Survival on Mars: Radiation & Temperature Challenges

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In summary: The conversation revolves around the challenges of surviving and colonizing Mars, including radiation protection and temperature issues, as well as the importance of addressing basic needs such as food, water, and air. The discussion also touches on the challenges of maintaining a base and producing necessary resources locally, as well as the potential of utilizing local resources like Martian soil.
  • #1
GTOM
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I'd like to have two main questions about it.

1. Radiation protection : theoretically, were thick leaded glass domes for settlements be enough for it, or you need to build underground anyway?

2. Temperature : I read, that heat conditions on Mars equator is similar to Antarctica. We already can sustain bases on Antarctica, however, due to dust storms and 40% solar power, were a settlement be ultimately dependant of fusion power? Or not entirely necessary?
(Other methods, solar power collection with large surface and orbital mirrors, producing fuel artifically that can be used during the dark times.)
 
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  • #2
You might try a forum search. Mars colonization is discussed here every now and then. A good place to start is the links at the bottom of this page.
 
  • #3
I see the links, but it isn't about whether we could possibly reach Mars in the next hunders of years or not?
This is all about survival (engineering questions) under the given conditions.
 
  • #4
You're jumping ahead a step...

There are three parts to surviving a visit to Mars.

1] Getting there

2] Being there

3] Getting back

The first is a major issue because the shortest route currently takes many months during which the travelers receive about 80% lifetime maximum radiation exposure. Providing the craft with a meter of so thickness of lead skin is an issue.

The second is made more critical if arriving with a large exposure; the subsequent exposure during the visit needs to be minimized.

The third, coming back, is the same issue as the trip there - exposure on the trip there plus exposure on the trip back exceeds lifetime max exposure by a large margin, no even counting the accumulation while there.
 
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  • #5
You're jumping ahead a step...

I thought the whole situation is hypotethical enough for the SF topic, it looks like i was wrong, but the topic assumes the getting there with enough equipment is solved. (Probably with ships mimicking Earth's magnetosphere, i read that it is a possibility to be viable.)

So you say, around one meter lead would be the minimum requirement for radiation protection. Mars offers little more protection than space, and i thinking in a lifetime of stay.
 
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  • #6
GTOM said:
i thinking in a lifetime of stay.

It would be a really short lifetime.
 
  • #7
bahamagreen said:
The first is a major issue because the shortest route currently takes many months during which the travelers receive about 80% lifetime maximum radiation exposure. Providing the craft with a meter of so thickness of lead skin is an issue.
Those limits are always arbitrary, they vary with country and occupation and can be changed.

There are inhabited places on Earth with radiation doses of about 100mSv/year. A trip to Mars without excessive shielding would exceed that, but just for 2-3 years, for a total dose of something like 1 Sv (number from space.com). That would increase the risk to get cancer, but so does smoking. The other risks of such a trip are probably much more dangerous.

If you want to stay there for a lifetime, you certainly want some shielding.

We already can sustain bases on Antarctica
Well, "sustain" - getting materials there is cheap so the base can be large, you have an infinite, easy accessible supply of oxygen and water ice and everything else comes via airplane. We did not even manage to get a true self-sustaining ecosystem on earth, with unproblematic size limits, with more light from the sun, better environment temperatures and no radiation shielding issues.

Conventional fusion reactors are huge by design and it is unclear if unconventional concepts will ever work. Fission looks like a better power source, or large areas of solar cells.
 
  • #8
GTOM said:
Mars offers little more protection than space, and i thinking in a lifetime of stay.
You are jumping the gun a tiny bit. Temperature and radiation are the least of concerns, and yet you put those concerns first. Those are rather easily solvable problems. The hard problems:
  • How do you breath?
  • How do you drink?
  • How do you eat?
  • How do you treat medical problems?
  • How do you treat psychological problems?
 
  • #9
Temperature and radiation are the least of concerns, and yet you put those concerns first. Those are rather easily solvable problems.

