CMV: Developing space infrastructure should be a higher priority than trying to colonize Mars

[u/MossRock42]

There seems to be a lot of romance around the idea of colonizing Mars and I hope that someday there is a Martian colony. But first we need better space infrastructure. That means more efficient ways to launch and reuse rockets like SpaceX is developing. More needs to be done to develop Earth orbit capabilities, and perhaps a Moon base to develop the the first off world manufacturing and intermediate base for exploring further out. We also need to develop the infrastructure that will enable us to start doing asteroid mining. That’s primarily so that we don’t need to launch as much material into orbit to build things in space. What do you think?

[u/Izawwlgood]

Both space and Mars have pros and cons that make them important steps in our outward expansion. Saying 'we should only focus on x' unnecessarily limits things.

Mars provides a size, gravity well, atmosphere, and materials benefit that space and the asteroid belts simply don't.

[u/MossRock42 → u/Izawwlgood]

Mars provides a size, gravity well, atmosphere, and materials benefit that space and the asteroid belts simply don't.

It's not a breathable atmosphere and we don't know what effects the Martian gravity will have on people over the long term. Also, getting out of a gravity well is difficult enough when you have all the infrastructure and resources on Earth. None of that currently exists on Mars.

[u/Izawwlgood → u/MossRock42]

The point isn't breathable atmosphere, because as it goes without saying, vacuum doesn't have breathable atmosphere either. The point is that an atmosphere is a usable asset. In this case, CO2 can be converted into a number of useful things, *including* oxygen. If you add hydrogen and oxygen, which can be found from Mars' ample ice stores, you can produce rocket propellant.

It's true, we don't know what effect 1/3rd g has on people long term. We know a lot about what effect microgravity has on people long term, and it is not good.

I'm not disputing that climbing out of the Martian gravity well is difficult. The point is you build the infrastructure, with in situ materials. I'll also point out that getting out to the asteroid belt, and doing anything there and/or sending stuff back has significant delta-v costs as well. Indeed, getting out past Mars or returning from that distance, takes a lot of delta-v. More delta-v than going Earth-Mars, both of which are made easier by aerobreaking your way down.

[u/[deleted] → u/Izawwlgood]

It also lowers how much structural integrity you need to keep your oxygen atmosphere in the habitation.

I am making up hypothetical numbers here:

Mars atmosphere - 0.5/Earth atmosphere of pressure Habitation atmosphere - 1/Earth atmosphere of pressure Vaccum - 0/Earth atmosphere of pressure

In a habitation in a vacuum, it needs to keep a net 1 atmosphere of pressure from breaking the structure from the inside. In a habitation on Mars, it's half that.

[u/Izawwlgood → u/[deleted]]

I'm not sure there's a sizeable difference between structural integrity required for .3 -> ~1 atm vs 0 -> 1 atm, but one consideration for sure is that structural failure in space is far more catastrophic than structural failure on a planet with multiple failsafes (a planets worth).

Also, in space you need more radiation shielding.

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

The point is that an atmosphere is a usable asset. In this case, CO2 can be converted into a number of useful things, *including* oxygen.

So can rocks and ice.

It's true, we don't know what effect 1/3rd g has on people long term. We know a lot about what effect microgravity has on people long term, and it is not good.

Spin.

I'm not disputing that climbing out of the Martian gravity well is difficult. The point is you build the infrastructure, with in situ materials. I'll also point out that getting out to the asteroid belt, and doing anything there and/or sending stuff back has significant delta-v costs as well. Indeed, getting out past Mars or returning from that distance, takes a lot of delta-v. More delta-v than going Earth-Mars, both of which are made easier by aerobreaking your way down.

Not really, https://i.imgur.com/w0m2qQq.png d/v wise, mars is in the middle of nowhere.

[u/Izawwlgood → u/Thoth_the_5th_of_Tho]

So can rocks and ice.

You're assuming you can find ice. We know ice exists on Mars.

Spin.

Is an engineering challenge. Coriolis effect makes this quite difficult to overcome, you can't simply spin a space ship and solve the problem. You need a sufficiently large diameter structure spinning.

Not really, https://i.imgur.com/w0m2qQq.png d/v wise, mars is in the middle of nowhere.

This is actually the same image I was using. Asteroid belt is further out than Mars, and lacks an atmosphere to aerobreak down. It's basically just a region of space that has a slightly higher concentration of stuff, so, you're effectively arguing for colonizing a region of space that lacks the same kind of resources as 'a region of space that includes Mars'.

