# Asteroids As Gas Stations

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This is how I think humans can best adapt to outer space.  What you need for survival is just water-ice.  If you can find a large supply of ice on an asteroid of maybe 100 miles in diameter, you can start building your space station there.  You can also get a centrifuge rotating at one g gravity for crew quarters.  How many g's of gravity would the workers experience working on a 100 mile diameter asteroid?  If a 10 mile diameter asteroid has about ONE NANO G.  Then a 100 mile diameter asteroid would have about 10 to 20 NANO G's?  Anyhow it is so low a gravity that very massive volumes of ice could be moved and processed with minimal amounts of energy.  You excavate the ice using laser cutters then the ice is transported to a nearby processing station that melts the water out of the rock and from the water you get oxygen for air, and hydrogen for fuel.  You can start using the hydrogen fuel to power the cutting lasers and excavation.  And the workers have air and water.  You can fabricate ice panels for building.  As you dig into the asteroid you can start building your space station INSIDE the asteroid where you dug out the ice, and you will be sheltered from cosmic rays and micro-meteors.

We can use asteroids as gas stations and as stepping stones to other stars.  Who cares about the Moon and Mars?

Edited by Airbrush

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15 hours ago, Airbrush said:

If a 10 mile diameter asteroid has about ONE NANO G.

I checked my math on this calculation. I think I improperly convertied the mass into consistent units (kg to g) so the number is wrong. There was a factor of 1000 in the numerator, rather than the denominator.

It's milli-g. Still small, but not nearly as small as I had stated.

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On 7/11/2019 at 9:11 AM, swansont said:

It's milli-g. Still small, but not nearly as small as I had stated.

Then one milli-g is one thousandth-g for an asteroid 10 miles in diameter.  How much gravity for an asteroid 100 miles in diameter?  I'm searching for the ideal size and gravity of an asteroid to attach an ice-processing factory.    Suppose an asteroid 100 miles in diameter has a gravity of about 20 centi-g or one-two-hundredth-g.  You divide the mass of your ice slab by 200 for Earth-weight conversion.  So if I could carry in a backpack 50 pounds on Earth I could carry a slab of ice that would weigh 1000 pounds or half a ton on Earth.

Do we even have the technology already to launch a module into orbit that can land in an ice field in Antarctica and start cutting into the ice with lasers and convert ice into air, water, and fuel automatically?

a = GM/r^2

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On 7/11/2019 at 11:09 AM, Airbrush said:

very massive volumes of ice could be moved﻿ and processed with minimal amounts of energy

I'm not sure that would be the case; yes you can push a big mass and it will keep moving, but you need to push against something to start and stop that big mass. Having gravity and friction are actually very helpful to moving and processing stuff - I think doing useful work in microgravity will be more difficult, not less because of their absence. And of all the processing steps for mining and refining most materials, the moving stuff around part is likely to be the least energy intensive part of the whole exercise. I would expect a lot of energy intensive processing just to make (and recycle) the raw ingredients needed for metal refining.

I am presuming energy will be some kind of fusion power - ie fusion that is simple enough that a small colony with limited economic and industrial capabilities can build and operate reliably, entirely with local skills and resources - no small step for getting that I am thinking. Fission is technically easier but fissionable elements are not abundant and will probably be mostly contained at very low concentrations within nickel-iron - and 'minimal amounts of energy' looks unlikely to be sufficient to refine it; energy costs of making energy using fission look like a serious issue in such conditions.

On 7/11/2019 at 11:09 AM, Airbrush said:

We can use asteroids as gas stations and as stepping stones to other stars.  Who cares about the Moon and Mars?

I've thought the 'stepping stone' approach is the most reasonable of the various virtually impossible ways we might use to get people to another star - if truly self-sufficient colonies capable of spawning new self-sufficient colonies can be successful using asteroid/comet materials, and each new colony is in the direction of a target star, then potentially, eventually, some distant descendants might get there. But except for the very last of that long line, the stepping stones will only be a step to another stepping stone; the people involved aren't going to that star - and if their lifestyle works they don't need to - so keeping society wide commitment to that far, far distant end goal may prove difficult to sustain for the thousands of generations needed.

I suggest the urge to find new territory - a primitive urge - underlies the sense of attraction people have for other stars and other worlds, but given the multi-generational nature of the goal, that is really not going to be sufficient to expect whole populations to repeatedly make economic sacrifices for something they will not see. That urge to up stakes and hit the road when things get tough in search of some place better is too vague and non-specific as a motivation, and is not (I think) sufficient for circumstances where you have the ability to make the 'someplace better' yourself, even if from such dismal and difficult raw material as asteroids and comets. Having worked hard and made some comfort and security - if you have successfully built someplace better and the way forward involves sacrificing that hard won security and comfort for starting all over again - that commitment to the far off end goal will be hard to keep going.