I thought about using the ice of the polar caps, hydrogen peroxides, CO2 to prduce biogen materials.

Peroxides on Mars

I don't doubt the enermous amount of infrastructure needed to do this, i supposed that some times in the future we could already built a huge space colony on Moon, or at L4 L5. And they can ship lots of equipment.

Recently i read that stuff.

Mercury base

So you disagree with that analysis, that put heat issues first.
 
  • #10
No air, no water, no food. These issues appear to merit a great deal of consideration in 'colony' planning.
 
  • #11
D H said:
You are jumping the gun a tiny bit. Temperature and radiation are the least of concerns, and yet you put those concerns first. Those are rather easily solvable problems. The hard problems:
  • How do you breath?
  • How do you drink?
  • How do you eat?
  • How do you treat medical problems?
  • How do you treat psychological problems?

I'd add to that:

  • How do you maintain your base? Build equipment locally or rely on shipments?
  • How do you ensure a sufficient skill set amongst your population?

On the subject of growing food, how good is our current understanding of Martian soil? I've read of studies where they made up what they thought would be Martian soil and tried to grow crops in it but I'm not sure how reliable that is. Seems like having a large and accurate amount of soil to test would be a necessary requirement.
 
  • #12
How do you maintain your base? Build equipment locally or rely on shipments?

Lets suppose, that spare parts can be shipped, they don't have to start with building an entire industry.
But in order to survive, produce food, water, air, habitats, they need to take advantage of the local resources after a time.

Seems like having a large and accurate amount of soil to test would be a necessary requirement.

Yes, i agree that is needed.
 
  • #13
GTOM said:
But in order to survive, produce food, water, air, habitats, they need to take advantage of the local resources after a time.
Not one of which is something humans can do at this point in time, at least not for any extended duration. The problems that Ryan_m_b and I mentioned are things we don't know how to do. The problems you mentioned, radiation protection and thermal regulation are far easier.

As far as colonizing Mercury goes, that's just plain nuts at this point in time.
 
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  • #14
D H said:
As far as colonizing Mercury goes, that's just plain nuts at this point in time.

+1 on that, for sure !
 
  • #15
The Mars Plant Experiment didn't make it on Mars 2020, unfortunately.

The ISS produces oxygen from electrolysis and recycles a significant fraction of the water used there - but it still needs a constant supply of water.

Food is a serious problem, together with the overall station maintenance.
 
  • #16
mfb said:
The Mars Plant Experiment didn't make it on Mars 2020, unfortunately.

The ISS produces oxygen from electrolysis and recycles a significant fraction of the water used there - but it still needs a constant supply of water.

Food is a serious problem, together with the overall station maintenance.

Well, that is sure not good, it could have answered at least a few questions, they will remain in the dark for a long time.

What are the problems with recycling on ISS, is there any proposed way to make it more efficient?
 
  • #17
Some waste water is hard to recycle if it contains problematic other substances (biological or not) or if oxygen or hydrogen get bound to other molecules - if it is cheaper to get new water from earth, that is preferred.

Currently, the ISS uses water to generate oxygen, and releases the hydrogen into space - that's not a closed cycle (and the carbon dioxide produced by humans is not used either), but I guess it is possible to make that better for a trip to mars.
 
  • #18
mfb said:
Some waste water is hard to recycle if it contains problematic other substances (biological or not) or if oxygen or hydrogen get bound to other molecules

It's worth bearing in mind that even if a method was developed to break down waste molecules for reuse those methods themselves could generate waste. Albeit less (otherwise it's a useless technology) but a 100% closed system is quite unlikely for the foreseeable future.
 
  • #19
I thought about some hydroponics garden for recycling.A bit offtopic, but Mercury colonisation was also mentioned here.
I read that Messenger was protected from the heat and radiation by sunshades and heat shields.
Could this method also work on the sunny surface of Mercury? Or no, because there is heat all around.
Or only if the machine is completely in some black box, and no access outside?
 
