Why colonize Mars and not the Moon?

[rbelli1]

A significant portion of the cost of Mars missions will be directly applicable to Earth based space programs. If you reduce the cost of lifting to orbit for a Mars mission you don't just reduce the cost of a Mars vehicle you also reduce to cost of anything you may want in orbit. Research on food production on Mars is applicable to food production on marginal land on Earth. All medical and manufacturing technologies must be size and weight reduced to transport them to Mars. These advances may beneficial to Earth dwellers.

Many of the advances needed to put humans on other bodies in the solar system are rather domain specific but there will be benefits to those that stay behind. Which is nearly all of us. This round of space exploration will not be in response to an immediate existential-ish threat. We can do it not in a panic mode and factor in profit and other Earthly benefits. Colonizing LEO for the tourist industry might be a short term goal to stone step to the next destination.

BoB

 

[1oldman2]

Okay, okay, getting back to this threads original topic. It seems that in any long term plans, both the Moon as well as Mars are going to be "Colonized" to what ever state the current Technological levels allow at the time.
First off there's plenty of references to Musk and his Mars ambitions on the web so I won't spend too much time on SpaceX, Elon is serious about "Mars or bust" and he is developing the capital as well as the infrastructure needed to get started on what even he describes as "an ambitious undertaking"

http://www.universetoday.com/130086/nasa-estimates-spacex-2018-mars-mission-will-cost-300-million/
http://spacenews.com/new-documents-reveal-state-of-spacexs-finances/
"The documents also reveal that the company expects launch revenue to continue to grow, but be eclipsed by much faster growth in revenue from a planned constellation of broadband satellites.
That system is projected to generate more than $30 billion a year in revenue by 2025". [Wall Street Journal]

(It won't be happening in 2020 )
http://spacenews.com/nasa-exploring-additional-cooperation-with-spacexs-red-dragon-mission/
"In April, NASA and SpaceX announced they had revised an existing unfunded Space Act Agreement to focus on a planned 2018 Mars lander mission, using a version of the Dragon spacecraft SpaceX is developing to carry crews. Under that agreement, NASA will offer technical support to SpaceX in a number of areas, while SpaceX will provide NASA with data from the entry, descent and landing (EDL) phase of Red Dragon’s mission to support NASA’s planning for future Mars missions of its own".
"Access to that data remains NASA’s primary interest in Red Dragon. "The SpaceX collaboration really is an EDL demonstration for us," he said, as the spacecraft demonstrates a concept called supersonic retropropulsion that could enable the landing of spacecraft far heavier than possible with techniques demonstrated on previous missions, including the Mars Science Laboratory"

As far as NASA goes concerning Mars exploration, along with the Lander I mentioned in post #.257, You may find some interesting as well as relevant reading here. (once again, PDF is recommended)
https://ntrs.nasa.gov/search.jsp?R=20160011469&hterms=Mars+spacex+propulsive+landing&qs=Nm=123|Collection|NASA%20STI||17|Collection|NACA&Ntx=mode%20matchallpartial&Ntk=All&N=0&Ntt=Mars%20spacex%20propulsive%20landing
Abstract: "The Evolvable Mars Campaign presents a long term strategy for NASA's Journey to Mars within a capability driven framework. By comparing each element to a set of criteria, this paper reviews the potential of acquiring those capabilities using a strategy similar to the Commercial Orbital Transportation Services program. The paper presents the criteria, assesses the elements against those criteria, and then discusses the suitability of each element to being developed using this acquisition strategy. Throughout the campaign, certain capabilities are well suited to being developed in this manner while others are not. This assessment is a snapshot in time, and should be revisited as the campaign and/or commercial capabilities change. This paper will explore each of these elements in the campaign and discuss how the COTS development and acquisition strategy could or could not be applied to those elements. This assessment will be based on the services or functionality required in the campaign, and will use the best practices discussed above to create a case for or against a COTS-style acquisition strategy for each given element".