Edited by Ken Fabian

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On 7/11/2019 at 3:09 AM, Airbrush said:

If ﻿you can find a large supply of ice on an asteroid of maybe 100 miles in diameter, you can start building your space station there.

There are just ~200 asteroids with diameter 100 km, and ~30 with diameter 200 km. Choice is very limited (at least in Solar System).

On 7/11/2019 at 3:09 AM, Airbrush said:

Who ﻿cares about the Moon and Mars? ﻿

People call it "baby steps"..

Step by step achieving goals from TODO list.

If you're unable to reach Moon, and stay there for longer time, it's rather unlikely you will succeed with much more troublesome exploration of the Mars, and very unlikely you will succeed with very troublesome travel to nearby star etc.

Edited by Sensei

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2 hours ago, Airbrush said:

Then one milli-g is one thousandth-g for an asteroid 10 miles in diameter.  How much gravity for an asteroid 100 miles in diameter?  I'm searching for the ideal size and gravity of an asteroid to attach an ice-processing factory.    Suppose an asteroid 100 miles in diameter has a gravity of about 20 centi-g or one-two-hundredth-g.  You divide the mass of your ice slab by 200 for Earth-weight conversion.  So if I could carry in a backpack 50 pounds on Earth I could carry a slab of ice that would weigh 1000 pounds or half a ton on Earth.

Do we even have the technology already to launch a module into orbit that can land in an ice field in Antarctica and start cutting into the ice with lasers and convert ice into air, water, and fuel automatically? ﻿

Couple of options being explored. One is to use an automated excavator and then simply melting it. Another is to use microwaves and sublimation.

You may need to remove contaminants, but can then use electrolysis to produce hydrogen and oxygen. In terms of technology everything is feasible. Look at 'in situ resource utilization' for more.

Note you would need a variety of resources to keep people alive, though most are out there in some form.

For colonization, I would expect to see a mix of artificial habitats, sleeper ships and robot driven methods. We have many billions of years to do all this in, so we don't need to rush. Having a number of self sufficient colonies out around/past Mars is the critical thing.

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On 7/10/2019 at 9:09 PM, Airbrush said:

We can use asteroids as gas stations and as stepping stones to other stars.  Who cares about the Moon and Mars?

Technology advancement is usually incremental. You didn't develop metal-skinned, single-wing jet airplanes as the first flying device because the supporting technology did not exist, and you had to identify the impediments to their use that were not apparent before the conditions of their use could be tested (or at least modeled)

Such as: you aren't going to get all of the details right for the design of a multi-generational spacecraft on the first try. A mars colony would identify some of the issues. And a moon colony would identify problems with a Mars colony design, in a circumstance that would entail much less risk to the inhabitants.

We went to the moon in 1969, not 1961, for similar reasons.

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2 hours ago, swansont said:

Such as: you aren't going to get all of the details right for the design of a multi-generational spacecraft on the first try. A mars colony would identify some of the issues. And a moon colony would identify problems with a Mars colony design, in a circumstance that would entail much less risk to the inhabitants.

We went to the moon in 1969, not 1961, for similar reasons.

This is why I think going to mars straight away is not only a bad idea but doomed to failure. Talk about a giant leap...

instead we should go to moon, orbit Venus, orbit Mars, land on Mars moon Phobos, then land on Mars.

15 hours ago, Ken Fabian said:

I suggest the urge to find new territory - a primitive urge - underlies the sense of attraction people have for other stars and other worlds, but given the multi-generational nature of the goal, that is really not going to be sufficient to expect whole populations to repeatedly make economic sacrifices for something they will not see. That urge to up stakes and hit the road when things get tough in search of some place better is too vague and non-specific as a motivation, and is not (I think) sufficient for circumstances where you have the ability to make the 'someplace better' yourself, even if from such dismal and difficult raw material as asteroids and comets. Having worked hard and made some comfort and security - if you have successfully built someplace better and the way forward involves sacrificing that hard won security and comfort for starting all over again - that commitment to the far off end goal will be hard to keep going.

At some point in the future the sun will die so we'll have no choice to leave (please correct me if I'm wrong).

but all the evidence to me seems to suggest that if we do get to another star, we'll be so advanced at living in space we won't need to colonise any planets.

this is why I think we need to put ourselves there instead. Sort of really advanced biological 3D printing, make us so that we are able to live in the local environment, but then could that still be considered human? Would the advanced AI you would need be like God? Or would we be like God?

Maybe best to use our knowledge to try and kick start life on other planets instead.

Edited by Curious layman

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5 hours ago, Curious layman said:

This is why I think going to mars straight away is not only a bad idea but doomed to failure. Talk about a giant leap...

instead we should go to moon, orbit Venus, orbit Mars, land on Mars moon Phobos, then land on Mars.

