Duration: 12 months
Four astronauts can generate 2,500 kilograms of waste during a yearlong mission. Storing waste presents a safety risk to the crew, including biological and physical hazards. For future exploration resupplying from Earth is not an option, but recycling and 3D printing re-configurable and reusable systems would reduce costs and resource stockpiling. Habitation systems are required for crewed missions to the Lunar surface or Mars, and without material loop closure and sustainability, discarding waste and polluting the environment become inevitable with large volumes of unwanted material producing bacterial growth and odours. If you take into account only the crew waste, the main contributors are food packaging and clothes. From the ISS, other items of waste that are in large quantities include foams and crew transfer bags. One of the options for sterilization, decontamination and re-use would be to use a simple, waterless cleaning system for plastics, based on the use of Super Critical CO2. The COtooCLEAN process would use CO2 from any source within an operational environment and be able to remove contaminants in a concentrated state and allow the CO2 to be reused for further cleaning stages. Clothing and packaging could be cleaned and sterilized in a single step ready for safe re-use. Plastics packaging and even suits that were damaged could be melted and stored as granules until required to build new components with 3-D printers. This would eliminate using precious storage space for waste and create the capacity to engineer new components on site. The complexity of the packaging can be resolved via the unique PolyPRISM marking system that can irreversibly tag each item with the composition of the package to separate these into unique fractions providing a range of mechanical properties (stiffness/toughness/melting point) for new products being made on the Moon base, such as densification of foams into 3D printing pellets.
