Colonizing other planets

[todofwar]

On 4/6/2016 at 10:51 PM, fredinno said:

Because Co2 is much more different from water than Ch4, and is not normally considered a good alt. solvent for life until recently.

CH4 is probably as different from water as you can possibly get. Water is polar, an acid and a base, and has other properties that make it a unique solvent for chemistry to happen. CH4 is non polar, can't dissolve salts, and at liquid methane temps all chemical reactions will proceed extremely slowly. At least CO2 (I wouldn't say either is "closer to water") is at high temperature so chemistry can happen at a fast rate.

[fredinno]

5 hours ago, todofwar said:

CH4 is probably as different from water as you can possibly get. Water is polar, an acid and a base, and has other properties that make it a unique solvent for chemistry to happen. CH4 is non polar, can't dissolve salts, and at liquid methane temps all chemical reactions will proceed extremely slowly. At least CO2 (I wouldn't say either is "closer to water") is at high temperature so chemistry can happen at a fast rate.

But CO2 will be super-critical. We have no clue if any super-critical liquid can host life at all.

[fredinno]

14 hours ago, AngelLestat said:

Storm shelter?  you mean mars dust storm?  but we were talking about solar flares, you need a shelter against radiation, no practical vehicle can provide you that, you need at least 2 meters of dirt between you and the radiation.
The question here is how much time of warning you have before the radiation reach mars.

 

14 hours ago, AngelLestat said:

There is no wind!  the sound is not carried away!  If it were wind, is becoz you are not traveling at the wind speed, so this wind push you, you get an acceleration until you match the wind speed, then the apparent wind is zero.

It won't matter, you need to cover your head to avoid it being eaten away by acid

14 hours ago, AngelLestat said:

I notice that even the NASA team who did the Havoc mission concept, they were wrong with the zonal and meridional winds they quote for that mission requirement, which is a big difference because they would save at least half of power and storage to counter the meridional winds they claim.

LOL, you think NASA is wrong on their own mission plans?

That's it, turn down your ego meter. I'd trust NASA 10x more than you.

14 hours ago, AngelLestat said:

All these conditions plus density, makes Venus the perfect place for airships or floating habitats, if you need to build airships here on earth you need big hangar to protect the airships from the winds meanwhile is on construction, there is no need there, with special procedures it become very simple.

What if you're in an area where the winds converge?

[todofwar]

If you think Titan is habitable I have bad news for you. We're talking all the problems of our own moon plus you are at liquid methane temperature. Most of your energy use will go towards heating your base up. Granted, you are in a litteral sea of fossil fuels, but for my money Europa is the most promising of the potential moons (excluding our own). You can harness the geothermal from tidal heating, all the water you can drink and split into H2 and O2 for rocket fuel, and if you are on the bottom of the ocean there will probably be substantial shielding from radiation already.

4 hours ago, fredinno said:

But CO2 will be super-critical. We have no clue if any super-critical liquid can host life at all.

Supercritical CO2 is actually a pretty good solvent, used for industrial extractions all the time. I'm not saying as a solvent for life it's any better than methane, as you said we have no idea if either can host life. I just think supercritical CO2 is as promising as methane as a potential sovlent for life to form in, and the higher temps mean chemistry can move a bit faster. But this is all getting off topic.

[AngelLestat]

11 hours ago, fredinno said:

Videos mars radiation

Not sure why you post videos, the discussion has nothing to do,  even your last answer did not have much sense.

The question was..  Solar Flare..  in the case it reach mars from above you (so the planet does not protect you), 1/4 of the atmosphere is not enough to protect you from huge radiation doses,.
The only thing that you can answer here is go underground, in case the warning time is enough to reach that place.

Or shield from other way (but not using vehicles or the natural magnetic anomalies of the planet), they are not enough.
We are discussing permanent stay on mars... no missions.

Quote

It won't matter, you need to cover your head to avoid it being eaten away by acid

And?  you can still lessen..sounds can pass through solids..  meanwhile is not vacuum.   a simple thin layer of plastic, latex, vinyl, neoprene or even any material that just keep your skin away, even if is not h2so4 resistant does not matter, because there is so little that even a normal clothe would last several days, but only helps if they can stop the tiny droplets..

Quote

LOL, you think NASA is wrong on their own mission plans?
That's it, turn down your ego meter. I'd trust NASA 10x more than you.
What if you're in an area where the winds converge?

Here only your ego is the problem, I cant find other explanation, after you accuse me of being wrong on 50 or 100 different things, I prove all of them without difficulty (100%), but still, no sign of recognition yet from your part.

