While the ever-growing mountain of trash presents increasing challenges to us on earth, there’s a similar problem playing out in space, where NASA is having to come up with innovative ways to handle trash for deep space missions.

Life aboard the International Space Station requires extreme measures in efficiency to preserve resources, reduce waste, repurpose materials, and recycle water and breathable air.

Regular cargo resupply missions deliver approximately 12 metric tons of supplies each year, which can lead to significant storage challenges aboard the orbiting laboratory.

When trash accumulates, astronauts manually squeeze it into trash bags, temporarily storing almost two metric tons of it for relatively short durations, and then send it away in a departing commercial supply vehicle, which either returns it to Earth or incinerates it during re-entry through the atmosphere.

Future spacecraft, much farther from Earth, likely will not have the regular cadence of visiting commercial ships that can remove trash, so NASA is turning to US industry to advance concepts for trash compaction and processing systems.

The agency has issued a call for prototypes, and eventually, flight demonstrations to fly on the space station.

Storing trash inside a spacecraft not only consumes precious volume, but also can create physical and biological hazards for the crew. Storage also removes the option to extract valuable leftover resources that could be recycled or repurposed.

The solicitation seeks solutions that compact trash, remove biological and physical safety concerns, and recover trapped resources for potential reuse or repurposing.

Proposing companies won’t have to start from ground zero, however. NASA has been developing waste management systems since the 1980s, including recent developments such as the Heat Melt Compactor and “trash to gas” technologies.

The development will occur in two phases. In Phase A, selected companies will create a concept trash compaction and processing system, conduct design reviews with NASA, and validate concepts through prototype ground demonstrations. Throughout this phase, the companies may request use of NASA facilities to conduct subsystem tests. In Phase B, a flight unit will be developed to demonstrate a system aboard the space station as early as 2022.