Why orbit Venus or land on Phobos? What new things do you learn?

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Venus is a lot closer to mars, so as a first step to long distance space travel it would be better. We'll allready have the tech to go the moon so why not land on Phobos first, maybe get fuel also. I'm thinking if we take longer, and do it in smaller steps it will be easier to achieve, and more likely also. Maybe cheaper too, as the private sector will be a lot bigger.

my feelings are that NASA should be focused on living long term in space and the moon(s) and sending probes/robots to planets, not people. Pointless waste of money (at the moment anyway). Mars should be just another stepping stone, not a one off mega project that's so expensive it's unlikely to be repeated for decades.

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16 hours ago, Curious layman said:

Venus is a lot closer to mars, so as a first step to long distance space travel it would be better.

What do you learn in the trip to Venus that can't be learned in going to the moon or on the ISS? The part about increased distance is probably the part that's best understood, since it's basically Newton's first law of motion. You don't have to do anything to keep going in a straight line. We've sent probes to other planets, so the mechanics are known. If it's simply mission duration, you can investigate that without leaving the earth-moon gravity well.

16 hours ago, Curious layman said:

We'll allready have the tech to go the moon so why not land on Phobos first, maybe get fuel also. I'm thinking if we take longer, and do it in smaller steps it will be easier to achieve, and more likely also. Maybe cheaper too, as the private sector will be a lot bigger.

"Why not?" is not an answer. Why waste the trip and land on a tiny moon with almost no gravity? What supplies are going to be there that aren't on Mars? How much smaller a step is this? You're going to go at least 55 million km and and then stop 10,000 km from Mars?

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On 7/13/2019 at 7:38 AM, Curious layman said:

... if we do get to another star, we'll be so advanced at living in space we won't need to colonize any planets.

As you note, it would also be worthwhile to build a comfortable spaceship with centrifuge for human compartments, for the luxury of one g gravity for a long-term mission of several decades, if not a one-way trip.   You find the best prospect asteroid with lots of, easy to extract, water-ice.  The spaceship parks nearby the asteroid and workers commute to the ice digs, in work in shifts, where ice blocks are hauled to a processor that extracts water, and creates air and hydrogen fuel to power the whole operation.

With climate change here on Earth, rising sea levels, coastal dwellers forced inland, and growing populations, scarcity of water, political strife, etc, etc, life on Earth could become quite miserable for the majority in the near future, and many people would be glad to take a one-way trip to Mars or an asteroid, IF they can have a good time going there and working there.  It will have to be fun, or at least MORE fun than their life on Earth.  On their one-way trip they should have great video games to play and something like the Star Trek "Holodeck" for recreation.

Edited by Airbrush

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14 hours ago, swansont said:

What do you learn in the trip to Venus that can't be learned in going to the moon or on the ISS? The part about increased distance is probably the part that's best understood, since it's basically Newton's first law of motion. You don't have to do anything to keep going in a straight line. We've sent probes to other planets, so the mechanics are known. If it's simply mission duration, you can investigate that without leaving the earth-moon gravity well.

"Why not?" is not an answer. Why waste the trip and land on a tiny moon with almost no gravity? What supplies are going to be there that aren't on Mars? How much smaller a step is this? You're going to go at least 55 million km and and then stop 10,000 km from Mars?

I'm thinking about the psychology/experience of the astronauts and mission control. being so far from earth, I've heard it could be a big problem psychologically. Keep going further and further out each time would be best I think. As Venus is closer, it would be best (and I assume safer) for a first extra long mission. Then a longer one to Mars. Then one around Mars but land on Phobos, you get the experience of going out that far and landing, but it will be safer because a lot of the equipment would have been tried and tested on Moon, this would be invaluable experience for mission control. Then, when we  land on Mars it's much more likely to be successful because of the experience we gained.

All this crap about landing on Mars in the 2030s seems like a recipe for disaster to me. Too rushed. 2050s would be better, and more realistic.

And also, I prefer Venus to Mars. Never been excited by Mars personally.

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8 hours ago, Curious layman said:

I'm thinking about the psychology/experience of the astronauts and mission control. being so far from earth, I've heard it could be a big problem psychologically. Keep going further and further out each time would be best I think. As Venus is closer, it would be best (and I assume safer) for a first extra long mission. Then a longer one to Mars. Then one around Mars but land on Phobos, you get the experience of going out that far and landing, but it will be safer because a lot of the equipment would have been tried and tested on Moon, this would be invaluable experience for mission control. Then, when we  land on Mars it's much more likely to be successful because of the experience we gained.

All this crap about landing on Mars in the 2030s seems like a recipe for disaster to me. Too rushed. 2050s would be better, and more realistic.

