Mars Colonization--a science question

gulberat

Obviously we'll have a LOT of issues to contend with if we ever hope to get a viable colony in place on Mars, but one of the questions I've been wondering about a lot is this: even if we can get supply issues solved and ensure that our colonists are properly shielded from radiation, etc., is human life inherently unsustainable due to the (approximate) .35G gravity environment? We know that zero-G is damaging to the body over time and we can see the effects on the ISS astronauts. But would Mars gravity still be too low for safe, long-term settlement?

Of course in space we know theoretically how to remedy that (spinning the craft at the right speed), though our current spacecraft don't do that. But on the surface of another planet, in the absence of Star Trek's artificial gravity generators, what would we do to compensate for the low gravity? Or would it be flatly impossible to compensate for in any way whatsoever?

(Note: The "compensation for low gravity" issue may be a separate, even more serious one when we consider fetal and infant development where an exercise regimen is not possible.)

gradii

I doubt its impossible. I mean Lord Kelvin was a greatly respected scientist in his day...

"X rays will prove to be a hoax"

jonsills

The damage to the bodies of the astronauts is only in relation to the return to a 1g field at the end of their deployment, as I understand it. As Mars colonists will likely be spending the rest of their lives there, adaptation to a .35g field shouldn't present any long-term health problems, so long as they're not intending to return to Earth. (Should they do so, a daily rigorous exercise regimen would be required during the entire time there, meaning they wouldn't be able to go very far from the habitat.)​​

smirk

> @gulberat said:
> Obviously we'll have a LOT of issues to contend with if we ever hope to get a viable colony in place on Mars, but one of the questions I've been wondering about a lot is this: even if we can get supply issues solved and ensure that our colonists are properly shielded from radiation, etc., is human life inherently unsustainable due to the (approximate) .35G gravity environment? We know that zero-G is damaging to the body over time and we can see the effects on the ISS astronauts. But would Mars gravity still be too low for safe, long-term settlement?
>
> Of course in space we know theoretically how to remedy that (spinning the craft at the right speed), though our current spacecraft don't do that. But on the surface of another planet, in the absence of Star Trek's artificial gravity generators, what would we do to compensate for the low gravity? Or would it be flatly impossible to compensate for in any way whatsoever?
>
> (Note: The "compensation for low gravity" issue may be a separate, even more serious one when we consider fetal and infant development where an exercise regimen is not possible.)


It is difficult to know what is possible and when, as the current US administration is actively de-stabilizing and crippling all our nation's functions on an unprecedented scale and may be the final nail in the coffin of our superpower/space power status.
Add to this that the Chinese, North Koreans, Russians, Iranians and even some of our allies may soon begin using their space-borne warfare tech against us, and you have a doom-and-gloom foundation for any building of hope for the future of space exploration.
That said, the Mars mission was READY to begin in two phases prior to the Viet Nam war! The first phase was to establish industrial operations in orbit and on the lunar surface, extending to deep sub-surface lunar colonization. The arguments against going ahead with this phase were mostly based on the uncertainty of finding hydrogen sources (esp water) and the certainty that Russia would make good on its threats to destroy our installations.
The second phase was to build an orbital drydock/ "shipyard" to facilitate the construction of a Mars expedition vessel. During Reagan's presidency, he attempted to REVIVE (not initiate) this program with its scheduled private/public co-investment of $2T/yr for about 20 years to fully industrialize the moon for the project. Had he succeeded, we would have launched our first manned expedition 10-15 years ago.
The biggest problem is the bone degeneration astronauts experience in extended space deployment, as the expedition would take anywhere from 8-24 months to arrive at Mars, depending on time of launch and what platform ultimately would be selected for the mission.
Another serious problem is the difficulty of shielding the cabin from radiation for the trip there and back.
Then there are the same issues as the lunar colony project had . . . Water/hydrogen source and protection from our enemies (no, the cold war did not end).
The psychological endurance issues have been deeply explored through the use of underwater exploration and habitats, Submarine deployment and actual space-faring experience, so while they are a concern, we probably have a good handle on them.
Beyond that, it would probably literally take a rocket scientist to explain the other difficulties.
Remember that unless and until we have the means AND the will to terraform Mars, all habitats would have to be self-contained (possible but very expensive).
Yes, it is possible. The barriers are that they have always been, and, given the deteriorating political climate, I fear they always will be.

gfreeman98

It's a good question. The answer is: we really don't know. Long-term exposure to near-zero G is still being studied, with no one much more than 1 year in such conditions. We literally have zero knowledge of how the body reacts to 0.375 G. Basically, we won't know until we go. But humans are adaptable, and if a colony could survive the people would no doubt acclimate in a few generations.

