Oil in Space?... Nay, WATER!

[Coyote]

It has been hypothesized that the discovery of a planet of oil or petroleum-substitute substance would be a boon to the space race and start all kinds of business ventures into space-- notwithstanding, of course, the incomprehensible cost of shipping the liquid megatonnage off planet and back to Earth.

On the other hand, take water-- a relatively common element, it appears, in space, and one that seems to exist in free-floating form on asteroids and the rings of the Jovians.

That there is a demand on Earth is without question.

What, besides monetary investment, would be the limitations on sending a ship, even a robot one (actually preferable, I'd wager) to go latch onto a orbiting ice chunk, give it a few minutes burn time with a trajectory towards Earth, and then leaving enough fuel for minor course corrections for a safe re-entry that would deliver the bulk of the frozen water to the planet-- maybe plopping it down in someplace like Arizona or New Mexico, or Saudi Arabia, or Africa, or some other place that could use a instant lake delivery via airmail?

Or, conversely, how about chunking a few free-floating icebergs down onto Mars for a nice, slow melt to make the place more attractive to eventual settlement?

[Count Dooku]

I don't care how good the science is, the majority of people aren't going to like the idea of sending a block of ice that could potentially wipe out the majority of life on Earth, to Earth, on purpose. I suppose, then, that convincing people it's safe (assuming it is) is one obstacle. As for sending it to Mars, you'd have to convince those same people it's a good investment for our future.

[Surlethe]

I'd actually thought about pulling a comet into orbit as a water source. On the one hand, pointing a comet toward Earth is playing with a big, big fire; on the other, we know enough about physics to control it and not actually dump it on the planet going at 30 km/s.

I like the idea of throwing a few comets at Mars better: we don't have to worry about killing anything, and the heat from the impacts will help melt the ice and warm up the planet. Plus, if we accompany it with actual seeding with bacteria and hardy plants (maybe let evolution do the cold-tolerance work for us in the lab?), we can start converting the planet for potential colonization a few centuries down the line.

[Darth Tanner]

Wouldn't ice simply disintegrate in the atmosphere, which I suppose would simple result in more rainfall, although an infinitesimally small amount. Still even if it survived to impact what use is it going to be, it'll create a massive shock wave if you target a lake and targeting land is simply going to add the water to the natural water cycle.

Is a desalination plant that expensive? we hardly have a shortage of salt water.

I think we are a a very long way away from the point where manipulating iceroids is remotely possible for financial reasons. Also I'd imagine attaching rockets to rapidly moving (and often spinning) objects in the void of space in going to be incredibly dangerous even for robotic craft. Not to mention the difficulty in operating robotic equipment by remote at the distance involved.

[Singular Intellect]

Why the fuck would we need to go to space for water?

It strikes me as ridiculas when we have oceans covering 78% of our planet's surface we can extra fresh water from.

I mean fuck, I can extra fresh water from the ocean with some simple equipment.

[Gigaliel]

What, besides monetary investment, would be the limitations on sending a ship, even a robot one (actually preferable, I'd wager) to go latch onto a orbiting ice chunk, give it a few minutes burn time with a trajectory towards Earth, and then leaving enough fuel for minor course corrections for a safe re-entry that would deliver the bulk of the frozen water to the planet-- maybe plopping it down in someplace like Arizona or New Mexico, or Saudi Arabia, or Africa, or some other place that could use a instant lake delivery via airmail?

Monetary investment is a reflection of inherent energy costs in this case. It takes 0.77kWh/kg to distill saltwater into freshwater (theoretical limit). In comparison it costs 17.4 kWhr/kg to launch something into GEO. (theoretical limit) Taking into account the massive amount of infrastructure required to adjust a comets orbit, using a comet to solve Earth's freshwater problems would be just a tad overkill.

Of course, assuming some kind of developed infrastructure, changing a comet's course to collide with a planet is fairly small, with a delta-V of ~3kps, I think. This requires clever use of orbital mechanics to nudge the comet at just the right time in orbit. This would make them useful for Martian terraforming, however throwing them at Earth would require energy roughly equivalent to that of GEO orbit. Ironically, that would mean importing water from Earth might make economical sense in some circumstances.*

*These numbers are taken from The Millenial Project by Marshall T. Savage and also from memory, so if they look funny feel free to yell at me. Also this exclude the chemical creation of water from hydrogen and oxygen, which would probably be waaay cheaper..

