Gateway to Space 2020

 Often the details of dealing with human waste, and turning it into food and clean water are ignored. Most space research to date has either focused on waste recycling in microgravity to extract water, and expel the rest, or focused on the food growth side, in hydroponic gardens and photobioreactors. These disparate ends ignore the details in the middle, i.e. what turns urine, feces, food waste, and other waste types into nutrients for plant growth, clean water, and clean air. What sizes and trades are required for the tanks, pumps, pipes, sceptic systems, incinerators, or bioreactors, to recycle wastes into the inputs for both agriculture and human use. How does this change in low gravity areas like the Moon or Mars? What are timeframes for chemical conversions required, and practical concerns? This paper will cover the masses and chemistry of wastes, existing real world methods, machines and structures, and time required to digest the wastes, and mediation methods to close the mass flow loop to limit resupply, for settlements of various durations and sizes, from small scientific outposts, to village sized long term settlements. Will include sizing of tanks and pumps, energy requirements, biological and non-biological options and tradeoffs, directions for needed research. The messy details matter, and this paper will expose the gap of going from excrement to entrée and provide solutions to get menus from manure in space.