NASA's 'MOXIE' Experiment Successfully Generated 122 Grams of Oxygen on Mars (cnn.com) 70
CNN reports:
The first experiment to produce oxygen on another planet has come to an end on Mars after exceeding NASA's initial goals and demonstrating capabilities that could help future astronauts explore the red planet. The microwave-size device called MOXIE, or Mars Oxygen In-Situ Resource Utilization Experiment, is on the Perseverance rover.
The experiment kicked off more than two years ago, a few months after the rover landed on Mars. Since then, MOXIE has generated 122 grams of oxygen, equal to what a small dog breathes in 10 hours, according to NASA. The instrument works by converting some of Mars' plentiful carbon dioxide into oxygen. During the peak of its efficiency, MOXIE produced 12 grams of oxygen an hour at 98% purity or better, which is twice as much as NASA's goals for the instrument. On August 7, MOXIE operated for the 16th and final time, having completed all its requirements...
Bigger and better versions of something such as MOXIE in the future could supply life support systems with breathable air and convert and store oxygen needed for rocket fuel used to launch on a return trip to Earth.
In a statement NASA applauded the performance of the MIT-created experiment. "When the first astronauts land on Mars, they may have the descendants of a microwave-oven-size device to thank for the air they breathe and the rocket propellant that gets them home...
"Rather than bringing large quantities of oxygen with them to Mars, future astronauts could live off the land, using materials they find on the planet's surface to survive."
The experiment kicked off more than two years ago, a few months after the rover landed on Mars. Since then, MOXIE has generated 122 grams of oxygen, equal to what a small dog breathes in 10 hours, according to NASA. The instrument works by converting some of Mars' plentiful carbon dioxide into oxygen. During the peak of its efficiency, MOXIE produced 12 grams of oxygen an hour at 98% purity or better, which is twice as much as NASA's goals for the instrument. On August 7, MOXIE operated for the 16th and final time, having completed all its requirements...
Bigger and better versions of something such as MOXIE in the future could supply life support systems with breathable air and convert and store oxygen needed for rocket fuel used to launch on a return trip to Earth.
In a statement NASA applauded the performance of the MIT-created experiment. "When the first astronauts land on Mars, they may have the descendants of a microwave-oven-size device to thank for the air they breathe and the rocket propellant that gets them home...
"Rather than bringing large quantities of oxygen with them to Mars, future astronauts could live off the land, using materials they find on the planet's surface to survive."
With MOXIE ready (Score:4, Funny)
... you'll go steady [youtube.com].
At last (Score:1, Flamebait)
The moment we've all been waiting for. Send Elon Musk already.
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Promising on many levels. (Score:4)
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No shock here. Sending humans to Mars is unmitigated bullshit and a complete waste of resources. This will not change until we can send self-replicating factories to Mars that can prepare everything needed. Say, 500 years from now. Maybe later. Definitely not before the upcoming (hopefully only partial) civilization collapse due to climate change.
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Observable reality and a real understanding of technology. What do you have to offer?
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I am a PhD-level engineer. That comes with some real understanding of technological questions, and also an understanding how long most things actually take to find out and make them work. "Attitude" does not figure into it. You basically said you are a fanboi, correct?
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A) an engineer who has a PhD in engineering
B) an engineer who does not have that PhD but is skill wise on the same level as A
More stupid questions?
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More stupid questions?
Nah man! I'll only get PhD level gibberish from you!
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Maybe later. Definitely not before the upcoming (hopefully only partial) civilization collapse due to climate change.
That would be if people like you succeed in running their industries on lignite. Fortunately, your political betters have other plans.
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It does very basic things that are trivial on Earth.
Having an autonomous vehicle motor around and flying a helicopter: two more things that are trivial on Earth.
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I'll try to explain using simple language. Just because something is simple to accomplish on Earth, does not guarantee that it is simple or even possible to accomplish on another planet. And what is interesting to you may or may not be interesting to others.
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He strives to become Major Obnoxious.
Small dog? (Score:4)
So NASA is planning a colony of small dogs on Mars?
Why not just say that it's about the amount a person breaths in two hours?
Re:Small dog? (Score:5, Funny)
Not yet. They haven't achieved the other mission goal yet, which is to train small dogs to breathe only once per week.
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I, for one, welcome our new puppy overloads that go away after ten hours!
