Spaceships recycle everything… except astronaut’s poop

Originally posted here: https://mcgill.ca/oss/article/did-you-know-technology/spaceships-recycle-everything-except-astronauts-poop

Astronauts inhale oxygen and exhale carbon dioxide, just like you and me. On Earth, where exhaled air warmed by our bodies naturally rises away from us, the possibility of inhaling too much carbon dioxide isn’t usually a worry. But for astronauts, it’s a major one. Without the ventilator fans installed in shuttles and stations, carbon dioxide would accumulate around an astronaut. This is especially a concern at night,since we tend to stay still while sleeping. This would allow CO2 to collect and starve astronauts of oxygen.

So what happens to the carbon dioxide once it’s suckedaway by the fans? Like almost everything on a spacecraft, it’s recycled.

Carbon dioxide removed from the air by the aptly named ‘carbon dioxide removal system’ is combined with hydrogen (a byproduct of the oxygen generator system) to produce methane (which is vented into space) and water, which re-enters the oxygen generating system. This cycle allows astronauts to keep breathing, drinking and flying for long periods of time without having to lug to space all the oxygen they will need for the trip.

So what isn’t recycled onthe International Space Station? Human feces. But Mark Watney seems to have inspired a potential use for that

Potatoes and Space Have a Long History

Originally posted here: https://mcgill.ca/oss/article/potatoesin-space

Intergalactic potatoes may seem like a side dish from the Mos Eisley Cantina, but potatoes and space have a common history.
 
In 1978, George Lucas began work on The Empire Strikes Back, but wanting to remain independent from Hollywood, he financed it all himself. This led to some interesting low-budget work-arounds. Most notably, the asteroid field of Hoth, whose asteroids were actually partially made of shoes and potatoes. Really!

Then again, in 2015’s The Martian, potatoes make an appearance on the space-themed silver screen with Matt Damon’s portrayal of Mark Watney, an astronaut/botanist, who grows potatoes while stranded on Mars. Although Watney might be a fictional character, thanks to scientists, he now has a spot in history. A newly-discovered flower, which belongs to the same botanical family as the potato, has been named after him – the “solanum watney”. 

Potatoes have even reached NASA’s radar. Growing food crops in space has been one of the space agency’s interests for years. Potatoes and sweet potatoes are serious contenders for space agriculture due to their high carbohydrate content and their tuberous nature that gives them low light requirements. As well, the eyes of potatoes produce sprouts that can be used to grow more plants, thereby making them a simple, reliable food source. For now astronauts have to rely on the freeze dried versions as, so far, only lettuce has actually been grown in space, but if NASA’s potato experiments here on Earth are successful, we could soon see spuds that are out of this world.