  • #20
Messenger was in a very elliptical orbit, only a very small part of it was close to the surface to minimise the head reflected from it. Note the key term there: reflected. On the surface heating through conduction would make the situation even worse, not to mention the fact that a day on Mercury is nearly two months long.

So unfortunately no, you can't put a shade on top of a building and survive on the Mercury surface.
 
  • #21
So if we wanted to send some surface rover there, even if it has all around protection, it has to stay constantly on the terminator.
Thanks.
 
  • #22
Landing on Mercury would be very difficult given the lack of atmosphere to slow down with. Aside from that I think staying in the dark would be a must, however the obvious problem there is powering the probe. Given that landers are solar powered how could you provide a permanently night time probe for any reasonable length of time?
 
  • #23
Curiosity on Mars works with nuclear decays, that should be scalable (a Mercury probe in the shadow would need more thermal power to keep it warm).

Shielding close to the poles could be possible: put a shield on the sunny side of a stationary probe. Sure, you get conduction, but the ground is not as hot as it gets at the equator, and you have nearly the full sky for blackbody radiation cooling.
 
  • #24
Hi, I have read all your ideas about survival on Mars. I have read things about it saying that it is possible to have life there but I think this has not been proven so far maybe its because a supply of food will be a big problem . However, I just hope our advance technology will have the answer to all the possibilities of survival on the said planet.
 
  • #25
mfb said:
Some waste water is hard to recycle if it contains problematic other substances (biological or not) or if oxygen or hydrogen get bound to other molecules - if it is cheaper to get new water from earth, that is preferred.

Currently, the ISS uses water to generate oxygen, and releases the hydrogen into space - that's not a closed cycle (and the carbon dioxide produced by humans is not used either), but I guess it is possible to make that better for a trip to mars.

I don't understand this objection, as I don't think the ISS is a very relevant example. There appears to be plenty of water on Mars in the form of sub-surface ice. There would be no need to bring it from Earth.
 
  • #26
phyzguy said:
I don't understand this objection, as I don't think the ISS is a very relevant example. There appears to be plenty of water on Mars in the form of sub-surface ice. There would be no need to bring it from Earth.
See the previous post, the question was
GTOM said:
What are the problems with recycling on ISS, is there any proposed way to make it more efficient?
 
  • #27
Heyo! This was an old obsession of mine! Here goes...

So, radiation: Yes, and no. Some shielding would be required, but not a whole lot. Using lead is a bad idea; it's a lot of dead weight you'd need to haul from Earth or mine on Mars. But first, the trip there. As mfb pointed out, this really isn't that bad.

I think smoking is actually much more dangerous than a trip to Mars and back, in terms of increasing your chances of cancer.

mfb said:
Those [radiation exposure] limits are always arbitrary, they vary with country and occupation and can be changed.

There are inhabited places on Earth with radiation doses of about 100mSv/year. A trip to Mars without excessive shielding would exceed that, but just for 2-3 years, for a total dose of something like 1 Sv (number from space.com). That would increase the risk to get cancer, but so does smoking. The other risks of such a trip are probably much more dangerous.

If you want to stay there for a lifetime, you certainly want some shielding.
[...]

One idea I like for radiation shielding once you're there, may be to simply pack dirt up against the side of your habitats. Martian dirt is free, and all you need to move it around is a shovel. That way you can still have windows, and the shielding is more than sufficient if you do it right.

http://www.examiner.com/images/blog/EXID21670/images/776px-Concept_Mars_colony.jpg

You'll notice that most artist depictions' and NASA renditions of Mars colonies don't have any shielding, though. Truth be told, you'd need to stay on Mars for 3 years to reach NASA's career radiation dose limits. So for something like a research base where the crew changes out every launch window or two, no radiation shielding would be necessary at all, apart from the structure's walls, and perhaps a special "storm shelter" for Solar Proton Events.

*For conjunction-class missions, surface stay duration is around a year, give or take. The entire trip would be in the ballpark of 2 years, with about 6-8 months each way.