This is the info used for NASA on havoc:

This was extracted from the oficial mission pdf
https://www.dropbox.com/s/y5gu06h0u7n7v66/HAVOC-Final-Outbrief-General-pdf.pdf?dl=0

First to understand, if you read the pdf, it clearly said that the altitude will be 50km (and all other values like temperature and density match that altitude)

You wanna know from what place they extract that graphic and values?
From this book "venus 2":

https://books.google.com.ar/books?id=b93lEgkPquoC&pg=PA3&source=gbs_toc_r&cad=4#v=onepage&q=eastward&f=false

Page 465 and 466
You can see that in the text above the picture it said  "at cloud top", "70km", "ultraviolet (wavelength that measure the top cloud section)", so this graphic is not for 50km, is for the 70km region.
There is another way to prove that this graphic does not represent the 50km range.

They said that the longitudinal winds at that point are 85 to 100 m/s at equator with 110 hours to circulate the planet.
You can even see that they took 96m/s as average speed, only that speed can allow circle the equator in 110 hours.
Well, at 50km the average longitudinal winds are 60m/s, and at 70km is 100m/s.

You can check my previous post with links to see the graphics 
The northward wind they said that it is 5m/s, which this value represent the 70km altitude..  the real average value for 50km in the equator is close to zero.
They choose the equator mainly for this error, because at lower latitudes at 70 km is very hard to counter meridional winds, but you can be at 50km, latitude 60, in that case meridional winds are close to zero, the circunference is reduce to half, the wind is a bit higher than equator, the temperature is 10 degrees less and  your day/night cycle last 81 hours. 
They can even drag a kite or a small wind turbine to harvest energy day and night, but they dont know that, because I am the first guy in internet who come out with that idea, the same than the thermal gradient.

They dont even bother to search the modern data from the probe "venus express", which is included in the venus climate pdf I shown, because the wind at cloud top was rising these last 10 years in venus. although does not change much the winds at 50km range.

Fredinno?  what is the next excuse? 

Edited April 8, 2016 by AngelLestat

[fredinno]

8 hours ago, todofwar said:

 

If you think Titan is habitable I have bad news for you. We're talking all the problems of our own moon plus you are at liquid methane temperature. Most of your energy use will go towards heating your base up. Granted, you are in a litteral sea of fossil fuels, but for my money Europa is the most promising of the potential moons (excluding our own). You can harness the geothermal from tidal heating, all the water you can drink and split into H2 and O2 for rocket fuel, and if you are on the bottom of the ocean there will probably be substantial shielding from radiation already.

 

Yeah, and building a base under the sea will be a pain

I would build a base in the ice if I was going to Europa, and put the ascent vehicle in launch silos. Then use submarines to explore the ocean below. Even then, the temperatures are extremely cold, and you'll face a lot of the same temperature problems as on Titan.

But I think the Moon is the best place for humans right now.

1 hour ago, AngelLestat said:

12 hours ago, fredinno said:

 

Not sure why you post videos, the discussion has nothing to do,  even your last answer did not have much sense.

The question was..  Solar Flare..  in the case it reach mars from above you (so the planet does not protect you), 1/4 of the atmosphere is not enough to protect you from huge radiation doses,.
The only thing that you can answer here is go underground, in case the warning time is enough to reach that place.

Or shield from other way (but not using vehicles or the natural magnetic anomalies of the planet), they are not enough.
We are discussing permanent stay on mars... no missions.

Did you even watch the videos? Watch them. They show how it's fairly easy to build a storm shelter in a HAB, or on a pressurized rover.

The provisions and wall material blocks lots of radiation, and if you use the storm shelter tanks as water tanks for a closed loop system, or a backup water tank, you have a very good storm shelter.

1 hour ago, AngelLestat said:

Quote

 

And?  you can still lessen..sounds can pass through solids..  meanwhile is not vacuum.   a simple thin layer of plastic, latex, vinyl, neoprene or even any material that just keep your skin away, even if is not h2so4 resistant does not matter, because there is so little that even a normal clothe would last several days, but only helps if they can stop the tiny droplets..

Yes, as if Venusians will constantly be tethered to each other during EVAs just so they can hear each other. Why is sound such a big deal anyways? Radio is very well understood, and has been used in space since the beginning.

1 hour ago, AngelLestat said:

The northward wind they said that it is 5m/s, which this value represent the 70km altitude..  the real average value for 50km in the equator is close to zero.

