Author Topic: SpaceX's Martian Underground  (Read 51668 times)

Offline pobermanns

  • Full Member
  • *
  • Posts: 114
  • Germany
  • Liked: 50
  • Likes Given: 166
Re: SpaceX's Martian Underground
« Reply #100 on: 01/28/2017 10:50 pm »
How about looking at some numbers?

Sea level pressure is 14.7 psi with 21% O2. That yields an O2 partial pressure of 3.1 psi.

Airliner cabins are pressurized at levels between 6000 ft and 8000 ft. This effective altitude is used because almost everyone can handle it without medical issues.

Using the high end of 8000 ft, air pressure is 76% of sea level, resulting in an O2 partial pressure of 2.4 psi.

NASA is incorporating that into their HI-SEAS (Hawai’i Space Exploration Analog and Simulation) Mars simulation on Hawaii's Mauna Loa, located at an altitude of only 8,200 feet.

So, NASA is already thinking about this, having the test at 8200 ft.

When I visit my relatives in Denver it takes me 1 to 1-1/2 days before my high altitude headaches go away, but I remain short of breath for a good week or more. They tell me that it took them almost a full year after they moved there before they were fully comfortable with the lower pressure and able to always breath easy like they used to in Connecticut before the move without shortness of breath.

Adaption can take awhile. . .

Once ITS goes thru TMI there will be 3+ months for pressure and O2 levels to be adjusted from Earth norm to
Mars norm, whatever that turns out to be.  Should be time enough to adapt.

That will be enough time for most people. Others may need to stay at an 8000 ft facility before launch.

Now remember that 2.4 psi O2 partial pressure I was talking about? In an 8 psi habitat that would be 30% O2. Slight increase in fire risk, so hab designers need to take that into consideration. An advantage of 8 psi with 30% O2 is someone can go straight to a spacesuit without prebreathing. Good for anyone who needs to work outside.

Speaking about spacesuits, they are at 4.7 psi with 100% O2 for a good reason. You don't really want to go lower pressure than that because you need to work, not be fatigued and just getting by.

Now how does this relate to the actual topic of this thread? Well, habs can be at 8 psi with 30% O2, the interior of the lava tube or tunnel can be at 4.7 psi with 100% inert gas (no fire risk at all) and anyone having to work exposed in the pressurized lava tube will only need an oxygen mask.

If everybody isn't comfortable at 8 psi, then the main habs can be at a more Earth-like atmosphere and only work areas with airlocks can be at 8 psi.

Check out www.altitude.org for information on going above 8000 ft.

Thanks -  for bringing some sanity to this discussion!
« Last Edit: 01/28/2017 11:11 pm by pobermanns »

Offline pobermanns

  • Full Member
  • *
  • Posts: 114
  • Germany
  • Liked: 50
  • Likes Given: 166
Re: SpaceX's Martian Underground
« Reply #101 on: 01/28/2017 11:07 pm »
FWIW there are ways to minimize the impact on altitude disruption. When going to high altitude, one can increase red meat consumption to allow for greater red blood cell demand to carry oxygen. Conversely, when losing the adaptation, one steers clear of iron bearing items in ones diet to allow for the liver to absorb the load of too much hemoglobin breaking down.

Curious! But don't understand the last part about avoiding iron-bearing foods. Why?

When I've been at extreme altitudes, primary concern is hypoxia - it sneaks up on you in peculiar ways. To train you for it, you're conditioned in a hyperbaric chamber for considerable time with a few others in somewhat humorous circumstance. Even then, when returning from a mission almost landed on the road next to the runway instead of the runway. The adjacent power/telephone poles were a dead giveaway …


Ok, that last part sounds pretty bad!

Many have nitrogen bubbles in bones/cartilage, so at altitude you get strange aches in weird places. A particular favorite is quite literally a pain in the tailbone (coccyx). I have decades old shrapnel wounds that have had trapped gas pockets that took awhile to find and "pop", would reliably give "charlie horse" in a muscle above 50,000 ft.

Where the h*** were you flying, that you got such wounds? And, my respects to you for your service!

There are many who have vision problems at altitude, and it may take a day or two before they show up. Have to chase that one down, but I think it has something to do with vitreous humor pressure.

And, decades back, watched many fall out of the AF academy because of sinus problems/allergies and altitude. They did not want to do be at the bottom of a silo or fly a desk.

