Space living: The Luna Gaia design would reduce the need for costly supply missions to ferry food, air and water backwards and forwards from colonies on the Moon and Mars.
Credit: NASA
SYDNEY: Australian-led scientists have designed a new space habitat that might one day allow astronauts on the Moon or Mars to be 90 to 95 per cent self-sufficient.
The development of such as system could save billions of dollars in shuttle trips to re-supply lunar or space colonies and brings closer the vision of a human habitat on Mars.
The technology could also have applications on Earth to develop more sustainable farming techniques and improve recycling processes.
Luna Gaia
Some systems to recycle water and air have already been developed and rudimentary versions are presently used in the International Space Station (ISS). However, the proposed new lunar habitat "combines our existing knowledge" of physical, chemical and biological processes to provide an "overall picture of how a minibiosphere would work," said James Chartres aerospace engineer at the University of Adelaide in South Australia. He gave a talk detailing the design at the Australian Space Science Conference held in Sydney last month.
The project is in some ways similar to the failed Biosphere 2 experiment, built in Arizona, U.S., in the late 1980s. Over an area of 12,000 m2, Biosphere housed a closed ecological system, incorporating a mini 'ocean' with coral reefs, as well as a grassland, desert, mangrove, rainforest and agricultural areas. Eight people survived in the habitat for two years, but a lack of food and low levels of oxygen hampered the experiment. Chartres detailed plans for a smaller, space-bound concept, dubbed Luna Gaia.
Devised by an international team of 30 space scientists, Luna Gaia would be a 'closed-loop' environment, meaning that almost all material within the system is recycled with very little need for input from outside sources. The current design caters for a team of 12 astronauts under isolation for up to three years.
Currently, recycling that occurs on the ISS is driven by chemical reactions. A big challenge to developing a totally integrated system is developing a biological recycling system said Chartres. He argues that for efficient recycling, microorganisms are required.
Crops in space
His team devised a new system that takes into account all details of living in an enclosed system in space, even down to the materials that supplies are packed in.
The Luna Gaia concept integrates technologies such as the Closed Equilibrated Biological Aquatic System (CEBAS), an enclosed aquarium designed by the German Aerospace Centre and the Micro-Ecological Life Support System Alternative (MELIiSSA) developed by the European Space Agency. MELIiSSA uses microbes to purify water, recycle carbon dioxide and derive edible material from waste products.
Algae – which generates oxygen from carbon dioxide via photosynthesis, and doesn't require pollinating – is the key to the proposed design.
The food required for astronauts would come from a mixture of tending small crops and from pre-packed supplies. Such crops would include peanuts, lettuce, tomatoes, carrots and wheat. In addition, certain types of algae, such as Spirulina or Chlorella would provide other vitamins, minerals and trace elements.
The diet would be largely vegetarian, said Chartres, but protein could potentially come from small-scale farming of fast-growing fish such tilapia.
A lunar base is unlikely to ever be 100 per cent self-sufficient, said Chartres, because no atmosphere is completely safe from leaks and it could not provide humans with all the nutrients that they need to survive.
Moreover, astronauts need the occasional break to the routine of standard food, so the odd "luxury item such as fruit salad, spices or chocolate," would ward off any doldrums, he said.
Significant hurdles
Pathogens introduced to the system by plants, as well as difficulties of pollination for crops still pose significant hurdles to the design. In addition, as much as 20 m2 of plants would be required to feed a single astronaut.
The proposed system, is unlikely to be up and running any time soon. Chartres estimates it will be another 20 to 30 years before the funding for the set-up and the practicality of providing the space for plant growth in a spacecraft is realised.
Mark Kliss a bioengineer with the NASA Space Biosciences Division in Moffett Field, California, said he found the project interesting.
"Certain subsystems could be, and in some cases are currently being used on Earth to provide improved water reclamation techniques, better contamination control methods, superior solid waste management technologies, advanced crop productivity techniques, as well as application to carbon credit and green building technologies," said Kliss of the wider applications.
He added that any knowledge gained from attempts to develop and operate "relatively closed, regenerable life support systems" is useful because it helps us understand how to utilise limited resources as efficiently as possible.
"This is an issue that is not only important for future long duration human space missions, but for humans on Earth as well," he said.
Raising insects for food
I do find that disgusting, but you may be on to something. However, perhaps insects are not being considered because they are hard to manage. It would really suck if everyone in your biosphere died because some of the bugs got loose, multiplied "in the wild" and then clogged up systems that your life depended on. Everything in such an environment must be controlled. Bugs are hard to control. Perhaps they could be confined to a giant, air-tight, transparent tank. When you wanted some protein, you flip a switch that powers a vacuum and sucks some of the buggers out of the tank, then grinds them into a nice tasty protein pudding. That's about the best way I can think of to minimize the risk of a "leak". I say "leak" because I think a few bugs getting loose in such an environment could wind up being as deadly as a leak of some bio-hazardous or nuclear material. Larger livestock are easier to manage. However, they require more resources. Something the size of a dog would be best I think.
Why not bring some goats
Why not bring some goats they can eat plant waste BTW 40 to 90% of a food plant's mass is not digestible to humans but a goat can make use of it and produce meat and milk.
Tilapia and cattle won't get
Tilapia and cattle won't get into the circuitry and short things out.
Tilapia aren't bad.
Tilapia have a big advantage in this area. They are well suited for these types of situations.