Then of course there's this take on Mars.
http://www.nature.com/news/nasa-rethinks-approach-to-mars-exploration-1.20758
Starting in the 2020s, scientists who participate in the agency’s Mars missions might no longer design and build their own highly specialized payloads to explore the red planet. Instead, planetary scientists could find themselves operating much as astronomers who use large telescopes do now: applying for time to use a spacecraft built with a generic suite of scientific instruments.

The proposed change is spurred by NASA’s waning influence at Mars. The agency’s long-running string of spacecraft is winding to a close, and international and commercial interests are on the rise. By the middle of the next decade, European, Chinese, Emirati and SpaceX missions are as likely to be at Mars as NASA is.

 

[Al_]

Research on food production on Mars is applicable to food production on marginal land on Earth.

What evidence do you have for this? There is already plenty of research into marginal land farming here on Earth. How can Mars make a difference? Unless, of course, you think we will just plonk down a working Mars food module on top of the marginal land?

 

[russ_watters]

What evidence do you have for this? There is already plenty of research into marginal land farming here on Earth. How can Mars make a difference? Unless, of course, you think we will just plonk down a working Mars food module on top of the marginal land?

Agreed. Even setting aside the fact that we can just build a test farm on marginal land here, so no need for the spin-off, the "marginal land" issues on Mars are different questions, with different answers:
-Soil composition and maintenance
-Air thickness, composition and maintenance
-Reduced sunlight and length of day, different mix of wavelengths
-Specific crop testing
-Impact of microbes or lack thereof

None of the answers to these questions will be directly applicable on earth.

I'm not a big fan of the spin-off tech argument because while the tech is great, most could have been developed much cheaper for other industries because in addition to the cost of development, they wouldn't have to spend an extra 10k a pound to test it in space.

 

[Al_]

A significant portion of the cost of Mars missions will be directly applicable to Earth based space programs. If you reduce the cost of lifting to orbit for a Mars mission you don't just reduce the cost of a Mars vehicle you also reduce to cost of anything you may want in orbit.

Pretty much all developments in access to space benefit all future space missions. Of course there's crossover. Therefore, Moon missions are just as beneficial.

To get back to question at the start of this thread, since we've found water on the Moon, it's possible to colonize the Moon.
http://www.space.com/7530-significant-amount-water-moon.html
And quicker, easier, safer, cheaper.
Quicker: A few days flight v. several months. And building up the numbers of people will faster.
Easier: Transport technology already exists and is proven.
Safer: Less radiation during the trip, and a quicker & simpler trip home in emergencies.
Cheaper: Less development of new technologies, less kit required, more things can be traded back to Earth.

 

[Al_]

And - easier in one more, really important way. Robots on the Moon can be driven from Earth, much more effectively than the snail's pace on Mars. So, prospecting, mining, construction, and even farming can be done ahead of time ready for the first people to arrive. And prospecting can continue while the colony grows, unhindered by the lack of manpower of the colony.

 

[Physics_Kid]

i did not read all the posts. but i thought there is substantial hypothesis that if humans can't take with them what we have here on Earth, it won't be possible to colonize someplace else. in essence, Earth is the only place where humans can live, unless that is, you find another Earth. seems prudent that before you attempt to colonize the other place, better have some good evidence that it can be done. wasn't BioSphere in AZ a failure?

 

[mfb]

Based on typical cost overruns for such large projects, that 500 billion estimate is really anywhere between 500 billion and 5 trillion.

Taking the most pessimistic estimate that takes cost overruns into account, and applying cost overruns to it again, sounds a bit pessimistic.

Even setting aside the fact that we can just build a test farm on marginal land here

But that is exactly what is done as part of spaceflight budgets.

Spin-offs are not always predictable. Consider solar cells, for example. The concept is more than 100 years old, but they were too ineffective and too expensive to be considered on Earth. Research got started for spaceflight - and made them so good that they got interesting for applications on Earth.

