7 ms·

I'm intrigued by what research and plans have been made for how Martian colonists will deal with this sort of problem. I'm guessing solar won't be enough to kee

by mabbo 8y ago

I'm intrigued by what research and plans have been made for how Martian colonists will deal with this sort of problem. I'm guessing solar won't be enough to keep a colony going. Wind power, even in a dust storm, wouldn't be possible because the air is so thin. Nuclear of some kind seems the only other option.

credit_guy 8y ago
Maybe the Kilopower reactor [1] [1]https://en.m.wikipedia.org/wiki/Kilopower https://en.m.wikipedia.org/wiki/Kilopower
- TheSpiceIsLife 8y ago
  Summary of the linked Wikipedia entry: a nuclear heat source driving a Stirling Engine connected to a regular electric generator. A test reactor has been constructed, called KRUSTY or Kilopower Reactor Using Stirling Technology. It is designed to produce up to 1 kilowatt of electric power and is about 6.5 feet tall (1.9 meters).[12] The goal of the KRUSTY experiment is to closely match the operational parameters that would be required in NASA deep space missions[13]. The prototype Kilopower uses a solid, cast uranium-235 reactor core, about the size of a paper towel roll. Reactor heat is transferred via passive sodium heat pipes, with the heat being converted to electricity by Stirling engines. Sounds neat, I'd like one at home. Electricity is always handy, and the waste heat can be used to keep my house and cars warm.
  - larkeith 8y ago
    Also cool: uses passive heat pipes rather than coolant, further reducing the number of moving parts (making it that much more reliable).
    - namibj 8y ago
      I still wouldn't want that much U-235 in a critical configuration in my home. If something goes wrong, I'm not a superfund site, I'm the reason why someone started WW3/why my neighbourhood is no more.
      - nitrogen 8y ago
        Why would it explode? Don't you need high purity and high compression with perfect timing for that? Wouldn't it just get really hot in a reactor design?
        bronson 8y ago
        It's not easy to contain really hot things. If it gets out, it won't be a nuclear explosion but, if water or combustibles are around, there will be some sort of explosion.
        yongjik 8y ago
        Frankly I'd be more worried about "passive heat pipes filled with liquid sodium" (read: "pipes filled with substance that transmutes water to fire"). Not in my backyard.
        azernik 8y ago
        In order to get a full-yield nuclear detonation, yes, but even a "fizzle" still has the power of a good-size conventional bomb.
        namibj 8y ago
        A criticality event is _bad_. If you are near it, you get cancer. And there are many ways a small nuclear reactor can malfunction without that much yield, and still ruin my neighbourhood. I have to agree, the crater is the worst case.
      - larkeith 8y ago
        Not to mention the whole no radiation shielding thing.
  - azernik 8y ago
    A quibble - in space applications, "nuclear heat source" makes me think a radioisotope thermal generator (i.e. a lump of an unstable isotope decaying naturally). That's what's used on the Curiosity and Mars 2020 rovers. Kilopower, on the other hand, is a for-real, critical-mass nuclear reactor.
    - TheSpiceIsLife 8y ago
      That's a good point. Too late you edit my comment now, but I agree it should have said something like "heat from a nuclear reactor ...'
- larkeith 8y ago
  As awesome as the Kilopower reactor is, this really isn't its intended use-case - it's supposed to provide low-output, very longterm power in spacecraft and rovers, where mass is limited, shielding unnecessary, and maintenance impossible. For mars colonization, a significantly larger purpose-built reactor would be much more feasible, and almost certainly a better solution than solar.
  - TheSpiceIsLife 8y ago
    This article[1] used as a reference in the Wikipedia entry certainly makes it sound like Mars colony is Kilopower's intended use-case. 1. https://www.space.com/37348-nasa-fission-power-mars-colony.html https://www.space.com/37348-nasa-fission-power-mars-colony.h...
    - larkeith 8y ago
      I stand corrected! Previous articles I had seen had only discussed the prototype and one kilowatt design, but both this and the Wikipedia article show heavier designs for Mars missions.
elihu 8y ago
The article doesn't say what the exact power drop is, but it appears to have been at least 75%: > Within days, Opportunity saw sunlight dimming as atmospheric opacity — a measure of how much dust is in the air — soared. The rover’s energy production dropped by half over the course of 2 days, and then half again in a single day, Callas said during a media briefing on 13 June. Aside from nuclear, some reasonable mitigations for this kind of thing might include substantial over-provisioning of panels, some kind of battery, or some kind of temporary measures to consume very little energy in an emergency. I think over-provisioning might actually be the most practical solution, particularly if any Martian settlement needs a massive solar farm anyways in order to produce electricity to convert water and carbon dioxide into methane and liquid oxygen. Making rocket fuel is important, but not so important that it can't be curtailed for a few weeks if that energy is needed elsewhere. > An optimized system of this design massing 50 kg "is projected to produce 1 kg/day of O2:CH4 propellant ... with a methane purity of 98+% while consuming 700 Watts of electrical power." Overall unit conversion rate expected from the optimized system is one tonne of propellant per 17 MWh energy input. https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturing_propellant_on_Mars https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturin... Burning rocket fuel to generate electricity might also be an option if there's a temporary shortage.
- deleted 8y ago
  [deleted]
- SECProto 8y ago
  Exactly this - giant solar farm for rocket fuel production, turn it off at night, turn it down or off during dust storms. Rocket fuel could be used during these lulls (nights/storms) to provide power, maybe recapturing the exhaust gases as pure feedstock. edit - batteries might be the better option for overnight, but would have serious mass penalty to use for long term backup power. Using fuel as storage is simple solution.
  - jagger27 8y ago
    Power from combustion seems like a bit of a tough sell in an environment severely lacking in O2. Then you also need to bring some sort of high efficiency engine (probably an LNG turbine) with you too with an appropriately sized generator. Capturing exhaust gasses is a neat idea, but now you need to bring compressors and high pressure storage tanks with you.
TeMPOraL 8y ago
> Wind power, even in a dust storm, wouldn't be possible because the air is so thin. From what I've read around the web, it actually would be possible. The efficiency would be around 10% of an equivalent wind turbine on Earth, but it has one thing in its favor: you could construct them with mostly local resources even at early stages of a Mars colony. PV cells are too high-tech for that, they would have to be shipped from Earth. https://space.stackexchange.com/a/5669 https://space.stackexchange.com/a/5669 https://www.youtube.com/watch?v=0xtW7g4R_vs https://www.youtube.com/watch?v=0xtW7g4R_vs
blanderman 8y ago
They might be able to store excess energy using a gravity system https://www.planetforward.org/tv-segments/storing-excess-power-using-gravity https://www.planetforward.org/tv-segments/storing-excess-pow...