As if you will constantly be at the equator. I thought one of the benefits of riding the winds was going wherever you want?

Either way, I see nothing about wind shear, which seems to be the bigger problem with these airships.

Edited April 8, 2016 by fredinno

[todofwar]

Well the moon is most logical stepping stone to the solar system, and will allow us to refine the ISRU technologies that have wide applicability like getting your life support as close to a closed loop as possible. And another problem I just thought of for Titan, you need oxygen. You can harness it from the ice on the surface or from rocks if someone can find a way to run SiO2 -> Si + O2 in a way that doesn't eat all your energy, but you will end up spending so much energy on getting the oxygen that I don't think you will see a return if you burn the fossil fuels for energy. Someone could check the thermodynamics, but assuming you use water as your oxygen source because it's easier, you need to see if the overall equation 2H2O + CH4 -> CO2 + 3H2 buys you any energy. I'm assuming not much at all, probably costs energy. So Titan has even worse energy problems than Mars cause solar is out, so you need some nuclear power. 

5 hours ago, fredinno said:

Either way, I see nothing about wind shear, which seems to be the bigger problem with these airships.

Wind shear is not too bad, depending on where you are. In fact, it provides a ready source of energy. From pictures of Venus I'm thinking any kind of long term settlement will be away from the equator because it looks like there's quite a bit of turbulance at the lower lattitudes, compared to those gentle looking collars closer to the polls. 

Getting back to Europa, I think the benefits of getting radiation shielding and access to geothermal (remember, solar is out for a settlement so far from the sun) outweighs the complications of being in an underwater base. I could be wrong, someone would have to do a detailed cost/benefit on transporting the geothermal generated energy closer to the surface or just building deep underwater. 

[fredinno]

3 hours ago, todofwar said:

but you will end up spending so much energy on getting the oxygen that I don't think you will see a return if you burn the fossil fuels for energy

You would only even use it for rocket fuel, as it would never see a return of energy by burning it.

3 hours ago, todofwar said:

Getting back to Europa, I think the benefits of getting radiation shielding and access to geothermal (remember, solar is out for a settlement so far from the sun) outweighs the complications of being in an underwater base. I could be wrong, someone would have to do a detailed cost/benefit on transporting the geothermal generated energy closer to the surface or just building deep underwater. 

There's also cryovolcanoes on Titan. http://www.space.com/10486-ice-volcano-saturn-moon-titan.html

This will have to be extracted for the force of the volcano, not the heat, due to how cold it is.

[insert_name]

2 hours ago, fredinno said:

You would only even use it for rocket fuel, as it would never see a return of energy by burning it.

There's also cryovolcanoes on Titan. http://www.space.com/10486-ice-volcano-saturn-moon-titan.html

This will have to be extracted for the force of the volcano, not the heat, due to how cold it is.

pretty sure titan has rivers of liquid methane, we can probably make a dam and use hydroelectric power but with methane

Edited April 8, 2016 by insert_name

[AngelLestat]

12 hours ago, fredinno said:

Yeah, and building a base under the sea will be a pain

It does not need to be under the sea, just under the ice, the same as a polar mars base.
The benefic that the same ice is your structure, you can add insulation layers to enable moderate temperatures without melt the ice.

Quote

But I think the Moon is the best place for humans right now.

I dont see any benefit for moon,   anything you can do on the moon, can be using teleoperated machines or even more usefull, capturing an asteroid in a close earth orbit.. so you save all the travel to the moon.
Extract water from lunar soil is not so easy either.  It can be done but a lot easier and practical is from asteroids. 

Quote

Did you even watch the videos? Watch them. They show how it's fairly easy to build a storm shelter in a HAB, or on a pressurized rover.

Post 4 videos (some of them of 1 hour) without even a single comment or exact video part in which it mention the info you wanna share, that is just a way to escape the question.
By the way.. I saw that documentary 2 years ago.
In the time it take you search all those videos, you could easily search the amount of shield you need to reduce in a considerable way the effects of a solar flare.
Well I did it, so now I can provide more accurate info:

Solar Flares

Treat:

You will have medium solar flare every 5 to 7 years on mars or a big one every 15 to 20 years, with radiation dose of 250msv (5x the max radiation limit  allowed for a nuclear worker in a year) or 1500msv for the big one.
On earth orbit is different due that is closer (inverse square rule), it takes the double amount of time between solar flares, because is harder to be in the path, but they strike with double intensity.