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With people, there's room for all sorts of distracting (but true nevertheless) tropes involving slurs like mouthbreathers, oxygen thieves, etc.
Dogs get much better PR, and if they are small (and cute) in addition, they have practically free marketing reign.
Re: Small dog? (Score:2)
So would that be imperial or metric puppy units?
Promising, but wish they would do more. (Score:5, Insightful)
This is promising, but you kind of wish they would do more testing than that in two years. Of course, it is a fairly power-hungry device and they probably have lots of other things to use the power for. From what I can find, it needs about 300 Watts to produce 12 grams an hour. An average human adult needs about 840 grams of oxygen per day, so about 35 grams an hour. So a scaled up version should be able to produce enough for a human from about a kiloWatt of power. That would be about 5 square meters of solar panels or so, but of course it's only day half the time so you would need at least 10 square meters or probably more. Basically you would want to overproduce and store it. That could mean tanks but, in a big enough habitat, you could probably just let the oxygen level drop a bit at night and raise it during the day. Overall, it's not too bad.
The thing to compare against is electrolysis. The power requirements to produce an equivalent amount of oxygen from electrolysis of water are only about 220 Watts. So, in terms of power requirements, electrolysis would be much better. Of course, you would need to obtain water. At this point, we do know of a number of places on Mars where you can get abundant water, but setting up a base near them might be impractical. Still, it might be practical to send out expeditions to mine it. For about a years worth of oxygen for one astronaut, you would need around 350 kilograms of water. If you have a Mars vehicle that can carry about a ton of cargo, on Mars that would be around 2600 liters of water, which would be enough for oxygen for 7 astronauts for a year. Now, you would probably want a lot more water than that for other uses, but it's really not a lot to keep people alive.
So, I see MOXIE as a transitional and emergency system if it gets used. There initially to provide oxygen before a water collecting operation is set up, and for emergencies if there are problems with collection or with the electrolyzers. Beyond that though, it will probably just sit around and get dusty while the extra power it would use gets used for something else.
Overall, it is a neat trick. I would be even more impressed though by something that could actually recycle the CO2 breathed out by the colonists. MOXIE technically can use that as a feedstock, but since it outputs oxygen and carbon monoxide, you couldn't use this in a closed loop. It's necessary to vent the CO outside, which means that you would be venting half the oxygen in a recycling scenario. So it only works in places where you can keep on replenishing the CO2 from outside, which mostly just means Mars. I would like to see a power-efficient method of splitting CO2 into O2 and just some form of carbon soot. That could actually be used anywhere without needing to vent or draw in fresh CO2. It can be done by using microwaves to generate a CO2 plasma causing the CO2 to disassociate. That results in some CO, some free carbon, and a decent amount of O2. If you can collect the O2 from such a system, separate out the carbon, and feed the CO back in, you can recover O2 from CO2. The problem is that it's energy intensive and requires very high temperatures.
Of course, another option is to use plants or algae and process the atmosphere through photosynthesis. Experiments like Biosphere 2 failed to produce enough oxygen for the participants to survive on, but it turned out that the main problem there was that the concrete the structure was built from was actually sucking up oxygen. Overall, it appears that it's at least difficult to use photosynthesis to keep astronauts alive, and it takes a lot of space for the plants. Plus, even in a closed environment, a source of water will probably be needed.
MOXIE power [Re:Promising, but wish they...] (Score:5, Informative)
Good comments, but a couple of corrections:
...So a scaled up version should be able to produce enough for a human from about a kiloWatt of power.
Most of the power requirement is heating the solid oxide to nominal operating temperature, 800C. If you run it full time, instead of starting from Mars ambient temperature, the required power would be somewhat less. And, since thermal losses don't increase linearly with scale, the more oxygen you produce, the less power required per unit oxygen.
That would be about 5 square meters of solar panels or so, but of course it's only day half the time so you would need at least 10 square meters or probably more.
Solar power at Mars averages about 500 W/m^2, so more like 7 square meters if your array-level efficiency is 29%, which is doable. However, in addition to the day-night cycle, you have power vary with distance from the sun (Mars' orbit is eccentric), and a lot of power lost to dust in the atmosphere even without dust storms. So, 14 square meters is unrealistically optimistic.
