Search Results

Humidity control within confined spaces is of great importance for existing NASA environmental control systems and Exploration applications. The Engineered Multifunction Surfaces (MFS) developed in this STTR Phase II form the foundation for a modular and scalable Distributed Humidity Control System (DHCS) while minimizing power, size and mass requirements. Key innovations of the MFS-based DHCS include passive humidity collection, control, and phase separation without moving parts, durable surface properties without particulate generation and accumulation, and the ability to scale up, or network in a distributed manner, a compact, modular device for Exploration applications including space suits, CEV, Rovers, Small and Transit Habitats and Large Habitats.

A prototype packed bed convective dryer has been studied for use in an energy-efficient closed air-loop heat-pump drying system for astronaut cabin waste. This paper presents a transient continuum model for the heat and mass transfer between the air and wet ersatz trash in the cylindrical drying vessel. The model is based on conservation equations for energy and moisture applied to the air and solid phases and its formulation includes the unique waste characteristic of having both dry and wet solids. It incorporates heat and mass transfer coefficients for the system measured on an ersatz trash in the dryer vessel, and experimentally determined moisture sorption equilibrium relationship for the wet material. The resulting system of differential equations is solved by the finite-volume method as implemented by the commercial software COMSOL. The validated model will be used in the optimization of the entire closed-loop system consisting of dryer, condenser, and heat-recovery modules.

A Plasma Air Decontamination System (PADS) is being developed by ORBITEC for trace contaminant control in spacecraft cabin air, based on non-thermal, atmospheric pressure plasma discharges that generate various highly reactive species that can react with and break down trace air contaminants. It uses a simple and modular design, and may be scaled up or down to meet the requirements of different applications. The prototype PADS reactor has successfully demonstrated removal of ammonia and other selected volatile organic carbons from air, including acetone, ethylbenzene, methane, and methylene chloride. It has the potential to replace the existing high-temperature catalytic oxidizers.

In-situ resource utilization (ISRU) is an important part of current mission architectures for both a return to the Moon and the eventual human exploration of Mars. ORBITEC has developed and demonstrated an innovative direct energy processing approach for carbon-reduction of lunar and Martian regolith that can operate in a nearly closed-loop manner. Carbon-reduction of regolith produces oxygen and a variety of other useful products, including silicon, iron and glass ceramic materials. In addition, various ISRU propulsion technologies that utilize lunar and Martian resources have been developed and demonstrated. Work is also being conducted with the USDA on techniques to use biomass and waste materials to manufacture items such as shelters, furniture, filters and paper. Atmospheric carbon dioxide on Mars would be used to support the production of biomass in excess of life support needs to be used as the raw material to manufacture useful products on-site.

The CANDS (Circulating, Aeration, and Nutrient Delivery System) Phase II SBIR is currently developing and testing methods and procedures to control moisture, oxygen, and temperature in the root zone of a particulate based micro-gravity nutrient delivery system. The completion of the first year and a half of the CANDS Phase II SBIR has shown significant engineering developments towards environmental control of the root zone. These developments include the measurement of root zone oxygen content, characterization of forced and flood-ebb aeration rates, successful control of root zone moisture using miniature heat-pulse moisture sensors, and successful control of root zone temperature via an insulating/temperature controlling water jacket. At the conclusion of the CANDS Phase II SBIR an integrated root zone environmental control system will be constructed for integration into plant growth systems to eliminate the uncertainties that exist in current plant growth data.