The Martian equator gets about as much sunlight as the equator on Earth (150-200 W/m²). The larger distance is canceled by the more transparent atmosphere and the lack of clouds.

wasn't BioSphere in AZ a failure?

It was discussed a few pages ago. Biosphere did not exchange any material with the outside world, while a colony on Mars (and to a lesser extent on Moon) would have access to oxygen, carbon and hydrogen from the outside. Colonies there also wouldn't try to reproduce tons of different environments, they would focus on what works best.

 

[rbelli1]

What evidence do you have for this?

If you spend the billions or possible trillions on the ecosystem and food production technology and systems for an off-world base I find it hard to believe that none of that will be useful here on Earth.

Selecting a narrow facet of that (the marginal land part) was probably not great for my point as I have no way of knowing the details of Mars mission research.

BoB

 

[Stavros Kiri]

Robert Zubrin's feedback on Elon Musk's ideas; Mars direct vs Space-X etc. :

 

[Phineas Far]

The moon has better tourist potential, because it is less expensive to get to. Colonists are tourists that don't come home. Somebody could take 6 weeks off from work and spend a month on the moon. Suppose that the government subsidizes Lunar tourism by paying 50 percent of the cost. That is better than paying 100 percent of the cost elsewhere. With the moon, you can have regularly scheduled flights once every 3 weeks, 4 weeks, 5 weeks, whatever you want. With Mars, flights would be once every 2 years. With monthly flights, you could keep your launch crew working full time. You could bring sick people home. It would be easier to ship 100 tons of supplies to the moon than Mars. We currently have nuclear submarines that can sustain life for months.

 

[pneguinapricotmelon]

Where are the thousands of bird species and countless millions of insects going to live on this Mars colony ?.

You have the Budget, Will and Technology to build a bunker and self-contained slime-farm on Mars, yet you can't solve the simplest social problem on Earth:
Exponential Human Population Growth.

You are happy to make a coffee-table out of carbon nano-tubes whilst trapped in a glass bubble on a hostile planet. But you sit by and watch Cedar-trees in the Amazon rain-forest be clear-felled by criminals.

This pointless distraction by Elon Musk is grotesquely offensive. We have such a beautiful Planet, and he is happy to entertain thoughts of of a forlorn existence in a sad dead wasteland. Instead he should devote all his time and effort to the improvement of humanity and the preservation of our planet. Travel to Mars would represent the ultimate failure of humanity.

 

[Stavros Kiri]

Where are the thousands of bird species and countless millions of insects going to live on this Mars colony ?.

Well potentially Mars would be terraformed, and it would be nice as a back-up plan, or as serving the expansion dream of humanity in space. But it would be a lot better investing that money on a class-M planet.
The only one around here, fortunately or unfortunately is earth! With all that money we could have made Earth a paradise!

 

[Corum10]

The main Extinction Event the human race faces is mass stupidity, the inability to see past the end of our noses, our inability to survive in harmony with other species and races, and the thought pattern that makes us believe we can persist regardless of the damage we do to our environment. I wonder if Mars could actually benefit from our arrival or would we destroy it also.

 

[Corum10]

Well,I think that this is linked with the Sun itself.
Without atmosphere,both Moon and Mars are vulnerable,but Mars is (at least) farther from the Sun,so it is more protected than the Moon.

The biggest problem is to find a method to protect against radiation which is stopped here on Earth by the magnetosphere and the atmosphere. Mars does not have much of an atmosphere and is void of a magnetosphere. So that really only leaves underground as an alternative for long term survival.

 

[Dr_Zinj]

Mars puts us that much closer to the asteroid belt. Escape velocity from the Martian surface is much lower than Earth's, and much less air resistance. Nothing humans do works very well in low to zero gravity; Mars solves that problem. There is a LOT of raw material in that belt that can be used for manufacturing, and requires very little fuel to de-orbit them and drop them toward Earth. Tectonic and hydrological forces on Mars may have done a good job of concentrating minerals into easily mined ores. The Moon has no such ore bodies.

