Why colonize Mars and not the Moon?

[1oldman2]

This could be useful.
http://hdl.handle.net/2060/20150016539

 

[mfb]

So yes, as you say, two vehicles. They dock in LEO, and as they transfer the payload they also transfer some Lunar fuel to the re-entry module.

LEO? I guess you mean a low lunar orbit (LLO).
You can replace the Lunar ascent/descend module with the space elevator, that also lowers delta_v requirements for the Moon/Earth transfer.

How did we start off making things on Earth without the original Uber-Tool that makes all the others?

With centuries of tools used to make better tools we established a complex network where you need parts from hundreds of companies to build anything. That won't work on Moon.

I didn't ask for a reference that you can pick up clumps of iron mixed into sand. I asked for a reference that you can pick up something valuable with a magnet on Moon. That is a completely different thing.

 

[Drakkith]

In the oxygen poor environment on the Moon, we know that some iron exists as ore, and some as pure iron or nickel iron. Metoerites, for example. Sweep a magnet over the lunar dust and it will jump out of the ground for you.

I seriously doubt that.

Why is there a feeling that "we've done the Moon, and it's barren"? A hang-over from Apollo? Like writing off Earth because you landed in the Pacific and found just clear salt water, and in the Sahara and found just sand.

In the last several years other space agencies sent probes to the Moon, with new technology they looked in new places, and they re-wrote the book. Several more probes by NASA and others, and we now have a big book of questions, mostly starting with "How much of this stuff is there?"

Well, the Moon is big. There's probably a lot.

Well, many of the chemicals and materials we use here on Earth are not located on the Moon for the simple reason that life has never existed there.

 

[sophiecentaur]

Well, many of the chemicals and materials we use here on Earth are not located on the Moon for the simple reason that life has never existed there.

Whilst that is probably true, we make a lot of use of totally non-organic based chemicals.

 

[Al_]

LEO? I guess you mean a low lunar orbit (LLO).
You can replace the Lunar ascent/descend module with the space elevator, that also lowers delta_v requirements for the Moon/Earth transfer.

Doh! I missed a trick here. I meant LEO, but you point out a useful saving too.

Three vehicles is the most fuel efficient arrangement.
1. Moon to LLO, and back. Carries the payload and 2 types of fuel up to the ion motor tug in LLO.
2. Ion motor tug. Using very little fuel and carrying payload and fuel from LLO to LEO, then cycling back to LLO.
3. LEO to re-entry, picks up fuel and payload from 2, releases payload into a precise re-entry trajectory, then boosts back to LEO without re-entering.

Number 2 is the leg that takes the most time, so you could have dozens of those on route and one of the others at each end.
- but that's after you build up the business.

(Space elevator is a neat idea, but I started this whole Moon mining tangent to say; there's a way to get the colony making some cash in it's early stages.
I'm thinking; putting some rockets and landers up there is going to happen faster than sending an elevator cable?
btw, while I'm talking cables, maybe a bolus would be more use because it imparts a velocity on leaving the space end? And it's shorter.
https://en.wikipedia.org/wiki/Momentum_exchange_tether#Cislunar_transportation_system)

Magnetic mining: https://www.researchgate.net/publication/224662745_Magnetic_Separation_of_Lunar_Soils

 

[Aditya Shende]

Still I don't agree on colonizing moon instead of Mars

I seriously doubt that.
Well, many of the chemicals and materials we use here on Earth are not located on the Moon for the simple reason that life has never existed there.

I agree with u bro

Can you provide some evidence for this statement?In the oxygen poor environment on the Moon, we know that some iron exists as ore, and some as pure iron or nickel iron. Metoerites, for example. Sweep a magnet over the lunar dust and it will jump out of the ground for you.Why is there a feeling that "we've done the Moon, and it's barren"? A hang-over from Apollo? Like writing off Earth because you landed in the Pacific and found just clear salt water, and in the Sahara and found just sand.

In the last several years other space agencies sent probes to the Moon, with new technology they looked in new places, and they re-wrote the book. Several more probes by NASA and others, and we now have a big book of questions, mostly starting with "How much of this stuff is there?"

Well, the Moon is big. There's probably a lot.Not autonomous, but remotely controlled.
And "industry" makes it sound big. You can start with a unit that makes a few gallons of fuel a month.
Then add a rover that sweeps a magnet along the surface collecting iron.
A robotic concentrating mirror to fuse dirt.
A basalt fibre spinner.
etcBut - going up from Earth is the most expensive step, and there's no absolute need for it in this cycle.
All you need to drop down is the precious metal, so all your expensive kit can stay up.