[Stile]

Why do need to send it to Earth?? Most ideas would use the water as premium reaction mass without having to haul it up Earth's gravity well.

[Darth Raptor]

Terra's incomprehensibly vast water supply would have to be ludicrously polluted before it becomes cost-effective to import water from extraterrestrial sources. That said, it would be cheaper to capture and move comets into low orbit over colonies on planets like Mercury than it would be to move water from home. For really serious planetary engineering projects on good candidates like Mars or Titan, an artificial comet bombardment would be the prelude to any large-scale permanent habitation. That way the oceans are already there when we move in.

[Shinova]

Problem with water on earth isn't because there isn't enough, but because it's hard to get at it and move it.

[Shroom Man 777]

So we make it easier to get and move by getting and moving water from space. Genius. Fucking genius.

[Singular Intellect]

So we make it easier to get and move by getting and moving water from space. Genius. Fucking genius.

That sounds suspiciously like government planning and spending to me.

[Coyote]

Bear in mind I'm not talking about capturing a comet (requires a lot of fuel to slow down) or keeping it at speed and nudging it to crash into Earth (dinosaurs!). I'm talking about the safe & slow capture of free-floating ice chunks in the asteroid belt or, more likely, the rings of Saturn-- then bringing them to Earth in a carefully calculated trajectory to bring them down. A dramatic impact, to be sure, but not a fate-tempting one.

See, the thing is (as has been pointed out) there is a lot of watre on Earth, but it is not where we want it to be. The more we divert from the ecosystem the less freshwater gets downstream, wetlands dry up, increased salinity in some areas, etc.

Even desalinization plants only reach the coastlines effectively, otherwise you have to pipe/ship it elsewhere. Good for those who live along coastlines (admittedly the majority of the population) but not so useful for many inland, in areas that are increasingly drought sensitive.

Also, if water has to be shipped or piped to (or through) places where there are conflicts, then things are not so easy. A war is not cheap to start or stop, and a war over water in places where there is little infrastructure or limited population mobility (ie, Africa, Middle East, etc) then plopping down a mail-order lake can go a long way towards alleviating some of the need.

[Enforcer Talen]

I can definitly see some use for this on Mars - new oceans, anyone?

[Dave]

Like others have said, I really can't see how moving "free floating chunks of ice in the Belt" down to Earth is a more cost-effective method of getting fresh water than distilling it or moving it a couple hundred miles by land. Granted, it's easier to move massive things in space, but it still gets really freaking expensive as soon as you mention that this occurs in Space.

Also, there's no reason to add water to Mars if we haven't even put a man on it yet. When people start looking at terraforming, then we can talk, but there's no need to move the water to Mars now.

And pardon my ignorance, but don't comets start growing a tail out by Saturn? If so, why would we have free-floating chunks of ice in the belt, if the water normally starts vaporizing several AU farther out?

[General Trelane (Retired)]

[. . .]plopping down a mail-order lake can go a long way towards alleviating some of the need.

Completely agree. By killing off the local population with an orbital ice bombardment, the need would certainly be alleviated.

[Uraniun235]

It would make a lot more sense to begin working on reducing the demand, both by short-term relocation and long-term population contraction, than to dick around and blow a bunch of resources on something that could backfire at any number of stages and produce limited benefits to an even more limited geographic region. (Just what is "dropping a ready-made lake" going to do to the environment anyway? Is it even all going to stay there or is it going to be gone in a couple of months?)

[Surlethe]

Is there any idea how much this might cost in terms of energy to quantitatively compare?

[Enola Straight]

I figure adding some fission-heated thrusters to a comet (ice in one end, heat it up, steam thrust out the other) to give it an initial thrust and occasional trajectory adjustments on the years/decades-long travel Mars-ward.

Eject the nuke-steam-thrusters before the comet enters Mars "atmosphere-zero".

The comet detonates in the atmosphere above the polar ice caps, releasing gaseous carbon dioxide, and thus starting a trend in an increased Greenhouse Effect.

Of course, theres no guarantee the comet will detonate in the atmosphere, so as a back up measure, I would also calculate for a surface strike where the dry ice cap is known to be the thickest, to minimize ejecta.

[Coyote]

I...I would also calculate for a surface strike where the dry ice cap is known to be the thickest, to minimize ejecta.

