As the nation of Asgardia develops, how should the internal biosphere of the nation be composed? The environments oxygen supply should be self sustaining through use of various tree species such as Aspen and Oak trees. A single mature tree can absorb carbon dioxide at a rate of 48 lbs./year and release enough oxygen back into the atmosphere to support two human beings which means large quantities of trees would be needed. Other plant species that may produce a suitable atmosphere inside of the station also include; Ferns, particularly the Japanese Royal Fern, not only release oxygen into the air but also absorb formaldehyde. The Boston fern is noted for adding oxygen and humidity to indoor air. Gerbera Daisy will purify and boost the oxygen level of the air while you sleep at night, making this plant a great choice for bedrooms. Other indoor plants considered highly efficient in oxygen production and air purification include Heartleaf Philodendron, Snake Plant, Spider Plant, Chinese Evergreen and Golden Pothos. What are your thoughts on the plant species needed to be involved in creating a self-sustaining atmosphere? (This subject is also involved with Physical sciences. I chose to post it here do to the main biological concept of flora and not the atmosphere itself as the main subject of discussion).

Let me start by saying that I am not an expert at all on botany, nor an expert really in any field. I like the idea of a self sustaining atmosphere though. I would think that the best way to go about using a botanical garden for a self replenishing atmosphere would be to select plants that have the highest CO2 to O2 conversion rate with regards to the plants size/mass, that way a higher amount of that particular species of plant could be brought up while also conserving space in the station

It's a good point to have similar plants on board with the proper CO2 to O2 conversion rates. A plant with high photosynthetic efficiency is Sugar Cane at about 7%. Instead of using a plant based method, algae has an efficiency rate that can go up to about 30%. An even better method is using the Protist Coccolithophore which are a unicellular algae that is responsible for 20% of Earths oxygen.

Do algaes require large bodies of water to photosynthesize effectively?

Yes, algae need large amounts of water, yet they need only sunlight (or another form of energy, like sugar), carbon dioxide and a few inorganic nutrients to grow. Another perk to algae would be their quick reproduction rate making oxygen production much higher than using plants as the main source of oxygen production.

Aye, such as nitrogen and phosphorus. Would separate botanical gardens spaced at intervals around the space station work better then a central unit? And how would the large bodies of water be stored?

Having botanical gardens around the ship seems to be a more efficient way of spreading out oxygen equally and would require less ventilation than if the system was centralized. Although it probably wouldn't hurt to have a centralized backup system. The bodies of water should be stored in protective units that have a source of natural or in most cases artificial lighting, along with proper methods of adding the needed energy for the proper oxygen outcome.

That's what I thought, but I wasn't sure if the separate gardens at intervals around the ship would pose a problem or not, but then again I am going off of my own assumption of the ship being a singular large rotating wheel, allowing anywhere from 5-15 separate gardens incase one or more ends up compromised.

I'm sure having multiple gardens would be the best idea either way, just in case one has technical difficulties. Besides that it would take less time to spread the O2 around.

I am sorry, I am not a biologist/botanist, but does plants "produce" oxygen? Cause there are two cycles of photosynthesis, light and dark ones. And if during the light there is indeed conversation of carbon dioxide into oxygen, the other way around goes for dark phase: oxygen to CO2. Plants can act as filters, yes, but for sustaining oxygen level, we either need chemical filters, or some sort of bacteria. Or maybe algae will do the trick, as I am saying: not a biologist.

Acquaponics with algae, both oxygen demand and food in one topic

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I remember looking at an idea for large scale removal of carbon dioxide from the atmosphere. The design was to put a high efficiency light bulb into a clear tube surrounded by a tube containing genetically engineered algae. The algae are engineered so that will will only multiply if a chemical indicator is introduced to their environment, the would also produce more chloroplasts, secret all access sugar, and reduce other metabolic activities. A CO2 scrubber would exhaust into one end of a very long tube, and oxygen would be allowed to bubble out of the other. A semipermeable membrane would allow sugar and minor other metabolic products to be filtered out of the water without interfering with algae. A slow drip would be required to keep the water level consistent.

Pros: Given that the algae is only maintaining it's population, very little in the way of fertilizer would have to be added. Using red leds it could very power efficient. Power can be turned up/down or off at any moment if more oxygen is needed or more power is needed elsewhere. Carbon dioxide is turned into solid sugar which can be stored or used as food.

Cons: The design would have to be altered for zeroG on spaceships. It may be possible to create more space/weight/power efficient synthetic materials like the synthetic leaf. It requires significant electrical power.

Many people are against the idea of genetic engineering, but it's almost imperative to do so. Genetic engineering gives us the ability to make some plants grow faster, produce more food that is more nutritious, all while using less resources.

I found this to be an interesting link in regards to the first steps of the station, at least until we can get a self sustaining system into place.

https://science.nasa.gov/science-news/science-at-nasa/2000/ast13nov_1

It's an older article, but it does highlight some great concepts for the initial habitation of a station. Especially in regards to reusing the expelled CO2 in combining with the H2 back into water to start the cycle over again at a lesser extent. As well as the expulsion of the methane byproduct for orbit adjustments.

The creation of water through water electrolysis, is a method that will work for Asgardia before a proper biosphere is implemented. The hydrogen gas also created through this process may also be very useful for fuel in a power generator (along with the solar panels and possible other methods). I'm happy to see that pwmmal has been giving input to the conversation from the beginning and the idea given by Keegan about the large scale removal of carbon dioxide, and the proper way to sustain the atmosphere. Such as the tubes and red leds for algae (the ship will most likely have an artificial gravity system implemented so that the process would continue to work as normal). I'm glad that this forum has reached this extent of conversation and I'm looking forward to future thoughts on the subject. I have been reading every comment of the forums I have created and I am not disappointed so far.