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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 require

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.

deleted 2y ago
[deleted]
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.
      - ceejayoz 2y ago
        Mars isn’t radioactive. A reactor would still need shielding.
        greenbit 2y ago
        Only if you intend to stand near it while it's running. Not trying to be glib, just pointing out that at least initially, there might not be any humans near. Admittedly, radiation might be a bother for high density electronics (CPUs, RAM, etc), but maybe it'd be cheaper to shield the bot-brains. Bots could rely on the power for a few years and when the humans get there, if nothing else you could drop all the rods in and let the rad flux die down. I know, I wouldn't want that in my back yard either, but Mars is exactly nobody's back yard at present. Bootstrapping a (necessarily!) technological civilisation on another planet is not an un-risky business.
        ceejayoz 2y ago
        Barring significant progress in robotics we'll still need humans to maintain the thing.
        JumpCrisscross 2y ago
- Manabu-eo 2y ago
  Submarines are encircled by water, that is very good at absorbing heat. Nuclear power stations are also invariably close to a large source of water. There is no such thing on Mars, and that significantly increases the mass and size of your radiators, making it uncompetitive with solar for example, unless the waste heat is needed for something else.
_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.

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.

deleted 2y ago

[deleted]

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.
    - ceejayoz 2y ago
      Mars isn’t radioactive. A reactor would still need shielding.
      - greenbit 2y ago
        Only if you intend to stand near it while it's running. Not trying to be glib, just pointing out that at least initially, there might not be any humans near. Admittedly, radiation might be a bother for high density electronics (CPUs, RAM, etc), but maybe it'd be cheaper to shield the bot-brains. Bots could rely on the power for a few years and when the humans get there, if nothing else you could drop all the rods in and let the rad flux die down. I know, I wouldn't want that in my back yard either, but Mars is exactly nobody's back yard at present. Bootstrapping a (necessarily!) technological civilisation on another planet is not an un-risky business.
        ceejayoz 2y ago
        Barring significant progress in robotics we'll still need humans to maintain the thing.
        JumpCrisscross 2y ago
Manabu-eo 2y ago
Submarines are encircled by water, that is very good at absorbing heat. Nuclear power stations are also invariably close to a large source of water. There is no such thing on Mars, and that significantly increases the mass and size of your radiators, making it uncompetitive with solar for example, unless the waste heat is needed for something else.

_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.