Colonizing Mars

[modest]

Originally Posted by Titas Aduksus

OK,

If I were to be given the task of colonizing Mars with the facilities and technologies of today I think it would go something like this, (with acknowledgement to Bob Newhart)...

I would plan the building of a shaft sunk into the ground at such a shallow angle below the horizon, and continue this shaft until it re-emerged that at it's deepest point the collected atmosphere within the tunnel would be close to 1 earth atmosphere.

At this depth a large cavern could be excavated to house the neccessary life support systems for both plant and human habitation

This is an interesting idea. We could figure the depth such a tunnel would need to reach on Mars to attain 1 earth atmosphere's pressure. The equation for atmospheric pressure at height is given by:

where p is pressure, is pressure on the surface, h is height above / below the surface, and is the so called "scale height" equal to . On mars the values are:

= 7 mb
= 10.6 km
-source

To solve for pressure as a function of h we rearrange:

And now to solve for 1013 mb (earth's atmospheric pressure at sea level)

So, in order to have a pressure on mars equivalent to earth we would need to dig a hole 52.73 kilometers deep. The deepest mine shaft on earth is 3.5km and the deepest we've been able to drill (a small hole) is 15 km. Therefore, there's probably a good argument to be made that making a ~50 km hole on Mars would have seemingly insurmountable practical problems. Rather than saying it's completely impossible, I would just say that making an airlock system for a shallow tunnel would be easier.

It also might be interesting to know how long this tunnel would be if it is constructed how Titas explains:

Originally Posted by Titas Aduksus

I would plan the building of a shaft sunk into the ground at such a shallow angle below the horizon, and continue this shaft until it re-emerged that at it's deepest point the collected atmosphere within the tunnel would be close to 1 earth atmosphere.

Knowing the radius of mars is 3390 km and the maximum depth of the tunnel would be 52.73,

The length of OE is AO-DE or 3390-52.73 = 3337.27. As , the total length of the tunnel would be,

And, again, the longest tunnel on earth (which isn't yet complete) is the Gotthard Base railway tunnel at 57 kilometers. The one on mars would be 20 times as long as anything we've done on Earth.

It's an interesting idea to think about, but I think there would be easier ways to build a settlement on mars.

~modest

[Eclipse Now]

Originally Posted by Titas Aduksus

Terraforming Mars is just not going to happen, we can't even keep the earth terraformed at the moment! colonizing Mars is possible but ONLY if it is done the way I laid out above, it can be done using mostly robotics, there's no argument, you know it makes sense!

"Mankind will never fly, it is simply not possible!"

"If God had meant mankind to fly, he'd have given us wings".

"There might be room for about 4 Computers in the world".
(Wasn't that from the head of IBM decades ago?)

"Women will never have the vote!"

"These United States of America can never have a strong economy without slavery!"

Titas, mere assertion is not an argument. Just dogmatically coming in and calling people names is not only rude, but poor argument form. Try backing up your argument with some data we can debate. The data above seems pretty devastating to your dogmatism that it is the ONLY way to do it?

Also keep in mind that it only takes a few advances from where we are now to begin some sort of terraforming on Mars, and you and I don't know the future or which tiny inch forward in one new technology will open up all sorts of other technological possibilities in other industrial applications. Nano-tech and materials science seems the great unknown, as does biomodification. One super-bug could probably do about 50% of the terraforming? It's just hard to know.

[Titas Aduksus]

Thanks Modest, I lost my calculations of years ago when I first had this idea, I was going to repeat them. Yes there would be problems. On earth tunnels are affected by geological instability caused through techtonics, such activities may not be such a consideration on mars. Will reply more fully later when work allows. Also tunnel would be inhabited during construction thus fully used (unlike tunnels on earth which provide no return until fully completed, thus time and length less of a problem, construction may also be simpler. Another benefit if Mars was always relatively geologically inactive then sub surface strata may be more stable and uniform than that which we tunnel through here on earth.

Thanks again.

I know I seem arrogant but I have thought through my ideas, and am a determined person.

