4 ms·

NASA's Oxygen-Generating Experiment Moxie Completes Mars Mission

49 points by sohkamyung 3y ago

ewams 3y ago
Takes CO2 and extracts one oxygen molecule. Really neat they can do that with Mars' thin atmosphere . Does anyone know if there is a similar process that can separate both oxygen molecules and the carbon molecule? Then use the C to 3d print things and the oxygen to breathe/fuel/etc? Probably energy limited?
- gus_massa 3y ago
  More details from https://en.wikipedia.org/wiki/Mars_Oxygen_ISRU_Experiment https://en.wikipedia.org/wiki/Mars_Oxygen_ISRU_Experiment the reaction is 2 CO2 + heat --> 2 CO + O2 CO is a gas, so they let it escape. (It's toxic for mammals (in particular humans), but there is no one around to worry about. It will get transformed back to CO2 in the atmosphere when we react with something else that has an oxygen to steal. And in extremely low concentrations it's not a problem. So it's safe to let it escape for now.) It's energy limited. You need heat to make the transformation.,
  - marcosdumay 3y ago
    Hum... There are plenty of ways to turn that CO into plastics, like the GP wants (but all will require even more energy).
- semi-extrinsic 3y ago
  If you go to pure C, you get a solid that's hard to work with. So you stay with the CO which is a gas, you add H2 to get syngas, and then you can Fischer-Tropsch your way into ethylene and propylene, which is your feedstock for polyethylene (as in HDPE) and polypropylene (PP).
  - panick21_ 3y ago
    On Mars its really all about energy. We have plenty of C and O and if we get water, you can already make so many different things already. We desperately need to develop a big surface nuclear reactor that fits on a Starship. Without that Mars just isn't gone work. Laying out 100s of football fields of solar panels is just stupid in comparison.
    - Beached 3y ago
      sure in comparison, but we have the existing technology, and capability to lay out 100 football fields of solar on Mars if we wanted to, today. it may cost a metric ton, but we.could do it. we straight up don't have the ability to build a big surface buclear reactor on Mars. we probably could develop that capability, but until then, it isn't stupid to brute force a large solar installation until something better comes along. solar likely would be used along side things like kilo power and maybe traditional generators slightly modified until that day comes. it's not stupid do do inefficient thing now, when you don't have a real alternative.
      - panick21_ 3y ago
        > existing technology, and capability to lay out 100 football fields of solar on Mars if we wanted to, today No we don't actually. Not in a ready state to deploy to Mars and maintain and set up automatically. I would say deploying small submarine navy reactors is closer to being a real thing. > we straight up don't have the ability to build a big surface buclear reactor on Mars I didn't say 'build it on Mars'. I said, put in on Starship and land it on Mars. > it isn't stupid to brute force a large solar installation until something better comes along. Technology doesn't magically fall from the sky. 'Something better' doesn't magically show up one day saying 'Hi, I'm ready'. NASA does targeted development investment and spending to get the capabilities they need. Everybody interested in Space has for 50 years known that space nuclear is a necessary part of the future and because of dumb politics NASA has done almost nothing. > it's not stupid do do inefficient thing now We are not flying to Mars right now ... > when you don't have a real alternative. If you refuse to develop an alternative your not gone have one.
toss1 3y ago
>> the instrument proved far more successful than its creators ... expected Always good to see that kind of result! And with technology that is cool and would be workable at a genuinely useful scale, not merely an interesting curiosity Congrats to the team!
euroderf 3y ago
They say oxygen with 98% purity. What's the other 2%?
- ComputerGuru 3y ago