**I'm pulling that bit about radiation from here, and decided to do some digging and wound up http://www.nasa.gov/centers/johnson/slsd/about/divisions/hacd/hrp/space-radiation-pubs2.html then here. How do I actually get to the paper itself?

As for temperature; you feel cold when its cold outside because the ground and air conduct heat from your body. The air is extremely thin on Mars; for our purposes here, virtually non-existent. So in terms of air temperature, taking a walk on Mars would be more or less identical to a spacewalk (aka, an Extra-Vehicular Activity, or EVA) in Low Earth Orbit (LEO) (except the sun won't be as intense, so it'd actually be a bit easier. EVA suits for LEO have to work day and night, in and out of the sun. For Mars, the range of temperatures would be less extreme since it wouldn't get as hot).

As for the ground... Yes, that will be cold. But not too cold. The temperatures there are very easily handlable with some good insulative materials, which you need a lot of in aerospace, anyways. It's really not that big of a problem; it's something engineers face with every spacecraft they build and launch; and often a few inches of very lightweight insulation would be far more than enough.

*Controlling the temperature of something in a vacuum is a surprisingly precise balancing act. You must insulate it so its heat doesn't all leak out by thermal radiation (the warmth you feel radiating from a hot stove, for example, is thermal radiation), and control how much you radiate out so too much heat doesn't build up in your insulation from things that produce waste heat like human beings, computers, engines, life support devices, etc. Spacecraft generally have specialized heat radiators for this purpose, that can radiate a variable amount of heat to keep the craft at the right temperature.

iss028e015556_small.jpg


In fact, the Space Shuttle's cargo bay doors are lined with heat radiators - that's what the reflective material is - aluminum with tubes running through it of coolant, wrapped in mylar. They're essentially air conditioners, but instead of using fans like air conditioners for your house would, they use thermal radiation (I think they even use Freon, iirc!). If the cargo bay doors were to jam, the shuttle would have to have pulled an emergency abort back to Earth.

Other things that were brought up:

Water:
VWHsC0d.png

http://phoenix.lpl.arizona.edu/edu_water_ice_dirty_ice_snowcones.php

Water + RTG, fission or Solar power = Oxygen.

Soil is also rich with peroxides and nitrogen.

To filter Co2, NASA has developed fully-reusable systems that do this. There's probably more options for systems to pick from, and better ones, but the RCRS is one that I know about, at least.

Growing food ain't no thang: aeroponics. It's like hydroponics, but better. No soil is needed, higher yield per volume and time with less labor, and far less water consumption.

3d printer technologies are looking more and more promising if you need to make replacement parts in-situ. ISRU means you can even use that local water (which you're already getting hydrogen and oxygen from for your life support) plus some martian atmospheric Co2 to make methane+LOX fuel/oxidizer.

Better yet, you can even do this:
2H2O -> 2O2 + H2
Put that O2 somewhere else, we just need that H2, and grab some atmospheric CO2.
2H+CO2 -> C+O+H2O
in a pressurized reactor to get yourself carbon, which is oh so nice for so many things.

Ryan_m_b said:
It's worth bearing in mind that even if a method was developed to break down waste molecules for reuse those methods themselves could generate waste. Albeit less (otherwise it's a useless technology) but a 100% closed system is quite unlikely for the foreseeable future.

True, and I thought I remembered someone mentioning the failed Biosphere experiments, but I couldn't find that post when I looked again. But fortunately, we don't need a 100% closed system for the reasons I listed. We only need it to be very efficient, and although I can't quote for sure, I think the level of efficiency present on the ISS is actually about enough. Although, of course, I guess that depends on how quickly you can extract resources from the Martian environment.

Mars is about as lush for us, with our current technology, as the colonial Americas were for the early colonists' technology. More so, I'd say, actually, since we wouldn't have to worry about disease and the cold of winter in the ways that they had to. Or hostile natives, heh. The big difference in-between us and them is that they had a real strong incentive to go and colonize the Americas. Natural resources/colonialism, and religious freedom, as I understand it. Interesting to me it is, that it wasn't until hundreds of years after the first explorers sailed there that colonies - or even the motivations for those colonists to go - appeared.

