WOULD YOU RATHER GROW ALGAE OR VEGETABLES IN SPACE?

 

BIOS-3 was a controlled ecological life support system (CELSS) which opened in 1972. The facility was atmospherically sealed, creating a need for oxygenation for the scientists living within the closed system. Initial prototypes from 1965 at the same facility proved that algae could moderate the oxygen and carbon dioxide levels in an environment that included human respiration. The system was not closed on all fronts; it required electrical energy from a nearby hydroelectric facility, and air tanks provided pressure to keep the interior atmosphere stable. Solid and liquid waste from the human crew was also removed from the facility.

The BIOS-3 complex included four major rooms: one for the crew living quarters, one algal cultivator (the room where algae would provide oxygen from carbon dioxide), and two phytotrons (greenhouses built for the purposes of research). There were three major two month long phases for BIOS-3 from 1972 to 1973. During phase 1, there were two phytotrons and a crew of three people. These phytotrons provided wheat and vegetables to sustain the crew. In phase 2, one phytotron was removed and replaced with the algal cultivator containing the Chlorella species. In phase 3, wheat was removed from the remaining phytotron, with the facility only providing vegetables and oxygenated air. The project was considered a success in the six months of its initial operation. No crewmembers fell ill or developed pathological problems, and the plants and algae did not deteriorate over the period.

The project highlights some of the difficulties of testing small-scale environmental closed systems. Though the phytotrons and the rest of the facility were highly controlled, trace elements (such as nickel, aluminum, titanium, and others) were detected, but had no adverse effects on the occupants or the vegetation. Within a small scale, these problems can easily multiply over a long period of time. The failure of Biosphere-2 highlights the difficulty of sustaining a small-scale operation, regardless of the control measures in place. The success of BIOS-3 was in its limited scale (it was less than 1700 cubic meters) and its control of occupancy (3 crewmembers and highly specified vegetation/algae growth protocols). Though large scale operations require more capital (as was the case in Biosphere-2), these operations also require more sophisticated systems to deal with unanticipated problems which become magnified in constrained spaces like CELSS.

 

KEYWORDS: CELSS, Oxygenation, Phytotron

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KEY FAILURES

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HUMAN WASTE: Human waste was not recycled within the closed loop system.

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EXTERNAL ENERGY SOURCE: Energy was supplied to the system from an external source.

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MORE SOPHISTICATION FROM SMALL TO LARGE-SCALE: The simplicity of the system works well at a small scale but further development into a more sophisticated system is required to sustain a larger closed environment.

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