Towards the development of artificial biospheres as means of enabling space urbanisms’ physiological sustainabiliy

The following posts are excerpts from my research project written as part of my thesis in Spring 2011. I post it because I still find the subjects interesting, and also to kick start my use of this blog to record more of my opinions on architecture on a wider scope,  in addition to personal and freelance project work…

 

“Space cannot become a settled, economically viable human domain until people establish their lives there. As the amount of space activity increases, the travel time, expense and risk will eventually make it more practical for people to transform staying in space to living in space. The requirements and effects of environments that support human living are subtle, and continue to be honed over millennia as societies evolve. Manipulating those environments with skill and grace demands a fine, multivariate balance that only human experience and wisdom can feasibly provide – in space as on Earth, as far into the future as we can foresee. It demands in fact the practice of architecture.”

– Brent Sherwood, Lunar Architecture and Urbanism, (Code 693, NASA Goddard Space Flight Centre, 2005)
Space exploration presents three great opportunities to the gestating field of space architecture – human habitation of orbital Space, the beginnings of which we have just described; habitation of the Earth’s Moon; and the eventual habitation of Mars and the other suitable planets and moons solar system. While the other locations in the solar system that could also potentially be settled, the proximity of orbital Space and the Moon to the Earth make them the most likely candidates for human habitation within the foreseeable future. While man has not yet set foot on Mars, manned missions to Mars have been in formulation for decades. Here I’ll look beyond vehicular modes into the future of space architecture, at a time when space urbanism might fully develop.


“Plant‐based life support systems offer self‐sufficiency and possibly cost reduction. Resupply is prohibitive for long duration missions as it increases the launch mass and consequently the launch costs. Risk to the astronauts is also increased by relying on frequent resupply from Earth. Greenhouses cannot only be used for the production of edible biomass but also as air and water regeneration processors.”

– I. Hublitz, et al., Engineering Concepts for Inflatable Mars Surface Greenhouses, (Elsevier, 18 June 2004)

In the current mode of space habitation spacecraft sustain the physiological needs of the occupying astronauts only temporarily before the astronauts must either return to Earth or be re‐supplied by an external source. This is due to the limited supply of food, water and oxygen that can be stored on board spacecraft, which itself is due to those materials mass and volume. Concepts of closed loop biospheres have featured in Sci‐Fi illustration for decades, but have begun to be developed in real science by groups such as the Biosphere II project based in Arizona.

In that project, eight people lived an air‐tight greenhouse for two years. The project aimed to recreate a complete biosphere in a closed building, meeting all their physiological needs by cultivating plants and animals in a closed environment. Paragon Space Development Corporation, a company started by the team that lived in Biosphere 2, sent biospheres to the international space stations for 16 months. Those miniature ecosystems managed to survive for 16 months before returning to Earth, going through complete multiple life cycles in space. The Biosphere 2 Project greenhouses were built of steel frames with glass panels, but this is not a feasible construction palette for a exo-planetary version because the materials weigh too much and are too bulky. Instead, inflatable enclosures have been investigated for use as agricultural greenhouses. The possibility of inflatable greenhouses being used to grow food on mars has been researched by numerous groups such as NASA and COSPAR. Shapes such as a hemisphere, a tube and a torus have been investigated.

All images: Biosphere II, taken from the lecture ‘Life in Biosphere II’, (May 2006).

In order for a settlement on Mars to be sustainable in the most basic sense it would have to have a steady supply of food, clean water and breathable atmosphere to meet settlers’ physiological needs. The ISRU unit outlined in the Mars Reference Mission has been proven capable of producing oxygen to support six astronauts, so it can be assumed that oxygen supply needn’t be worried about. It has also been proven that there is a large amount of frozen water ice on the surface of mars. It is taken that this water ice can be melted to be used for drinking water by the settlers. For this reason it can also be assumed that water supply needn’t be worried about. The obstacle is the lack of a source of food. There are two solutions for this; the first solution is to import food from earth in sufficient quantity and with sufficient regularity to support the settlers, but this is prohibitively expensive. The second solution is to grow food on Mars.
This is likely to be carried out in greenhouses imported from earth. While agriculture on Mars would not actually have to produce 100% of the required oxygen for human habitation as the ISRU units would meet the most part of that requirement, the oxygen producing nature of the plants would be valuable as a back‐up system in the event of failure of the ISRU units. The plant beds could also be used to purify water. Martian agriculture used as a life support system would probably be based on the systems similar to those used in Biosphere 2:

Based on figures derived from the agricultural section of the Biosphere 2 experiment59, I will assume an area of 2,500m2 would be required to support eight settlers including both accommodation and agricultural land with 100% use, with 2300m2 intensive agriculture land and 200m2 accommodation use. This works out as a density of 3200 people per km2 within the dome area, exclusive of unpopulated areas outside the dome boundary.

The real merit in this system lies in its potential once fully developed to sustain an off‐world colony such as the mega‐urbanisms described in the next section.

More to come.

K.

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