I think the bigger worry is the radiation. Perhaps living underground is the only viable way, again something we haven't really mastered.

smirk

True, but then we have the more real and abiding threats from our enemies as well as those posed by bureaucratic incompetency in a program on a scale that would be more massive than any we have seen before. Even Obamacare pales by comparison to the manpower and materielle required for such an endeavor.

gradii

Actually we could have at least landed people on mars with 1980s technology. Most of the technology we need to get there, and a large portion of what we'd need to live there is already in place by now.

What we have is a lack of will to actually try.

deaftravis05

There are several problems.

1. proper shielding. Our astronauts that went to the moon were exposed and it was considerable levels. that's just a few days. No solar flares went off at the time. Those would had fried them.
2. too long of a journey in zero g.


Now number 2 is getting better and we have ways around that. We're still having issues with proper shielding. The tech is there, but it's expensive and difficult to do this. Mainly because it's difficult to launch into Earth's orbit. Solve this one problem and we can solve the other two.

gulberat

@jonsills, In your scenario the colonists would never come home again--but wouldn't their children also be destined to remain on Mars permanently, since they will *never* contend with Earth-normal gravity? What are the socioeconomic implications? (Was that covered in The Moon Is a Harsh Mistress, and if so, how close to the mark might Heinlein be?) IMO abnormal fetal development could be an additional concern.

If procreation turns out to have serious problems, it almost makes me wonder if we should consider (once adequate shielding is available) a large space habitat in Martian orbit that we can rotate for gravity, with temporary excursions to the surface for industry as opposed to constant habitation. Just thinking out loud here...I realize that is likely to come with cost problems and other concerns.

Or again, is there another method to simulate higher gravity on the surface that I am missing (besides an exercise program so demanding as to curtail a lot of activities)?

smirk

Shielding, we can do, but it is costly to get that much material and bulk off of Earth and into orbit, hence moon-mining and industrialization is almost a must.

Zero-g can be somewhat mitigated by a rotating habitat ring, but that creates its own design challenges.

Fuel is a concern, though solar power augmentation, hafnium reactors, ion drives, nuclear-heated hydrogen thrusters and a great deal more of 1960's level technology could indeed have gotten us there and back a long time ago.

Landing poses a lot of challenges that most of us don't fully understand. Give it to an engineer and you would get a more thorough explanation, but it might be in engineerese and unintelligible for the layman.
You have to deal with atmosphere (Mars has some, thought not as much as we do), ground impact, fuel capacity, shielding and so many other issues, and you have to have a lander capable of Mars' escape velocity, or at least of reaching orbit.
Meanwhile there are ethical issues. How do we protect Mars from contamination?
Then, once on the ground there, given that we have a well-developed ground-based exploration capacity, you must handle the human factor.
Bear in mind that this is a very inexhaustive and abbreviated list of issues, and it does not begin to address the military issues involved when Russia, China, North Korea, Iran and other countries which have space programs are threatening to harm us and demonstrating a capability to do so. You can't afford to build a $9,000,000,000,000 training target for your neighbor's fledgling space weapons program.

gulberat

When you say a rotating habitat ring, are you suggesting that could somehow be implemented on the surface or are you thinking of a massive orbital station like the one I threw out there?

deaftravis05

Actually we could establish a rotating space station and sail it to Mars. It would act as a station in orbit of Mars to handle logistics. You'd need automaton technology to establish a mine to filter out the water on Mars, establish an outpost and get some farming going to establish a reliable source of food and oxygen. It also needs to be shielded as Mars's core isn't generating a strong enough magnetic shield to properly protect the planet.

smirk

> @gulberat said:
> When you say a rotating habitat ring, are you suggesting that could somehow be implemented on the surface or are you thinking of a massive orbital station like the one I threw out there?

That would be in space. Gravity, meanwhile, is higher as you get closer to the center of mass, which implies that deeper sub-surface development may yield somewhat improved gravity conditions, but you still have an issue, and that development may pose its own challenges.
Hydroponic/"aquaponic" farming could easily address the food/oxygen needs.
Stations in orbit and on Mars' moons would be needed, as pointed out, for logistics (and defense).
Militarily, though, the whole thing would be one big, fat, sitting duck,

deaftravis05

Who would shoot it down? Why do people think there'd be shooting?

gulberat

Because people may well take their problems into space (remember, a treaty is just a piece of paper and can be violated), or new problems (a la Heinlein) may arise when they get there.

smirk

> @deaftravis05 said:
> Who would shoot it down? Why do people think there'd be shooting?

