Solid wastes generated during long-duration manned missions beyond Low Earth Orbit (LEO) contain valuable resources that must be recovered and reused to reduce the resupply burden or be jettisoned to reduce fuel requirements. It is vital that water be reclaimed from metabolic wastes since the cost of resupply becomes prohibitively expensive for long duration missions. Therefore, practical means of recycling wastes are needed. Feces contains between 65 and 85% water that can be reclaimed. The remaining 15-35% solids is composed of mixed organic compounds that must be dried for bio stabilization. Umpqua Research Company (UMPQUA) proposes an innovative Graded Temperature Fecal Dryer-Densifier (GTFD-D) for the safe and efficient reclamation of water from feces. In particular, we propose to collect the fecal bolus in a flexible cylindrical silicone container. The container is sealed with a magnetic lid. The silicone container is then transported to the GTFD-D where the lid is automatically removed. Pressure on the outside of the silicone cylinder forces the feces through a set of reciprocating perforated plates and then down through heated rectangular channels for drying and densification. The channels are heated in a graded fashion to regulate the removal of water and densification of the feces in the channel. Water is collected on a cooled porous surface. This process prevents the formation of particulates during the production of densified solid feces. The silicone cylinder is then shifted to the cleaning station where water from the condenser is used to clean the surface of the silicone cylinder. The dirty water is directed back to the drying channels. The cylinder is then sterilized before reuse. The GTFD-D will efficiently recover water from feces leaving a densified, bio inactive solid lowering the Equivalent System Mass (ESM) for life support supplies.
The NASA application of the GTFD-D technology will be in support of future long duration manned missions where the reduction of resupply logistics are highly valued. The primary application of this technology will be the recovery of water from feces and improved storage efficiency of the dried feces The GTFD-D technology will be purchased as Flight Hardware by NASA, or by an aerospace contracting firm on behalf of NASA, resulting in enhanced capability in support of manned missions beyond LEO.
GTFD-D commercial applications apply to geological regions where traditional waste treatment is impractical, such as polar regions. where discarded human waste will not decompose and presents a biological hazard. One method of destroying human waste is incineration using flammable liquids. A more efficient process of drying the feces followed by incineration will be more energy efficient.