They have the following advantages:
- quick growth
- very high tolerance for stress
- eat almost anything but prefer plants
- don't collect toxins
- make very useful fertilizer
- work well, balanced, and actually promote growth of other more preferred types of fish (cod)
- limit the growth of algae and other organisms
- easy to keep a clean environment (they constantly dig, fight, and are very active thus the water never stays calm and nothing settles in any specific location so a simpler automated water filtation system is required)
- managable, they are stuck in one spot, they can't leave the pool.
With these characteristics, you end up with very a tolerant protein source that is very efficient, sustainable, and closed loop (plants feed fish, fish feed plants).
Most insects also have many of the same advantages, but I think their biggest negatives is that they have sensitive points in their lifecycles and their waste clean up (however minor) is not as easy to automate. Plus there is the issue that they can escape and get into locations (computer equipment, filtation systems, & scientific instrunments) that they aren't supposed to.
Western cultural biases taken into consideration... Bugs! Eewh ^_^
Re: Self-sufficient space habitat designed
I am really pleased that this article has recieved so many comments again showing a definite interest in Human spaceflight.
The actual study was done within a team of 32 professionals from 12 different countries and was not Australian led as we worked as a cohesive a team. The life support system design team consisted of 9 people from 6 different countries including Australia, Canada, China, Japan, Spain and the United Kingdom.
One of the aims of the research was to develop a life support system that would reduce the amount of required resupply. As mentioned in the artivle things like leakage, luxury items and spare parts prohibit the system from being completely self sufficient or closed loop. The research was intended to provide recommendations for future avenues of research and identify where current gaps are.
The reason for the large lead-time is that such a biological system on such a massive scale would take a long time to research and understand. Additionally the construction and development of such a large system would take a long period of time due to the heavy lift capabilities required to get that much mass to the moon. Understanding such a complex system including the mass balance and where storage buffers would be required would need significant research and there are many issues to overcome. Studies have shown that the use of bio-regenerative methods only become feasible if mission durations exceed 2.5 to 3 years depending on the size of the crew. The 20 to 30 years is an estimate and like most research could change dramatically given the required resources and personnel.
We also actually looked at the possibility of including insects as a food source. There have been some published studies in Japan about the use of insect and as a source of protein they are another possible option that was considered and further research was recommended.
I recently spent 3 months in China interacting with students and also CASC the Chinese Aerospace Science and Technology Corporation. I would argue from my experience in China that the Chinese do not view space as a plaything and there is a tremendous amount of national pride for their space program. This is demonstrated in such things as astronaut images on bottle of water and the large amount of news coverage it receives on the CCTV stations.
Lunar Gaia
While it may be possible to run lunar facilities without a stable self-sufficient ecosystem, it would be impossible to mount a 5 year mission to mars.
Anybody that's ever owned an aquarium knows how hard it is to maintain a miniature ecosystem.
Biosphere 2, which was probably more of a performance art work than a scientific project, also showed that it is a non-trivial problem. Indeed this is probably the foremost challenge facing long term human occupancy in space.
The long and short of it is that we have never successfully managed an isolated ecosystem which included large organisms such as human beings for any significant length of time. The effort to learn how to do this will probably be a larger engineering challenge than any other in such an endeavor.
This sort of research and
This sort of research and development is something that we will be continually develop for centuries or more. Sure we may be able to get something working in 20 - 30 years. And to use bugs as food and a step in recycling does seem a rather efficient way to go. They are far more resistant to harsh conditions than mammals. Not only that but they reproduce quickly and take less space. Besides, how are you going to strap in a pair of breeding cows into a shuttle? Sure bugs are gross but, there are plenty of people willing to go even if they are the primary source of protein.
The entire system will require many separate components all of which will be vitally important as the people to resources ratio here on earth continues to get heavier on the people side. Space is a long term goal of which are great grand kids will likely not see. Yet it does not change it's importance.
A smaller version maybe?
Hi James
It's an interesting idea, but a rather large base construction project to support with the planned "Ares" style HLLVs. There has been research on microbial-based closed-loop mini-ecosystems - eating Chlorella paste might not be overly appealing but explorers have toughed it eating far worse. And desk-top manufacturing technologies are reaching the point where parts can be made on demand (almost) so there's no reason why a self-sufficient lunar base shouldn't be feasible in 10-20 years, at least as detailed plans. The recycling technologies of a closed-loop mini-ecosystem would also have direct spin-off applications here on Earth, which you're well aware I am sure.
Could a mobile base with a mini-ecosystem be feasible?
It would probably be better
It would probably be better to shoot for close loop rather than closed-loop, if I can use LCMS terminology here. ;-)
Reduce the need for mass fraction devoted to consumables where they can be recycled, but realize that it is actually very, very hard to get a fully closed-loop to work, and problems might appear along the way in zero and low-g that weren't anticipated, just as the biospherians discovered that concrete soaked up oxygen which they needed to breath.
Then use that saved mass fraction for redundancy, rather than for using cheaper, smaller launchers.
Yay for space tech
Very exciting. *sigh* I'm yearning for the day when all the money spent on wars will spent on exploring space, medicine and technology instead. And commercial news will have a science update rather than a sports update.
I'm disappointed I haven't seen anything about this on Australian news.
Projects like these will be an important first step toward colonising Mars. We'll be able to work out all the kinks in the system, do research and improve our designs at far lower costs and with a much faster return trip.