What if Mars is the wrong path for Human exploration?

[Malatrope]

False choice. Do both. The better will out.

[TrevorMonty]

The only advantage Mars has over Moon is higher gravity, 24hr day night cycle doesn't matter as nobody will be living on surface of either planet.
It is possible to create 1G on moon and Mars by use rotating ring  with living surface at angle. If ring was inside large pressure dome moving from 1G to 1/6 is just case of hopping off moving ring maybe via transit elevator.

While I'm a fan of Oneil Cylinders they require massive space industry to build. For same resources we could build huge lunar cities that house vastly more people.

Closer a colony is to earth easier it will be to support as dependancy on earth for critical supplies will never go away. Bigger colony more items it will be self sufficient but greater demand for items earth needs to supply. For any colony to be succesful would also need to be exporting products back to earth which means closer the better.

[Robotbeat]

Mars has built in radiation protection (from virtually all solar flare effects, some GCR), micrometeorite protection, reduced day/night temperature swing, ability to fly without propellant, ability to capture carbon, oxygen, nitrogen, and even hydrogen (from water vapor) all directly from the atmosphere anywhere on the planet. It has pre refined iron sitting on the planet all over the place, a history of Earthlike hydrological cycles that concentrated minerals in true ore bodies (including bentonite clays, gypsum, etc), has all elements needed in abundance.

No other place beside Earth comes close to the livability and accessibility of Mars.

And the near 24 hour day DOES matter as it means your batteries can be reasonably sized compared to the Moon.

if you’re using nuclear, you actually can dump heat into the air, unlike the Moon or other airless bodies.

[nicp]

I’m not keen on Mars.
This is probably the fault of Larry Niven (whose science fiction I love) . In a possible future where asteroid mining is well established, plus the effects of radiation in space, micro-gravity etc are fixed or mitigated he writes something like…
“What could you want with Mars? A million tons of dust?” The gravity well is also considered a negative.

[TrevorMonty]

Mars has built in radiation protection (from virtually all solar flare effects, some GCR), micrometeorite protection, reduced day/night temperature swing, ability to fly without propellant, ability to capture carbon, oxygen, nitrogen, and even hydrogen (from water vapor) all directly from the atmosphere anywhere on the planet. It has pre refined iron sitting on the planet all over the place, a history of Earthlike hydrological cycles that concentrated minerals in true ore bodies (including bentonite clays, gypsum, etc), has all elements needed in abundance.

No other place beside Earth comes close to the livability and accessibility of Mars.

And the near 24 hour day DOES matter as it means your batteries can be reasonably sized compared to the Moon.

if you’re using nuclear, you actually can dump heat into the air, unlike the Moon or other airless bodies.

Power beaming from space gives 24/7 power and is a must for Mars or Lunar colony to enable industrial processes to run 24/7. Shutting aluminium smelting planet down every 12 hrs isn't practical and batteries required to sustain it through night would be massive.

In case of lunar colony building space solar power stations for earth may well be its big export earner.

[VSECOTSPE]

I wonder what is a better use of NASA's and World governments' future resources, if not better to go to YG 2022 or other nearby asteroids, besides the Moon, to create O'Neill colonies.

The downside to asteroid resources is that asteroids are tumbling and spinning, sometimes really fast.  And they’re heavy, so we’re talking about a lot of momentum.  Even small ones are usually beyond the capabilities of today’s spacecraft to dump momentum, de-spin, and control.  Of course, there are all kinds of technical schemes to address this issue, but they’re at the level of theoretical engineering.  Bringing them into practice remains to be seen and will probably be expensive and specific to each asteroid in question.

In the case if YG 2022, it’s only a few tens of meters across, at best.  To get to 1g at low enough rpms to avoid nausea and disorientation, we’re talking about a structure hundreds of meters across.  So it’s unclear if YG 2022 has enough useful material to make a large station, even if it was de-spun and even if we had machines that could eat asteroids and poop out big honkin space stations.

For the foreseeable future, space station construction will require materials shipped from Earth.  There are a couple start-up companies pursuing spinning space stations:

https://www.vast.space/
https://orbitalassembly.com/

I don’t know if Orbital will attract investment, but Vast is backed by an investor with deep pockets.

These aren’t O’Neill-scale space stations and no one is going to settle — live out their lives and have children — on them.  But they are a partial step in that direction.

But more important than that, Mars is... full of radiation

NASA tries to keep the increased risk of cancer from exposure to cosmic radiation to under 3% in its astronaut population.  NASA had an instrument on the Curiosity mission that indicated the risk would rise to 5% on a round-trip Mars mission.  Medical experts currently debate whether it is ethical to expose astronauts to that risk, but I would guess professional astronauts and others will make short (weeks- to a couple years-long) visits Mars and the Moon for research, resources, and recreation, just as we visit dangerous environments on Earth (Antarctica, Himalayas, deep ocean, open ocean, etc.) for the same reasons.