Yes, of course, on both the sinus probs and the career probs! For our guys, the equivalent would have been driving a ship, but your point is well taken.
« Last Edit: 01/28/2017 11:19 pm by pobermanns »

Offline Lar

  • Fan boy at large
  • Global Moderator
  • Senior Member
  • *****
  • Posts: 13463
  • Saw Gemini live on TV
  • A large LEGO storage facility ... in Michigan
  • Liked: 11864
  • Likes Given: 11086
Re: SpaceX's Martian Underground
« Reply #102 on: 01/28/2017 11:30 pm »
Guys, be excellent to each other.

Meanwhile I suggest dueling studies instead of dueling assertions. What does the data say?
"I think it would be great to be born on Earth and to die on Mars. Just hopefully not at the point of impact." -Elon Musk
"We're a little bit like the dog who caught the bus" - Musk after CRS-8 S1 successfully landed on ASDS OCISLY

Offline nacnud

  • Extreme Veteran
  • Senior Member
  • *****
  • Posts: 2691
  • Liked: 981
  • Likes Given: 347
Re: SpaceX's Martian Underground
« Reply #103 on: 01/29/2017 12:02 am »
Well the highest inhabited village in Europe is Ushguli at about 2100m (7000'). Populations live higher than that, and in large numbers, but they are genetically adapted to the altitude.

If you are thinking of having permanent populations of physiologically adapted I'd suggest that as an upper limit for now.

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2181
Re: SpaceX's Martian Underground
« Reply #104 on: 01/29/2017 12:03 am »
Curious! But don't understand the last part about avoiding iron-bearing foods. Why?

I interpreted it as trying to reduce the load on the liver, while it's removing excess haemoglobin.



Now remember that 2.4 psi O2 partial pressure I was talking about? In an 8 psi habitat that would be 30% O2. Slight increase in fire risk, so hab designers need to take that into consideration.

No. You can't expect a whole colony to be like a vehicle/lander. You have to assume that you can't control the materials that closely. Hence, any increased fire risk is unacceptable.

IMO, even the baseline fire risk of Earth at sea-level is unacceptable in a closed atmosphere. That's why I've suggested higher total pressure (right back to 14-15psi) but the lowest O₂ levels we can get away with, without making people lethargic/clumsy when doing heavy work or complex mental tasks, say 2-2.25psi. Keep the oxygen fraction below 15%. Reduce the fire risk, not debate how much we can increase it.

Remember, you're going to be doing stuff that would never be allowed in a more conventional NASA moon/Mars mission. Welding, grinding, fabbing, moulding, lubing, etc. Fumes and sparks and hydrocarbons and random materials and machinery. And those are precisely the areas where the workers themselves will need the most oxygen for breathing (coz they're working). And if you aren't running the workshop/machine-room/repair areas at reduced pressure, what's the point of doing it through the rest of the hab?

the interior of the lava tube or tunnel can be at 4.7 psi with 100% inert gas (no fire risk at all) and anyone having to work exposed in the pressurized lava tube will only need an oxygen mask.

Although it's worth remembering that even with nitrogen, the effects of losing oxygen are quick and deceptive. (Faster than holding your breath. Biology is weird.) You will still need to treat every trip into a non-oxygenated area like a deep dive or cave dive. With buddy-systems and checklists and safety-areas and people "up top" ready to call in a rescue if you don't check in on cue. (And pure CO₂ doesn't have to leak much around your mask before you're symptomatic.)

Offline nacnud

  • Extreme Veteran
  • Senior Member
  • *****
  • Posts: 2691
  • Liked: 981
  • Likes Given: 347
Re: SpaceX's Martian Underground
« Reply #105 on: 01/29/2017 12:07 am »
Reply to myself....

Highest town in the US is about 3000m so it is possible to live higher for us sea level dwellers.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39271
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: SpaceX's Martian Underground
« Reply #106 on: 01/29/2017 12:23 am »
Curious! But don't understand the last part about avoiding iron-bearing foods. Why?

I interpreted it as trying to reduce the load on the liver, while it's removing excess haemoglobin.



Now remember that 2.4 psi O2 partial pressure I was talking about? In an 8 psi habitat that would be 30% O2. Slight increase in fire risk, so hab designers need to take that into consideration.

No. You can't expect a whole colony to be like a vehicle/lander. You have to assume that you can't control the materials that closely. Hence, any increased fire risk is unacceptable.

