The Mars Gravity Biosatellite: Atmospheric Reconditioning Strategies for Extended-Duration Rodent Life Support 2007-01-3224
We present results which verify the design parameters and suggest performance capabilities/limitations of the Mars Gravity Biosatellite's proposed atmospherics control subassembly. Using a combination of benchtop prototype testing and analytic techniques, we derive control requirements for ammonia. Further, we demonstrate the dehumidification performance of our proposed partial gravity condensing heat exchanger.
Ammonia production is of particular concern in rodent habitats. The contaminant is released following chemical degradation of liquid waste products. The rate of production is linked to humidity levels and to the design of habitat modules in terms of bedding substrate, air flow rates, choice of structural materials, and other complex factors. Ammonia buildup can rapidly lead to rodent health concerns and can negatively impact scientific return. We present experimental data on long-term ammonia production in our novel flight-ready habitat modules, and we use this information to justify our on-orbit ammonia control strategy.
A recent reanalysis of the atmospherics subassembly led to exploration of custom-designed low-power condensing heat exchanger options for control of atmospheric humidity. We show experimental and analytic data that suggests the feasibility of this approach within certain control envelopes in a partial gravity environment. A side-by-side comparison with silica gel desiccant, the baseline alternative, identifies the merits of a hybrid approach.
The aforementioned results are employed to present a systems engineering analysis for filter sizing and condensing heat exchanger power based on ammonia production rates and active dehumidification results.
Citation: Fulford-Jones, T., Grosse, E., Heafitz, A., Li, R. et al., "The Mars Gravity Biosatellite: Atmospheric Reconditioning Strategies for Extended-Duration Rodent Life Support," SAE Technical Paper 2007-01-3224, 2007, https://doi.org/10.4271/2007-01-3224. Download Citation
Thaddeus R. F. Fulford-Jones, Emily B. Grosse, Andrew M. Heafitz, Richard Li, Jeffrey A. Hoffman
Massachusetts Institute of Technology
International Conference On Environmental Systems