Wouldn't some ejecta on Mars be good, in certain circumstances, creating a potential greenhouse effect?

[Enola Straight]

I would think ejecta...airborne martian soil and dust...would keep out the heat of sunlight...the opposite of greenhouse effect.

[Plekhanov]

Bear in mind I'm not talking about capturing a comet (requires a lot of fuel to slow down) or keeping it at speed and nudging it to crash into Earth (dinosaurs!). I'm talking about the safe & slow capture of free-floating ice chunks in the asteroid belt or, more likely, the rings of Saturn-- then bringing them to Earth in a carefully calculated trajectory to bring them down. A dramatic impact, to be sure, but not a fate-tempting one.

See, the thing is (as has been pointed out) there is a lot of watre on Earth, but it is not where we want it to be. The more we divert from the ecosystem the less freshwater gets downstream, wetlands dry up, increased salinity in some areas, etc.

Even desalinization plants only reach the coastlines effectively, otherwise you have to pipe/ship it elsewhere. Good for those who live along coastlines (admittedly the majority of the population) but not so useful for many inland, in areas that are increasingly drought sensitive.

Also, if water has to be shipped or piped to (or through) places where there are conflicts, then things are not so easy. A war is not cheap to start or stop, and a war over water in places where there is little infrastructure or limited population mobility (ie, Africa, Middle East, etc) then plopping down a mail-order lake can go a long way towards alleviating some of the need.

Are you being ironic here or are you seriously suggesting that getting water from space would be more practice than a desalination plant & pipeline approach?

[Coyote]

Basically I'm wondering about the feasability & the political reality.

Pop a ice berg down in a remote drought area and let it melt. No need to, say, develop infrastructure, build pipelines or roads for tankers, etc.

A desal plant is all well & good, but you need to build pipelines, roads and/or rails, protect these assets, distribute the water, etc. Maybe it would be better to just drop a 'berg.

It sounds like it would be useful to consider this for dropping water onto Mars (the 'plan-B' of my OP) more so than doing it for Earth.

I know that thechnically there's plenty of water, but for some reason it ain't getting where it is frequently needed. Is cost & politics the problem?

[Shogoki]

We could drop this huge chunks of frozen water in the ocean with some regularity, to fight off global warming, of course we would have to use increasingly bigger ice cubes, solving the problem once and for all.

Seriously, though, i don't really see much point on it at this time.

[Plekhanov]

Basically I'm wondering about the feasability & the political reality.

Pop a ice berg down in a remote drought area and let it melt. No need to, say, develop infrastructure, build pipelines or roads for tankers, etc.

A desal plant is all well & good, but you need to build pipelines, roads and/or rails, protect these assets, distribute the water, etc. Maybe it would be better to just drop a 'berg.

They'd have to be some pretty spectacular and intractable problems.

It sounds like it would be useful to consider this for dropping water onto Mars (the 'plan-B' of my OP) more so than doing it for Earth.

I know that thechnically there's plenty of water, but for some reason it ain't getting where it is frequently needed. Is cost & politics the problem?

Ok so you seem to really like the idea of dropping large chunks of ice in the middle of deserts. Going with that if we had the tech to safely and reliably deliver large chunks of ice from space to the surface wouldn't we also have the tech to pick up and move large chunks of ice from the middle of Antarctica to deserts?

[Darth Tanner]

No need to, say, develop infrastructure, build pipelines or roads for tankers, etc.

But people can't just get all their water from some massive crater created by the impact! Their still going to need pipes to get it to their homes and treatment plants to purify it and sewers to take the used stuff away.

Not to mention the impact is going to kill most of the people in the area.

The only problem with water supplies is the piping (a critical problem here in the UK) Humans don't use up water, everything we drink comes back out again. The only loss from the system is leaking pipes, so the best solution would be a much better and more cheaply maintained pipe system, like the Victorians had.

In the third world however all this goes out the window as they just don't have the water in the first place. However there is no real solution to this other than simply not living in desserts! If they can't afford desalination plants their not going to spend the money on space ships to bombard their country from orbit with ice missiles.

We could drop this huge chunks of frozen water in the ocean with some regularity, to fight off global warming

Wouldn't adding large amounts of fresh water make the problem worse? as it would both increase sea levels and destabilise the gulf stream further. Not to mention the massive tidal waves.