  I’m guessing CO2 that didn’t undergo conversion? Or the non-CO2 gases (comprising ~5% of the Martian atmosphere) that made it into the system and thus weren’t affected? Or the CO byproduct that wasn’t expelled separately? Edit: thinking about the numbers some, I think non-CO2 (Martian!) atmospheric gases is a good guess for the bulk because they’re 5% of the atmosphere and the conversion input is two CO2 for one O2 out, so at the 2:1 ratio with 0.95 of the input converted you end up with 98.96% converted to either O2 or CO, and the rest is whatever else you had mixed in there, if I did the math right. Depending on how the O2 and CO are separated, the non-CO2 gases not affected by the conversion/reaction could plausibly end up all with the O2, all with the CO, or some mix of the two (probably by weight?). Add in a few ppm of CO2 that slipped through the process unconverted and Bob’s your uncle. Maybe.
  - marcosdumay 3y ago
    Hum... If you don't expel the CO separately, you will very soon get all of your CO2 back and have no CO.
    - ComputerGuru 3y ago
      Obviously the bulk of it is expelled separately - I’m just saying it could be an imperfect process.
- marcosdumay 3y ago
  Probably CO2, as it's the main gas in the atmosphere there. The wikipedia page on the mission has more information, including that they managed to get up to 99.6% purity. That later number makes the resulting atmosphere not toxic anymore (assuming the impurity is CO2). But it still doesn't specify the impurity.
  - 3y ago
ComputerGuru 3y ago
This works (and works well enough) because the atmosphere on Mars is 95% CO2. On Earth, CO2 concentration is around 425 ppm (parts per million). On Mars, it is ~953,200 ppm! If we had the same CO2 concentration on Earth, atmospheric carbon dioxide scrubbers and CO2 sequestration solutions would be many orders of magnitude more efficient (and therefore more feasible - enough to actually clean up the mess we’ve made of things, even). But we’d all be dead.
- hoseja 3y ago
  There's actually only about 15 times higher partial pressure of carbon dioxide on Mars because the atmosphere is so much thinner.
  - ComputerGuru 3y ago
    Good point. But a compressor pre-stage is still a lot cheaper and more scalable than actually filtering through that many particles to get at each gram of CO2, no?
flerchin 3y ago
So MOXIEs would inject O2 to a martian habitat, CO2 scrubbers would remove exhaled CO2 from the habitat. I suppose Nitrogen would be initially fed into the system, but then would be unconsumed. I wonder what the power budget to run a MOXIE per astronaut would be.
- panick21_ 3y ago
  If you are gone produce your fuel on Mars, the power budget to actual make the fuel is gigantic. The power need to produce enough for a human in comparison isn't very much.
  - flerchin 3y ago
    Someday there might be a permanent presence on Mars, where the fuel budget is not the primary concern.
- Vecr 3y ago
  A nuclear power plant would almost certainly be required. All plans that only use solar plans are overly optimistic.
mikewarot 3y ago
The amazing part to me is that the experiment required more than the available power, and they made it work anyway, with some clever engineering.
hulitu 3y ago
> NASA's Oxygen-Generating Experiment Moxie Completes Mars Mission Total Recall is becoming reality. /s
darklycan51 3y ago
I'm wondering, I know that Earth originally went through an atmospheric change process by bacteria that changed a previously toxic (to us) process into a fully breathable atmosphere... considering that, wouldn't it be feasible to bring closed containers full of said bacteria (I assume one that does that might still exist) to mars and have them transform CO2 into oxygen in a closed environment? you pull CO2 into the place with the bacteria then when it's purified into oxygen you pull it into the base. Of course there's always the risk your bacteria somehow die but still
- gus_massa 3y ago
  Cyanobacteria. Those morons almost killed everyone. They are still floating around https://en.wikipedia.org/wiki/Cyanobacteria https://en.wikipedia.org/wiki/Cyanobacteria I think the total weight of Cyanobacteria is bigger than the total weight of Humanity, but I can't find hard numbers. I guess it's possible to send a container with them to Mars. The biggest problem would be to get enough water so they don't disécate. Also preventing them freezing may be difficult, but I guess it's possible. Anyway, for now people is trying to not send bacterias to Mars, just in case there are some bacteria-like things living there. It would be very interesting to have a second independent example of life to investigate and compare.

