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Design and Validation of Atmospheric Life Support Systems for the Mars Gravity Biosatellite.  T.R.F. Fulford-Jones¹, A.M. Heafitz², E.B. Grosse¹, M.A. Scott³, J.C. Franklin⁴ and J.A. Hoffman^{1 1}MIT Department of Aeronautics and Astronautics, ²MIT Edgerton Center, ³Cambridge University Department of Electrical Engineering, ⁴MIT Department of Mechanical Engineering.

   The atmospherics control subassembly of the Mars Gravity Biosatellite will cleanse and continuously recirculate breathable air throughout the spacecraft’s fifteen habitat modules. The design incorporates canisters of lithium hydroxide, silica gel desiccant and activated carbon to control contaminants and regulate humidity.

    Generation of ammonia through interaction of waste products is a particular concern because of the dangers associated with mycoplasmosis. We present results from an extended-duration experiment to investigate the rate of ammonia production in a closed-loop system with a single mouse in a flight-like habitat module. This experimental data suggests that an appropriately-sized activated carbon bed will adequately control ammonia buildup while also eliminating trace contaminants.

   We additionally present data which shows effective control of humidity and carbon dioxide. The laboratory system incorporates silica gel and lithium hydroxide canisters together with computer-activated valves and variable-speed pumps. Combining this data with theoretical values for mouse contaminant production rates generates accurate sizing predictions for the atmospherics control hardware on board the biosatellite.

(Supported in part by NASA grant NCC2-1369)