Mars is not really terraformable. Too small and too low gravity means you can't keep a dense enough atmosphere without constantly re-supplying it. The Moon has even lower gravity, and virtually no atmosphere, breathable or otherwise. The Moon's sole advantage is it's the most easily accessible planetary body for us.

 

[Stavros Kiri]

So that really only leaves underground as an alternative for long term survival.

Or terraforming, if possible.

 

[Corum10]

Or terraforming, if possible.

Well, that is the whole point. Terra forming (that science we haven't figured out yet) would not be possible due to a few seemingly insurmountable problems. The first being the absence of a molten core (I'm pretty sure that's the case), the absence of sufficient gravity, the absolute absence of a magnetic field and worst of all the incredibly severe Martian weather.

 

[Corum10]

Well potentially Mars would be terraformed, and it would be nice as a back-up plan, or as serving the expansion dream of humanity in space. But it would be a lot better investing that money on a class-M planet.
The only one around here, fortunately or unfortunately is earth! With all that money we could have made Earth a paradise!

Well said, I also wish in vane that funds on Earth were spent in a more logical way. Having said that...Mars...of all the uninhabitable planets is still my favourite. I'd be well happy to live there underground like a little Martian mole.

 

[Corum10]

Where are the thousands of bird species and countless millions of insects going to live on this Mars colony ?.

You have the Budget, Will and Technology to build a bunker and self-contained slime-farm on Mars, yet you can't solve the simplest social problem on Earth:
Exponential Human Population Growth.

You are happy to make a coffee-table out of carbon nano-tubes whilst trapped in a glass bubble on a hostile planet. But you sit by and watch Cedar-trees in the Amazon rain-forest be clear-felled by criminals.

This pointless distraction by Elon Musk is grotesquely offensive. We have such a beautiful Planet, and he is happy to entertain thoughts of of a forlorn existence in a sad dead wasteland. Instead he should devote all his time and effort to the improvement of humanity and the preservation of our planet. Travel to Mars would represent the ultimate failure of humanity.

I do agree with you. However Elon Musk cannot be expected to repair all the damage caused by US...as a race. We ALL should dedicate ourselves to the preservation of our planet.

 

[mfb]

You have the Budget, Will and Technology to build a bunker and self-contained slime-farm on Mars, yet you can't solve the simplest social problem on Earth:
Exponential Human Population Growth.

There is no exponential population growth in industrialized countries. A Mars or Moon colony would be the most extreme example of an industrialized "country".

This pointless distraction by Elon Musk is grotesquely offensive. We have such a beautiful Planet, and he is happy to entertain thoughts of of a forlorn existence in a sad dead wasteland. Instead he should devote all his time and effort to the improvement of humanity and the preservation of our planet. Travel to Mars would represent the ultimate failure of humanity.

Musk could start producing solar cells, batteries and electric cars for a better environment on Earth?

He is doing that already.

Was going out of Africa the ultimate failure of humanity as well?

Mars is not really terraformable. Too small and too low gravity means you can't keep a dense enough atmosphere without constantly re-supplying it.

Re-supply would be a potential issue millions of years into the future, probably solved with technology we cannot even imagine today. We could create an artificial magnetic field with (nearly) today's technology. If we manage to make a Mars colony that survives for a million years I can't imagine this to be an issue. Don't worry about atmospheric losses.

 

[Gardenman]

I haven't read all fifteen pages of posts, so this may have been addressed, but if not, I'm giving it a shot here. I think a lot of people assume terra-forming a planet will be more difficult than it may ultimately prove to be. There are bacteria that thrive here on Earth in nearly every condition imaginable. The right mix of bacteria inserted into a currently uninhabitable planet could transform it fairly quickly. In ideal conditions bacteria can spread quickly. Once the transformation starts different bacterial cultures could be inserted to refine the process until we eventually ended up with an Earth-like planet with a stable atmosphere. Finding the right bacteria that could survive in Mars as it exists now and that excrete what we want Mars to become is something of a challenge, but we know what the surface of Mars is like and we could simulate that in a lab to try and find a suitable mix of bacteria. I suspect the bacterial soup would need to be adjusted throughout the process as the conditions on the planet changed, but a thriving colony of bacteria on Mars churning out what we want Mars to become could transform the planet fairly quickly.