49 points by sohkamyung 3y ago

Takes CO2 and extracts one oxygen molecule. Really neat they can do that with Mars' thin atmosphere . Does anyone know if there is a similar process that can separate both oxygen molecules and the carbon molecule? Then use the C to 3d print things and the oxygen to breathe/fuel/etc? Probably energy limited?

gus_massa 3y ago
More details from https://en.wikipedia.org/wiki/Mars_Oxygen_ISRU_Experiment https://en.wikipedia.org/wiki/Mars_Oxygen_ISRU_Experiment the reaction is 2 CO2 + heat --> 2 CO + O2 CO is a gas, so they let it escape. (It's toxic for mammals (in particular humans), but there is no one around to worry about. It will get transformed back to CO2 in the atmosphere when we react with something else that has an oxygen to steal. And in extremely low concentrations it's not a problem. So it's safe to let it escape for now.) It's energy limited. You need heat to make the transformation.,
- marcosdumay 3y ago
  Hum... There are plenty of ways to turn that CO into plastics, like the GP wants (but all will require even more energy).
semi-extrinsic 3y ago
If you go to pure C, you get a solid that's hard to work with. So you stay with the CO which is a gas, you add H2 to get syngas, and then you can Fischer-Tropsch your way into ethylene and propylene, which is your feedstock for polyethylene (as in HDPE) and polypropylene (PP).
- panick21_ 3y ago
  On Mars its really all about energy. We have plenty of C and O and if we get water, you can already make so many different things already. We desperately need to develop a big surface nuclear reactor that fits on a Starship. Without that Mars just isn't gone work. Laying out 100s of football fields of solar panels is just stupid in comparison.
  - Beached 3y ago
    sure in comparison, but we have the existing technology, and capability to lay out 100 football fields of solar on Mars if we wanted to, today. it may cost a metric ton, but we.could do it. we straight up don't have the ability to build a big surface buclear reactor on Mars. we probably could develop that capability, but until then, it isn't stupid to brute force a large solar installation until something better comes along. solar likely would be used along side things like kilo power and maybe traditional generators slightly modified until that day comes. it's not stupid do do inefficient thing now, when you don't have a real alternative.
    - panick21_ 3y ago
      > existing technology, and capability to lay out 100 football fields of solar on Mars if we wanted to, today No we don't actually. Not in a ready state to deploy to Mars and maintain and set up automatically. I would say deploying small submarine navy reactors is closer to being a real thing. > we straight up don't have the ability to build a big surface buclear reactor on Mars I didn't say 'build it on Mars'. I said, put in on Starship and land it on Mars. > it isn't stupid to brute force a large solar installation until something better comes along. Technology doesn't magically fall from the sky. 'Something better' doesn't magically show up one day saying 'Hi, I'm ready'. NASA does targeted development investment and spending to get the capabilities they need. Everybody interested in Space has for 50 years known that space nuclear is a necessary part of the future and because of dumb politics NASA has done almost nothing. > it's not stupid do do inefficient thing now We are not flying to Mars right now ... > when you don't have a real alternative. If you refuse to develop an alternative your not gone have one.

toss1 3y ago

>> the instrument proved far more successful than its creators ... expected Always good to see that kind of result! And with technology that is cool and would be workable at a genuinely useful scale, not merely an interesting curiosity Congrats to the team!

euroderf 3y ago

They say oxygen with 98% purity. What's the other 2%?