250msv - atmosphere = 200msv in a short time, is enough to feel instant radiation poison symptoms, but nothing severe, although increase the chance of health issues on long term. By the other hand 1500msv - atmosphere= 1200msv, this is enough to kill 1/5 of the population reached (without shielding) in a month and many other with health issues in the long term.     

Shielding:

If you want to have the same amount of radiation shielding provided it by the atmosphere, you need 11 meters of mars soil over your shelter, that is equal to 1000g/cm2 aprox.
You can reduce considerably the effects with much less, but if is not enough thick, you can even increase your health risk due a secondary radiation generated when this solar flare strike your shield.
There are materials rich in hydrogen that are good to prevent this secondary radiation arise like a polyethylene plastic called RFX1, water is also moderate good.
https://www.nasa.gov/pdf/284275main_Radiation_HS_Mod3.pdf

In the next two graphics we can see the effectiveness of shield vs some historical solar flares which total radiation dose is measured in REM, but no only depends on the total radiation, it also depends on the speed of the particles and other characteristics as we can see in the graphics. 
Example: you get 50g/cm2 of radiation shielding with 50cm of water shield thickness. 

http://www.lpi.usra.edu/lunar/documents/NTRS/collection3/NASA_TP_3079.pdf

As you can see, some storms can be totally stop it with that, but some others just the half.

Warning time and prediction:

Here we found another issue, meanwhile more energetic (powerful) the solar flare is, shorter is the time for warning, because protons travels much faster, that was the case for 2005 solar flare which had only 3 min of warning.
Other cases can be hours.  Scientist can also now if one is close to happen or not, but that is still not certain, so it can generate many false positive.

 Book

Mars radiation issue is not something we can just skip, I guess the prediction time should be increase and most habitats should be located underground with some exceptions..

Quote

Yes, as if Venusians will constantly be tethered to each other during EVAs just so they can hear each other. Why is sound such a big deal anyways? Radio is very well understood, and has been used in space since the beginning.

Why they should be tethered?  Put a bag in your head and tell me if you can still lessen..  By the way.. the suits does not need to be airtight as I said.
If you can lessen noice, it helps you to feel you more like earth, on mars you will feel weird, like in space. All our senses together are the ones that shape our reality.

Quote

As if you will constantly be at the equator. I thought one of the benefits of riding the winds was going wherever you want?

Either way, I see nothing about wind shear, which seems to be the bigger problem with these airships.

At 50km to 55km height at latitudes lower than 60 degree, you dont have almost meridional winds, you can have 2m/s for north, but then change to 2m/s to sought..  in average.. is close to zero.
But at 70km, if you are at 40 degree latitude, the meridional wind can be 10m/s, so yeah, is a big difference.
In the same book Venus2, search with the tool, the word shear, it said clearly that is less than many cases in earth but constant, you can also see a shear graph in my venus resume, is there from long time ago.
Turbulence cases on venus are soft vs turbulence cases on earth. 

6 hours ago, todofwar said:

Getting back to Europa, I think the benefits of getting radiation shielding and access to geothermal (remember, solar is out for a settlement so far from the sun) outweighs the complications of being in an underwater base. I could be wrong, someone would have to do a detailed cost/benefit on transporting the geothermal generated energy closer to the surface or just building deep underwater. 

30 minutes ago, insert_name said:

pretty sure titan has rivers of liquid methane, we can probably make a dam and use hydroelectric power but with methane

For Titan, or any other under ice place, Nuclear seems a better alternative if you are care enough with safety  (mostly for mars).
Hydroelectric does not have any sense on Titan, because the gravity is low..
Geothermal has more sense in enceladus than on europe, but even in that case I dont see much beneftis vs nuclear.

 

Edited April 8, 2016 by AngelLestat

[Vanamonde]

The discussion in this thread has become personal at several points, and if it keeps up, we will have to lock the thread. Keep things civil, guys. 

[todofwar]

7 hours ago, AngelLestat said:

I dont see any benefit for moon,   anything you can do on the moon, can be using teleoperated machines or even more usefull, capturing an asteroid in a close earth orbit.. so you save all the travel to the moon.
Extract water from lunar soil is not so easy either.  It can be done but a lot easier and practical is from asteroids. 

 

The moon is benefitial because it gives you a relatively stable platform, and you can test drive all your colonization equipment with the relative safety of being able to return to Earth in a week if everything fails. As far as a long term home for humanity it's pretty bad, but the proximity to our home planet makes it sustainable in the long run. Plus, a space elevator is actually possible on the moon making it the most attractive source of materials for large scale material exports to burgeoning colonies. An easy way to make money now is to harvest oxygen from the lunar soil (not easy at all, you have to drive the SiO2 -> Si + O2 reaction which is pretty uphill, but the Si byproduct will let you make more solar panels providing a feedback loop for your energy production) and ship it to LEO. Then you just have to get the payload to LEO with enough hydrogen to consume the oxygen you have provided.