I strongly suspect we could transform Mars into a livable planet in a matter of a few decades if we got the bacterial cocktails just right. We could see a planet with a breathable atmosphere, oceans, storms, and a livable surface created at a relatively low cost within a relatively short window of time. The use of unmanned drones to seed the planet with the bacterial soup is possible and could speed up the process. The lack of water on the surface is a challenge for now, but I suspect it could be overcome.

If it's true that Mars had seas and oceans in the past, along with rainfall, then there are likely caves and caverns on Mars just as there are caves and caverns on Earth. If there's liquid water left on Mars, it would most likely be found in a deep cavern. If you could find a deep cavern or multiple caves/caverns with pools of liquid water, those would be good places to seed the initial bacteria. Bacteria and primitive life are the things that made Earth into the Earth we know. Rather than wait for them to evolve naturally on Mars, we could insert specific lifeforms to shape the planet to suit our needs. I don't think it would be too complicated or expensive and could be accomplished in a relatively short timeline.

 

[Corum10]

I haven't read all fifteen pages of posts, so this may have been addressed, but if not, I'm giving it a shot here. I think a lot of people assume terra-forming a planet will be more difficult than it may ultimately prove to be. There are bacteria that thrive here on Earth in nearly every condition imaginable. The right mix of bacteria inserted into a currently uninhabitable planet could transform it fairly quickly. In ideal conditions bacteria can spread quickly. Once the transformation starts different bacterial cultures could be inserted to refine the process until we eventually ended up with an Earth-like planet with a stable atmosphere. Finding the right bacteria that could survive in Mars as it exists now and that excrete what we want Mars to become is something of a challenge, but we know what the surface of Mars is like and we could simulate that in a lab to try and find a suitable mix of bacteria. I suspect the bacterial soup would need to be adjusted throughout the process as the conditions on the planet changed, but a thriving colony of bacteria on Mars churning out what we want Mars to become could transform the planet fairly quickly.

I strongly suspect we could transform Mars into a livable planet in a matter of a few decades if we got the bacterial cocktails just right. We could see a planet with a breathable atmosphere, oceans, storms, and a livable surface created at a relatively low cost within a relatively short window of time. The use of unmanned drones to seed the planet with the bacterial soup is possible and could speed up the process. The lack of water on the surface is a challenge for now, but I suspect it could be overcome.

If it's true that Mars had seas and oceans in the past, along with rainfall, then there are likely caves and caverns on Mars just as there are caves and caverns on Earth. If there's liquid water left on Mars, it would most likely be found in a deep cavern. If you could find a deep cavern or multiple caves/caverns with pools of liquid water, those would be good places to seed the initial bacteria. Bacteria and primitive life are the things that made Earth into the Earth we know. Rather than wait for them to evolve naturally on Mars, we could insert specific lifeforms to shape the planet to suit our needs. I don't think it would be too complicated or expensive and could be accomplished in a relatively short timeline.

I believe the biggest problem with the thought of Terra Forming is the lack of a viable atmosphere. It as been well stated that the water vapours of Mars have dispersed from the surface into space. How it could be possible to reverse that problem prior to the establishment of a bacteria solution is beyond me. It is a cart before the horse scenario. Many, when discussing Terra forming fail to perceive the immense volume of atmosphere we are talking about and an atmosphere that varies between just above 0C to minus 165?? or so. In addition, the many complicated steps in the Terra forming of Earth itself took place over millions of years. To think we could speed that up and compress it into a couple of decades is just wishful thinking.

 

[mfb]

Bacteria cannot revert losses to space, of course, but they could produce oxygen out of CO2 from the atmosphere (and ice caps, once sublimated) or water.