IMO, even the baseline fire risk of Earth at sea-level is unacceptable in a closed atmosphere. That's why I've suggested higher total pressure (right back to 14-15psi) but the lowest O₂ levels we can get away with, without making people lethargic/clumsy when doing heavy work or complex mental tasks, say 2-2.25psi. Keep the oxygen fraction below 15%. Reduce the fire risk, not debate how much we can increase it.

Remember, you're going to be doing stuff that would never be allowed in a more conventional NASA moon/Mars mission. Welding, grinding, fabbing, moulding, lubing, etc. Fumes and sparks and hydrocarbons and random materials and machinery. And those are precisely the areas where the workers themselves will need the most oxygen for breathing (coz they're working). And if you aren't running the workshop/machine-room/repair areas at reduced pressure, what's the point of doing it through the rest of the hab?

the interior of the lava tube or tunnel can be at 4.7 psi with 100% inert gas (no fire risk at all) and anyone having to work exposed in the pressurized lava tube will only need an oxygen mask.

Although it's worth remembering that even with nitrogen, the effects of losing oxygen are quick and deceptive. (Faster than holding your breath. Biology is weird.) You will still need to treat every trip into a non-oxygenated area like a deep dive or cave dive. With buddy-systems and checklists and safety-areas and people "up top" ready to call in a rescue if you don't check in on cue. (And pure CO₂ doesn't have to leak much around your mask before you're symptomatic.)
So basically, you're guaranteeing terrible bends if pressure is lost.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline pobermanns

  • Full Member
  • *
  • Posts: 114
  • Germany
  • Liked: 50
  • Likes Given: 166
Re: SpaceX's Martian Underground
« Reply #107 on: 01/29/2017 12:25 am »
Reply to myself....

Highest town in the US is about 3000m so it is possible to live higher for us sea level dwellers.

Thanks for that!

To me the problem is that while generalities make this seem like a minor problem, for most people who'd go to Mars these would be big deals! 3000 m is really high, and I seriously doubt that, even with acclimation, most people could prepare for a trip to Mars. I could be totally FOS, but that's my opinion. Better to go slow on this, rather than risk the lives of a bunch of guys and gals on Mars.

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39271
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: SpaceX's Martian Underground
« Reply #108 on: 01/29/2017 12:40 am »
3000m is not that high, really. I've stayed at such altitudes for weeks at a time on several occasions. Almost anyone can adapt, given enough time. Some people who have only a single lung engage in strenuous physical activity (skiing) above this altitude. 3000m is only about what a commercial jet operates at internally, so if you've flown on a jet, you've gotten close.

It takes time. I've gotten my butt kicked by high altitude before (hiking near the tree line), but your body WILL adapt if you live there for months unless you have such serious health conditions that you might not even be cleared to fly to Mars in the first place.

Ultimately, this is a pretty minor compromise that makes EVAs easier and safer and faster and more productive, fire risk lower, power requirements less, reduces tissue damage from rapid decompression, improves structural safety, and reduces mass and cost for habitable structures while also bringing us closer to living on a terraformed Mars.
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39271
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: SpaceX's Martian Underground
« Reply #109 on: 01/29/2017 12:48 am »
Another benefit: everything being equal, EVA performance will be much higher if the oxygen partial pressure of the hab is lower. As your body adapts, you get less winded even at sea level oxygen levels. This is one reason why athletes train at high altitude.

By the way, I'm going to make a splinter thread.
« Last Edit: 01/29/2017 12:51 am by Robotbeat »
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline Robotbeat

  • Senior Member
  • *****
  • Posts: 39271
  • Minnesota
  • Liked: 25240
  • Likes Given: 12115
Re: SpaceX's Martian Underground
« Reply #110 on: 01/29/2017 12:50 am »
Here, in the general Mars section, is a better home to these discussions: http://forum.nasaspaceflight.com/index.php?topic=42174.0
Chris  Whoever loves correction loves knowledge, but he who hates reproof is stupid.

To the maximum extent practicable, the Federal Government shall plan missions to accommodate the space transportation services capabilities of United States commercial providers. US law http://goo.gl/YZYNt0

Offline RonM

  • Senior Member
  • *****
  • Posts: 3340
  • Atlanta, Georgia USA
  • Liked: 2231
  • Likes Given: 1584
Re: SpaceX's Martian Underground
« Reply #111 on: 01/29/2017 03:46 am »
Now remember that 2.4 psi O2 partial pressure I was talking about? In an 8 psi habitat that would be 30% O2. Slight increase in fire risk, so hab designers need to take that into consideration.