Our technological nearness to being able to settle there (I'd say we're much, much closer to that, than we were to landing on the moon in 1959!) and lack of colony might be somewhat analogous to that span of time in-between the first explorers finding America and the colonies appearing there, if not only very roughly so - I'm really no historian at all.



Thing is, I'm very hopeful about Mars colonization. As Robert Zubrin put it, in the ancient days before the world was explored, it was common to draw fearsome dragons on maps in unknown lands, and put "there be dragons," and other fears of the unknown, fears of doing what hasn't been done before.

Radiation, temperature, low gravity... All of these things are managable, but a lot of people go on as if they're show-stoppers. "There be dragons." In truth, we could have built a Mars colony in the 80's with "Mars Direct." The only reason we didn't was a lack of political drive or unity in NASA.

I'm very hopeful SpaceX will live up to its ambition to have one there by 2035. They've been doing an awful lot of "impossible things" in the aerospace industry already, like lowering the price of spaceflight to where some companies think it'll be profitable to mine asteroids. I think they'll pull through. I'm not so sure about the 2035 deadline, but I'm certain by 2050 there'll be people on Mars.



EDIT: I suppose ultimately, though, we can only conjecture about how easy/close we are, but I don't think anyone can really say for certain until some group, perhaps SpaceX, actually develops the In-Situ Resource Utilization (ISRU) technologies and proves they can work at a rate to make up for inefficiencies in recycling in test facilities here on Earth (Something I should note that Robert Zubrin and a few colleagues - not a single of whom were chemists or chemical engineers, but aerospace engineers - did to prove that CH4/LOX could be produced from Martian resources at an acceptable rate. iirc, they did it fairly quickly and without too much effort).

But my educated guess is; it's going to be easier than a lot of people make it out to be. Not easy by any means, but not harder than the really amazing stuff SpaceX has done already, and certainly, by a far cry, not nearly as hard as landing on the Moon was in 1959.
 
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  • #28
Currently there is no known way for a colony to survive on Mars without regular shipments. This would be cost prohibitive so money is the chief obstical.

In addition, with our current rocket technology the resupply mission would take about 2 years so packing enough supplies for two years is also a problem.

And then there is the problem of landing humans there. Believe it or not that is also a big unknown right now. It was a HUGE achievement when NASA landed curiosity on Mars, it was a far from a sure thing, nothing that heavy had ever been landed on Mars before...and it was the size of a small car. To land humans on Mars you are talking something the size of a small house. I haven't seen any answers to that one yet.
 
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  • #29
I expect ion thrusted ships assembled in orbit, or on the Moon, Lagrange points to ease travel.

Otherwise i thought about lead glass protected settlements so they could see the sky, but it is definitally far future, yeah packing dirt onto them sure a nearer soultion.
 
  • #30
DHF said:
Currently there is no known way for a colony to survive on Mars without regular shipments. This would be cost prohibitive so money is the chief obstical.

In addition, with our current rocket technology the resupply mission would take about 2 years so packing enough supplies for two years is also a problem.

And then there is the problem of landing humans there. Believe it or not that is also a big unknown right now. It was a HUGE achievement when NASA landed curiosity on Mars, it was a far from a sure thing, nothing that heavy had ever been landed on Mars before...and it was the size of a small car. To land humans on Mars you are talking something the size of a small house. I haven't seen any answers to that one yet.

Currently there's no way to put a colony on Mars, either. I think the topic here is: what kind of technology is possible, in say, 5 years? The kind of technology to live off of Mars for most of your resources is actually rather attainable. Ice, aeroponics, ISRU (In-Situ Resource Utilization; referring specifically to using Martian resources to generate Liquid Oxygen (LOX) and CH4 fuel), etc.