The sunlight Mars receives is more than sufficient to produce an oxygen-rich atmosphere within years, as calculated earlier in a different thread. We would have to find a way to cover the surface with algae or bacteria, however, and it is unclear how to do that.
A few decades don't look completely impossible.

 

[Corum10]

Bacteria cannot revert losses to space, of course, but they could produce oxygen out of CO2 from the atmosphere (and ice caps, once sublimated) or water.

The sunlight Mars receives is more than sufficient to produce an oxygen-rich atmosphere within years, as calculated earlier in a different thread. We would have to find a way to cover the surface with algae or bacteria, however, and it is unclear how to do that.
A few decades don't look completely impossible.

Agreed, however there is still the somewhat substantial problem of having no magnetosphere ergo no ionosphere. Don't get me wrong I am all for trying and spend much time trying to evaluate the various methods, but fear that people do not fully realize the need from every aspect for a magnetic field around a possible new home, which Mars will never have due to a lack of an molten core.

 

[mfb]

Agreed, however there is still the somewhat substantial problem of having no magnetosphere ergo no ionosphere.

It is not a problem, see post #301 for example.

 

[russ_watters]

Taking the most pessimistic estimate that takes cost overruns into account, and applying cost overruns to it again, sounds a bit pessimistic.But that is exactly what is done as part of spaceflight budgets.

I'm sorry, but I'm just not buying it. Even if what you say is true - that attempts were made to be extra pessimistic at 500 billion - that still doesn't mean it is pessimistic enough. No policy planner would try to make a realistic estimate and then multiply it arbitrarily by a factor of 10, even if that is what it needs. Cost estimators are handcuffed by the limitations of their job: They have to be "reasonable".

Cost estimators base their estimates on the scope of work in front of them and then add safety factors (20%? 30%? 50%?) for common escalations and missed scope issues. These types of issues are normal, rational and at least somewhat predictable.

But the what actually plays the biggest role in determining the cost of a mission to Mars is not reasonable. There is no "whim of Congress" factor that can be applied to a cost estimate. No "I thought this piece of technology would be easy to invent but it turns out it isn't so now we have to re-design the entire project" factor. No "Russia said they'd contribute but balked" factor. No "the first pre-supply mission crashed so now we have a 3-year setback to produce a new one" factor. These factors are inherently unpredictable and unreasonable to include in a cost estimate. But they are real. And in particular, the bigger the project the more likely the "Whim of Congress" factor is to be the one to do-in a project.

Space Station Freedom's demise was in large part due to the "Whim of Congress" factor. Congress demanded repeated re-designs ostensibly to cut costs, but the re-designs and delays themselves added to the costs. A complicated series of problems following that led to the cancellation of it and conversion to the ISS. No cost estimator in 1980 could possibly have had that captured in their budget.

 

[Al_]

Well potentially Mars would be terraformed, and it would be nice as a back-up plan, or as serving the expansion dream of humanity in space. But it would be a lot better investing that money on a class-M planet.
The only one around here, fortunately or unfortunately is earth! With all that money we could have made Earth a paradise!

Do you really think so? How many have tried and failed. How much effort, over millennia, has gone to create paradises or utopias.
There are really deep fundamental driver in human and natural processes that mess up such plans. No everyone wants the same end result. Are science people supposed to solve politics?
Come on, allow some techies the chance to escape the madness.

 

[Al_]

Deimos has a day/night cycle of 30 hours, that doesn't sound healthy.

In experiments where people were isolated from all day/night cycles and clocks in a cave, they naturally adopted a 30 hour cycle. People here on Earth have all sorts of odd sleep patterns, with known marginal health problems. 30 hours is far from the worst pattern we know of. As long as you are not tired, stay healthy and get enough sleep, does it matter?

 

[mfb]

@russ_watters: It is an estimate of the total costs, not for congress, but for a book ("The Scientific Exploration of Mars.").

ESA and Russia made a plan in 2002 and estimated that it would cost $20 billions (Reference).

