Scientists think they may have cracked life support for Martian occupation
- Reference: 1686133992
- News link: https://www.theregister.co.uk/2023/06/07/photoelectrochemical_life_support_mars/
- Source link:
The International Space Station (ISS) relies on photovoltaic-driven water electrolyzers to get oxygen from water. But the two-stage process – converting sunlight into electricity and then using electricity in the electrolysis of water – is costly.
A [1]paper published this week said about 1.5kW out of the 4.6kW energy budget of the Environmental Control and Life Support System on the ISS is used up by the Oxygen Generator Assembly (OGA), which relies on electrolysis. The approach was a dead end in terms of future space exploration and habitation, the study published in Nature Communications states.
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As well as the high energy demand, the OGA and the Carbon Dioxide Reduction Assembly "currently in place on the ISS bear the challenge of being notoriously cumbersome and prone to breakdowns due to obsolete, inefficient, or ageing compartments," it said.
[3]
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As an alternative approach, lead researcher Katharina Brinkert, assistant professor of catalysis at the University of Warwick, assessed the viability of photoelectrochemical (PEC) devices to aid the chances of long-term survival.
[5]Mars helicopter went silent for six sols, imperilled Perseverance rover
[6]Perseverance rover shows up Curiosity with discovery of Martian water park
[7]China's Mars rover finds signs of 'modern' water
[8]NASA InSight lander spills the beans on Mars' core
PEC devices use semiconductor materials to convert solar energy directly to chemical energy to produce hydrogen and oxygen without requiring the intermediate production of electricity. The technology is the subject of intense research on Earth because it might help in the sustainable energy problem, but its potential in space has yet to be studied.
"This work seeks to establish the theoretical foundations for the application of PEC devices in habitats on the Moon and Mars and delivers the first foray into exploring the feasibility of utilising them for oxygen production and carbon dioxide recycling," Brinkert said in the paper.
The researchers concluded it was possible, but with some caveats.
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"Although high long-term efficiencies and power densities of PEC devices are still integral parts of ongoing terrestrial research efforts, we have shown that the application of these devices could go beyond Earth and potentially contribute to the realisation of human space exploration," the paper said.
The research also looked at whether the PEC devices could be built in an extra-terrestrial settlement using In-Situ Resource Utilization (ISRU), meaning what you can find where you've landed.
"The device construction can draw from a variety of semiconductors and electrocatalyst materials that are available on the Moon and Mars and the required materials can eventually be produced via ISRU. Moreover, we have previously demonstrated that PEC devices can work efficiently in microgravity and our theoretical analysis suggests that it can suitably be scaled up," the study said. ®
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[1] https://www.nature.com/articles/s41467-023-38676-2
[2] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2ZICpovLlW4VLDDIDCw2xBgAAAIA&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
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[5] https://www.theregister.com/2023/05/30/ingenuity_mars_helicopter_offline/
[6] https://www.theregister.com/2023/05/12/more_water_evidence_mars/
[7] https://www.theregister.com/2023/05/01/asia_tech_news_roundup/
[8] https://www.theregister.com/2023/04/25/nasa_insight_lander_mars_paper/
[9] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_offbeat/science&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44ZICpovLlW4VLDDIDCw2xBgAAAIA&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[10] https://whitepapers.theregister.com/
Re: How about plants ?
There is no "martian soil".
Soil is the product of biological processes, decomposing organic matter to enrich the surrounding substrate with usable nitrogen, trace elements and organic compounds.
The martian surface is covered in regolith. Dead, sterile, irradiated, dessicated, pulverized silica compounds, contaminated with toxic chemicals like perchlorate salts.
Re: How about plants ?
But you can shit on it. I've seen the film.
Re: How about plants ?
You mean the film that starts with a storm on mars blowing away heavy equipment, which is completely impossible in an atmosphere of less than 1% the density of earths?
Re: How about plants ?
He wants to shit on the soil, not the movie.
Sorry, regolith.
Re: How about plants ?
The film? I say: the documentary! Clearly, it was a very strong storm. And all of it is fully true and and it worked: if you need proof, I recently saw Matt, he made it back from Mars indeed.
Re: How about plants ?
That's a lot of plants (a quick google said about 800 per person) and they take a long time to grow too.
More practically, if they swapped all the ISS astronauts out for Sherpas or other people who can live and operate at 18,000ft - where the Oxygen is only 50% of the level it is at sea-level - they could halve their energy budget. Apparently the ISS is kept at 21%, 1013hpa [edit: [1]wikiperida tells me it's because they're worried some of the equipment would suffer at lower pressures]
[1] https://en.wikipedia.org/wiki/ISS_ECLSS#Atmosphere
Re: How about plants ?
Unless Sherpas are magical metabolic machines, the amount of oxygen they use is similar to the rest of us. Their adaptation makes them more efficient in absorbing oxygen from the rarified air, but they spend the same amount of oxygen per calorie metabolised.
Re: How about plants ?
...and with some of the equipement they mean the crew?
May??
"...may have cracked life support for Martian occupation"
That "may" is doing a lot of heavy lifting in that sentence!!!
Re: May??
In the first place, aren't cosmic radiations due to the lack of magnetic field the biggest problem?
Re: May??
Who knows, they may turn out to be a resource. Radiotrophic fungi are a thing, apparently, so if we can do artificial photosynthesis, maybe we can also do artificial whatever the hell it is they do.
It's not an energy budget, it's a power budget.
An energy budget would be measured in Joules or kWh....
Re: It's not an energy budget, it's a power budget.
Budgets are typically assigned to a period of time - e.g. the chancellor sets a budget of £x billion for a given year. By analogy, an energy budget of MJ per day (or second or whatever) seems reasonable.
Scientists?
Not boffins? Has there been a change in El Reg's style guide?
Re: Scientists?
change in El Reg's style guide
Get used to it. The sooner, the better.
How about plants ?
Grow them in Martian soil. One by product is vegetation that might be useful as food.