by mabbo 8y ago

credit_guy 8y ago

Maybe the Kilopower reactor [1] [1]https://en.m.wikipedia.org/wiki/Kilopower https://en.m.wikipedia.org/wiki/Kilopower

TheSpiceIsLife 8y ago
Summary of the linked Wikipedia entry: a nuclear heat source driving a Stirling Engine connected to a regular electric generator. A test reactor has been constructed, called KRUSTY or Kilopower Reactor Using Stirling Technology. It is designed to produce up to 1 kilowatt of electric power and is about 6.5 feet tall (1.9 meters).[12] The goal of the KRUSTY experiment is to closely match the operational parameters that would be required in NASA deep space missions[13]. The prototype Kilopower uses a solid, cast uranium-235 reactor core, about the size of a paper towel roll. Reactor heat is transferred via passive sodium heat pipes, with the heat being converted to electricity by Stirling engines. Sounds neat, I'd like one at home. Electricity is always handy, and the waste heat can be used to keep my house and cars warm.
- larkeith 8y ago
  Also cool: uses passive heat pipes rather than coolant, further reducing the number of moving parts (making it that much more reliable).
  - namibj 8y ago
    I still wouldn't want that much U-235 in a critical configuration in my home. If something goes wrong, I'm not a superfund site, I'm the reason why someone started WW3/why my neighbourhood is no more.
    - nitrogen 8y ago
      Why would it explode? Don't you need high purity and high compression with perfect timing for that? Wouldn't it just get really hot in a reactor design?
      - bronson 8y ago
        It's not easy to contain really hot things. If it gets out, it won't be a nuclear explosion but, if water or combustibles are around, there will be some sort of explosion.
      - yongjik 8y ago
        Frankly I'd be more worried about "passive heat pipes filled with liquid sodium" (read: "pipes filled with substance that transmutes water to fire"). Not in my backyard.
      - azernik 8y ago
        In order to get a full-yield nuclear detonation, yes, but even a "fizzle" still has the power of a good-size conventional bomb.
      - namibj 8y ago
        A criticality event is _bad_. If you are near it, you get cancer. And there are many ways a small nuclear reactor can malfunction without that much yield, and still ruin my neighbourhood. I have to agree, the crater is the worst case.
    - larkeith 8y ago
      Not to mention the whole no radiation shielding thing.
- azernik 8y ago
  A quibble - in space applications, "nuclear heat source" makes me think a radioisotope thermal generator (i.e. a lump of an unstable isotope decaying naturally). That's what's used on the Curiosity and Mars 2020 rovers. Kilopower, on the other hand, is a for-real, critical-mass nuclear reactor.
  - TheSpiceIsLife 8y ago
    That's a good point. Too late you edit my comment now, but I agree it should have said something like "heat from a nuclear reactor ...'
larkeith 8y ago
As awesome as the Kilopower reactor is, this really isn't its intended use-case - it's supposed to provide low-output, very longterm power in spacecraft and rovers, where mass is limited, shielding unnecessary, and maintenance impossible. For mars colonization, a significantly larger purpose-built reactor would be much more feasible, and almost certainly a better solution than solar.
- TheSpiceIsLife 8y ago
  This article[1] used as a reference in the Wikipedia entry certainly makes it sound like Mars colony is Kilopower's intended use-case. 1. https://www.space.com/37348-nasa-fission-power-mars-colony.html https://www.space.com/37348-nasa-fission-power-mars-colony.h...
  - larkeith 8y ago
    I stand corrected! Previous articles I had seen had only discussed the prototype and one kilowatt design, but both this and the Wikipedia article show heavier designs for Mars missions.