But visits are not the same thing as long-term settlement, and radiation damage and risks are cumulative with time.  Whether at Mars, the Moon, or elsewhere outside the Van Allen Belts, over a couple decades of exposure to cosmic radiation, the probability of an early death by cancer starts to tip over into certainty.  It seems unlikely that humanity will truly settle — live out decades and entire lifespans — in an environment that will shorten lifespans by decades.

The other showstopper issue with Mars (and lunar) settlement is the low gravity environment’s impact on reproduction.  Settlement implies multi-generational colonies, but experiments with mice and rat reproduction in Earth orbit and in clinostats show all kinds of problems, from implantation in the the uterine wall to blastocyst folding to voids in the brains of embryos.  If these issues persist at 17% and 38% of Earth’s gravity, then multi-generational lunar and Martian settlement is not a good bet.

It’s not a solid surface, but aerostats at the right altitude in the atmosphere of Venus would offer 90% of Earth’s gravity and protection from cosmic radiation.  The atmospheric pressure and temperature range would also be about equivalent to the surface of the Earth (although not breathable and potentially corrosive).  Aside from a completely artificially constructed environment aboard a space station, those Venusian altitudes are probably the environment most conducive to true human space settlement.  That doesn’t mean that the Venusian atmosphere will be settled — just that it is a less hostile environment than the Moon and Mars and (probably) requires less work than a big, spinning, shielded space station.

The other space settlement alternative is to transcend the limitations of the human body, which is a product of billions of years of biological evolution in a highly shielded, 1g, 1 bar, liquid water temperature range environment.  Although it would not be Homo sapiens sapiens settling the solar system, maybe genetic engineering and/or artificial consciousness would allow our biological and/or technological descendants to live and have children beyond Earth.

Hope this helps.

[Tywin]

I wonder what is a better use of NASA's and World governments' future resources, if not better to go to YG 2022 or other nearby asteroids, besides the Moon, to create O'Neill colonies.

The downside to asteroid resources is that asteroids are tumbling and spinning, sometimes really fast.  And they’re heavy, so we’re talking about a lot of momentum.  Even small ones are usually beyond the capabilities of today’s spacecraft to dump momentum, de-spin, and control.  Of course, there are all kinds of technical schemes to address this issue, but they’re at the level of theoretical engineering.  Bringing them into practice remains to be seen and will probably be expensive and specific to each asteroid in question.

In the case if YG 2022, it’s only a few tens of meters across, at best.  To get to 1g at low enough rpms to avoid nausea and disorientation, we’re talking about a structure hundreds of meters across.  So it’s unclear if YG 2022 has enough useful material to make a large station, even if it was de-spun and even if we had machines that could eat asteroids and poop out big honkin space stations.

For the foreseeable future, space station construction will require materials shipped from Earth.  There are a couple start-up companies pursuing spinning space stations:

https://www.vast.space/
https://orbitalassembly.com/

I don’t know if Orbital will attract investment, but Vast is backed by an investor with deep pockets.

These aren’t O’Neill-scale space stations and no one is going to settle — live out their lives and have children — on them.  But they are a partial step in that direction.

But more important than that, Mars is... full of radiation

NASA tries to keep the increased risk of cancer from exposure to cosmic radiation to under 3% in its astronaut population.  NASA had an instrument on the Curiosity mission that indicated the risk would rise to 5% on a round-trip Mars mission.  Medical experts currently debate whether it is ethical to expose astronauts to that risk, but I would guess professional astronauts and others will make short (weeks- to a couple years-long) visits Mars and the Moon for research, resources, and recreation, just as we visit dangerous environments on Earth (Antarctica, Himalayas, deep ocean, open ocean, etc.) for the same reasons.

But visits are not the same thing as long-term settlement, and radiation damage and risks are cumulative with time.  Whether at Mars, the Moon, or elsewhere outside the Van Allen Belts, over a couple decades of exposure to cosmic radiation, the probability of an early death by cancer starts to tip over into certainty.  It seems unlikely that humanity will truly settle — live out decades and entire lifespans — in an environment that will shorten lifespans by decades.

The other showstopper issue with Mars (and lunar) settlement is the low gravity environment’s impact on reproduction.  Settlement implies multi-generational colonies, but experiments with mice and rat reproduction in Earth orbit and in clinostats show all kinds of problems, from implantation in the the uterine wall to blastocyst folding to voids in the brains of embryos.  If these issues persist at 17% and 38% of Earth’s gravity, then multi-generational lunar and Martian settlement is not a good bet.