[Nibb31]

The Moon is 3 days away with launch windows just about anytime if you use a parking orbit.

Let's demonstrate that we can actually go and live on the surface of low-gravity near-vacuum body, develop ISRU and closed-loop ECLSS with the backup ability to send supplies if necessary and abort at anytime and a cost of access that we might actually be able to afford. We have SLS, Orion. All we need to develop is a lander and surface hardware. 

Sure some of the hardware design will be different for Mars or Venus, but the actual procedures and ECLSS will be very similar. Hardware design isn't nearly the hardest piece of the puzzle. The hard part is organisation, budget, political and economical sustainability, procedures, infrastructure.

Mars or Venus are simply out of reach in terms of economics and politics, and that is not going to change any time soon.

[YumonStudios]

On 4/8/2016 at 1:03 PM, AngelLestat said:

It does not need to be under the sea, just under the ice, the same as a polar mars base.
The benefic that the same ice is your structure, you can add insulation layers to enable moderate temperatures without melt the ice.

I know that, but the guy wanted it in the sea, so

And you need a lot more ice to cover a Europa Base than soil on a Mars Base. The latter is good to have. The former is essential.

On 4/8/2016 at 1:03 PM, AngelLestat said:

Hydroelectric does not have any sense on Titan, because the gravity is low..

No, but considering that we build hydroelectric dams on relatively small rivers like Stave River in BC, building a dam on Titan isn't wholly a bad idea.

On 4/8/2016 at 1:03 PM, AngelLestat said:

Geothermal has more sense in enceladus than on europe, but even in that case I dont see much beneftis vs nuclear.

Europa has more gravity, so the less impressive geysers on Europa could carry a lot more energy.

On 4/8/2016 at 1:03 PM, AngelLestat said:

Why they should be tethered?  Put a bag in your head and tell me if you can still lessen..  By the way.. the suits does not need to be airtight as I said.
If you can lessen noice, it helps you to feel you more like earth, on mars you will feel weird, like in space. All our senses together are the ones that shape our reality.

The glass in a suit is usually pretty thick. I doubt you will hear a person from very far in one, even on Earth.

On 4/8/2016 at 1:03 PM, AngelLestat said:

Here we found another issue, meanwhile more energetic (powerful) the solar flare is, shorter is the time for warning, because protons travels much faster, that was the case for 2005 solar flare which had only 3 min of warning.

3 minutes is plenty to get in the pressurized rover or base- and we are building satellites that are now going absurdly close to the Sun, like Solar Probe Plus, and ESA's Solar Orbiter.

http://sci.esa.int/solar-orbiter/

 

[AngelLestat]

@todofwar , @Nibb31

I really hate to disagree in this one, even taking into account that all you have said made sense.
Tech is growing very fast lately, and it will start to grow even faster in the next 20 years (according to my guess which also match Elon Musk biggest fear).
This is not the time to delay our achievements (which may be the last obtained based on our inventiveness) with safety procedures that not fulfil any future human need.
So if we dont have future living on the moon as a second home, then the only other possible application would be as business case.  But anything you can do on the moon as ISRU, it will have much more sense capturing asteroids in Leo orbit.
Many said that moon has sense as a refuell base, you need the same amount of deltav to land on the moon than reach venus clouds, or just a bit more to land on mars with a really good aerodynamic design.

So it does not help as refuel base, we need that refuel in LEO.
About safety procedures and learning curve, we can kinda achieve that with big vacuum chambers or long stays in remote places of earth, is not the same but it will save billions and 30 years of history.

16 hours ago, YumonStudios said:

And you need a lot more ice to cover a Europa Base than soil on a Mars Base. The latter is good to have. The former is essential.

About mars I was thinking in the poles, like this:

Europa´s radiation is much higher, but going few meters more deep in ice does not require more habitat cost.

Quote

No, but considering that we build hydroelectric dams on relatively small rivers like Stave River in BC, building a dam on Titan isn't wholly a bad idea.

First you need to think in energy source..  the energy source for hydroelectric power here on earth is the sun, on Titan is the same sun which is several times more weak.
Then if you want to calculate potential energy, you need height by gravity, In titan the gravity is around 7 times weaker than earth, and the water density is higher than liquid methane.
But if you use nuclear power you have a perfect cold spot much better than any other location, you just pump methane from lakes using a heat exchanger with the reactor working fluid, that makes nuclear energy cheaper than earth.

