes. Not just 'still launch' but "have a capability for launching without the launch being well-enough observed to let others know the orbit of the satellite". Plus ability to retrieve/refuel military satellites.