It’s not a solid surface, but aerostats at the right altitude in the atmosphere of Venus would offer 90% of Earth’s gravity and protection from cosmic radiation.  The atmospheric pressure and temperature range would also be about equivalent to the surface of the Earth (although not breathable and potentially corrosive).  Aside from a completely artificially constructed environment aboard a space station, those Venusian altitudes are probably the environment most conducive to true human space settlement.  That doesn’t mean that the Venusian atmosphere will be settled — just that it is a less hostile environment than the Moon and Mars and (probably) requires less work than a big, spinning, shielded space station.

The other space settlement alternative is to transcend the limitations of the human body, which is a product of billions of years of biological evolution in a highly shielded, 1g, 1 bar, liquid water temperature range environment.  Although it would not be Homo sapiens sapiens settling the solar system, maybe genetic engineering and/or artificial consciousness would allow our biological and/or technological descendants to live and have children beyond Earth.

Hope this helps.

Hello this is the only one I found...

https://www.nature.com/articles/s41598-021-82013-w

Can you share these studies?

[spacenut]

To me an O'Neil cylinder would be best in an orbit around the moon and use moon materials for manufacturing.  It could provide long them gravity for workers inside.  The moon however, can be used for mining/manufacturing with rotating crews without an O'Neil cylinder. 

However, Mars offers a lot more.  Minerals, atmosphere, water, a 24-1/2 hour day, etc.  Even though the gravity is low and may not be suitable for living on the planet for a long time.  Staying for a couple of years or one synod and returning to earth is not out of the question, like a mining/manufacturing colony with rotating workers. 

[Roy_H]

There are no unsolvable problems with Martian, Lunar, Jovian(moon) colonies.

Except gravity. What makes you so confident that 1/3rd or 1/6th gravity is a non-issue for colonists?

[punder]

For humans and their technology, engineering and construction are vastly easier in gravity than out of it. We have hundreds of thousands of years’ experience building stuff on land, in g, and that’s based on hundreds of millions of years of our ancestors’ prior experience living on land in g.

“I was strolling on the Moon one day, in the merry merry month of December—“ “MAY!” I keep saying it, watch the Apollo astronauts and compare their speed, agility, rapid problem solving, and general sense of comfort to astronauts on any microgravity EVA. The difference is profound.

So yes, “in a possible future where asteroid mining is well established”, O’’Neill habitats will be built (I hope so, anyway). But in the next few decades, Mars is a far more accessible environment for human civilization-building than orbital space.

[VSECOTSPE]

Can you share these studies?

Summary of research:

https://www.mdpi.com/2075-1729/11/2/109

A couple journal articles (among others):

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0006753

https://academic.oup.com/nsr/article/7/9/1437/5819033

A couple popular articles (among others):

http://www.cdb.riken.jp/eng/04_news/articles/09/090830_gravity.html

https://www.wired.com/2009/08/spacebabies/

[punder]

There are no unsolvable problems with Martian, Lunar, Jovian(moon) colonies.

Except gravity. What makes you so confident that 1/3rd or 1/6th gravity is a non-issue for colonists?

It might be an issue, but not nearly as big an issue as microgravity.

For one thing, all the tech we’ve developed over the centuries to work in 1g, can probably work just fine, with some adaptation, in Mars or Moon g. Plumbing, pumps, combustion, convection, compressive structures, on and on.

I would also make a common-sense bet that humans will do fine, or at least okay, long-term in Mars g.

Humans already do many things that shorten their projected lifespans in 1g, when they feel the benefits are large enough. Maybe Mars g will become “the new smoking.” 

[Tywin]

Can you share these studies?

Summary of research:

https://www.mdpi.com/2075-1729/11/2/109

A couple journal articles (among others):

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0006753

https://academic.oup.com/nsr/article/7/9/1437/5819033

A couple popular articles (among others):

http://www.cdb.riken.jp/eng/04_news/articles/09/090830_gravity.html

https://www.wired.com/2009/08/spacebabies/

Excellent, thanks...

[Roy_H]

...engineering and construction are vastly easier in gravity than out of it...

If you include the breathable, low radiation air on Earth, I agree. But on the Moon or Mars, space suits will be required, making construction more difficult and I argue it would be easier to move, align, fasten large parts in space than on the ground. So no, I do not agree, and engineering is agnostic to gravity.

[Roy_H]

There are no unsolvable problems with Martian, Lunar, Jovian(moon) colonies.

Except gravity. What makes you so confident that 1/3rd or 1/6th gravity is a non-issue for colonists?

It might be an issue, but not nearly as big an issue as microgravity.