And also, I prefer Venus to Mars. Never been excited by Mars personally.

While Venus is closer in terms of travel time, it is actually slightly harder to get to in terms of the delta v needed for a ship to get there, and that's not counting the extra needed to enter and leave orbit around a planet significantly more massive than Mars.  In addition,  solar radiation is ~90% stronger at Venus than is at Earth.  One of the issues spacecraft have to deal with is how to get rid of excess heat. You may have heard that space is cold, but it is not, it has no temp at all.  What it is, is a good insulator, as the only way to lose heat is through radiation. A spacecraft sent to Venus would have to be able to shed a lot more heat.  Landing would be out of the question, and you would be stuck orbiting above the clouds of a world that it a good description of Hell on the surface.   I'm not to sure how good psychologically speaking that would be for the astronauts, nor any safer.

Maybe if Venus had turned out to be like some of our earlier imaginings, basically a sister planet to Earth, but just warmer, it would have made a better target for manned Missions, but as it is, it's not as alluring.

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In addition to the excellent post by Janus, consider that if you want to simulate/test a longer flight (whether it's crew endurance or equipment longevity testing), you can do that in orbit around the earth (or perhaps the moon), where rescue/evacuation is much easier, and therefore safer.

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14 hours ago, Janus said:

While Venus is closer in terms of travel time, it is actually slightly harder to get to in terms of the delta v needed for a ship to get there, and that's not counting the extra needed to enter and leave orbit around a planet significantly more massive than Mars.  In addition,  solar radiation is ~90% stronger at Venus than is at Earth.  One of the issues spacecraft have to deal with is how to get rid of excess heat. You may have heard that space is cold, but it is not, it has no temp at all.  What it is, is a good insulator, as the only way to lose heat is through radiation. A spacecraft sent to Venus would have to be able to shed a lot more heat.  Landing would be out of the question, and you would be stuck orbiting above the clouds of a world that it a good description of Hell on the surface.   I'm not to sure how good psychologically speaking that would be for the astronauts, nor any safer.

Maybe if Venus had turned out to be like some of our earlier imaginings, basically a sister planet to Earth, but just warmer, it would have made a better target for manned Missions, but as it is, it's not as alluring.

I was thinking of just a flyby of Venus, not actually landing. Didn't think about the difficulty of heat loss in space and the extra gravity compared to Mars. Always thought the extra solar radiation would be a plus. Solar flares would be a bigger problem as well I imagine.

Id still rather visit an airship above Venus than a base on Mars though. What a shame the Russians stopped going to Venus. Just think of the robotics and advanced materials they would have if they'd kept sending landers.

Edited by Curious layman

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9 hours ago, Curious layman said:

...Id still rather visit an airship above Venus than a base on Mars though. What a shame the Russians stopped going to Venus. Just think of the robotics and advanced materials they would have if they'd kept sending landers.

If it would be idyllic to float above the clouds of Venus in a giant airship, you better not fall out because you will land in hell.  It takes just one crazy, homicidal, suicidal person to destroy a huge airship, and there is no parachuting to safety

I do wish they would send a super tough lander to Venus, just to see how robust they can build a rover, comparable to the Curiosity Rover on Mars, but able to withstand such high temperature and pressure.  Maybe it is still impossible.

Edited by Airbrush

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10 hours ago, Curious layman said:

Id still rather visit an airship above Venus than a base on Mars though. What a shame the Russians stopped going to Venus. Just think of the robotics and advanced materials they would have if they'd kept sending landers.

Why? I'd think it get boring after a while.  You'd be stuck in the airship and the view would be monotonous (you couldn't see the ground, just the surrounding clouds.)   At least with a Mars base you could get out a take a walk once in a while, even if it is in a pressure suit.

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I

2 hours ago, Janus said:

Why? I'd think it get boring after a while.  You'd be stuck in the airship and the view would be monotonous.

It would be boring on Mars too. I think of it like being in the middle of the Sahara desert, the excitement would wear off pretty quick for me. Unless it was near Hydrothermal vents. That would be exciting.

I don't think watching 185 mph (300km/h) winds go around a whole planet would be monotonous, think of the view, I could watch it all day.

3 hours ago, Airbrush said:

If it would be idyllic to float above the clouds of Venus in a giant airship, you better not fall out because you will land in hell.  It takes just one crazy, homicidal, suicidal person to destroy a huge airship, and there is no parachuting to safety

I do wish they would send a super tough lander to Venus, just to see how robust they can build a rover, comparable to the Curiosity Rover on Mars, but able to withstand such high temperature and pressure.  Maybe it is still impossible.

Above is an idea by NASA, - HAVOC airship.

Some lander ideas for Venus. There are also some advantages to colonising Venus.

Edited by Curious layman

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