Repurposing Space Station Trash for Power and Water
If trash disposal and recycling on Earth are challenging, imagine what it’s like managing waste on the International Space Station. So NASA is looking at ways to reduce and repurpose trash generated on the space station, as well as on crewed spacecraft for future missions beyond low earth orbit.
NASA’s Glenn Research Center is one of six centers involved in the Advanced Exploration Systems Logistics Reduction and Repurposing project (LRR) designed to identify the most effective systems for recycling waste now and for future deep space missions. Repurposing trash reduces mission costs, launch mass and the amount of trash for disposal.
“Currently, astronauts on the space station sort wet and dry trash that’s stored until other space vehicles bring supplies. The supplies are unloaded, and the waste is wrapped into dozens of small packages, each in the shape of a little football in transparent plastic with duct tape. It’s then loaded into the vehicle and burned up during reentry,” explains Dr. John Lytle of Glenn’s Space Technology Project Office.
Glenn is supporting two components of the LLR project: conversion of trash to usable products using a heat melt compactor (HMC) and conversion of trash to methane gas to make rocket propellant. Determining the best use of different categories of waste and recycling water are important components of the LRR project to reduce volume and mass. For example, the carbon, hydrogen and water in organic waste could be used to make more methane for propulsion or more water for life support.
The HMC recovers water from compacted waste materials to produce dry, sterilized, plastic encapsulated tiles that may be used for radiation protection, building materials, storage or disposal. “We’re working with NASA Ames on the compactor to make sure it works in a low gravity environment,” says Lytle. “Glenn conducted low gravity parabolic aircraft experiments last year and the unit will eventually be tested on the space station.”
Glenn is also responsible for testing two waste conversion technologies that could turn trash into methane gas for propellant in space. One is a steam reformer developed by Pioneer Aeronautics using technology developed at NASA Glenn. It uses both steam and oxygen to create a chemical reaction with the trash that produces hydrogen, carbon dioxide, water and methane.
The other technology is a catalytic wet air oxidation unit that requires minimal heat for activation. This process uses a catalyst to decompose polymers producing mostly carbon dioxide and hydrogen and offers additional chemical conversion benefits.
The technologies developed for LRR will be critical not only for identifying future logistics systems to support multiple exploration missions, but also for innovative waste management and energy alternatives here on Earth.