Reference https://arc.aiaa.org/doi/pdf/1... [aiaa.org]
The thing to compare against is electrolysis. The power requirements to produce an equivalent amount of oxygen from electrolysis of water are only about 220 Watts. So, in terms of power requirements, [water] electrolysis would be much better.
Not really. The fundamental electrolysis energy per oxygen atom is about the same-- actually slightly less for electrolyzing CO2. The good news is that you can do water electrolysis at much lower temperature, but for large systems that becomes less and less important. If you're working from Martian water, though, the energy required to dig it up, melt it, distill it (Mars water is going to be full of salts, perchlorates among them, and electrolysis systems are finicky about what they're fed with) and keep it liquid is going to eat a lot of power.
...I would like to see a power-efficient method of splitting CO2 into O2 and just some form of carbon soot.
There are a number of ways to do this, but the engineering difficulty in that "soot" is tremendous. Deposited carbon ends up caking on everything, and it's difficult to clean off.
Good reference on MOXIE here, by the way: https://www.science.org/doi/10... [science.org]
...and, fwiw, I suppose I should also link this one: https://arc.aiaa.org/doi/abs/1... [aiaa.org]
Re:MOXIE power [Re:Promising, but wish they...] (Score:4, Interesting)
Most of the power requirement is heating the solid oxide to nominal operating temperature, 800C. If you run it full time, instead of starting from Mars ambient temperature, the required power would be somewhat less. And, since thermal losses don't increase linearly with scale, the more oxygen you produce, the less power required per unit oxygen.
Fair enough. It's only a rough estimate though. I doubt it's really that far off. It might be 800 Watts or 700, but I doubt it's as low as 500 Watts, for example. There are definitely parts of it that will scale pretty linearly, such as compression. Also, thermal losses are not just going to be to the outside. The heat in this device is actually doing work. Heat will be lost to the reaction.
Solar power at Mars averages about 500 W/m^2, so more like 7 square meters if your array-level efficiency is 29%, which is doable. However, in addition to the day-night cycle, you have power vary with distance from the sun (Mars' orbit is eccentric), and a lot of power lost to dust in the atmosphere even without dust storms. So, 14 square meters is unrealistically optimistic.
You know, I think I was thinking of the Moon when I wrote that. Good point. Still a manageable number of solar panels to maintain oxygen for a single astronaut, but it does add up. Power lost to dust in that atmosphere is a bit iffy. It's not clear that they would be much of a problem as long as the panels are regularly cleaned. Also, a combination of solar and wind power could mitigate the problem. During the daytime, it will either be windy or sunny, never neither.
Not really. The fundamental electrolysis energy per oxygen atom is about the same-- actually slightly less for electrolyzing CO2. The good news is that you can do water electrolysis at much lower temperature, but for large systems that becomes less and less important. If you're working from Martian water, though, the energy required to dig it up, melt it, distill it (Mars water is going to be full of salts, perchlorates among them, and electrolysis systems are finicky about what they're fed with) and keep it liquid is going to eat a lot of power.
I'm not going by theoretical minimum numbers there. I'm going by the best known numbers I can find for real world devices that actually do what we need. There are actual electrolyzers that can produce that much oxygen with that energy input. For cracking CO2, the only example device I have good numbers for is MOXIE and it's basically throwing out half the oxygen as carbon monoxide which probably puts it at a disadvantage. I mentioned another possibility, which is a microwave powered CO2 plasma, but that's probably even less efficient because you have no control over how it splits. As you pointed out, MOXIE may become more power efficient at scale, but there does not appear to be any scaled up device that's actually had any numbers published, so that's just speculative. So I'm pretty much forced to go with the numbers I've found. If you can find more definitive information I would welcome it.
There is going to be an energy cost to mining and purifying the water as well. How much energy the mining takes depends on where you get it. There are cliffsides of ice on Mars pretty much sitting there for the taking. How far you need to travel to get to them depends on where the colony is located, but if you can get there with a vehicle with a backhoe and a trailer, you can mine enough water for years worth of oxygen in a matter of a half hour or so. If you don't have the ability to travel to one of the locations where it's abundant, then you do have to extract it in what's probably an energy intensive manner from some pretty dry soil. I'm not so worried about the salts and perchlorates. Reverse osmosis can remove those along with the other salts without needing to distill it. On Earth, reverse osmosis can produce fresh water from seawater using as little as 10.8 kiloJoules per liter. That's very small co
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Of course, another option is to use plants or algae and process the atmosphere through photosynthesis. Experiments like Biosphere 2 failed to produce enough oxygen for the participants to survive on, but it turned out that the main problem there was that the concrete the structure was built from was actually sucking up oxygen. Overall, it appears that it's at least difficult to use photosynthesis to keep astronauts alive, and it takes a lot of space for the plants. Plus, even in a closed environment, a source of water will probably be needed.
