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> Shorter periods of exposure to space radiation and microgravity could help mitigate its effects on the human body. Of course once astronauts are on mars they

> Shorter periods of exposure to space radiation and microgravity could help mitigate its effects on the human body. Of course once astronauts are on mars they will still be exposed to radiation, until some sort of shielding can be built. Which would be an obscene undertaking, and involves moving lots of raw and refined materials to mars. Which means hopefully the price of this rocket to get stuff off of earth is dirt cheap, because moving squishy humans to Mars, no matter the speed, is not the limiting factor! (Getting humans to Mars and keeping them alive there is!)

sandworm101 2y ago
>> obscene undertaking, and involves moving lots of raw and refined materials to mars. Or they can dig a hole and/or pile mars dirt on top of their living structures. Some materials are better than others at absorbing radiation but, as a general rule, mass/depth of the protection counts more than composition.
dyauspitr 2y ago
Building an underground chamber doesn’t seem like an impossible undertaking. Alternatively, maybe mars already has caves and tunnels.
- OnlyMortal 2y ago
  There are tunnels that appear to have been created by volcano lava. Lava tubes.
- heavyset_go 2y ago
  It takes a lot of energy to displace sand/dirt/rocks to build anything underground. Human-powered shovels require a lot of food and water, and machinery requires combustion and a lot of hydrocarbons.
  - acchow 2y ago
    Submarines run on nuclear. Wouldn't nuclear be the natural choice on mars?
    - ceejayoz 2y ago
      Those are big, and heavy. https://www.oregon.gov/energy/safety-resiliency/Pages/Naval-Nuclear-Transport.aspx https://www.oregon.gov/energy/safety-resiliency/Pages/Naval-... > The submarine reactor compartments that have been taken to Hanford are about 33 feet high and 40 feet in length. They weigh between 1,130 and 1,680 tons. Eventually, the Navy may deactivate its Ohio class submarines in the same manner. Those compartments would be much larger and heavier. Submarines don't have to get them into orbit.
      - JumpCrisscross 2y ago
        In case you're serious, nobody is suggesting launching a water-cooled reactor to Mars. Between the idiot ends of the power-source spectrum bounded by, on one end, a U.S. Navy PWR and, on the other end, Martian Aramco, we have the reasonable options of solar power, batteries, RTGs and fission-powered Stirling engines [1][2]. [1] https://www.nasa.gov/directorates/stmd/tech-demo-missions-program/kilopower-hmqzw/ https://www.nasa.gov/directorates/stmd/tech-demo-missions-pr... [2] https://www.nasa.gov/tdm/fission-surface-power/ https://www.nasa.gov/tdm/fission-surface-power/
        ceejayoz 2y ago
        I think solar's the far more likely option, yes. Cheap, light, low-maintenance. Maybe fuel cells for night. RTGs aren't gonna power a good-sized base; they're a few hundred watts at best. edit: I very much hope Kilopower pans out.
        jujube3 2y ago
        What is wrong with launching a water-cooled reactor to Mars? Or more likely launching the materials needed to build it. The active components of a reactor are quite tiny -- most of the bulk is in the shielding, which won't be necessary on an already radioactive planet like Mars.
  - deleted 2y ago
    [deleted]
  - _visgean 2y ago
    > machinery requires combustion solar power / RTGs could power such effort. Digging shelters could be done by unmanned missions before the manned missions would arrive.
    - Alupis 2y ago