For one thing, all the tech we’ve developed over the centuries to work in 1g, can probably work just fine, with some adaptation, in Mars or Moon g. Plumbing, pumps, combustion, convection, compressive structures, on and on.

I agree with the above statements

I would also make a common-sense bet that humans will do fine, or at least okay, long-term in Mars g.

Your opinion, fine, but I do not agree with it. We really need some experimental evidence before committing to building colonies for people to live long term.

Humans already do many things that shorten their projected lifespans in 1g, when they feel the benefits are large enough. Maybe Mars g will become “the new smoking.” 

So maybe Mars will not be attractive to everyone. I don't smoke, and I don't understand why people do, so I cannot be a good judge of this.

[punder]

There are no unsolvable problems with Martian, Lunar, Jovian(moon) colonies.

Except gravity. What makes you so confident that 1/3rd or 1/6th gravity is a non-issue for colonists?

It might be an issue, but not nearly as big an issue as microgravity.

For one thing, all the tech we’ve developed over the centuries to work in 1g, can probably work just fine, with some adaptation, in Mars or Moon g. Plumbing, pumps, combustion, convection, compressive structures, on and on.

I agree with the above statements

I would also make a common-sense bet that humans will do fine, or at least okay, long-term in Mars g.

Your opinion, fine, but I do not agree with it. We really need some experimental evidence before committing to building colonies for people to live long term.

Humans already do many things that shorten their projected lifespans in 1g, when they feel the benefits are large enough. Maybe Mars g will become “the new smoking.” 

So maybe Mars will not be attractive to everyone. I don't smoke, and I don't understand why people do, so I cannot be a good judge of this.

Agree, we just don’t know how low (but not micro) gravity affects human physiology, because NASA has spent decades diligently avoiding the question.

I don’t smoke either, but it is a habit that hundreds of millions of people choose to take up, despite the well-known health impacts and very low probability of being able to quit—because, apparently, nicotine is AWESOME. (“Who won WWII? The people who had better access to nicotine and caffeine!”) I used it as only one example. Was also riffing on the “sitting is the new smoking” or really “x behavior we don’t like is the new smoking” meme that I see now and then. The point is, human population is so large that there will be no shortage of people eager to accept shortened lifespans and the prospect of ugly death for a life on Mars.

But yep, we are in the realm of opinion, that’s for sure.

[MickQ]

I’m trying not to bang on any particular company’s drum here but when a specific spacecraft comes online in the near ( as opposed to far ) future then I expect the human race will go to Mars, regardless of whether it is the most economically viable option or not.  Someone will go because they can.  It is the nature of the beast.  There will be relevant data on the effects of .38g from boots on the regolith way before any studies done in low gravity facilities in Earth orbit.

[daedalus1]

You'd be missing 1/3G. People wouldn't buy it.

[spacenut]

In zero G, astronauts have to move very slowly.  Every action has an opposite reaction.  Construction will be very very slow.  Mars gravity will allow faster construction of most anything.  Moon, not so much as it is too close to zero G. 

Because Mars has an atmosphere, space suits might be lighter and easier to move around in.  They could be heavy enough to mimic one G gravity thus allowing for normal construction and operation of equipment. 

Mars has resources to start small and build on it to expand a colony.  Building blocks can be carved from basalt rocks.  Then they can be melted together to build a pressure proof wall.  This could build the colonies block by block and pressurize with an oxygen/nitrogen atmosphere inside.  Windows could be manufactured from the sand on Mars.

O'Neil colonies would have to bring everything manufactured on Earth to build the giant cylinder.  This requires a lot of launches of big rockets.  Mars would require a lot of launches initially carrying the manufacturing equipment and power supplies, but using Martian raw material to build requiring no launches to orbit.  Thus a Martian civilization would grow much larger over time.  A cylinder would be limited in size to about 10,000 people.  Mars could continuously build more habitats, and structures, and continuously expand it's manufacturing base. 

The moon itself might give raw materials, but water would eventually have to come from earth, as well as nitrogen. 

[Mark K]

In zero G, astronauts have to move very slowly.  Every action has an opposite reaction.  Construction will be very very slow.  Mars gravity will allow faster construction of most anything.  Moon, not so much as it is too close to zero G. 

  There is no reason you have to move any slower in zero g. You need attachments so you don't torque things around. I think by far the reason spacewalks take a long time to do things is the fact there is no air and people have to wear bulky spacesuits with heavy thermal and micro-meteoroid requirements. If you had a large pressurized interior space with good attachment systems to couple what you are working on to the outer walls I see no reason you can't move as fast as on Earth, and you could certainly have much more efficient work holding. Look at the guys running around in Skylab.