Why do astronauts burn their used underwear?

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An existential question for you! Have you ever asked yourself what astronauts do with their dirty underwear? Recently, the man who “dresses” astronauts for the International Space Station was interviewed. 

We already known that astronauts can scratch their noses in their space suits with the help of a piece of velcro attached to the inside of their helmets. However, the question of dirty underwear is less frequently broached. Robert Trevino, an engineer working for the “equipment and thermal systems” division of NASA was interviewed by Motherboard on the 6th March 2017.

With his team, astronautical clothing expert needs to consider the astronauts’ comfort, taking into account the weight and durability of the clothes. It appears that the question of laundry isn’t as simple as we may think, and it is a factor that is taken into very serious consideration for future long term space missions.

The shorts and t-shirts worn by ISS astronauts, provided by the company Lockheed Martin, are nothing special, apart from the fact that they are comfortable. Flammability is not the only factor taken into account, as these clothes need to stand up to an astronaut’s various activities, including maintenance operations and experimental work. For exercise (one hour a day), breathable clothing is also available.

The fact that there is no laundry system on the International Space Station means that the astronauts wear their clothes until the clothes start to smell bad, at which point they throw them in the bin. The classic outfits worn on the ISS can last between 3 and 6 months, while the sports clothes can only be worn for a maximum of two weeks.

According to Robert Trevion, while the Russian transport vehicle Progress is loading its cargo on the ISS, it is loaded with waste from the station that it burns in the atmosphere.

During long term missions, it won’t be possible to bring enough new clothes to throw the existing ones out when they start to smell bad. This is why engineers are trying to come up with a laundry system, while evaluating the necessary cost of installing such a system, using water and electricity. For the moment, it is less onerous to replace the clothes, because water is too precious a resource.

Water is always a real problem, and the ideal would be to find ice Mars (the first planet flagged for long term missions) in order to secure access to large quantities of water. Robert Trevino indicated that it is necessary to develop clothing that is “much more antibacterial”. He also queries the possibility of “alternative laundry systems that don’t depend on water”, for example using ultraviolet light or micro-waves -technologies that are currently being tested.

Although the clothes will never be as clean as they were before, the engineer believes that they could double their life expectancy, which would make it possible to carry only half the amount of clothes. This research is part of a more general project aiming to reduce the logistical problems involved in long term space missions: Logistics Reduction for Advanced Exploration Missions.

While they await an efficient and economical device for doing space laundry, astronauts haven’t yet seen the end of burning their boxer shorts!

Sources: MotherboardLibérationPopSci