elihu 8y ago

The article doesn't say what the exact power drop is, but it appears to have been at least 75%: > Within days, Opportunity saw sunlight dimming as atmospheric opacity — a measure of how much dust is in the air — soared. The rover’s energy production dropped by half over the course of 2 days, and then half again in a single day, Callas said during a media briefing on 13 June. Aside from nuclear, some reasonable mitigations for this kind of thing might include substantial over-provisioning of panels, some kind of battery, or some kind of temporary measures to consume very little energy in an emergency. I think over-provisioning might actually be the most practical solution, particularly if any Martian settlement needs a massive solar farm anyways in order to produce electricity to convert water and carbon dioxide into methane and liquid oxygen. Making rocket fuel is important, but not so important that it can't be curtailed for a few weeks if that energy is needed elsewhere. > An optimized system of this design massing 50 kg "is projected to produce 1 kg/day of O2:CH4 propellant ... with a methane purity of 98+% while consuming 700 Watts of electrical power." Overall unit conversion rate expected from the optimized system is one tonne of propellant per 17 MWh energy input. https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturing_propellant_on_Mars https://en.wikipedia.org/wiki/Sabatier_reaction#Manufacturin... Burning rocket fuel to generate electricity might also be an option if there's a temporary shortage.

deleted 8y ago
[deleted]
SECProto 8y ago
Exactly this - giant solar farm for rocket fuel production, turn it off at night, turn it down or off during dust storms. Rocket fuel could be used during these lulls (nights/storms) to provide power, maybe recapturing the exhaust gases as pure feedstock. edit - batteries might be the better option for overnight, but would have serious mass penalty to use for long term backup power. Using fuel as storage is simple solution.
- jagger27 8y ago
  Power from combustion seems like a bit of a tough sell in an environment severely lacking in O2. Then you also need to bring some sort of high efficiency engine (probably an LNG turbine) with you too with an appropriately sized generator. Capturing exhaust gasses is a neat idea, but now you need to bring compressors and high pressure storage tanks with you.

TeMPOraL 8y ago

> Wind power, even in a dust storm, wouldn't be possible because the air is so thin. From what I've read around the web, it actually would be possible. The efficiency would be around 10% of an equivalent wind turbine on Earth, but it has one thing in its favor: you could construct them with mostly local resources even at early stages of a Mars colony. PV cells are too high-tech for that, they would have to be shipped from Earth. https://space.stackexchange.com/a/5669 https://space.stackexchange.com/a/5669 https://www.youtube.com/watch?v=0xtW7g4R_vs https://www.youtube.com/watch?v=0xtW7g4R_vs

blanderman 8y ago

They might be able to store excess energy using a gravity system https://www.planetforward.org/tv-segments/storing-excess-power-using-gravity https://www.planetforward.org/tv-segments/storing-excess-pow...