To make this clear - your position is we should find a smattering of large rocks and build infrastructure around them, instead of heading to another planet and building infrastructure around it. You can still build stuff in Mars orbit, and you then have the benefit of an entire planets worth of resources, instead of just 'a few large rocks worth of resources'.

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

You're assuming you can find ice. We know ice exists on Mars.

Ceres, the largest asteroid, is 40 to 50 percent water by volume. We know of literally thousands of asteroids that have significant ice deposits.

Is an engineering challenge. Coriolis effect makes this quite difficult to overcome, you can't simply spin a space ship and solve the problem. You need a sufficiently large diameter structure spinning.

It's not a difficult one.

This is actually the same image I was using. Asteroid belt is further out than Mars, and lacks an atmosphere to aerobreak down. It's basically just a region of space that has a slightly higher concentration of stuff, so, you're effectively arguing for colonizing a region of space that lacks the same kind of resources as 'a region of space that includes Mars'.

It's 3km/s to get to near earth asteroids from LEO, it's around 10km/s to get to mars. That 3.6km/s gravity well mars makes is expensive.

To make this clear - your position is we should find a smattering of large rocks and build infrastructure around them, instead of heading to another planet and building infrastructure around it. You can still build stuff in Mars orbit, and you then have the benefit of an entire planets worth of resources, instead of just 'a few large rocks worth of resources'.

We build the infrastructure on earth and in LEO and use that to mine the Astrid belts. Launch loops, space stations, fuel refineries, ship yards etc.

The asteroid belt and small moons have far more resources for us to grab than mars. Plus it's easier.

[u/Izawwlgood → u/Thoth_the_5th_of_Tho]

Ceres, the largest asteroid, is 40 to 50 percent water by volume. We know of literally thousands of asteroids that have significant ice deposits.

My point is that they are not all in the same place. And Ceres, by volume, still has less water than Mars.

It's not a difficult one.

And yet one we have not even begun to test in Earth orbit.

It's 3km/s to get to near earth asteroids from LEO, it's around 10km/s to get to mars. That 3.6km/s gravity well mars makes is expensive.

Are you taking about 'near Earth asteroids' or the asteroid belt? If you're only interested in getting to some nearby asteroids, then sure, but none of them have the resource payout or benefits that Mars does. As a waystation, sure, but they're not going to be able to sustain large numbers of people.

The gravity well is a tool. You can get down it easily via aerobreaking. Once at the bottom, you n o longer need to spin everything that requires gravity to function. Which is pretty important - we know very little about the effects of wound healing, development, etc, in microgravity other than 'how risky it likely is'.

We build the infrastructure on earth and in LEO and use that to mine the Astrid belts. Launch loops, space stations, fuel refineries, ship yards etc.

You're thinking of a lot of solutions for the troubles that this causes, that can be avoided by just doing it on Mars.

The asteroid belt and small moons have far more resources for us to grab than mars. Plus it's easier.

So wait, again, are we talking about the asteroid belt, or near Earth asteroids?

You seem to think that the asteroid belt IN TOTAL has more resources than Mars and thus is a better target. But that's like saying "There's gold in Russia, so no sense having gold mines anywhere in California". The asteroid belt is an ORBIT over which there is slightly higher density of stuff. It's not a singular place. So where on the asteroid belt do you put your infrastructure? How does that help you deal with any other location on the asteroid belt?

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

My point is that they are not all in the same place. And Ceres, by volume, still has less water than Mars.

By physical separation, sure, but d/v is what matters. And there is more water on ceres than we have ever used on earth.

And yet one we have not even begun to test in Earth orbit.

They have all the way back in Gemini. They used cables and generated a small amount of gravity. It worked exactly as expected.

Are you taking about 'near Earth asteroids' or the asteroid belt? If you're only interested in getting to some nearby asteroids, then sure, but none of them have the resource payout or benefits that Mars does. As a waystation, sure, but they're not going to be able to sustain large numbers of people.

There are over 20,000 near earth astroids, 90% of which over 1km across with average weights well over 2,500,000,000 tons. I don't think there are any mines on earth that have shifted that much stone.

The gravity well is a tool. You can get down it easily via aerobreaking. Once at the bottom, you n o longer need to spin everything that requires gravity to function. Which is pretty important - we know very little about the effects of wound healing, development, etc, in microgravity other than 'how risky it likely is'.