I can't say I know a whole lot on nutrition, other than; I've seen a number of Mars mission architectures proposed, and none of them seemed to imply that it's really much of an issue. Von Braun even had a plan that could've had us there in 1980. Mars Direct could've had us there in 1990.

As for landing on Mars, it's a challenge, but not one that we're not up to. The Mars Reference Design Mission was a NASA study done Constellation-era, that proposed using a retropropulsive burn in addition to atmospheric braking (there's even a neat little animation of the whole thing on youtube). More realistically, SpaceX is considering doing something similar with canted thrust; by angling the exhaust plumes out the side, you avoid issues of flying through your own exhaust trail at supersonic speeds.

But personally, my bets are on the LDSD, coupled with a terminal-phase powered descent for the last few hundred m/s.

(I've got a funny story behind this one. I've always just assumed that large payloads could land like small ones. Then, I got Kerbal Space Program and this "Realism Overhaul" mod pack for it. Trying to land on Mars, I got frustrated because I faced these same problems mentioned here. I finally just decided to basically do as LDSD does - open a parachute at a very high altitude. What's funny is I didn't think that was realistic - but only later I actually discovered that the LDSD actually exists, heheh)

GTOM said:
I expect ion thrusted ships assembled in orbit, or on the Moon, Lagrange points to ease travel.

Otherwise i thought about lead glass protected settlements so they could see the sky, but it is definitally far future, yeah packing dirt onto them sure a nearer soultion.

LEO would be the place to assemble things; anywhere else is less efficient. Ion engines and other plasma-electric systems have a much higher fuel efficiency, but require large electrical power sources that limit their thrust, and thus the craft's acceleration, in such a way that it's really not beneficial in terms of flight time versus conventional chemical rocket propulsion.

There was a "39 days to Mars" thing that hit magazine covers, but that study assumed some rather optimistic (to say the least) kW/kg ratios for the craft's nuclear powerplants (while I, myself, don't see the problem with nuclear powerplants in space, its something that causes some political fuss so I'm not sure how likely it is for, say, multi-MW reactors to ever fly in the manned program).

In truth, your best shot is a plain'ol conventional combustion rocket. LOX and LH2, or maybe even LOX and CH4. I'm confident SpaceX will make a good call on that one. Six months travel time one-way is rather attainable with that and ISRU. The whole mission will be, though, yes, roughly 2 years, but that has to do with planetary alignment and getting there faster really won't do much to that.
 
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  • #31
If you assemble things near to the Moon, you could mine lunar resources, and send them to orbit much cheaper.

Well alternatively, what if the electric spacecraft has lots of solar panels, and you direct a mirror forest on Moon to it?
 
  • #32
Then you rely on even more technology that does not exist now. And it will take a long time until moon-mined things in space are cheaper than stuff launched from earth. Just think of the mass ratios - Apollo needed ~40 tons in LEO for a mission that could return a few tons (including the astronauts of course) from moon. You would need some program that increases that ratio beyond 1. This does not even take the actual mining on moon into account.

Mirrors to space have a horrible efficiency.
 
  • #33
Greetings
Although I am of the opinion that a man will not walk on Mars before 2050, maybe even much later, the only way even that timeline can occur is if we begin...somewhere. It seems to me that the first hurdle is propulsion because faster, cheaper power not only reduces travel time, and therefore all of the other mentioned obstacles like food, water, air and radiation exposure, but ultimately also makes for a more attractive budget and nothing gets done without that. It also makes re-supply more feasible if and when longer stays become desirable.

So let's begin there, with propulsion. What do we currently have that could actually fill the bill? As I understand it, Project NERVA, nuclear propulsion, exceeded it's design goals and was certified able to achieve manned flight to Mars in 1972. It was only the climate of fear of all things nuclear and the neolithic political objectives of the Nixon Administration (I suppose he figured his "most historic phone call ever" self-promotion was all the mileage he need get from Science) that canceled the project.