      I don't think this comment fully appreciates the density of hydrocarbon-based energy sources. No, a RTG-powered bulldozer isn't going to be clearing caves and trenches on Mars, ever.
      - _visgean 2y ago
        rtgs can be used to aid solar in charging batteries, the digging process can take a long time, if you space it correctly you would be able to get that energy from solar etc
        Alupis 2y ago
        No, you cannot. You are still dramatically underestimating the density of hydrocarbon energy. Solar, electric, batteries, etc do not even remotely come close. This line of thinking also dramatically underestimates the energy requirement to excavate dirt and rock... Then, figure it's on another planet with dust storms that have already killed solar-powered rovers, etc.
        _visgean 2y ago
        > You are still dramatically underestimating the density of hydrocarbon energy. Solar, electric, batteries, etc do not even remotely come close. I never mentioned hydrocarbon energy. You keep bringing it up for some reason. > Solar, electric, batteries, etc do not even remotely come close. I don't need them to come close. I need them to do the job, and they do it > This line of thinking also dramatically underestimates the energy requirement to excavate dirt and rock... here are some electric, battery powered excavators: - https://www.volvoce.com/europe/en/products/electric-machines/ec230-electric/ https://www.volvoce.com/europe/en/products/electric-machines... - https://www.wackerneuson.cz/en/zero-emission/electric-excavators/tracked-zero-tail-excavator-ez17e https://www.wackerneuson.cz/en/zero-emission/electric-excava... - https://www.komatsu.jp/en/newsroom/2023/20230721 https://www.komatsu.jp/en/newsroom/2023/20230721 - https://www.jcb.com/en-us/products/compact-excavators/19c-1e https://www.jcb.com/en-us/products/compact-excavators/19c-1e - https://www.bobcat.com/na/en/equipment/excavators/compact-excavators/e10e https://www.bobcat.com/na/en/equipment/excavators/compact-ex... - https://www.volvoce.com/europe/en/products/electric-machines/ https://www.volvoce.com/europe/en/products/electric-machines... - https://www.hitachicm.com/eu/en/onsite/article/Introduction_to_two_new_Hitachi_electric_excavators2/ https://www.hitachicm.com/eu/en/onsite/article/Introduction_... - https://www.casece.com/en/europe/products/excavators/d-series-mini-excavators/cx15ev https://www.casece.com/en/europe/products/excavators/d-serie... - https://www.kubota.com/news/2023/20231218.html https://www.kubota.com/news/2023/20231218.html There are excavators both small and big so yes you can definetely excavate using electricity alone. > dust storms that have already killed solar-powered rovers Looking at list here https://en.wikipedia.org/wiki/Mars_rover https://en.wikipedia.org/wiki/Mars_rover I guess you talk about Zhurong and Opportunity? Both of these seems like success story given that they survived way longer than they were expected to..
  - arrosenberg 2y ago
    Seems like a use-case for a "controlled" thermonuclear demolition project.
  - mr_toad 2y ago
    Tunnel boring machines often use electric motors, often in the thousands of kW range. The ones the boring company uses are battery powered (using containers full of batteries). The batteries are swapped out periodically and charged overnight.
- ortusdux 2y ago
  I still think that this would explain Musk's dalliance with tunnel boring machines.
malfist 2y ago
The easiest solution is to set up shop in a cooled volcano tube
dmurray 2y ago