While the effect was the same, this is incorrect, or at least misleadingly simplistic. The concrete was absorbing, and sequestering, carbon dioxide, not oxygen [Equation: Ca(OH)2 + CO2 => CaCO3 + H2O]. The oxygen levels dropped as a result of microbial activity, basically the decay of organic material in the soil, but the additional carbon dioxide this produced was then absorbed by the concrete, which resulted in a net drop in oxygen levels. There were also large daily and seasonal swings in both carbon
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> There were also large daily and seasonal swings in both carbon dioxide and oxygen levels, because of the day / night difference in photosynthetic activity, which caused concern.
That one wouldn't worry me too much - in a fully artificial environment it could be as simple as having multiple greenhouses on different cycles to keep things in the overall system more stable.
However, my understanding is that living in a small closed-system greenhouse ultimately results in a dangerous rise in O2 and pressure o
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Didn't mean to mislead, but you're right that was simplistic. The point was that there were material reasons that came down to design choices and unexpected variables that, once understood, could have been avoided in future experiments. It's not clear if anyone has since done any experiments that conclusively show sufficient O2 production/CO2 scrubbing through photosynthesis in an enclosed environment. Basically something that says if you have X amount of biomass and Y amount of light, and follow a particul
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Interesting comment, but I have to quibble with one thing: "in a big enough habitat, you could probably just let the oxygen level drop a bit at night and raise it during the day". It seems to me that this would simply induce altitude sickness on a nightly basis, since you're dropping the partial pressure of O2. The two problems are a) the humans would breathe more at night to compensate for lower O2, causing them to blow off CO2 and raise blood pH, and/or b) their O2 sats might drop during sleep, which is
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When I say big enough habitat, I mean one big enough that the drop would be negligible. That might be impractically large, of course. If we have the typical colonist breathing 840 grams of O2 per day, then they'll use at least half of that during the night (obviously there is not really a sheer day/night cutoff, it would be more like declining power in the evening, max power at noon, etc. ) If the O2 in the atmosphere of the station matches Earth partial pressure, there will be something like 300 grams of o
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How did you calculate this: For about a years worth of oxygen for one astronaut, you would need around 350 kilograms of water. it sounds like a pretty low amount.
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Bear in mind it's a back of the envelope calculation and does not really account for wastage, etc. An average adult astronaut consumes about 840 grams of oxygen per day. So it's just 365.23X0.84 kg to get 306.7932 kg for the amount of oxygen an astronaut needs in one Earth year. Then, by mass, water is about 88.89% oxygen. So 306.7932 kg /0.8889 is about 345.1424 kg, which I rounded up to 350 kg. Realistically, you would want a lot more water than that per astronaut for them to drink, bathe, cook, etc. and
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I find it difficult to find a reliable number for your: An average adult astronaut consumes about 840 grams of oxygen per day. ... not sure how much carbon would there in it, to convert 840grams into carbon dioxide. Was just wondering ...
First I thought that is quite a lot. No idea though. I mean: I eat less than 1kg food a day. Assuming most is water
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0.84 kgs are the typical NASA numbers. Can't find a primary source right now but see here [cnet.com] where it discusses 2.52 kg per day for the IIS (which, if you divide by three for three astronauts is 0.84) For the amount of O2 required, that actually always seemed low to me relative to the numbers for, for example, fossil fuels. With those, it's more like 3X the mass of O2 to fuel. If you consider the composition of, for example, glucose - C6H12O6 - and alkanes (one of the main components of gasoline) - CnH2n+2 - t
Story has the numbers but misses the obvious (Score:2)
Humans consume about 35g O2 per hour, so three of these devices (working at peak) could sustain a human on the surface.
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Interesting, but (Score:5, Interesting)
Carbon dioxide is a really stable compound, and it's quite thermodynamically unfavorable to try and split it into components.