Quote

Europa has more gravity, so the less impressive geysers on Europa could carry a lot more energy.

Gravity in this case does not have nothing to do, you are extracting energy from the thermal gradient.

Quote

The glass in a suit is usually pretty thick. I doubt you will hear a person from very far in one, even on Earth.

It depends how you imagine a venus suit, in my case does not need a glass.  Is not a spacesuit.

Quote

3 minutes is plenty to get in the pressurized rover or base- and we are building satellites that are now going absurdly close to the Sun, like Solar Probe Plus, and ESA's Solar Orbiter.

http://sci.esa.int/solar-orbiter/

We are talking about solar flares (radiation), so not sure why you mention "pressurized" as your shelter needs.

Edited April 10, 2016 by AngelLestat

[PB666]

On 4/9/2016 at 10:19 PM, todofwar said:

The moon is benefitial because it gives you a relatively stable platform, and you can test drive all your colonization equipment with the relative safety of being able to return to Earth in a week if everything fails. As far as a long term home for humanity it's pretty bad, but the proximity to our home planet makes it sustainable in the long run. Plus, a space elevator is actually possible on the moon making it the most attractive source of materials for large scale material exports to burgeoning colonies. An easy way to make money now is to harvest oxygen from the lunar soil (not easy at all, you have to drive the SiO2 -> Si + O2 reaction which is pretty uphill, but the Si byproduct will let you make more solar panels providing a feedback loop for your energy production) and ship it to LEO. Then you just have to get the payload to LEO with enough hydrogen to consume the oxygen you have provided.

With regard to exploitation, you left out possibly the most important point, we have samples from the moon and we know very well now what we have to do to convert those crude minerals into usable materials. You can even take some of these and try it out of small scale. Also the moon has the highest surface densities of usable energy of any satellited in the inner solar system. Since Venus is pretty much out of the question and has no satellites with current technology and landing on a Mercurian polar crater would be tough in many kinds of ways (not to mention dV required), this only leaves earth crossing asteroids and the moon with comparable or higher energy densities. The surface of the moon is stable and not subject to disruptive tidal forces from earth (no earthquakes or cavitations to speak of).

With regard to the martian satellites, the exterior satellite may not have a stable surface because of its small size
Phobos -  radius - 11 km. Surface gravity - 0.0057 (581 microg). 
Advantage  escape velocity is 11.5 m/s
Advantage  could potentally accept horizontal landers and mass accelerated take offs.
Advantage  could provide a staging area for mars missions complete with laid out solar panels.
Advantage  no dust storms. The moon travels around the planet every 11 hours so it is possible to have a greenhouse on the sun facing side.
Advantage 3.5+/3.5h- hour light cycle for sun facing surface (synchronous) less need for batteries. Greenhouses possible, it a stable site can be found
Advantage no atmosphere - no wind storms, solar panels should not get dusted over (like mars), greenhouses also.
Advantage is basically on equitorial trajectory, there are launch windows from mars that allow almost direct single orbit interception, so from that point phobos is a good candidate for staging fuel for mars return missions. It could be a mars filling station [Mexxon]

Disadvantage health situation because of microg.
Disadvantage mining situation because surface is not gravitational rounded, may be too lose to burrow into the planet
Disadvantage the proximity to Mars and its low relative mass might make surface operations dangerous.
Disadvantage no atmosphere, and no magnetic field, meaning very strong flux toward conversion of surface energy into loss of elements on the right side of the periodic table.
Disadvantage insolance is fractional (0.362) to the earth or moon. Approximately 0.476 kW/ meter about 300w/meter  of that exploitable for energy production, at current efficiencies is about 120 w/meter, but because of the extremely low gravity we could reduce the thickness of the panels to a fraction required on earth, we could send fairly light weight panels to these moons and supply alot of power. The problem here is that you would need step transformers and radiators close to a cluster of panels to boost the voltage otherwise you would have a huge mass of wires carrying small amounts of power. 
 