Most of the materials could surely be found on Mars. A shelter built out of sandbags would be a low tech solution that would get you a large part of the way there. Further, Mars itself shields you from half the radiation (at night), the Martian atmosphere shields you from a little more, and Mars is further away from the Sun on average than an Earth-Mars spaceship. Radiation during transit really does seem like a bigger issue.
- pmontra 2y ago
  There are also cosmic rays. They come from every direction, so even at night. An experiment measured that kind of radiation about 20 years ago https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Experiment https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Exp...
  - dmurray 2y ago
    The planet still shields you from half of those.
lupusreal 2y ago
It's not an intractable problem, just send a robot bulldozer and excavator a few years beforehand. The real problem with a Mars colony is the economics for making it anything more than a small scientific outpost / political stunt. Forget the upfront cost of the habitat/etc, how do you actually create a self sustaining Martian economy? I've never heard a realistic answer for this.
- mongol 2y ago
  It is an interesting problem of energy. How would a robot bulldozer or excavator be powered? They require more power than a rower.
  - lupusreal 2y ago
    They don't require more than a rover if you accept them doing their work far slower than their normal earth equivalents. Hence sending them years in advance to dig out a some holes that would only take a few days for excavators on Earth.
    - tsimionescu 2y ago
      While speed is a factor as well, you still need a lot more energy consumption to move a mass of rock&dust some distance away than to move a small rover. This immediately follows from the formula for work and the gravitational force.
      - lupusreal 2y ago
        Given enough time, you can dig out a house foundation with a spoon, power is not an issue here. The less power you have available the slower you work. If your robots wear out, you send more. The real problem is finding enough time and money to waste on such a fruitless endeavor. If that can't be managed it nullifies the entire problem of digging a hole on Mars since a Mars base is nothing but a waste of time and money. Wasting time and money is table stakes.
kallistisoft 2y ago
As far as I know the plan has always been to use the martian regolith and water as primary radiation shielding -- same as the moon. Here is a recent (2022) paper[1] on the concept, but you can easily find scholarly work on this going back many decades... [1] https://www.sciencedirect.com/science/article/abs/pii/S0032063322001039 https://www.sciencedirect.com/science/article/abs/pii/S00320...
- ceejayoz 2y ago
  https://en.wikipedia.org/wiki/Martian_lava_tube https://en.wikipedia.org/wiki/Martian_lava_tube have also been proposed as pre-existing possible shelters. https://en.wikipedia.org/wiki/Caves_of_Mars_Project#/media/File:Mars;_Arsia_Mons_cave_entrance_-MRO.jpg https://en.wikipedia.org/wiki/Caves_of_Mars_Project#/media/F... "HiRISE image of Mars hole 'Jeanne', about 150 meters (492 feet) across and at least 178 meters (584 feet) deep."
phkahler 2y ago
>> Of course once astronauts are on mars they will still be exposed to radiation, until some sort of shielding can be built. Send tunnel boring machines. There a company making electric ones.
TheDudeMan 2y ago
"hopefully the price of this rocket to get stuff off of earth is dirt cheap" This is not a launch technology.
- JumpCrisscross 2y ago
  Not with that attitude!
  - mr_toad 2y ago
    Attitude isn’t going to help when the thrust to weight ratio is less than one.
  - optimalsolver 2y ago
    *altitude
    - JumpCrisscross 2y ago
      Got to have the correct attitude to gain altitude. (Attitude has a second meaning in respect of spacecraft.)