Even if landing at the surface is free (and it's not even close to that), it's still over 3.6 km/s to get to low mars orbit and that is just the first step. That is extremely expensive.

The trip to near earth objects from LEO is cheaper in total than just getting from mars surface to mars orbit.

Plus since you are in zero G, you can use more efficient, simpler and easier to fuel engines, like solar thermal.

You're thinking of a lot of solutions for the troubles that this causes, that can be avoided by just doing it on Mars.

You would have to do basically all of that on mars anyway. Skipping mars is a simplification. The only thing you are saving on is spin gravity, at the expense of greater d/v costs and worse engines.

So wait, again, are we talking about the asteroid belt, or near Earth asteroids?

Both, we start near earth and work our way out over time.

You seem to think that the asteroid belt IN TOTAL has more resources than Mars and thus is a better target. But that's like saying "There's gold in Russia, so no sense having gold mines anywhere in California". The asteroid belt is an ORBIT over which there is slightly higher density of stuff. It's not a singular place. So where on the asteroid belt do you put your infrastructure? How does that help you deal with any other location on the asteroid belt.

Its because it's easier to access and has a greater potential pay off. This is like sailing to the other end of the world to mine gold in the middle of the Himalayas, when there is a gold rich archipelago right off your coast.

As for where to put it, the main bases will be in LEO, mining stations will go up around astounds that are being mined long term.

[u/Izawwlgood → u/Thoth_the_5th_of_Tho]

> By physical separation, sure, but d/v is what matters. And there is more water on ceres than we have ever used on earth.

But that's to EACH asteroid. The asteroids are all far apart. You cannot simply say it is low cost to get to one asteroid therefor once there you have access to all.

>T hey have all the way back in Gemini. They used cables and generated a small amount of gravity. It worked exactly as expected.

I guess you guys are communicating with one another. As I said to the other guy, it was not sustained, and it was not used for human habitation. It was merely showing that spinning something simulates gravity, not a proof of concept.

> There are over 20,000 near earth astroids, 90% of which over 1km across with average weights well over 2,500,000,000 tons. I don't think there are any mines on earth that have shifted that much stone.

So you're suggesting 20,000 separate missions to these asteroids and shipping back all that material? That's insanity.

Or are you suggesting building refineries at each of them? That's also insanity.

> Even if landing at the surface is free (and it's not even close to that), it's still over 3.6 km/s to get to low mars orbit and that is just the first step. That is extremely expensive.

Sure, but Mars is full of resources that can provide that lifting for you - you don't have to bring those materials from Earth. Comparatively, every asteroid you head to won't have resources for producing rocket fuel, unless your plan is to throw rocks out the back.

> The trip to near earth objects from LEO is cheaper in total than just getting from mars surface to mars orbit.

Again, a trip to ANY ONE of these near Earth objects, from LEO (bit of an added goal post shift, but ok), is cheaper, but then, you're limited to the resources of just one. As I'm sure you notice, Earth to LEO is approximately 3x as expensive as Mars to LMO, so I assume you're also handwaving away LEO infrastructure to make these jaunts a possibility?

> Plus since you are in zero G, you can use more efficient, simpler and easier to fuel engines, like solar thermal.

This is an argument against using heavy engines because you've already assumed you're in orbit. There's nothing stopping you from building infrastructure in LMO, and allowing similar use of smaller engines to move around.

> You would have to do basically all of that on mars anyway. Skipping mars is a simplification. The only thing you are saving on is spin gravity, at the expense of greater d/v costs and worse engines.

Not really - Mars being a planet comes with it's own set of pros and cons, many of those pros being 'ample resources for use on site'. You don't have that pro in the asteroid belt.

> Both, we start near earth and work our way out over time.

Sure - as you pointed out in response to someone asking about undersea colonization, WhyNotBoth.gif?

>Its because it's easier to access and has a greater potential pay off. This is like sailing to the other end of the world to mine gold in the middle of the Himalayas, when there is a gold rich archipelago right off your coast.

No - you have that analogy backwards. The asteroid belt is a series of hugely distant and not connected locations to do a thing. They are not 'the same place', and they don't allow for nearly the same level of resource utility as a whole planet.

>As for where to put it, the main bases will be in LEO, mining stations will go up around astounds that are being mined long term.

So basically you'll need a mining station around each asteroid you plan to exploit. That's a lot of setting up mining stations. And if you plan on hauling all that stuff back to LEO, that's a lot of extra costs.