Deimos - 5 to 8 km. Surface gravity -  308 microg ( spectra, albedos and densities similar to those of a C- or D-type asteroid-wikipedia) Basically similar to Phobos, ... Deimos's orbit is nearly circular and is close to Mars's equatorial plane.
Advantage - Deimos is so relatively easy to get from high earth orbit it is strange that we do not have extensive equipment already on Deimos, in terms of C-D class asteroids it would not be too challenging to bring material back.
Advantage - Deimos is further from mars gravity well, easier to get to from earth particularly when an earth mission is traveling a minimal transect at apogee its orbital velocity is slower than mars, but it could be more easily picked up by diemos as it transects Mars.
Adantage - A great place to stage supplies for deep system missions, short period comet intercepts, etc. It could also be a great place to bring gathered materials from comets its low surface escape potentials means you could simply bury comets under the soil and store them in thin walled containers.
Disadvantage - Soils looser than Phobos, surface is smoother, probably the effect of micrometeorites hitting its surface.
Disadvantage - synchronous, its period is much longer than phobos with a 15h+/15h- phase.
Disadvantage - Burying down in the loose surface maybe problematic. To reduce high energy solar radiation, particularly during solar storms the living quarters might need to draft earth moving equipment to move soil followed by landing the quarters, and then burying them under the till.
Disadvantage - trivial gravity, health issue but can be compensated for with inertial equipement. It might also be considered an advantage, a single human could lift 300,000 kg (albeit hideously slow). You could just land housing anywhere and the astronauts could move them with basically twine as handles. Moving deimos (regolith) of  would be tricky, you couldn.t use a shovel.

If I was a serious private concern desirous about creating a manned mars mission and I needed a proving ground, my first step would be a sample return mission (robotic) from Deimos. So once I had established a colony on the moon and working toward getting ISRU working, I would have unmmaned sample return mission to Deimos going on and I would have that material sent to scientist to see what the prospects are. The next mission would be a manned mission to Deimos and an unmanned sample return mission from Phobos. I might even be looking for asteroid ejecta on these satellites derived from Mars.

There are immediate advantages for taking on 70's like Mars satellite sample gathering missions and manned missions to the regions, not economic but from a space or private concern they could make a profit by lowering the cost of these missions and getting the government as a buyer. I think this is within the reach of SpaceX with their current technology, provided the robotics are public sourced.

As I say repeated its often not the issue of one or the other, if we really want to see a meaningful (usefully scientific and engineering) manned mars in our lifetime, we need to do all. The problem is getting a funder on board and now it would seem lowering the cost as part of the process. Space X showed us on Friday that they could rapidly decrease the turnover time on the high payload MEO and HEO missions, the will have a pad in canaveral and one in Bocachica, they can have several launches that haul the materials into LEO that without to much engineering get stuff to either of the Martian satellites.

 

[todofwar]

59 minutes ago, PB666 said:

Since Venus is pretty much out of the question

Actually, I'll bet on a manned mission to Venus before Mars. It's been suggested elsewhere that since its easier to "land" (is there a word for placing an airship in the atmosphere on another planet? Saying land with quotes around it doesn't seem right) a large enough payload to get you onto the planet and back, and since it's a bit closer, it might actually be the more feasible target. Some more Mars centric people have even conceded it as a good test run for Mars. 

Back to the moon, I think since any self perpetuating colony will need all the equipment to establish the supply chains we already have handy on Earth, you need to ship several tons of material. If we can get the tech down for the most bare bones supply chain on the moon, which is capable of refining the materials necessary to replicate and grow itself, than you can divert the Lunar economy towards colony establishment and launch all your materials from there. Thus, establishing a Lunar colony makes all other colonies much cheaper. Assemble an interplanetary ship for ferrying material that never lands, and all you need from Earth at that point is some hydrogen (you could use Lunar derived O2 for some monopropellant engines, but your ISP will be terrible) and the more sophisticated components to maintain said interplanetary ship and the landers. Get a lunar space elevator built (actually possible with current materials) and you don't even need to worry about launching from the moon, you can dock your interplanetary ship at the top of the elevator and load it up. 

Side question: based on dV needed to get in and out of Jupiter's gravity well, does anyone know if it's easier to get hydrogen from Earth or Europa for a Lunar or Venusian colony? (Let's pretend Mars gets shot into the sun or something and is not on the table anymore for the purposes of this little aside)

[Bill Phil]

The issue with Venus, and very much Earth as well, is that it's hard to get to Orbit. So you'll basically have to bring along a launch vehicle and keep it afloat on air.

[PB666]

16 minutes ago, todofwar said:

Actually, I'll bet on a manned mission to Venus before Mars. It's been suggested elsewhere that since its easier to "land" (is there a word for placing an airship in the atmosphere on another planet? Saying land with quotes around it doesn't seem right) a large enough payload to get you onto the planet and back, and since it's a bit closer, it might actually be the more feasible target. Some more Mars centric people have even conceded it as a good test run for Mars. 