[Eclipse Now]

Originally Posted by Titas Aduksus

Thanks Modest, I lost my calculations of years ago when I first had this idea, I was going to repeat them. Yes there would be problems. On earth tunnels are affected by geological instability caused through techtonics, such activities may not be such a consideration on mars. Will reply more fully later when work allows. Also tunnel would be inhabited during construction thus fully used (unlike tunnels on earth which provide no return until fully completed, thus time and length less of a problem, construction may also be simpler. Another benefit if Mars was always relatively geologically inactive then sub surface strata may be more stable and uniform than that which we tunnel through here on earth.

Thanks again.

I know I seem arrogant but I have thought through my ideas, and am a determined person.

Unless we come up with super-cheap "Mr Fusion" power, I just don't think 52 km's deep is worth it compared to the other alternatives. But until that time, we'll pretty much rely on wind turbines, solar thermal energy, solar PV, etc..... (and whatever nuclear fuel is left after "peak uranium" hits, which is why I'm against nuclear power here on earth when solar thermal is cheaper. We'll need our uranium for Mars!)

52 km's is a LONG lift ride to get to the surface to maintain our energy systems and agriculture.... let alone a long, deep, nasty tunnel to build.

Financially if I were running the colony I'd rather mine out a subsurface underground colony as suggested by many Mars colonising sites, and pay for a series of 10 airlocks to the colony. (And of course have regular airlocks within.)

However, if "Mr Fusion" reactors arrive and we've got a fusion powered tunnel borer and no worries about cost, then why not? With "Mr Fusion" on board, there are no limits. We could eventually sculpt out an underground paradise and forget about the surface altogether. Gosh, the recycling systems they'd have to have would make a permaculture systems engineer weep with joy to behold.

[Moontanman]

Enow, the peak Uranium idea ignores Breeder reactors, Fast breeder reactors, and thermal breeder reactors which convert thorium into usable fissionable materials. the breeder reactors can increase the supply of uranium by 100 fold and after that is gone we have three times as much thorium as uranium to use in thermal breeder reactors. Peak uranium is an idea that assumes quite a bit too much about only using U-235 and ignores U-238, plutonium and thorium.

[Eclipse Now]

For sure, but here on earth I think the main barrier is cost. Peak uranium will make reprocessing more economically viable within the nuclear industry, but my guess is that as peak oil, gas, and coal eventually kick in over the next few decades the true cost of energy systems is going to become far more apparent. As solar thermal plants scale up, economies of scale really start to kick in and companies like Ausra in California are promising baseload solar competetive-with-coal sometime soonish.

So while reprocessed uranium may sound like a great idea, but maybe it only makes economic sense on Mars? And then we've got to get it there. Cost, cost, cost.

Part of me still wonders if Polywell will prove to be almost as good as Back to the Future's Mr Fusion, but we will see. Polywell - Wikipedia, the free encyclopedia



As I said above, we're inching forward in all sorts of areas and it only takes a breakthrough in one area to have massive implications in other industries. So giant artificial magnetosphere's, balloon assisted floating atmospheric "wraps" or even deep underground civilisations may be possible in 100 years. We shall see. We've got to get through peak oil and overpopulation here first though!

(Yes there's plenty of types of renewable energy, but most of them produce electricity not liquid fuels. We face a massive and serious liquid fuels and transport crisis in the next few years, probably leading to a Greater Depression... but decades after that our grandchildren will be living in cleaner, greener cities... and who knows what they will achieve?)

[Moontanman]

The polywell is a cool looking device, I hope it works but do you think there is no Uranium on Mars? to be honest I'm not sure how usable all the solar and other green technologies will be, everyone seems to think they will make fission obsolete but in space nuclear is the only real way to power large space craft. solar is far to weak as is chemical. large power sources are needed to power space craft, and martian colonies. Even our own space probes would be many times more effective if nuclear power as used instead of solar or thermal isotope power (I know that technically that is nuclear but it's still weak compared to fission)

[Eclipse Now]

I've never read what the concentrations might be on Mars? If you think there is viable quantities of uranium on Mars.... cool! At least Mars will never get hooked on cheap oil and then have to go through an unnecessary and painful withdrawal process**. Mars will be all "Moonbase alpha" elevators and tunnels if underground... with I imagine very, very local economies managing local industrial and biological ecologies.

