Artificial Photosynthesis Could Be The Secret to Colonizing Space (sciencealert.com) 23
Artificial photosynthesis, inspired by the natural process that enables plants to convert sunlight, water, and carbon dioxide into oxygen and energy, could be crucial for space exploration and colonization. By using semiconductor materials and metallic catalysts, these devices could efficiently produce oxygen and recycle carbon dioxide, reducing reliance on heavy and unreliable systems currently used on the International Space Station. ScienceAlert reports: As my colleagues and I have investigated in a new paper, published in Nature Communications, recent advances in making artificial photosynthesis may well be key to surviving and thriving away from Earth. [...] We produced a theoretical framework to analyze and predict the performance of such integrated "artificial photosynthesis" devices for applications on Moon and Mars. Instead of chlorophyll, which is responsible for light absorption in plants and algae, these devices use semiconductor materials which can be coated directly with simple metallic catalysts supporting the desired chemical reaction. Our analysis shows that these devices would indeed be viable to complement existing life support technologies, such as the oxygen generator assembly employed on the ISS. This is particularly the case when combined with devices which concentrate solar energy in order to power the reactions (essentially large mirrors which focus the incoming sunlight).
There are other approaches too. For example, we can produce oxygen directly from lunar soil (regolith). But this requires high temperatures to work. Artificial photosynthesis devices, on the other hand, could operate at room temperature at pressures found on Mars and the Moon. That means they could be used directly in habitats and using water as the main resource. This is particularly interesting given the stipulated presence of ice water in the lunar Shackleton crater, which is an anticipated landing site in future lunar missions.
On Mars, the atmosphere composes of nearly 96% carbon dioxide - seemingly ideal for an artificial photosynthesis device. But the light intensity on the red planet is weaker than on Earth due to the larger distance from the Sun. So would this pose a problem? We actually calculated the sunlight intensity available on Mars. We showed that we can indeed use these devices there, although solar mirrors become even more important. [...] The returns would be huge. For example, we could actually create artificial atmospheres in space and produce chemicals we require on long-term missions, such as fertilizers, polymers, or pharmaceuticals. Additionally, the insights we gain from designing and fabricating these devices could help us meet the green energy challenge on Earth.
There are other approaches too. For example, we can produce oxygen directly from lunar soil (regolith). But this requires high temperatures to work. Artificial photosynthesis devices, on the other hand, could operate at room temperature at pressures found on Mars and the Moon. That means they could be used directly in habitats and using water as the main resource. This is particularly interesting given the stipulated presence of ice water in the lunar Shackleton crater, which is an anticipated landing site in future lunar missions.
On Mars, the atmosphere composes of nearly 96% carbon dioxide - seemingly ideal for an artificial photosynthesis device. But the light intensity on the red planet is weaker than on Earth due to the larger distance from the Sun. So would this pose a problem? We actually calculated the sunlight intensity available on Mars. We showed that we can indeed use these devices there, although solar mirrors become even more important. [...] The returns would be huge. For example, we could actually create artificial atmospheres in space and produce chemicals we require on long-term missions, such as fertilizers, polymers, or pharmaceuticals. Additionally, the insights we gain from designing and fabricating these devices could help us meet the green energy challenge on Earth.
The univerise (Score:2)
The abundance of elements in the universe is clear and they are there for the taking we just need to work out efficient processes that turn space rocks into raw materials; solids, liquids, gases, to create environments that we need to survive and flourish.
At some point we will have enough knowledge that we can automate these processes and set machines to work to hollow out asteroids and create structures in space. Its just a matter of knowledge, time and experience.
I dream of a far off future where our kno
Re:The univerise (Score:5, Insightful)
More important are the abundance of elements in the solar system: Earth or Mars or moons. Funny thing about the rest of the Universe, you cannot get there from here...at least not very easily and not within one's lifetime. The rest of the planets are either gas giants or Venus or Mercury. The latter two are too close to the Sun. The gas giants have too much gravity and we'd only be able to scoop up hydrogen if we could get close enough without friction burning us up.
Re:The univerise (Score:4, Informative)
Blah (Score:2)
undoing incorrect moderation
There is not going to be any one secret (Score:4, Interesting)
Re:There is not going to be any one secret (Score:4, Interesting)
It's not just that humans can't survive in zero gravity (so a minimal gravity is required), but current electronics has a finite lifetime in space due to cumulative radiation damage (see Total Ionizing Dose, Enhanced Low Dose Rate Sensitivity etc) so while a colony on another planet may well be possible as self-sustaining, the process of setting up the colony will be expensive with short worker human and equipment lifespans.
