Down under

The BioSUB Project will compare life underwater to life inside a closed ecological system. It requires the same specially-designed regenerative or recycling technology needed for any long-term manned mission to Mars. Lloyd must generate oxygen, grow food, obtain fresh water and deal with his waste. In order of importance Lloyd needs air, water and food.

How about air?

As mentioned above, air is the most critical factor. A “Standard Man” consumes about 0.83 kg of oxygen (O₂) per day. The critical limiting factor is the carbon dioxide (CO₂) that we breathe out at a concentration of about 3.5% (35,000 ppm). This corresponds to 0.71 kg of CO₂ produced per day. Humans are affected by too much CO₂ in the air more quickly than by lack of O₂.

CO₂ can be removed from the air chemically, using a CO₂ scrubber. A scrubber contains particles of soda lime, which reacts with the CO₂ to form chalk. But there’s a more simple way to get rid of CO₂ which lasts forever. Plants take in CO₂ and give off O₂ in a process called photosynthesis. The processes by which humans and plants can mutually support each other in an artificial, closed bioregenerative microcosm are therefore simple yet extremely elegant. Plants take in CO₂ and release O₂ to their surroundings. People can breathe O₂ the plants produce and exhale CO₂ to sustain the plants.

Lloyd will breathe O₂ the algae produce and exhale CO₂ to sustain its growth in a photosynthetic bioreactor called a Biocoil. This is been developed by Cascade High School’s Advanced Biology Class in Idaho, USA.

And food, water?

While life support systems can use physical methods alone to purify water and create O₂ from exhaled CO₂, only bioregenerative systems (those involving plants) can also produce food and thereby qualify as completely self-sufficient systems. Crops must rank high in energy, nutritional content, and taste. An underwater agricultural endeavour must also consider limitations of growing area. Unfortunately one person would need about 80m² of higher plants to keep them going. For this reason (and several others), Lloyd has chosen to use a unicellular green algae, such as Chlorella. Algae require much less space as almost the whole biomass of algal cells is an apparatus that promotes photosynthesis and the biosynthetic processes that are associated with it. There is no inert or dead biomass in it at all. Also, Chlorella has been researched as a potential food because it is high in protein and other essential nutrients. When dried, it is about 45 percent protein, 20 percent fat, 20 percent carbohydrate, and 10 percent various minerals and vitamins. So algae is going to be on the underwater menu in the last days of the project only, just to make sure we don't have to abort the experiment because of 'indigestion'! Other than that, Lloyd will be enjoying normal food brought to him by the volunteer divers on surface.

Air2water has provided us with a perfect solution for drinking water while still respecting the idea of a self-sustaining habitat. Utilizing innovative technology the dragon fly M18 device extracts moisture from the air and gives out fresh drinking water! A very smart device that can be customized to fit any home, office or even an underwater habitat.

How about energy?

Of course, to live underwater he will also need power to generate light and run some basic appliances. This will be in the form of renewable energy, like his Pedal Powered Prime Mover 12 Volt DC Generator. Finally, there will be solar panels mounted to the top of a container on shore, providing all the main underwater energy needed. Solarco Albury is sponsoring enough panels to power the whole habitat along with a battery bank provided by Adelaide Hills Solar. In addition, to top up the energy needs, EFOY Australia is sponsoring the latest generation of SFC fuel cells, an environmentally friendly energy solution that produces 1.2 kWH/day. Some natural sunlight will be able to filter un through the clear polycarbonate manhole in the bottom of the habitat, giving Lloyd some idea of what the weather is like outside.

And safety?

Draeger Safety Pacific Pty Ltd has provided a device to meet Lloyd's individual needs. The Dräger X-am 7000 is an innovative solution for the simultaneous and continuous detection of up to five gases. Molecular Products and Chem-Supply are also part of our safety back-ups. They specialise in manufacturing chemical absorbents, chemical based devices and catalysts, for emergency air purification. Molecular Products have recently developed the CASPA device, designed to remove respired CO₂ to maintain a safe and breathable environment in a confined space like an underwater habitat.