Mars Society Germany suggested another mission profile, mainly based on existing rockets, with overall costs of 10-15 billion Euros (Reference).

SpaceX estimates $10 billion for development of ITS and something like a billion for a first mission (much less for subsequent missions).

And so on. Most estimates are somewhere between 10 and 50 billion dollars. And all those people making the estimates take into account that things can go wrong. They all know the history of cost estimates for previous programs much better than we do.

You picked the massive outlier, which is questionable on its own, and then you claim you know it better than the book author and go even further away from all other estimates.

 

[Al_]

This thread is not about a first mission. It is about a possible global, large-scale effort to establish a permanent and eventually self-sufficient colony.

Deimos colony could be huge!
In "Mining the Sky" by John Lewis, he reminds us that in the negligible g of an asteroid (or Deimos) you don't confine yourself to the surface of a planet. You inhabit the volume. If one person requires say, a luxury apartment size dwelling of 300 metres squared, by 3m high, round up to 1000 cubic, and the same for services such as food production. 2000m3 per person. Then some of that needs to rotate for gravity, so add maybe 3000m3 spinning space. 5000m3 per person. Very generous.
Diemos is roughly 1000000000000m3.
So roughly 200 million people. That's not a first mission.

Of course, where do the resources come from? Well, quite possibly Deimos has enough for a few thousand people. But for a bigger colony, in micro g, the most economic site for a colony is at a crossroads where all the resources will be transported by. And that will be a crossroads on the Interplanetary Superhighway. http://www2.esm.vt.edu/~sdross/superhighway/description.html
Deimos might be on such a crossroads one day? If so, why not buy it for a few glass beads?

 

[russ_watters]

ESA and Russia made a plan in 2002 and estimated that it would cost $20 billions (Reference).

C'mon, mfb; that is just plain garbage. It says in the link that the Russia made the plan, to include the ESA, but the ESA didn't buy it. 2/3 of the article is about how unserious it is.

SpaceX estimates $10 billion...
And so on. Most estimates are somewhere between 10 and 50 billion dollars...

I'm having a hard time believing you are taking this issue seriously, mfb. The ISS cost that much just to build it, so these numbers aren't even good as fantasies. They are lower and shake your head numbers. They aren't even in the right order of magnitude. Elon Musk is allowed to be P.T. Barnum because that is part of his schtick/aura that gets investors to invest in crazy projects that sometimes work out, but we can be better than that. I can't possibly fathom how you could believe a manned Mars mission could be done for $10-$50B.

More to the point, this "most estimates" you cite really aren't. Those are the outliers. All I did was take an estimate I thought you thought was realistic (and for the record, I think it is too, just without the "whim of Congress" factor) and double it.

It is an estimate of the total costs, not for congress, but for a book ("The Scientific Exploration of Mars."). ...and then you claim you know it better than the book author and go even further away from all other estimates.

No, I'm not saying I know better than the book author. What I'm saying is that I'm not constrained by the limitations of the book author. It's also worth pointing out that everyone has biases and motives here; almost everyone putting out a book or a low estimate has a bias toward a low-end estimate. My bias is the opposite: I'm biased against wasting money.

 

[Al_]

Ask not what the colony will cost. Ask what the colony can sell to Earth!

 

[Al_]

... and then ask what it will cost

 

[rootone]

Ask what the colony can sell to Earth!

That's really the central question.
Even if a colony was to provide stuff to Earth for FREE, the cost of maintaining the colony and transporting the stuff would be high.
Almost certainly much higher that producing the same stuff on Earth, unless it's something unique that can't be done on Earth.
A small manned base could provide useful scientific research, but no need of a fully self sufficient colony for that.
The argument for establishing a second home planet for humans is logical, but I think is politically unsellable except in a doomsday scenario.
Most people would I think probably prefer to see environmental degradation on Earth curtailed first,
or even uninhabitable regions on Earth made habitable, (at a fraction of the cost per inhabitant).