What ever became of the closed ecological system? (Score:3)
Whatever became of using a closed ecological system for long-duration space travel?
Russian rocket and spacecraft designer Sergei Korolev was said to be serious about it.
The Biosphere 2 experiment of a bunch of people closing themselves into a facility in the Southwest Desert, didn't work out because reasons. Maybe the problem is that such a thing doesn't even exist in nature as Earth's biosphere is not a tightly self-regulated ecological system as once thought? Complementary to how most hydrocarbons in the Earth's crust are fossil fuels (OK, alright already, abiogenic origin of oil and gas is something people claim, but work with me, people), the oxygen in the Earth's atmosphere is a fossil gas (see Nick Lane's book Oxygen)?
So have planners given up on the idea of spacecraft or off-Earth colonies with algae ponds as being Too Hard to design and get to work?
Re:What ever became of the closed ecological syste (Score:4, Interesting)
The short answer of what became of it is it doesn't work. Even in huge facilities, you run up against the 2nd Law of Engineering*. There have been studies with semi-closed systems where you have a small system with light inputs but not completely closed. Those run into the problem that a system that makes 100% of the oxygen a crew needs will only produce 50% of the food a crew needs; and a system that produces 100% of the food a crew needs will produce 200% of the oxygen they need, which will eventually kill either the crops or the crew. You can add animals that eat parts of the plants that people don't; but then either half your crew are livestock or you have to deal with the (surprisingly homicidal) consequences of make astronauts eat bugs for about half their nutrition. CELS can supplement but not replace other life support methods.
*1st Law of Engineering
Everything breaks.
2nd Law of Engineering
Everything leaks.
3rd Law of Engineering
Everyone is stupid & lazy.
Re: (Score:1)
Certainly you can find something to do with that oxygen... and if not, then vent it out.
Re: (Score:2)
If you're venting volatiles constantly then your system isn't closed. You do actually need that oxygen for the system. You just need it to be cycled instead of building up and killing everyone and everything. This actually isn't just a problem in CELS. It's technically been a problem for Earth in general. Oxygen build up is directly responsible for the Iron Catastrophe, the Oxygen catastrophe, at least two Snowball Earths, and spiders the size of footballs.
Re: (Score:2)
There's no law of nature which says that a planet/moon colony _must_ be a closed system, is there?
If nothing else, it's always getting sunlight...
Re: (Score:3)
The term "closed system" refers to material being cycled through the system with little to no loss. A biosphere is always energetically open or it will be in a rather rapid collapse.
If your life support system is constantly loosing critical resources, growth becomes difficult if not impossible. You'd at least want your CELS to last the length of the mission you put it on. As it stands, a CELS can reduce certain life support demands and reduce inputs enough to net reduce mass and give you a dV increase on b
Re: (Score:2)
If you're on the Moon or Mars, you'll be mining rock, no?
MORE IMPORTANTLY all commenters have ignored the first thing I wrote: "Certainly you can find something to do with that oxygen".
Re: (Score:2)
Oxygen by itself is quite dangerous to keep around. And the problem is a CELS that produces all the food a crew needs will produce twice the oxygen they can consume.
One of the main by products of refining metal is actually oxygen. Also, mining rock is hard. Most early mining efforts are directed at mining water ice, not minerals for refining. There's no material in space that's worth mining for itself. The only reason you mine material in space is for ISRU.
Re: (Score:2)
We're clever enough to think of some way to store it.
Water isn't the be-all and end-all of life. Colonists need a place to live, and new colonists can't just keep bringing new "pods" with them. Thus, you either dig tunnels, or dig for "rock" to make buildings.
Anyway, self-sustaining colonies away from Earth are a non-starter. We take for granted too much that Mars fans imagine.
Re: (Score:2)
The Biosphere 2 experiment of a bunch of people closing themselves into a facility in the Southwest Desert, didn't work out because reasons.
The Biosphere experiments were always ridiculous overreaches. They tried to incorporate whole Earthly ecosystems in a bottle, which is absurdly unnecessary for the task of creating a biologically driven human life support system for space. It's part and parcel of one of the core lies promulgated by the environmentalist movement, who are fond of claiming that the wild food web is somehow relevant to human life. It's not, but the Biosphere experiments took that silly lie as gospel and went nuts with it, wa
No. (Score:2)
Time to grow space weed! (Score:1)
But Why? (Score:1)