Because there would be. China has specifically threatened to do so, as has Russia, in its own hyper-enigmatic fashion. Iran and North Korea, that is a no-brainer, as they are trying to figure out how to deploy city-killer weapons in North America and Europe...
Then there are those nations who are ostensibly our friends but may soon fall to the jihadi hoardes they have invited to invade them, and their space programs are almost as advanced as our own.
If drones can strike targets here, and most spacecraft in existence are drones, you do the math.
What will we do, outlaw them?
We must have a defensive capacity before we can explore any further.

gfreeman98

jonsills

Gravity is not "greater as you approach the center of mass". Gravity is an effect of mass on space-time, not some sort of centrally-generated energy field (thus why we can't find a way to do contragravity - yet); if you tunnel underground, the gravitic pull of the mass above your head is "up", with only what remains below to be "down". Were you able to tunnel to the center of Earth and survive, you'd be in free-fall, as the gravitic pull of the sphere of Earth "above" you would be uniform in all directions.

Tunneling below the surface of Mars would similarly result in lesser effective gravity, although you'd have to delve quite a long way before you ever noticed.

And no, no one has threatened to bomb space habitats. China is threatening to build one, not destroy one. Further, of the nations you cite, only one of them even has the vague capability of reaching orbit with, well, much of anything - honestly, if Iran had developed even so much as suborbital flight, Israel would no longer exist. "But they're trying to make ICBMs!" Yeah, and I'm trying to get the car in my garage running, with inadequate tools and budget. And I'll probably succeed before they will, because at least there's no international organizations trying to prevent me from developing Hyundai Accent technology.

I submit, smirk, that you know not of which you speak.

gradii

Bomb Space Habitats? Ouch.

lordrezeon

Well getting to and from Mars orbit is relatively straight forward, albeit costly. Landing somebody on the surface in one piece is a bit trickier. As was mentioned above Mars has a thin atmosphere and about a third of Earth's gravity, which creates several problems that have to be worked out. Parachutes are less effective in Mars thinner atmosphere which means a heavy landing craft would need landing thrusters, however the planet has higher gravity than the Moon which means you need much more fuel to do it which again makes the craft even heavier which means you need more powerful rockets which guzzle more fuel... you get the idea.

Getting there is doable it is just really expensive, and without some kind of immediate payout you aren't going to find a lot of financial backers for a project of this scale.

Aside from the long term health issues from living in low G on a planet without a strong magnetic field, there is also the major road block of water. People and particularly agriculture need large quantities of water to live, which means that before we even consider sending people we will need to establish some kind of automated or remote based infrastructure to support life on Mars.

Sadly all this might come crashing to a halt due to the possibility of future warfare. We have already seen multiple nations demonstrate their ability to destroy satellites with ground based missiles. With satellite communications being so prominent it is almost inevitable that the next big war will wind up causing Kessler syndrome, where debris from destroyed satellites makes space flight to risky to attempt.

gulberat

Jonsills, one thing I do think might have to be considered is if you get a class of people effectively marooned to Mars due to physical differences and whose children are even more incompatible with life on Earth. I think there's at least some chance that we end up with a Heinleinesque scenario if we do not ensure that any colonists remain robust enough to handle Earth gravity, given the power differential it creates if Earth natives are able to relocate at will and Mars natives are stuck. I still have to read the book but I am pretty sure the "Loonies" in The Moon Is a Harsh Mistress could not leave the Moon but Earth-born, temporary visitors were free to do as they wished. That right there is IMO a problem.

In other words, we might run a risk of accidentally creating space serfdom if we don't think carefully about what we are doing and do something to prevent it either by putting an O'Neill cylinder or something in orbit, or finding a way to make things work on the surface without creating two classes of humanity in which one is seriously physically handicapped compared to the other. One side that can land troops (who are effectively "supermen" because of spending most of their time in 1G) and one side that physically can't is a problem. Maintaining parity and freedom of travel seems to me the only way to prevent resentments or exploitation.

smirk

Jonsils, I am not here for a flamefest, so let it suffice it to say that you and I are essentially saying the same thing about gravity, though you are abusing terms to create an image for your own purposes.
As to threatening to bomb space habitats . . .
Russia has threatened WAR against us. What part of war would not extend to the farthest reaches of their capability?
China has threatened to rain down fire upon our cities and is relentlessly attacking us in economic and cyber warfare. What makes you think they could resist a nice, fat, $9 trillion national asset when they have the capability to destroy or disable it.
Iran has launched things to an orbital level, and they have a great deal of assistance from Russia and China. North Korea is just a messed-up place led by psychotic imbeciles and will use any weapon or platform they can acquire . . . and it is no stretch to say they have a significant space program.
If we are here to mock each other, take it to another forum.
If we are here to discuss the real problems of space exploration and colonization, . . . lead on.

jonsills

gulberat wrote: »

@jonsills, In your scenario the colonists would never come home again--but wouldn't their children also be destined to remain on Mars permanently, since they will *never* contend with Earth-normal gravity? What are the socioeconomic implications? (Was that covered in The Moon Is a Harsh Mistress, and if so, how close to the mark might Heinlein be?) IMO abnormal fetal development could be an additional concern.