One important factor is not only that it was certified in 1972 and perhaps usable in that form but that is also almost a half-century ago but we have learned and developed rather a lot. The most powerful Microprocessors in 1972 were less capable than some modern digital watches. Besides just the Microprocessor, all of the support chips suffered as well. We are all familiar with the red shift regression technique of creating a map of the timeline of our Universe, try running Moore's Law backwards to get a perspective on how bulky and weak data processing and control was in 1972.

For reference, UNIVAC was in operation for several more years after 1972. It would even be a few years before LSIs were invented and those merely had 10s of thousands of components (10^4). It wasn't until 1986 the first 1 megabit (not byte) chips were available. Now, ICs with 10s of Billions (10^10) are commonplace.

I think this is extremely important not only in terms of how much more can be done (and there is lots! to be done on a manned flight to Mars) but how little weight of itself and also the power required to run them is now feasible.

So, unless I am missing some important element on the downside unknown in 1972, why don't we start by a rebirth of the NERVA Project? Do we petition Senators? NASA? Universities?

How do we breach the coffee-table conversation stage and get started doing it?
 
  • #34
Nuclear things in space (and on earth) are even more frowned upon now.
Yes microprocessors follow Moore's law, but engines and power sources do not.

To speed up travel time in a relevant way, you have to get away from Hohmann orbits, and then you need a significantly more powerful propulsion system.
 
  • #35
enorbet said:
Greetings
Although I am of the opinion that a man will not walk on Mars before 2050, maybe even much later, the only way even that timeline can occur is if we begin...somewhere. It seems to me that the first hurdle is propulsion because faster, cheaper power not only reduces travel time, and therefore all of the other mentioned obstacles like food, water, air and radiation exposure, but ultimately also makes for a more attractive budget and nothing gets done without that. It also makes re-supply more feasible if and when longer stays become desirable.

So let's begin there, with propulsion. What do we currently have that could actually fill the bill? As I understand it, Project NERVA, nuclear propulsion, exceeded it's design goals and was certified able to achieve manned flight to Mars in 1972. It was only the climate of fear of all things nuclear and the neolithic political objectives of the Nixon Administration (I suppose he figured his "most historic phone call ever" self-promotion was all the mileage he need get from Science) that canceled the project.

One important factor is not only that it was certified in 1972 and perhaps usable in that form but that is also almost a half-century ago but we have learned and developed rather a lot. The most powerful Microprocessors in 1972 were less capable than some modern digital watches. Besides just the Microprocessor, all of the support chips suffered as well. We are all familiar with the red shift regression technique of creating a map of the timeline of our Universe, try running Moore's Law backwards to get a perspective on how bulky and weak data processing and control was in 1972.

For reference, UNIVAC was in operation for several more years after 1972. It would even be a few years before LSIs were invented and those merely had 10s of thousands of components (10^4). It wasn't until 1986 the first 1 megabit (not byte) chips were available. Now, ICs with 10s of Billions (10^10) are commonplace.

I think this is extremely important not only in terms of how much more can be done (and there is lots! to be done on a manned flight to Mars) but how little weight of itself and also the power required to run them is now feasible.

So, unless I am missing some important element on the downside unknown in 1972, why don't we start by a rebirth of the NERVA Project? Do we petition Senators? NASA? Universities?

How do we breach the coffee-table conversation stage and get started doing it?

mfb said:
Nuclear things in space (and on earth) are even more frowned upon now.
Yes microprocessors follow Moore's law, but engines and power sources do not.

To speed up travel time in a relevant way, you have to get away from Hohmann orbits, and then you need a significantly more powerful propulsion system.

I honestly must say I disagree with the assertion that new propulsion systems are required for Mars.

First off, new propulsion systems are expensive and a needless extra step. They don't actually do much to reduce flight times because as I said, the thrust/weight ratio becomes a major issue with current power systems' power/weight ratios. As for NERVA-NTR, the time savings really still aren't that great even when you can double delta-vee.* And time really isn't even much of an issue; we've had astronauts spend six months in space before. We know how to do aeroponics and how to store other foods for long periods of time.