sandworm101 2y ago

>> obscene undertaking, and involves moving lots of raw and refined materials to mars. Or they can dig a hole and/or pile mars dirt on top of their living structures. Some materials are better than others at absorbing radiation but, as a general rule, mass/depth of the protection counts more than composition.

dyauspitr 2y ago

Building an underground chamber doesn’t seem like an impossible undertaking. Alternatively, maybe mars already has caves and tunnels.

OnlyMortal 2y ago
There are tunnels that appear to have been created by volcano lava. Lava tubes.
heavyset_go 2y ago
It takes a lot of energy to displace sand/dirt/rocks to build anything underground. Human-powered shovels require a lot of food and water, and machinery requires combustion and a lot of hydrocarbons.
- acchow 2y ago
  Submarines run on nuclear. Wouldn't nuclear be the natural choice on mars?
  - ceejayoz 2y ago
    Those are big, and heavy. https://www.oregon.gov/energy/safety-resiliency/Pages/Naval-Nuclear-Transport.aspx https://www.oregon.gov/energy/safety-resiliency/Pages/Naval-... > The submarine reactor compartments that have been taken to Hanford are about 33 feet high and 40 feet in length. They weigh between 1,130 and 1,680 tons. Eventually, the Navy may deactivate its Ohio class submarines in the same manner. Those compartments would be much larger and heavier. Submarines don't have to get them into orbit.
    - JumpCrisscross 2y ago
      In case you're serious, nobody is suggesting launching a water-cooled reactor to Mars. Between the idiot ends of the power-source spectrum bounded by, on one end, a U.S. Navy PWR and, on the other end, Martian Aramco, we have the reasonable options of solar power, batteries, RTGs and fission-powered Stirling engines [1][2]. [1] https://www.nasa.gov/directorates/stmd/tech-demo-missions-program/kilopower-hmqzw/ https://www.nasa.gov/directorates/stmd/tech-demo-missions-pr... [2] https://www.nasa.gov/tdm/fission-surface-power/ https://www.nasa.gov/tdm/fission-surface-power/
      - ceejayoz 2y ago
        I think solar's the far more likely option, yes. Cheap, light, low-maintenance. Maybe fuel cells for night. RTGs aren't gonna power a good-sized base; they're a few hundred watts at best. edit: I very much hope Kilopower pans out.
      - jujube3 2y ago
        What is wrong with launching a water-cooled reactor to Mars? Or more likely launching the materials needed to build it. The active components of a reactor are quite tiny -- most of the bulk is in the shielding, which won't be necessary on an already radioactive planet like Mars.
- deleted 2y ago
  [deleted]
- _visgean 2y ago
  > machinery requires combustion solar power / RTGs could power such effort. Digging shelters could be done by unmanned missions before the manned missions would arrive.
  - Alupis 2y ago
    I don't think this comment fully appreciates the density of hydrocarbon-based energy sources. No, a RTG-powered bulldozer isn't going to be clearing caves and trenches on Mars, ever.
    - _visgean 2y ago
      rtgs can be used to aid solar in charging batteries, the digging process can take a long time, if you space it correctly you would be able to get that energy from solar etc
      - Alupis 2y ago
        No, you cannot. You are still dramatically underestimating the density of hydrocarbon energy. Solar, electric, batteries, etc do not even remotely come close. This line of thinking also dramatically underestimates the energy requirement to excavate dirt and rock... Then, figure it's on another planet with dust storms that have already killed solar-powered rovers, etc.
        _visgean 2y ago
        > You are still dramatically underestimating the density of hydrocarbon energy. Solar, electric, batteries, etc do not even remotely come close. I never mentioned hydrocarbon energy. You keep bringing it up for some reason. > Solar, electric, batteries, etc do not even remotely come close. I don't need them to come close. I need them to do the job, and they do it > This line of thinking also dramatically underestimates the energy requirement to excavate dirt and rock... here are some electric, battery powered excavators: - https://www.volvoce.com/europe/en/products/electric-machines/ec230-electric/ https://www.volvoce.com/europe/en/products/electric-machines... - https://www.wackerneuson.cz/en/zero-emission/electric-excavators/tracked-zero-tail-excavator-ez17e https://www.wackerneuson.cz/en/zero-emission/electric-excava... - https://www.komatsu.jp/en/newsroom/2023/20230721 https://www.komatsu.jp/en/newsroom/2023/20230721 - https://www.jcb.com/en-us/products/compact-excavators/19c-1e https://www.jcb.com/en-us/products/compact-excavators/19c-1e - https://www.bobcat.com/na/en/equipment/excavators/compact-excavators/e10e https://www.bobcat.com/na/en/equipment/excavators/compact-ex... - https://www.volvoce.com/europe/en/products/electric-machines/ https://www.volvoce.com/europe/en/products/electric-machines... - https://www.hitachicm.com/eu/en/onsite/article/Introduction_to_two_new_Hitachi_electric_excavators2/ https://www.hitachicm.com/eu/en/onsite/article/Introduction_... - https://www.casece.com/en/europe/products/excavators/d-series-mini-excavators/cx15ev https://www.casece.com/en/europe/products/excavators/d-serie... - https://www.kubota.com/news/2023/20231218.html https://www.kubota.com/news/2023/20231218.html There are excavators both small and big so yes you can definetely excavate using electricity alone. > dust storms that have already killed solar-powered rovers Looking at list here https://en.wikipedia.org/wiki/Mars_rover https://en.wikipedia.org/wiki/Mars_rover I guess you talk about Zhurong and Opportunity? Both of these seems like success story given that they survived way longer than they were expected to..
- arrosenberg 2y ago
  Seems like a use-case for a "controlled" thermonuclear demolition project.
- mr_toad 2y ago
  Tunnel boring machines often use electric motors, often in the thousands of kW range. The ones the boring company uses are battery powered (using containers full of batteries). The batteries are swapped out periodically and charged overnight.
ortusdux 2y ago
I still think that this would explain Musk's dalliance with tunnel boring machines.