If procreation turns out to have serious problems, it almost makes me wonder if we should consider (once adequate shielding is available) a large space habitat in Martian orbit that we can rotate for gravity, with temporary excursions to the surface for industry as opposed to constant habitation. Just thinking out loud here...I realize that is likely to come with cost problems and other concerns.

Or again, is there another method to simulate higher gravity on the surface that I am missing (besides an exercise program so demanding as to curtail a lot of activities)?

The socioeconomic situation in The Moon Is a Harsh Mistress were governed primarily by the fact that at the outset of the novel, the lunar colonies are penal colonies for those with life sentences; the Lunar Authority administers the place as the next best thing to a plantation, while the internal socioeconomy of Luna is extremely libertarian. After the Loonies successfully rebel against Earth, the most influential voices in the rebellion (Prof. de la Paz and Mike) draw upon the founding documents of the United States for their inspiration, modified for lunar conditions ("free as the air" doesn't mean a lot when air is supplied by private corporations and if you don't make your quarterly payments your habitat might be cut off - for Luna City that's included in the quarterly tax). The gravitic issues entered into it only insofar as it was very difficult for Lunar representatives to meet Terran representatives anywhere but in Luna - not impossible, especially after Stuart joined, but difficult.

I believe there might be issues with fetal development in free fall, as we're evolved to use a gravitic field for much of our biological reference; however, I'm not sure that will be a problem so long as there's a gravity field to provide a definite "down". 0.35g should be more than enough to provide for successful gestation. If not, one could always build a centrifuge in one's colony to provide higher effective gravity for a given exercise period - that was how Manny and Wyoh prepared for their trip to Earth in the novel.

gulberat

Much as animal experimentation is problematic, I suspect we will need to breed several generations of rats on the Martian surface to check for fetal development problems before we ever consider a permanent surface colony. At least I would do it first because to me, even if you do not start as a penal colony, there are many paths to exploitation as a result of significant differences in physical capabilities (if not compensated for).

smirk

Using an extraterrestrial outpost as a penal colony would be a bad idea for a lot of reasons.
Animal experimentation is only problematic if you presume these animals which, left in the wild, would kill and eat each other and die of horrible conditions, are of a higher order than what all of science and reason would imply. If a reasonable case could be made for sentient rabbits, rats, guinea pigs, etc, then animal experimentation would indeed become problematic.
True, there are a lot of differences between how dogs and rabbits handle weightlessness and how humans do, but the similarities allow insight into our own processes.
It makes a lot more sense to experiment on a rabbit, which would at best make a nice lunch for a fox or a wolf, and which will die in 4-7 years regardless, than to experiment on a human, whose sentient interaction could yield a cure for cancer or a bride for your son . . .

gulberat

RE: Kessler Syndrome--definitely another perk of what SpaceX just did. While we have a TON of space debris we still have to clean up, and old rocket stages are only one type of orbiting junk, their recyclable rockets don't just have potential to be cost effective...they also show us how to put less of a mess into space.

deaftravis05

They have never threatened war if the world builds a space habitat. Never. It'd be governed by the UN or something.

Iran meh. They don't care
North Korea is full of hot air.

Gravity does not get greater the deeper you dig, but rather weaker.


Next.

oldravenman3025

A station in orbit as a secondary base of operations and logistics, generating gravity by rotation, would negate many of the health issues of long-term Mars settlement and exploration. Combined with a scheduled exercise regime groundside, similar to those on past/CURRENT long term missions (Skylab, Mir, I.S.S.) in shifts, this would be a viable undertaking.

lilchibiclari

oldravenman3025 wrote: »

A station in orbit as a secondary base of operations and logistics, generating gravity by rotation, would negate many of the health issues of long-term Mars settlement and exploration.

That of course assumes that access to the orbital station is granted to all--which will happen if most of the people are employees of whatever organization manages the station, but once a full capitalist economy develops, I am sure that whoever is providing accommodations at the station and passage to and from it will start charging for access, and those who can't pay won't get any access.

gradii

lilchibiclari wrote: »

oldravenman3025 wrote: »

A station in orbit as a secondary base of operations and logistics, generating gravity by rotation, would negate many of the health issues of long-term Mars settlement and exploration.

That of course assumes that access to the orbital station is granted to all--which will happen if most of the people are employees of whatever organization manages the station, but once a full capitalist economy develops, I am sure that whoever is providing accommodations at the station and passage to and from it will start charging for access, and those who can't pay won't get any access.

I love how you seem to imply access to the station wont be a problem under a non capitalist system. I needed a laugh.

jorantomalak

Lots of debate on this topic lets ask the martians about it