No. You can't expect a whole colony to be like a vehicle/lander. You have to assume that you can't control the materials that closely. Hence, any increased fire risk is unacceptable.

IMO, even the baseline fire risk of Earth at sea-level is unacceptable in a closed atmosphere. That's why I've suggested higher total pressure (right back to 14-15psi) but the lowest O₂ levels we can get away with, without making people lethargic/clumsy when doing heavy work or complex mental tasks, say 2-2.25psi. Keep the oxygen fraction below 15%. Reduce the fire risk, not debate how much we can increase it.

Remember, you're going to be doing stuff that would never be allowed in a more conventional NASA moon/Mars mission. Welding, grinding, fabbing, moulding, lubing, etc. Fumes and sparks and hydrocarbons and random materials and machinery. And those are precisely the areas where the workers themselves will need the most oxygen for breathing (coz they're working). And if you aren't running the workshop/machine-room/repair areas at reduced pressure, what's the point of doing it through the rest of the hab?

There are many engineering tradeoffs to consider. It will depend on what the colony can produce. A Mars research base could easily be designed with flame resistant materials, but if a colony can't produce those materials then a higher pressure would be safer.

We can discuss the options, but without actually designing all the colony systems we can't definitely say which option is best.

the interior of the lava tube or tunnel can be at 4.7 psi with 100% inert gas (no fire risk at all) and anyone having to work exposed in the pressurized lava tube will only need an oxygen mask.

Although it's worth remembering that even with nitrogen, the effects of losing oxygen are quick and deceptive. (Faster than holding your breath. Biology is weird.) You will still need to treat every trip into a non-oxygenated area like a deep dive or cave dive. With buddy-systems and checklists and safety-areas and people "up top" ready to call in a rescue if you don't check in on cue. (And pure CO₂ doesn't have to leak much around your mask before you're symptomatic.)

Maybe it's not a good idea to pressurize the lava tube. Might be better to use a spacesuit anyway.

Offline Space Ghost 1962

  • Senior Member
  • *****
  • Posts: 2780
  • Whatcha gonna do when the Ghost zaps you?
  • Liked: 2925
  • Likes Given: 2247
Re: SpaceX's Martian Underground
« Reply #112 on: 01/29/2017 05:21 am »
Conversely, when losing the adaptation, one steers clear of iron bearing items in ones diet to allow for the liver to absorb the load of too much hemoglobin breaking down.

Curious! But don't understand the last part about avoiding iron-bearing foods. Why?

Your liver can be damaged by excessive iron. Fairly easily.

Offline DigitalMan

  • Full Member
  • ****
  • Posts: 1679
  • Liked: 1178
  • Likes Given: 76
Re: SpaceX's Martian Underground
« Reply #113 on: 01/29/2017 05:49 am »
I can tell a lot of people have misconceptions about high altitudes. Maybe we have people who live in Denver (Lockheed, etc) design the habs so we don't get this low lander bias in the design. :)

When I visit my relatives in Denver it takes me 1 to 1-1/2 days before my high altitude headaches go away, but I remain short of breath for a good week or more. They tell me that it took them almost a full year after they moved there before they were fully comfortable with the lower pressure and able to always breath easy like they used to in Connecticut before the move without shortness of breath.

I think low pressure acclimation here on Earth for altitude changes is something that is not completely understood, or at least not predictable without actually experiencing it.

For instance, I've done a lot of backcountry backpacking, mostly at altitudes between 7-12,000 feet, and once even to 14,000.  I live along the coast (but you knew that) and I've never had altitude sickness.  At most we would acclimate for one night before doing our backpacking trips.  And this is while humping 50 lb loads on our backs while climbing sometimes aggressively vertical trails.

But one of my backpacking buddies was concerned about altitude sickness, and his doctor prescribed him something for our 14,000 foot trip - which apparently helped (or at least didn't hurt).

So maybe one way to know ahead of time if someone is going to being able to acclimate quickly or not is to send them to a high altitude camp for a couple of weeks of strenuous work?  Cheaper than taking the trip to Mars and finding out that low pressure is an issue.