Ok bro
See
Sweeping a magnet over ain't going to help
I m guessing that u think the moon has got solid blocks of ores of iron , etc.
NOT TRUE
The surface of the Moon has been subject to billions of years of collisions with uncountable space rocks .These impacts have pulverized and churned up the metals,etc. Forming a layer on the moon's surface
Its called regolith
It's 20 metres thick
So I don't think sweeping a magnet is going to help
[emoji28][emoji28][emoji28]

 

[sophiecentaur]

maybe a bolus would be more use because it imparts a velocity on leaving the space end?

The vehicle at the top end of the tether is in lunostationary orbit. That involves significant KE (the equivalent to the work done getting it there - but you know that). I can't think of a system that would give the vehicle more velocity for a given amount of work done. How would the bolus (bolas?) function? A winch on the surface? That would be more efficient than a rocket but how much extra KE would you get? All these things are so much easier to arrange on the Moon. No weather and very few objects to run into - plus easier engineering.
A bolus is the lump of chewed food that's formed just before we swallow. Thanks to Mr Jackson, my Biology master. He's 90+ and I met him last year after more than 50 years.

 

[sophiecentaur]

Its called regolith

Interestingly, regolith would be very well suited to surface mining (more like ploughing) with various methods of separating the various component parts. Separation by magnetisation, by size, by density. Lack of atmosphere would mean dealing with the dust could be done by panning methods. On the whole, it could be much more convenient than it is on Earth - at least for the first pickings. Then there's no NIMBYs and no sacred sites or sites of special Scientific interest.

 

[mfb]

Three vehicles is the most fuel efficient arrangement.
1. Moon to LLO, and back. Carries the payload and 2 types of fuel up to the ion motor tug in LLO.
2. Ion motor tug. Using very little fuel and carrying payload and fuel from LLO to LEO, then cycling back to LLO.
3. LEO to re-entry, picks up fuel and payload from 2, releases payload into a precise re-entry trajectory, then boosts back to LEO without re-entering.

Why do you want to go to LEO at all? Going from LEO back to anything is such a waste of fuel - several km/s delta_v.
1. Moon to LLO and back with chemical rockets, if the lunar space elevator doesn't work out.
2. LLO (or space elevator counterweight) to highly eccentric Earth orbit. On Earth approach, release the payload, then raise the perigee enough to avoid the atmosphere.

With a rotating tether at the space elevator, you don't need spacecraft (1) and you can directly release spacecraft (2) on a suitable orbit. Total delta_v for the whole delivery: ~400 m/s to get back from the elliptic orbit to meet with the counterweight, or 600 m/s to meet at the Lagrange point.
Momentum exchange tethers are an interesting concept, but significantly beyond current technology. And based on the Wikipedia article you need a similar total tether mass.

Magnetic mining: https://www.researchgate.net/publication/224662745_Magnetic_Separation_of_Lunar_Soils

They sifted through sub-millimeter grains with some high-tech equipment and got some enrichment in ilmenite (FeTiO₃) and pyroxene (silicon, aluminium, oxygen, and various other metals mixed together). That is not just holding a magnet over the lunar surface, and the result is not iron.

 

[sophiecentaur]

That is not just holding a magnet over the lunar surface

I don't think anyone thought the clause was to be taken literally.

 

[Drakkith]

I don't think anyone thought the clause was to be taken literally.

I did. Perhaps erroneously.

 

[Aditya Shende]

Interestingly, regolith would be very well suited to surface mining (more like ploughing) with various methods of separating the various component parts. Separation by magnetisation, by size, by density. Lack of atmosphere would mean dealing with the dust could be done by panning methods. On the whole, it could be much more convenient than it is on Earth - at least for the first pickings. Then there's no NIMBYs and no sacred sites or sites of special Scientific interest.

You ain't getting the problem.
Ok ,
Consider it like this ,
On Earth there's dust everywhere it's in the air .
In the same way on moon there's dust everywhere the only difference is that the lunar dust has got SPIKES on it.

Dust on Earth has been jostled about by wind and water, rounding off the sharp corners.
While the Lunar dust has sharp edges, very abrasive because there's no water and lack of winds to wear off the edges. This poses a problem because it gets into moving parts and causes problems.
It also messes up seals to keep enclosures airtight.

So about mining and stuff that you are talking about won't work coz the mining , separating equipments ,etc have got moving parts and regolith messes up with them it doesn't matter if you try to keep moving parts sealed .
It still would mess them up (as I said above).
So, I don't think it's going to work.

PS: the moon doesn't lack atmosphere
It actually has an atmosphere that's
why there's lunar dust.

 

[Drakkith]

So about mining and stuff that you are talking about won't work coz the mining , separating equipments ,etc have got moving parts and regolith messes up with them it doesn't matter if you try to keep moving parts sealed .
It still would mess them up (as I said above).
So, I don't think it's going to work.