(** Once we on Earth are in the "electron economy" we should be OK though... whether that is Battery Electric Vehicles or more trains, trams and trolley buses remains to be seen).

PS: Check out who promoted the Polywell reactor. He's even got a part of the Star Trek Enterprise named after him! Let alone being mentioned in Niven and Pournelle's "Footfall" with the aliens using a Bussard Ramjet.)
Robert W. Bussard - Wikipedia, the free encyclopedia

Lastly, have you read the Mars trilogy by KSR?

[Moontanman]

I wondered if it was the same Bussard.

Since I subscribe to Thomas Gold's ideas on "fossil" fuels I think we are likely to find natural gas, oil, and coal on Mars. Possibly harvesting oxidizers from the surface will be more of limiting factor than hydrocarbons.

Yes I have read the Mars trilogy. great books, I always liked Heinlein's Mars but sadly it didn't turn out to be real

[Eclipse Now]

Oh no... not Gold? I thought that was still "out there" as a bit of a crank theory?

The geological argument against
Oil deposits are not directly associated with tectonic structures.

Key arguments against chemical reactions, such as the serpentinite mechanism, as being the major source of hydrocarbon deposits within the crust are;

* The lack of available pore space within rocks as depth increases
o This is contradicted by numerous studies which have documented the existence of hydrologic systems operating over a range of scales and at all depths in the continental crust. [49]
* The presence of no commercial hydrocarbon deposits within the crystalline shield areas of the major cratons especially around key deep seated structures which are predicted to host oil by the abiogenic hypothesis [31]
* Limited evidence that major serpentinite belts underlie continental sedimentary basins which host oil
* Lack of conclusive proof that carbon isotope fractionation observed in crustal methane sources is entirely of abiogenic origin (Lollar et al. 2006)[3]
* Mass balance problems of supplying enough carbon dioxide to serpentinite within the metamorphic event before the peridotite is fully reacted to serpentinite
* Drilling of the Siljan Ring failed to find commercial quantities of gas[31], thus providing a counter example to Kudryavtsev's Rule and failing to locate the predicted abiogenic gas
o Helium in the Siljan Gravberg-1 well was depleted in 3He and not consistent with a mantle origin[50]

* The distribution of sedimentary basins is caused by plate tectonics, with sedimentary basins forming on either side of a volcanic arc, which explains the distribution of oil within these sedimentary basins
* Kudryavtsev's Rule has been explained for oil and gas (not coal): Gas deposits which are below oil deposits can be created from that oil or its source rocks. Because natural gas is less dense than oil, as kerogen and hydrocarbons are generating gas the gas fills the top of the available space. Oil is forced down, and can reach the spill point where oil leaks around the edge(s) of the formation and flows upward. If the original formation becomes completely filled with gas then all the oil will have leaked above the original location.[51]
* Ubiquitous presence of diamondoids in natural hydrocarbons such as oil, gas and condensates are composed of carbon from biological sources, unlike the carbon found in normal diamonds.[52]

[edit] Arguments against the incidental evidence

* Gas ruptures during earthquakes are more likely to be sourced from biogenic methane generated in unconsolidated sediment from existing organic matter, released by earthquake liquefaction of the reservoir during tremors
* The presence of methane hydrate is arguably produced by bacterial action upon organic detritus falling from the littoral zone and trapped in the depth due to pressure and temperature
* The likelihood of vast concentrations of methane in the mantle is very slim, given mantle xenoliths have negligible methane in their fluid inclusions; conventional plate tectonics explains deep focus quakes better, and the extreme confining pressures invalidate the hypothesis of gas pockets causing quakes
* Further evidence is the presence of diamond within kimberlites and lamproites which sample the mantle depths proposed as being the source region of mantle methane (by Gold et al.). [23]

Abiogenic petroleum origin - Wikipedia, the free encyclopedia

In any case, the oil is demonstrably not refilling in old fields in any measurable rate fast enough to offset the peak oil crisis.

If Gold is right, there might be a little oil on Mars... if the temperatures were ever high enough there for it to form... and high enough long enough? But the main issue is getting there with an economic incentive to do so. For that we might need big business motivated by minerals exploration and either advances in launch systems or something straight out of KSR, like the space elevator.