ComputerGuru 3y ago
I’m guessing CO2 that didn’t undergo conversion? Or the non-CO2 gases (comprising ~5% of the Martian atmosphere) that made it into the system and thus weren’t affected? Or the CO byproduct that wasn’t expelled separately? Edit: thinking about the numbers some, I think non-CO2 (Martian!) atmospheric gases is a good guess for the bulk because they’re 5% of the atmosphere and the conversion input is two CO2 for one O2 out, so at the 2:1 ratio with 0.95 of the input converted you end up with 98.96% converted to either O2 or CO, and the rest is whatever else you had mixed in there, if I did the math right. Depending on how the O2 and CO are separated, the non-CO2 gases not affected by the conversion/reaction could plausibly end up all with the O2, all with the CO, or some mix of the two (probably by weight?). Add in a few ppm of CO2 that slipped through the process unconverted and Bob’s your uncle. Maybe.
- marcosdumay 3y ago
  Hum... If you don't expel the CO separately, you will very soon get all of your CO2 back and have no CO.
  - ComputerGuru 3y ago
    Obviously the bulk of it is expelled separately - I’m just saying it could be an imperfect process.
marcosdumay 3y ago
Probably CO2, as it's the main gas in the atmosphere there. The wikipedia page on the mission has more information, including that they managed to get up to 99.6% purity. That later number makes the resulting atmosphere not toxic anymore (assuming the impurity is CO2). But it still doesn't specify the impurity.
- 3y ago

ComputerGuru 3y ago

This works (and works well enough) because the atmosphere on Mars is 95% CO2. On Earth, CO2 concentration is around 425 ppm (parts per million). On Mars, it is ~953,200 ppm! If we had the same CO2 concentration on Earth, atmospheric carbon dioxide scrubbers and CO2 sequestration solutions would be many orders of magnitude more efficient (and therefore more feasible - enough to actually clean up the mess we’ve made of things, even). But we’d all be dead.

hoseja 3y ago
There's actually only about 15 times higher partial pressure of carbon dioxide on Mars because the atmosphere is so much thinner.
- ComputerGuru 3y ago
  Good point. But a compressor pre-stage is still a lot cheaper and more scalable than actually filtering through that many particles to get at each gram of CO2, no?

flerchin 3y ago

So MOXIEs would inject O2 to a martian habitat, CO2 scrubbers would remove exhaled CO2 from the habitat. I suppose Nitrogen would be initially fed into the system, but then would be unconsumed. I wonder what the power budget to run a MOXIE per astronaut would be.

panick21_ 3y ago
If you are gone produce your fuel on Mars, the power budget to actual make the fuel is gigantic. The power need to produce enough for a human in comparison isn't very much.
- flerchin 3y ago
  Someday there might be a permanent presence on Mars, where the fuel budget is not the primary concern.
Vecr 3y ago
A nuclear power plant would almost certainly be required. All plans that only use solar plans are overly optimistic.

mikewarot 3y ago

The amazing part to me is that the experiment required more than the available power, and they made it work anyway, with some clever engineering.

hulitu 3y ago

> NASA's Oxygen-Generating Experiment Moxie Completes Mars Mission Total Recall is becoming reality. /s

darklycan51 3y ago

I'm wondering, I know that Earth originally went through an atmospheric change process by bacteria that changed a previously toxic (to us) process into a fully breathable atmosphere... considering that, wouldn't it be feasible to bring closed containers full of said bacteria (I assume one that does that might still exist) to mars and have them transform CO2 into oxygen in a closed environment? you pull CO2 into the place with the bacteria then when it's purified into oxygen you pull it into the base. Of course there's always the risk your bacteria somehow die but still

gus_massa 3y ago
Cyanobacteria. Those morons almost killed everyone. They are still floating around https://en.wikipedia.org/wiki/Cyanobacteria https://en.wikipedia.org/wiki/Cyanobacteria I think the total weight of Cyanobacteria is bigger than the total weight of Humanity, but I can't find hard numbers. I guess it's possible to send a container with them to Mars. The biggest problem would be to get enough water so they don't disécate. Also preventing them freezing may be difficult, but I guess it's possible. Anyway, for now people is trying to not send bacterias to Mars, just in case there are some bacteria-like things living there. It would be very interesting to have a second independent example of life to investigate and compare.