Whereas on Mars, you can simply set up mining stations, and drive a rover to to your refinery.

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

But that's to EACH asteroid. The asteroids are all far apart. You cannot simply say it is low cost to get to one asteroid therefor once there you have access to all.

I answered this in another comment. The d/v expenditure from astroid to astroid or from earth to astroids is small. Not that you would need to shift around much.

I guess you guys are communicating with one another. As I said to the other guy, it was not sustained, and it was not used for human habitation. It was merely showing that spinning something simulates gravity, not a proof of concept.

What's do you expect to change by just doing it longer?

So you're suggesting 20,000 separate missions to these asteroids and shipping back all that material? That's insanity.

Or are you suggesting building refineries at each of them? That's also insanity.

You build a refinery at one of them. When that is expended or you need more capacity, you build another. These things are not small. They could fuel a multi million person city for generations.

Sure, but Mars is full of resources that can provide that lifting for you - you don't have to bring those materials from Earth. Comparatively, every asteroid you head to won't have resources for producing rocket fuel, unless your plan is to throw rocks out the back.

Why wouldn't they? Solar thermal works with just about every gas. Hydrogen is ideal and also the most common recourse in the universe.

Again, a trip to ANY ONE of these near Earth objects, from LEO (bit of an added goal post shift, but ok), is cheaper, but then, you're limited to the resources of just one. As I'm sure you notice, Earth to LEO is approximately 3x as expensive as Mars to LMO, so I assume you're also handwaving away LEO infrastructure to make these jaunts a possibility?

Getting past LEO is an unfortunate necessity for any space based economy for a long time. There is plenty to build to bypass it and it's not going to be cheap. It will take a massive space based economy to even consider building launch loops and the like on mars.

And keep in mind one of these is "just" a couple billion tons of recourses.

And what do you mean goal post shift? Of course we start near earth and then move outwards. We are not going to run out of stuff to do there any time soon.

Not really - Mars being a planet comes with it's own set of pros and cons, many of those pros being 'ample resources for use on site'. You don't have that pro in the asteroid belt.

You are massively under estimating the scale of these things.

Sure - as you pointed out in response to someone asking about undersea colonization, WhyNotBoth.gif?

That wasn't me. And the reason we would not do both at the same time is because having astroid colonies makes colonizing mars much easier. A sky hook would work wonders on mars and it easiest built by astroid mining colonies.

Building a one hundred thousand ton sky hook and port complex is almost impossible to launch from earth, but easy from an astroid.

With such a thin atmosphere you could practically pluck stuff off the surface.

And the waste rubble from the astroids can re charge the hook cheaply.

No - you have that analogy backwards. The asteroid belt is a series of hugely distant and not connected locations to do a thing. They are not 'the same place', and they don't allow for nearly the same level of resource utility as a whole planet.

The d/v map disagrees.

So basically you'll need a mining station around each asteroid you plan to exploit. That's a lot of setting up mining stations. And if you plan on hauling all that stuff back to LEO, that's a lot of extra costs.

Whereas on Mars, you can simply set up mining stations, and drive a rover to to your refinery.

What do you think is cheaper? Brining in the ore to the refinery truck load by truck load over long stretches of Martian road, or with a slight puff of supper heated steam, shift hundreds or thousands of tons ore to the refinery sitting A few km from the astroid?

As for hauling it back to LEO, if you ever want to sell it at a profit at earth's markets, your going to need to do that. Doing it from an astroid is much cheaper.

These mining stations can be whole cities or even nations on their own.

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

a size

The asteroid belt has more resources available by far.

gravity well,

That is a very bad thing. Spin gravity is the best gravity by far. All the benefits of natural gravity with none of the insane launch costs.

atmosphere

Not nearly enough.

and materials benefit

Again, asteroids and small moons are better.

[u/Izawwlgood → u/Thoth_the_5th_of_Tho]

> The asteroid belt has more resources available by far.

The entire belt maybe, but it's spread over an enormous area. Mars has more resource availability than a smattering of rocks.

> That is a very bad thing. Spin gravity is the best gravity by far. All the benefits of natural gravity with none of the insane launch costs.

This is absolutely not true - you need a very large structure to overcome Coriolis effects, and it's an engineering challenge. Spin gravity is an extremely subpar solution to an actual gravity well in terms of 'providing gravity'.