While certainly an obstacle, I doubt a little spiky sand is a obstacle that cannot be overcome.

 

[Aditya Shende]

While certainly an obstacle, I doubt a little spiky sand is a obstacle that cannot be overcome.

Well it's not just a little spiky sand
It's a 20 m thick layer of regolith
It's the churned form of
iron+ silicon+ Manganese+ Magnesium+ calcium+ aluminum+titanium+ glass
That's a lot deadly things churned up
And it's all spread in the atmosphere of the moon
It's in the air
Probably yes
It can be overcome
But still moon isn't a place suitable for colonizing
Building a space station on moon?
Great idea
But colonizing on moon
Not such a great idea

 

[Drakkith]

Well it's not just a little spiky sand
It's a 20 m thick layer of regolith
And it's all spread in the atmosphere of the moon

Estimates place the total mass of the dust in the 'atmosphere' of the Moon at 120 kg. This is an extremely small amount of dust and is unlikely to cause significant issues. The dust in the regolith is a much larger problem, but I see little reason to believe dust is a major inhibitor in colonizing the Moon.

 

[Aditya Shende]

Estimates place the total mass of the dust in the 'atmosphere' of the Moon at 120 kg. This is an extremely small amount of dust and is unlikely to cause significant issues. The dust in the regolith is a much larger problem, but I see little reason to believe dust is a major inhibitor in colonizing the Moon.

Yep
Ok
I just said
It isn't impossible to overcome this problem
But colonizing moon ain't such a good idea
Building a space station on moon=great

Colonizing on moon = not so great

Colonizing on Mars= great

 

[sophiecentaur]

It's in the air

What is in what "air"?
Compare the way a 'cloud' of dust behaves on Earth and how the dust from the wheels of the Lunar Rover behaves in that famous film.
You may not like the idea of colonising the Moon (I rather share your opinion on that) but I really don't think that the mineral gathering technology would need to be all that different from what's used in deep mining on earth. The dust and shards in a mine haven't been weathered; they've only just been exposed.
But, as usual, we haven't defined what we mean by 'a Colony'. Any station on the Moon would not be a holiday camp and only a minimum of human staff would be needed. (The management would all be tucked up in their posh ranches on Earth). How many staff does it take to make a 'colony'?
For Mars, the cost of transport is so much higher that staff would need to be there for much longer; long enough to breed? That would be one definition of a colony. We would be talking in terms of hundreds of colonists. Ye gods, there go all my taxes.

 

[Al_]

The surface of the Moon has been subject to billions of years of collisions with uncountable space rocks

Yes, exactly. It's those rocks themselves that bring the Iron. Some of them are Iron meteorites.

It's 20 metres thick

What, everywhere? Can you provide a reference?

But, as usual, we haven't defined what we mean by 'a Colony'.

Can I suggest a definition: People go to stay, and have children. Enough of them so the children can stay and have families.

Colonizing on moon = not so great

Why? I just don't get this. Sure, Mars looks prettier, and it has a kinder day/night cycle.
But the Moon should be first, because it would be much quicker, and it gives a really useful platform to go further and more easily.
What we learn on the Moon is very likely to be useful elsewhere, and it's material resources too.
Mars is down a deep gravity well. So, in the Solar System's economy of the 22nd century, it will be an isolated backwater compared to the asteroids, trojans, rings and small moons.

For Mars, the cost of transport is so much higher that staff would need to be there for much longer; long enough to breed? That would be one definition of a colony. We would be talking in terms of hundreds of colonists. Ye gods, there go all my taxes.

Elon Musk's idea is that it would be self-funding. He might even be right!
"Need to be there" you say? Like it's an difficult mission? Can't wait to get home?
Imagine, you're on the Moon. You are making a fortune from precious metals, TV rights sales, comms, etc. You buy architect services and robots from Earth and they build you a palace with gardens, pools, low-g sports gym, etc. Now, want to go home?
If Elon does start to offer tickets I will be looking for the Lunar Return prices!

 

[sophiecentaur]

Yes, exactly. It's those rocks themselves that bring the Iron. Some of them are Iron meteorites.

This all puts me in mind of the way 'they' extract gold from sediments. They go over the same river bed time and time again, squeezing harder every pass as the particles get smaller and the cost per gram goes up. Most of the Moon's surface is the equivalent to this river bed. No need to drill for a long long time.

 

[Al_]

This poses a problem because it gets into moving parts and causes problems.
It also messes up seals to keep enclosures airtight.

This problem has been solved.
Rotary seals like those used on Curiosity's wonky-looking arm are excellent at keeping out the most abrasive dust.
The seal itself can be made of an extremely hard ceramic. As it rotates it sheds any trapped particles outward from the axis, and at the same time grinds its surfaces flatter and closer together so they fit better over time.
The airlocks can use the same sealing method. And on the inner airlock door you can clean with gas before sealing.