Back to the moon, I think since any self perpetuating colony will need all the equipment to establish the supply chains we already have handy on Earth, you need to ship several tons of material. If we can get the tech down for the most bare bones supply chain on the moon, which is capable of refining the materials necessary to replicate and grow itself, than you can divert the Lunar economy towards colony establishment and launch all your materials from there. Thus, establishing a Lunar colony makes all other colonies much cheaper. Assemble an interplanetary ship for ferrying material that never lands, and all you need from Earth at that point is some hydrogen (you could use Lunar derived O2 for some monopropellant engines, but your ISP will be terrible) and the more sophisticated components to maintain said interplanetary ship and the landers. Get a lunar space elevator built (actually possible with current materials) and you don't even need to worry about launching from the moon, you can dock your interplanetary ship at the top of the elevator and load it up. 

Side question: based on dV needed to get in and out of Jupiter's gravity well, does anyone know if it's easier to get hydrogen from Earth or Europa for a Lunar or Venusian colony? (Let's pretend Mars gets shot into the sun or something and is not on the table anymore for the purposes of this little aside)

Deimos is even easier, and the astronauts would be able to land. Venus and Mercury have the advantage that they could take advantage of at least some ION drive dV for relatively low cost. For mars that is pretty much out of the question. Once you have ION and 2 to 4 kw per meter of insolance you can start thinking about ION driving anything, yeah you could prolly extract argon from Venus or use metals from Mercury.

THe problem of supply chaining, assuming that lunar colony 1 ISRU can make metallic aluminum, and you can start making tanks and new facilities, within that assumpton is a huge (hands stretched out) and sophisticate forging and stamping operation. Once you make something you have to store it. Think legistically about what has to come from earth just for storage, then think about what has to come from earth to create storage (and we are talking big time operational management) SpaceXs 5000 people get 3 launches a year . . . . . imagine the support network required to get a factory on the moon that has a hatch that can fit a full sized fuel tank or rocket engine through it. If you are talking gases you could make a long truss and meter diameter spherical tanks that can be assembled outside. Aluminum does not weld well either, its one of those things for tanks you might want things that can be welded in the vacuum of space with a fairly compact assembly facility. 

ISRU right now is a work in progress, check out NASAs site. http://isru.nasa.gov/

So yeah, lowering the cost per kg of fuel is an important thing. We have docking ports, we have the ability to build stations and to link ships together, so if we need a bunch of dV to get to mars, you are better off with an in orbital factory and a cheapest possible supply chain from earth. As for hydrogen, If you have a presence in the Western gulf, just build a production platform in about 2 years, make some commitments and someone is going to drill deepwater close enough to the platform, trade platform usage for methane (which they would give you anyway rather than pay the pipeline fees to onshore), you have all the hydrogen potential you would ever want, for free. You would make money off the production platform, you'de get free methane you could have a landing pad that does not rock, and a second potential lauchsite. You could use the methane as an energy source to purify oxygen (saving money on methane transport).

 

 

 

 

[AngelLestat]

I remember to everyone that the topic is about colonization.. No one single mission or a business case profit for earth citizens..

Colonization means a second place to live permanent, where you can get everything you need, at reasonably low cost.
This might include in some cases profits for exports as a way to help the economy.  but a single business case does not make a whole place sustainable or a good place to live.
There are many cities in earth that does not rely on exports to keep their economies growing.

I hope it helps as a guide to build your case with the different arguments you considerer that worth it.

Edited April 10, 2016 by AngelLestat

[Bill Phil]

*Points at Gundam*

Be sure to ignore the mecha.

[todofwar]

@PB666 I agree that there are lots of problems that need to be worked out, but for true colonization and not just short term bases on other planets, we need to be able to create closed loops. That means you mine, refine, and manufacture everything on the colony itself. So, the real challenge of colonizing anything is finding out the bare minimum amount of equipment needed from Earth to get something going. You need an ability to refine basic metals, an ability to refine Si, design everything for analogue rather than digital control, ability to manufacture everything by hand, etc. It's a long list, but about 90% of it will be transferable from system to system, so once we achieve it once the system need only be refined to be replicated. If we can get the basics figured out on the Moon so that it's capable of growing on its own, then it will be able to produce everything needed for further colonies. You'll need to modify things a bit, Mars or Venus or Europa will all have certain benefits and costs that must be taken into account, but the downstream refining and manufacturing parts will look pretty similar to the versions on the Moon.