These lava tubes could be the safest place for explorers to live on Mars

[admin]

The Martian surface is a radiation hot zone. But ancient lava tubes might offer explorers safety from the cosmic bombardment

These lava tubes could be the safest place for explorers to live on Mars : Read more

 

[Aaron C]

Just as a few calculation issues. If 6200 μSv is the yearly recommended dose and astronauts in the Hellas basin are believed to get around 342 μSv/day then it would exceed that in 18.13 days, not 19, and it's not clear if Earth days or Martian sols are being used. Since the Martian day is 37 minutes longer than an Earth day, this would mean that would happen in about 17.7 martian days. More importantly, if the dosages were reduced to 61.64 μSv/day in the lava tubes then this would mean a maximum stay time of 101.6 Earth days or 98 Mars days, and that would only be if one never left the tubes to do anything outside. So it would not really be possible, with this alone, for astronauts to safely stay there for years, as the article discusses.

 

[Broadlands]

At the risk of being too 'tongue-in-cheek' facetious, if you go, don't forget to take toilet paper and a garbage disposer along with your oxygen generator. The carbon cycle won't be working. TV and cell phone reception might not be very good to call home

 

[LMH]

Two thoughts:
1.) Floors of the lava tubes might be a source of ice as well as a ground-shielded habitat location. Reason -- On exploring a lava tube at Craters Of The Moon Nat'l Mon. in central Idaho, I recall being surprised to find ice in the floor cracks, even though it was a very hot day in the middle of summer! Granted, Idaho is not Mars, but it was only 25-30 feet below the ground's surface and apparently permanently shaded.
2.) Any chance that lead ore deposits (Pb) have been or could be detected from orbit, or by the Martian rovers? Reason -- Some ground-up lead ore included on the outside (solar exposed sides) of building bricks could go a long ways in reducing the daily radiation exposure of individuals working in dirt-sheltered brick-type structures. I remember the heavy use of even leaded glass in radiation protection at the Idaho Nat'l Lab on a school field trip 50 years ago. Even a small indigenous lead ore deposit could be much more valuable than gold or diamonds for long term habitation of a Mars colony.

 

[khuber]

I wasn't very happy crawling through lava tubes in Southern Oregon some years ago. Felt very confining. Maybe we ought to send mole rats first.

 

[Aaron C]

Two thoughts:
1.) Floors of the lava tubes might be a source of ice as well as a ground-shielded habitat location. Reason -- On exploring a lava tube at Craters Of The Moon Nat'l Mon. in central Idaho, I recall being surprised to find ice in the floor cracks, even though it was a very hot day in the middle of summer! Granted, Idaho is not Mars, but it was only 25-30 feet below the ground's surface and apparently permanently shaded.
2.) Any chance that lead ore deposits (Pb) have been or could be detected from orbit, or by the Martian rovers? Reason -- Some ground-up lead ore included on the outside (solar exposed sides) of building bricks could go a long ways in reducing the daily radiation exposure of individuals working in dirt-sheltered brick-type structures. I remember the heavy use of even leaded glass in radiation protection at the Idaho Nat'l Lab on a school field trip 50 years ago. Even a small indigenous lead ore deposit could be much more valuable than gold or diamonds for long term habitation of a Mars colony.

I like the fact that you are thinking about this. I suspect that it would be easier to use a bulldozer and push a big pile of rocks and rubble over the ground that is above the inhabited part of the lava tube. A dirt berm probably wouldn't cut it, since mars can have some pretty intense winds, but a tarp and rocks can solve that problem, I suppose.

I too have explored lava tubes, like the Big Skylight Cave in New Mexico. You are right that things can be colder there, though remember that Mars is already considerably colder than freezing, even at the equator, at most times of year.

We could do something like they are proposing on the Moon where we land a prefabbed module inside a crater and then push a lot of dirt and rubble on top of it.

But in the scheme of things it will still be far easier and more economical to build bases on the Moon than Mars in the foreseeable future. There is clearly ice there too, and we have done so little exploration on the lunar surface.

 

[Aaron C]

I wasn't very happy crawling through lava tubes in Southern Oregon some years ago. Felt very confining. Maybe we ought to send mole rats first.

the article noted that it is probable that these tubes will be bigger, given the lower gravity.

 

[LMH]

Hmmm.... Besides people, lots of other things are also sensitive to radiation. Unprotected polymers (plastic pipes, conduits, wiring insulation, pneumatic tires, door seals) initially brokedown rather quickly under UV radiation on Earth: that's why tires and electric cords are protected with carbon black and other opaque pigments on Earth. With Mars' thin atmosphere, I suspect the UV exposure is significantly worse even though Mars is further from the Sun than the Earth is. I wonder if a LOT more pigment or even mineral shielding on wires, plastic pipes, door seals, etc. will be needed on Mars? Plastic windows would be attacked as well -- wonder if something like "leaded clear acrylic" can be made for large windows, rather than the much heavier leaded glass? What are windows on current spacecraft made from, anybody know?

Sounds like we'd better send a DitchWitch for making trenches with the first long-term visitors! (Though, the perchlorates in the Mars soil may be a chemical attack/corrosion hazard too??) One supposes small pump houses and electric/solar panel control stations will have to be sheltered from radiation with stone or bricks to protect the wiring's insulation, circuit boards, electrical equipment, and the workers maintaining them during the day. Perhaps a lot of the human surface work could be done at night, simply to avoid the harsher daytime radiation? Having heavier "grunt" surface work done during the day by radio-controlled drone rovers might help avoid humans' radiation overexposure.

Perhaps carbon fibers incorporated in structures and insulation could 'kill two birds with one stone'? That is, provide lightweight structural strength and radiation resistance, since (at least the cheaper pitch-based) carbon fibers are very black like the carbon black used for tire/electric cord's UV blockers. Musings. . . .