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Living in Space Will Mean Recycling Everything

From air and water to clothes and wet wipes.
Italian astronaut Samantha Cristoferetti checking on atmosphere monitoring equipment on the ISS. Image: ESA

NASA is trying to get us to increasingly distant areas of space with increasingly intriguing technologies (like flinging spacecraft around using space tethers). But once we're there—or even while we're on the way—we need to be able to live.

That means the basics of survival, like radiation safety, breathable air, and drinkable water. It also means more mundane everyday living solutions, like clothing and washing. The space agency needs to build rockets capable of getting humans to Mars, but it also needs to figure out a sufficient supply of wet wipes for everyone.

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Based on NASA's 2015 draft technology roadmaps, published this week, downtime on a future far-flung mission might look something like this:

You take a shower in an enclosed system for "full-body cleansing" with all of the water collected for re-use, and pull on your lightweight, antimicrobial clothes that you've probably been wearing for most of the mission after "freshening" them with the closest thing to laundry you've got.

You breathe some air you've previously breathed, and drink some water you've previously urinated.

You grab some super-compact and innovatively-packaged space food and fresh veggies from your space garden, and eat them after cleaning them to make sure they're safe (no side-order of unknown space microbes for you).

Even with a full-on Mars habitat, reusability of everything is key. Image: NASA

You retire to the crew quarters, which are constructed out of repurposed storage bags like some kind of high-tech den; the material provides some radiation protection thanks to compacted trash, and helps keep out the noise. Maybe you give it a bit of a wipe-down with a wet wipe, but don't think about throwing it away; like almost everything else in your new home, that wipe is reusable.

A recurring feature of life aboard NASA's future is re-use and recycling. With a trip to Mars taking about eight months with current tech, a crew would need to be able to live off only whatever they take with them, and also reduce any build-up of waste, both human and otherwise.

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In the most basic sense, this means stuff like air and water.

"As mission durations increase to months and years, the mass of consumables grows until, depending on specific mission parameters, it becomes more advantageous from a life-cycle cost perspective to recover water and oxygen from metabolic byproducts for subsequent re-utilization by the crew," explains NASA's draft dedicated to life support and habitation systems.

All that pee has to go somewhere. Image: NASA

This happens already on the International Space Station to some extent: Water is recycled, and oxygen is processed from carbon dioxide. But NASA writes that "less than 90 percent of the available water and less than half of the potential oxygen that could be is actually recovered." Additionally, the ISS depends on items such as air filters that need to be replaced regularly with resupply missions.

So our future space habitat needs even more efficient recycling systems; there's less-to-no opportunity to stock up when things run low.

On the ISS, air is recycled using the Sabatier method, which reacts carbon dioxide breathed out by astronauts with hydrogen to create water. Some of this then goes through electrolysis to produce more oxygen (and hydrogen). With this method, NASA can currently recover about 50 percent of oxygen; it wants to improve this first to 75 percent, and then 90. To do this, they need to step up everything from the materials used to collect carbon dioxide in the first place, to filters that can capture any stray planetary dust particles.

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As for water, the ISS already recycles astronauts' urine using chemicals and distillation, but the problem is that you can't recycle 100 percent of it without getting solid precipitants that a liquid processing system may not be able to deal with. The space agency also wants to develop biocides—which would kill microbes in stored water—that are safe for humans to drink so they don't have to be filtered out.

Hey, maybe one day we'll have more expansive settlements where you can throw away a wet wipe after just one use. Image: Wikimedia

Less life-dependent but also important are things like making objects reusable so they're never just taking up precious space without a purpose. One example is stowage bags used to hold cargo during launch: NASA envisages a "reconfigurable logistics stowage bag that unfolds into a flat sheet used for outfitting crew structures." Nothing says wasted space more than an empty container.

Another is wet wipes for cleaning purposes. The state-of-the-art for now is the single-use disinfectant and baby wipes we use on Earth, but NASA wants to develop an alternative that can be re-used more than half the time for housekeeping.

Similarly, there's no room for laundry in a space capsule. Astronauts at the ISS live in a throwaway culture when it comes to clothes, discarding them after a couple days' wear. A study from earlier this month reports that astronauts' clothes add 900 pounds of freight to the ISS.

NASA plans to design clothes that are suitable for "extended" use, "that remain hygienically safe and acceptable for use and that do not release fibers and lint into the cabin environment during use."

You might not have thought of lint as a great space hazard, but the recent clothing study explains that lint can clog air filters (another thing that's harder to replace if you don't have an easily accessible supply for restocking) and increase the need for cleaning (which means more cleaning products, more trash, and the cycle continues). So lint-free fabrics make NASA's list.

That soft touch of fresh cotton may become an exclusively earthly sensation.