NASA is incorporating that into their HI-SEAS (Hawai’i Space Exploration Analog and Simulation) Mars simulation on Hawaii's Mauna Loa, located at an altitude of only 8,200 feet.

We used to bring diamox sequels for climbs above 18,000 feet.   there was one incident with other folks on the mountain who were unprepared.  We shared some with them and they recovered.

Offline clongton

  • Expert
  • Senior Member
  • *****
  • Posts: 12053
  • Connecticut
    • Direct Launcher
  • Liked: 7348
  • Likes Given: 3749
Re: SpaceX's Martian Underground
« Reply #114 on: 01/29/2017 11:58 am »
Remember, you're going to be doing stuff that would never be allowed in a more conventional NASA moon/Mars mission. Welding, grinding, fabbing, moulding, lubing, etc. Fumes and ...

As an aside it's worth noting that an additional angle to this is the normal outgassing of very commonly used solvents and lubricants that can contaminate the atmosphere in close loop systems. Used normally on earth they are simply absorbed into the air and dissipated with no harmful effects. In closed loop systems, like submarines for instance, studies have demonstrated the O2% of the breathable air and the ambient pressure both, individually and in conjunction with each other, affects the outgassing process. So it's not just a matter of how much oxygen is available to breath. Naturally produced outgassing of the materials we use everyday that are health harmful need to part of the equation of determining the pressure/O2 mix ratio. And because we don't have a planet's whole atmosphere readily available to dissipate them into, removal of those contaminates may be harder than one would normally expect before they can be vented into the Martian air.
Chuck - DIRECT co-founder
I started my career on the Saturn-V F-1A engine

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2181
Re: SpaceX's Martian Underground
« Reply #115 on: 01/29/2017 05:34 pm »
There are many engineering tradeoffs to consider. It will depend on what the colony can produce. A Mars research base could easily be designed with flame resistant materials,

I disagree that it would be "easy". A real working civilisation cannot operate under the same restrictions of the inside of a 3 or 4 man capsule, or the inside of a spacesuit. Unless you want to restrict your colony to always be a limited outpost, you have to deal the bulk of materials are not being chosen from the NASA safe-materials catalogue, and where not every activity is merely operating systems under approved conditions (with manufacture and maintenance done on Earth).

We can discuss the options, but without actually designing all the colony systems we can't definitely say which option is best.

But that doesn't stop people from casually (and in some cases insistently) suggesting increasing the fire risk.

the interior of the lava tube or tunnel can be at 4.7 psi with 100% inert gas
[wah, wah, inert can be bad too]
Maybe it's not a good idea to pressurize the lava tube. Might be better to use a spacesuit anyway.

In spite of what I said, even if you had to wear a full "bunny suit", that's still vastly easier on you (and on the technology) than a spacesuit.

So IMO the deciding factors are: whether there's enough activity outside the hab but inside the tube/tunnel to justify it; whether there's enough resources to waste on such an area; and just how hard EVAs remain after years of Mars-suit development.

For eg, if you have a lot of extra gas lying around, either waste or low value, you might as well shove it into the tube/tunnel ahead of where you're working and deliberately move certain operations there just because you've got a lot of low cost volume (for vehicle & systems maintenance, etc.)

Likewise, if it's difficult it is to seal the tube/tunnel, you would only do it in areas you are actually using, the actual hab. If it's easy, you might as well run ahead of habitat construction, even if there's only a minor benefit from having all that extra volume.

Similarly, how much time your crews need to spend on the actual surface, versus how much time they would spend in the tube, versus how much time in the habitat? It might turn out that most activity is either in-hab or on the open surface, with very little time spent in the unfinished tube/tunnels, hence creating an inert-gas volume isn't worth any extra construction cost. Whereas if there's a lot of activity inside the tube/tunnel but not inside the habitat (such as habitat construction), there may be a huge advantage to pressurising that space.

Offline Paul451

  • Senior Member
  • *****
  • Posts: 3553
  • Australia
  • Liked: 2518
  • Likes Given: 2181
Re: SpaceX's Martian Underground
« Reply #116 on: 01/29/2017 05:38 pm »
Re: Lava tubes specifically.

The two main downsides of lava tubes is that you are site limited, and the site of an accessible lava tube may not be where the other key resources are located. And that, AIUI, they generally occur in higher altitude areas, hence reduced pressure, lower temps, higher radiation, blah blah.

