The pause that refreshes: Pondering space travel and drinking water


by Jeff Fecke • 11/15/08 • I’ve been a space geek since I was roughly four, and while we don’t have the moon bases, space habitats, and manned Mars missions I was promised back in 1978, we’ve finally started making some nice incremental improvements in space technology of late, primarily related to the impending retirement of the space shuttle fleet, which were far more expensive and far less useful than originally advertised, and tragically much less reliable. The Ares/Orion pairing should be, if nothing else, far safer than the shuttle fleet, and while Orion capsules are only expected to be reusable up to ten times, they should be less expensive to maintain than the shuttles, which are incredibly fragile.

The shuttles’ retirement does eliminate one key resupply element for the International Space Station. While people and supplies will continue to be supplied by Soyuz capsules after 2010, and until Orion debuts, water is used much more frequently by humans, and is expensive and heavy to launch. Previously, water came from the shuttles’ fuel cell electrical systems, which creates water as a byproduct of electricity generation. The water was saved up and delivered to the ISS. With crew for the ISS scheduled to increase to six, and only twenty shuttle missions left, there’s obviously a need to wring every drop of usefulness out of water on the station. And that’s where the current mission of Space Shuttle Endeavour comes in. Because Endeavour is carrying new sleeping compartments for the ISS, as well as a new water recycling system that will recycle up to 92 percent of water in the air and wastewater into potable drinking water.

If you do the math, you realize quickly that wastewater includes, well, waste water:

NASA plans to double the size of the space station crew from three members to six next year. The shuttle carries two new sleeping compartments and a water recycling system that will enable the crew to purify urine and other wastewater for drinking.



And it probably does. It doesn’t usually pay to think too deeply about the many processes that water goes through on its way through the cycle, but there’s about a 100 percent chance at least part of that glass of water you’re drinking was at some point part of some creature’s waste, if not a human’s. And, you know, so what? It’s gone through a long natural process of filtering through ground and into an aquifer and out into a river, or lake, or well, or what have you; it’s not part of waste any more.

Similarly, most of urine is simply water — remove the waste and what’s left is all water. And aside from the psychological hurdle of realizing that the water you’re drinking was inside someone recently, it’s just H2O.

What’s important about this, other than extending the life and efficiency of the ISS, is that its development is key to any sort of long-term manned missions. While I tend to be pessimistic about a human mission to Mars any time in my lifetime (for a variety of reasons, it’s very, very difficult), a human base on the Moon will probably be established in the next thirty years. Astronauts are going to be expected to live there for months, even years. And while there is ice on the Moon and Mars alike, the less time our astronauts have to spend gathering ice, the more they can spend doing productive things, like golfing. Doing this work now allows us to have one less thing to invent in 2023. And that’s a good thing for those, like me, who believe humankind’s future includes travel beyond this island Earth.