malfist 2y ago

The easiest solution is to set up shop in a cooled volcano tube

dmurray 2y ago

Most of the materials could surely be found on Mars. A shelter built out of sandbags would be a low tech solution that would get you a large part of the way there. Further, Mars itself shields you from half the radiation (at night), the Martian atmosphere shields you from a little more, and Mars is further away from the Sun on average than an Earth-Mars spaceship. Radiation during transit really does seem like a bigger issue.

pmontra 2y ago
There are also cosmic rays. They come from every direction, so even at night. An experiment measured that kind of radiation about 20 years ago https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Experiment https://en.wikipedia.org/wiki/Mars_Radiation_Environment_Exp...
- dmurray 2y ago
  The planet still shields you from half of those.

lupusreal 2y ago

It's not an intractable problem, just send a robot bulldozer and excavator a few years beforehand. The real problem with a Mars colony is the economics for making it anything more than a small scientific outpost / political stunt. Forget the upfront cost of the habitat/etc, how do you actually create a self sustaining Martian economy? I've never heard a realistic answer for this.

mongol 2y ago
It is an interesting problem of energy. How would a robot bulldozer or excavator be powered? They require more power than a rower.
- lupusreal 2y ago
  They don't require more than a rover if you accept them doing their work far slower than their normal earth equivalents. Hence sending them years in advance to dig out a some holes that would only take a few days for excavators on Earth.
  - tsimionescu 2y ago
    While speed is a factor as well, you still need a lot more energy consumption to move a mass of rock&dust some distance away than to move a small rover. This immediately follows from the formula for work and the gravitational force.
    - lupusreal 2y ago
      Given enough time, you can dig out a house foundation with a spoon, power is not an issue here. The less power you have available the slower you work. If your robots wear out, you send more. The real problem is finding enough time and money to waste on such a fruitless endeavor. If that can't be managed it nullifies the entire problem of digging a hole on Mars since a Mars base is nothing but a waste of time and money. Wasting time and money is table stakes.

kallistisoft 2y ago

As far as I know the plan has always been to use the martian regolith and water as primary radiation shielding -- same as the moon. Here is a recent (2022) paper[1] on the concept, but you can easily find scholarly work on this going back many decades... [1] https://www.sciencedirect.com/science/article/abs/pii/S0032063322001039 https://www.sciencedirect.com/science/article/abs/pii/S00320...

ceejayoz 2y ago
https://en.wikipedia.org/wiki/Martian_lava_tube https://en.wikipedia.org/wiki/Martian_lava_tube have also been proposed as pre-existing possible shelters. https://en.wikipedia.org/wiki/Caves_of_Mars_Project#/media/File:Mars;_Arsia_Mons_cave_entrance_-MRO.jpg https://en.wikipedia.org/wiki/Caves_of_Mars_Project#/media/F... "HiRISE image of Mars hole 'Jeanne', about 150 meters (492 feet) across and at least 178 meters (584 feet) deep."

phkahler 2y ago

>> Of course once astronauts are on mars they will still be exposed to radiation, until some sort of shielding can be built. Send tunnel boring machines. There a company making electric ones.

TheDudeMan 2y ago

"hopefully the price of this rocket to get stuff off of earth is dirt cheap" This is not a launch technology.

JumpCrisscross 2y ago
Not with that attitude!
- mr_toad 2y ago
  Attitude isn’t going to help when the thrust to weight ratio is less than one.
- optimalsolver 2y ago
  *altitude
  - JumpCrisscross 2y ago
    Got to have the correct attitude to gain altitude. (Attitude has a second meaning in respect of spacecraft.)