But... Once you go past collapse-openings, the inside of a lava tube should be at or close to the average annual surface temperature for that location (underground sites generally are), which is far enough below freezing that water vapour might collect there as it does at the poles, through the handful of collapse-openings along the length of the tube. Even at higher altitude, hence lower pressure, the temperature may be far enough below the sublimation temperature for accumulation to dominate. Shaded from sunlight, kept at near-constant temperature, without seasonal evaporation. Millions of years, perhaps hundreds of millions of years, of gradual accumulation.

It might be the easiest site on Mars to access pure-ice water. With new shelter created as you excavate the ice. Plus a heat-sink for habitat and fuel-processing waste heat.

Offline Space Ghost 1962

  • Senior Member
  • *****
  • Posts: 2780
  • Whatcha gonna do when the Ghost zaps you?
  • Liked: 2925
  • Likes Given: 2247
Re: SpaceX's Martian Underground
« Reply #117 on: 01/29/2017 07:04 pm »
Remember, you're going to be doing stuff that would never be allowed in a more conventional NASA moon/Mars mission. Welding, grinding, fabbing, moulding, lubing, etc. Fumes and ...

As an aside it's worth noting that an additional angle to this is the normal outgassing of very commonly used solvents and lubricants that can contaminate the atmosphere in close loop systems. Used normally on earth they are simply absorbed into the air and dissipated with no harmful effects. In closed loop systems, like submarines for instance, studies have demonstrated the O2% of the breathable air and the ambient pressure both, individually and in conjunction with each other, affects the outgassing process. So it's not just a matter of how much oxygen is available to breath. Naturally produced outgassing of the materials we use everyday that are health harmful need to part of the equation of determining the pressure/O2 mix ratio. And because we don't have a planet's whole atmosphere readily available to dissipate them into, removal of those contaminates may be harder than one would normally expect before they can be vented into the Martian air.
Correct. There's more too.

There are studies of interesting effects WRT biological agents/viruses/bacteria/mold/fungus/biofilms behaving differently on atmospheric partial pressure/mixtures. Also, in mines, contaminates from the walls/tunnels have interesting surprises. And we've known about them for some time.

In my youth I explored abandoned railroad tunnels from the 1800's. Many had buildups of explosive and or poisonous gases, which led to them needing to be carefully vented with positive airflow. Found interesting things growing in them when they were abandoned and left untended. I suppose forms of what would later be called "extremophiles".

Which Dr. Chris McKay suspect might exist on Mars. Possibly as a surviving form of paleo Mars life from the past ...

And no, not "concern trolling" but what is called positive "threat assessment".

Offline guckyfan

  • Senior Member
  • *****
  • Posts: 7438
  • Germany
  • Liked: 2332
  • Likes Given: 2891
Re: SpaceX's Martian Underground
« Reply #118 on: 01/29/2017 09:54 pm »
Just mentioned in the Hyperloop life stream. Elon Musk mentioned his tunneling plans. They are doing tests. His plan is to increase tunneling speed by at least a factor of 5, maybe 10. He believes, physics will allow that. Sure he is thinking not only about traffic in cities on earth but about Mars habitats even if he did not mention it.

Offline Dalhousie

  • Senior Member
  • *****
  • Posts: 2766
  • Liked: 780
  • Likes Given: 1132
Re: SpaceX's Martian Underground
« Reply #119 on: 01/31/2017 10:58 pm »
Well the highest inhabited village in Europe is Ushguli at about 2100m (7000'). Populations live higher than that, and in large numbers, but they are genetically adapted to the altitude.

If you are thinking of having permanent populations of physiologically adapted I'd suggest that as an upper limit for now.

Much higher than that is possible.

I was in Ladakh last year, capital Leh, 3,400 m.  The plane was depressurised when we landed.  Many of the 270,000 people who live there are low landers and do fine after acclimatisation. 

I was seedy the first day, spots in front of the eyes, headaches, having come from Delhi. Blood O2 82%. Basically slept for 24 hours.  Three days later I crossed a 5,400 m pass and felt fine although short of breath.  Five days later I was back at the pass and doing field work.  Blood O2 at the pass second time was 87% and 92% back at Leh.  By the time I finished working in the area (two weeks) blood O2 was 97% at Leh which was normal for me.  The only difference I noted was I was still more prone to headaches.

Low landers can adapt to living and working at altitude given time and patience (a few weeks)
Apologies in advance for any lack of civility - it's unintended

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
1