*For a Hohmann Transfer, it's roughly 3.5 km/s, and a flight time of 8.5 months. For 4.3 km/s, you can bring the time down to about 5 or 6 months, if I remember right. But below 5 or 4.5 months, the delta-velocity needed to decrease flight time by a given amount goes up very, very sharply.

Secondly, I don't see anything on the table that could even fit the bill without putting large amounts of enriched radioactive material in orbit. While I have no issue with this personally because I actually understand the risks involved, politicians and the public have a radiation fear blown massively out of proportion, so I don't see nuclear powerplants or NTRs going up anytime soon. Solar power might be a way out of this, though, if solar-electric systems can get their power/weight ratios higher than what they currently are.

I'm very happy to see Curiosity/MSL wielding the largest RTG yet, though. Hopefully this trend will continue. I think the unmanned program has been far more successful because it's a lot less politically tied down.

Anyways, using a combination of aerocapture and ISRU to produce the propellant for return on Mars, you could send a mission with only two launches of a Saturn-V-sized craft. I very highly encourage anyone interested in Mars colonization to read up, at least a little, on Mars Direct.

As for; "how do we actually get this done?," fortunately, I think people are already doing it. Google, youtube, etc, "Mars One" and "SpaceX."
Here's a start.
SpaceX:
Mars One:

Personally, I actually don't much like the idea of one-way trips. But, I suppose the first colonies to the Americas were that way. SpaceX plans to sell two-way tickets later on, as far as I know.
 
<h2>1. What are the main challenges of surviving on Mars?</h2><p>The main challenges of surviving on Mars include extreme radiation levels, harsh temperature fluctuations, lack of breathable air, and limited access to resources.</p><h2>2. How does radiation on Mars affect human health?</h2><p>Radiation on Mars is significantly higher than on Earth due to the planet's thin atmosphere and lack of a protective magnetic field. This can lead to increased risk of cancer, damage to the central nervous system, and other health issues.</p><h2>3. What measures can be taken to protect against radiation on Mars?</h2><p>To protect against radiation on Mars, astronauts can use shielding materials, such as lead or water, to reduce exposure. They can also limit their time outside and use specialized suits and habitats designed to block radiation.</p><h2>4. How do temperature fluctuations on Mars impact survival?</h2><p>Mars experiences extreme temperature fluctuations, with average temperatures ranging from -80°F to -195°F. This can make it difficult to maintain a habitable environment and can also affect equipment and technology.</p><h2>5. What are the potential solutions for surviving the harsh conditions on Mars?</h2><p>Potential solutions for surviving on Mars include developing advanced technologies for radiation protection, creating self-sustaining habitats, and finding ways to terraform the planet to make it more habitable. Additionally, conducting further research and experiments on the planet will help us better understand how to adapt and survive in its unique environment.</p>

1. What are the main challenges of surviving on Mars?

The main challenges of surviving on Mars include extreme radiation levels, harsh temperature fluctuations, lack of breathable air, and limited access to resources.

2. How does radiation on Mars affect human health?

Radiation on Mars is significantly higher than on Earth due to the planet's thin atmosphere and lack of a protective magnetic field. This can lead to increased risk of cancer, damage to the central nervous system, and other health issues.

3. What measures can be taken to protect against radiation on Mars?

To protect against radiation on Mars, astronauts can use shielding materials, such as lead or water, to reduce exposure. They can also limit their time outside and use specialized suits and habitats designed to block radiation.

4. How do temperature fluctuations on Mars impact survival?

Mars experiences extreme temperature fluctuations, with average temperatures ranging from -80°F to -195°F. This can make it difficult to maintain a habitable environment and can also affect equipment and technology.

5. What are the potential solutions for surviving the harsh conditions on Mars?

Potential solutions for surviving on Mars include developing advanced technologies for radiation protection, creating self-sustaining habitats, and finding ways to terraform the planet to make it more habitable. Additionally, conducting further research and experiments on the planet will help us better understand how to adapt and survive in its unique environment.

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