 

[Aditya Shende]

What is in what "air"?
Compare the way a 'cloud' of dust behaves on Earth and how the dust from the wheels of the Lunar Rover behaves in that famous film.
You may not like the idea of colonising the Moon (I rather share your opinion on that) but I really don't think that the mineral gathering technology would need to be all that different from what's used in deep mining on earth. The dust and shards in a mine haven't been weathered; they've only just been exposed.
But, as usual, we haven't defined what we mean by 'a Colony'. Any station on the Moon would not be a holiday camp and only a minimum of human staff would be needed. (The management would all be tucked up in their posh ranches on Earth). How many staff does it take to make a 'colony'?
For Mars, the cost of transport is so much higher that staff would need to be there for much longer; long enough to breed? That would be one definition of a colony. We would be talking in terms of hundreds of colonists. Ye gods, there go all my taxes.

At least someone shares my opinion [emoji28]

 

[sophiecentaur]

At least someone shares my opinion [emoji28]

Only about the principle - not about the problems that you foresee about mining on the Moon.

 

[Aditya Shende]

Yes, exactly. It's those rocks themselves that bring the Iron. Some of them are Iron meteorites.What, everywhere? Can you provide a reference?Can I suggest a definition: People go to stay, and have children. Enough of them so the children can stay and have families.Why? I just don't get this. Sure, Mars looks prettier, and it has a kinder day/night cycle.
But the Moon should be first, because it would be much quicker, and it gives a really useful platform to go further and more easily.
What we learn on the Moon is very likely to be useful elsewhere, and it's material resources too.
Mars is down a deep gravity well. So, in the Solar System's economy of the 22nd century, it will be an isolated backwater compared to the asteroids, trojans, rings and small moons.Elon Musk's idea is that it would be self-funding. He might even be right!
"Need to be there" you say? Like it's an difficult mission? Can't wait to get home?
Imagine, you're on the Moon. You are making a fortune from precious metals, TV rights sales, comms, etc. You buy architect services and robots from Earth and they build you a palace with gardens, pools, low-g sports gym, etc. Now, want to go home?
If Elon does start to offer tickets I will be looking for the Lunar Return prices!

No
The moon is still not the place where we should set up our colonies
We know that the moon saves Earth from so many asteroid and space rock impacts
Just think
If such a space rock or asteroid hits the colony?
Still think moon is a better place to colonize than Mars
Answer: a)yes if the colonists want to die anyway
b)No if the colonists want to live
I would ho with b)

Only about the principle - not about the problems that you foresee about mining on the Moon.

Yes I got that
In 2 of my previous posts I said
'It's not a problem that we cannot overcome'
The thing is that
Moon is just not the right place to be colonized

 

[Al_]

We know that the moon saves Earth from so many asteroid and space rock impacts
Just think
If such a space rock or asteroid hits the colony?

The larger asteroids are very, very rare. They don't hit the Moon so much more often than they hit Earth. The smaller ones are not a problem if you live below metres of lunar regolith.
Even on Earth the large ones are a risk.
You can put enough regolith overhead to make the asteroid risk on the Moon the same as the risk on Earth.
Nothing and nowhere is zero risk.

 

[Aditya Shende]

Alright forget about the place for colonization (we both are never going to end up on a solution[emoji28])
We talked about ways to set up colonies like mining ,etc
What do you guys think about Terraforming ?

(Terraforming : Terraforming of a planet or moon, or other body is the process of deliberately modifying its atmosphere, temperature, surface, geology or ecology to be similar to the environment of Earth to make it habitable by Earth-like life.)

 

[Al_]

I did. Perhaps erroneously.

I meant it as an ideal case, picking the low-hanging fruit so to speak.
Given that we can spot pure Iron from orbit using spectral analysis, when we send the robot to pick it up, a magnet will probably work very nicely. Both for the main lump and some others that might be just below the surface.
Of course, later on, when scaling up the mining using less targeted methods, raking through acres of regolith, you may need to adapt this.

 

[Al_]

What do you guys think about Terraforming ?

I think that's a different thread!

 

[Aditya Shende]

I think that's a different thread!

Well let's talk about it here

 

[DrClaude]

Well let's talk about it here

No. Do not derail this thread with this off-topic subject.

Warning: threads on terraforming usually have a very short half-life because there is not much science and much speculation in them.

 

[Aditya Shende]

No. Do not derail this thread with this off-topic subject.

Warning: threads on terraforming usually have a very short half-life because there is not much science and much speculation in them.

Ok sorry
I am new to PF