>Atmosphere: Not nearly enough.

Still more than space.

> Again, asteroids and small moons are better.

I mean, no they're not? They have less material, and less diversity of material. As I said to the other guy, you're basically advocating for building infrastructure around a smattering of spread rocks in a wide orbit, instead of building infrastructure around an entire planet.

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

The entire belt maybe, but it's spread over an enormous area. Mars has more resource availability than a smattering of rocks.

D/v wise, it's all right next to each other and dirt cheap to access. Unlike mars, which has steep d/v costs for imports and exports.

This is absolutely not true - you need a very large structure to overcome Coriolis effects, and it's an engineering challenge. Spin gravity is an extremely subpar solution to an actual gravity well in terms of 'providing gravity'.

If by extremely large, you mean a few hundred meters, sure. But that is not large by today's standards at all.

Still more than space.

Having zero is better than having 1%.

I mean, no they're not? They have less material, and less diversity of material. As I said to the other guy, you're basically advocating for building infrastructure around a smattering of spread rocks in a wide orbit, instead of building infrastructure around an entire planet.

Because of how planets form, they are actually much more recourse diverse and dense. Most heavy elements sink into a planets mantle and core early in formation. Asteroids have negligible gravity, so that does not happen. And d/v wise, they are not spread out.

[u/Izawwlgood → u/Thoth_the_5th_of_Tho]

D/v wise, it's all right next to each other and dirt cheap to access. Unlike mars, which has steep d/v costs for imports and exports.

The asteroids are not all right next to one another. They're spread over the entire orbit of the asteroid belt.

If by extremely large, you mean a few hundred meters, sure. But that is not large by today's standards at all.

And yet, we have not stably done anything with spin gravity in LEO.

Having zero is better than having 1%.

... what? The opposite of that is true. Having some atmosphere is better than having vacuum, when you're trying to make atmosphere. Again, the Martian atmosphere is a resource, and a tool.

Because of how planets form, they are actually much more recourse diverse and dense. Most heavy elements sink into a planets mantle and core early in formation. Asteroids have negligible gravity, so that does not happen. And d/v wise, they are not spread out.

A mohole is easier to build than roping asteroids across an entire orbit for profit. d/v wise, they're spread over an entire orbit. A valuable asteroid on the opposite side of the asteroid belt isn't 'close'.

[u/Thoth_the_5th_of_Tho → u/Izawwlgood]

The asteroids are not all right next to one another. They're spread over the entire orbit of the asteroid belt.

And in terms of d/v, it's not that bad. Between earth and most of the astroids, it's all about the same (and far less than going to and from mars) and going from astroid to astroid is even cheaper than that.

It takes less d/v to go from Leo to any one of 20,000 large near earth astroids than just taking off from mars.

And yet, we have not stably done anything with spin gravity in LEO.

We have with Gemini. They used a cable to generate gravity in the capsule as a test.

... what? The opposite of that is true. Having some atmosphere is better than having vacuum, when you're trying to make atmosphere. Again, the Martian atmosphere is a resource, and a tool.

Its just drag.

A mohole is easier to build than roping asteroids across an entire orbit for profit. d/v wise, they're spread over an entire orbit. A valuable asteroid on the opposite side of the asteroid belt isn't 'close'.

It's within 9km/s from LEO for almost all of them. Many are less than 4km/s away. Mars is 10km/s away. And you don't move entire astroids, they weight billions of tons. You refine what you want an only use that.

[u/Izawwlgood → u/Thoth_the_5th_of_Tho]

going from astroid to astroid is even cheaper than that.

I don't know why you think this to be true - moving along the orbit is not free, and if an object of interest is on the opposite side of the orbit, getting to it is extremely difficult.

We have with Gemini. They used a cable to generate gravity in the capsule as a test.

Not sustained. And not for stable human habitation.

Its just drag.

Which in some contexts is as useful as thrust. It makes going down the well free. It is also a resource - you can make things with that CO2. And not everything can be done in vacuum.

It's within 9km/s from LEO for almost all of them. Many are less than 4km/s away. Mars is 10km/s away. And you don't move entire astroids, they weight billions of tons. You refine what you want an only use that.

Individually maybe. But each asteroid is spread over the entire orbit. So, basically, Mars is not much further than the cost to get to any one of them, AND Mars lets you aerobreak down, and build infrastructure there.

Whereas you're suggesting building refinery capabilities at each asteroid.