Waste in Space

Space is extreme, and the problems it presents require extreme solutions. These solutions are often translated into application on Earth.

In the case of waste, space travel confronts the particularly interesting dynamic that a spaceship's ecosystem is so small, so extreme. The ecosystem makes the saying "there is no away" immediately and always apparent.

Luna 24 site on moon, about 5,800 kg

To date, space exploration has either dealt with waste by leaving stuff where it finished up (hence 170 tonnes of artificial objects that have been left on the moon, and an estimated 5,500 tonnes of space debris)

NASA and the Defense Advanced Research Projects Agency (DARPA) are both supporting significant research to do better.

Recycling satellites in space

DARPA is spending $180 million to test technologies that can assemble a space communication system from parts scavenged off defunct satellites.

Recycling satellites in space

The idea is to launch a robotic mechanic outfitted with a toolkit that can rendezvous with defunct satellites (there are 140 to choose from) and mine them for parts. The plan also calls for the separate launch of minisatellites. The robotic mechanic would then string together the minisatellites and old satellite parts to create a new communication system.

The thinking is that it is immensely expensive to launch a satellite into space. Once you've invested that money, why would you leave it there to rot after a brief window of operation?

Waste as space shielding

Researchers at NASA's Kennedy Space Center in Florida are evaluating small tiles made of rubbish generated on spacecraft to find out whether they can be stored aboard spacecraft safely or even used for radiation shielding during a deep space mission.

The circular tiles were produced by a compactor that melts the waste but doesn't incinerate it. The compacted tile is about 20 cm in diameter and about 1 cm thick. Research is ongoing to understand if the melting process sterilises bacteria.

Waste as space shielding

The bigger picture is the thinking required to make a resource of garbage in space. Given NASA does not want to jettison waste in space, potentially contaminating planets or a moon, a very tight focus on the saying "there is no away" is required.

Garbage a power source for deep space

NASA researchers focusing on the difficulties of traveling into deep space have also identified that waste might be an alternative source of fuel.

The idea is to use a gasifier that converts waste into methane gas. During the course of a year in space – one half the length of time a mission to Mars is expected to take – garbage processing for a crew of four would create about one tonne of methane fuel. That is apparently enough to power a launch from the lunar surface.

Space waste gasifier to generate fuel

Gasification is not a new technology. However research done for space missions will have a powerful effect in developing the technology for civilian use. In particular, research to shrink and lighten the reactor will be very useful on Earth.

What does it mean?

Well, other than the opportunity for a wry response to "waste ain't rocket science", research done for space typically spins off into civilian applications. These research might never have happened otherwise.

The thinking enforced in these space applications requires close attention to closing loops. That shift is immense. It could be a game changer. It could, truly, create a world without waste.