Add to that the other major problem that Mars poses: the martian dust is full of perchlorates, which are toxic to humans and other mammals, including the proverbial dog which would have been able to breathe for 10h every 2 years. Perchlorates however can be relatively easily decomposed to generate chlorates/chlorides (which are much less toxic) and produce oxygen in the same process.
I wonder if investigating this method instead (or in addition to) MOXIE would be worth it.
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Might want to tell the trees outside photosynthesis is thermodynamically unfavorable.
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It is actually. It requires a lot of energy from the sun, and some pretty complicated photochemical tricks to make it happen.
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Plants are really the backbone of life on earth. They don't move around picking stuff up, but instead make do what they have - carbon from CO2, sunlight for energy, water that falls from the sky or is transported on the ground.
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Yeah, but luckily thermodynamics are for steam based heat engines and other compressed/hot gases.
Splitting a CO2 molecule does not care about any thermodynamics.
HUmans on Mars is a pipe-dream (Score:2, Insightful)
At least at this time and for the foreseeable future. The whole thing is an unmitigated waste of money and resources. Even with the worst climate-change scenarios and a global nuclear war on top, some place in an Earth dessert is still several orders of magnitude easier to survive in and much more pleasant. The whole thing is stupid. Maybe when we have self-replicating factories (not this century) that can make everything needed, but not before. And then actually traveling there and surviving that trip is s
It Is Utterly Pointless. (Score:2)
It's not really a pipe dream, it is feasible.
But it is utterly pointless.
microwave-size device (Score:4)
The microwave-size device called MOXIE, ...
That's *really* small -- unless they mean microwave oven-sized. #journalism :-)
publicity stunt (Score:2)
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The problem isn't that of getting people to walk on Mars - it's not having them die of radiation sickness within a few months of arrival on Mars.
Small dog breaths whatnow? (Score:2)
What a silly reference to a real world example - a small dog breathing for 10 hours?
This amount of oxygen is about 85 L of oxygen. If they mixed this with air at the normal 4:1 N2/O2 ratio, that comes to 427 L of air. A typical breath is ~0.5 L, se we're talking about 850 breaths. At 12 breaths/min that's about 70 min of breathing. So here's a more useful reference - it produced enough oxygen to sustain a person for about an hour.
If we consider the 12 g/hr capability, that's about 42 L air per hour, which w
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Potentially. Also, the atmosphere has 3% nitrogen and 1.6% argon, with 95% CO2. So if you could just scrub out the CO2 from the atmosphere (I'm sure easier than pulling O2 out), you could get pretty inert filler gas
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If you breath in, and breath out ... what percentage of the oxygen you breathed in is now CO2?
Most certainly not 100%.
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Fair point. I'm seeing figures that look like ~25% of O2 is consumed per breath. So if they could capture the exhalation, scrub the CO2 and reuse the O2, maybe we're talking increasing the lifetime of the O2 by up to 4x.
Great news (Score:3)
We can ship Elon Musk out to Mars immediately.
Hm (Score:2)
122 grams is a decent amount if it is crack cocaine. But oxygen, not so much.
An idiotic stunt (Score:1)
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This is an experiment that could have been done in any of a hundred college basements. It wasted space, resources and money for a non-scientific human spaceflight "experiment" on a science mission.
Have you considered that a large part of the experiment is proving the equipment survives the trip to Mars? If the goal is to send humans to the surface of Mars then we need to send every piece of equipment needed for their survival first, have it tested vigorously, or the first "glitch" in the systems means everyone dies.
There's a reason why it was the eleventh Apollo mission that landed humans on the moon. It took ten missions to prove everything worked, and even then people died in the process. That's
We have good working prisons here on earth ! (Score:2)
>> If the goal is to send humans to the surface of Mars
You are working on wrong base assumptions. There is no meaningful goal of sending people to Mars.
We have good working prisons here on earth, why build one on Mars ?
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If you do not want to go to Mars, up to you.
I want.
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The third is expected to have humans make bootprints on the lunar surface again.
Well, they will walk over to the supposed Apollo landings, make photos and post them on Facebook and declare: nothing here, that all was fake! We are the first! A great step for social media and all humankind! (You know: they can not write "mankind" because of gender issues)
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