Water is critical for astronauts up in space, but as it weighs so much, getting it up there is pretty costly.
A European Space Agency blog post explains that the filtering equipment currently used up on the International Space Station to make fresh water from sweat and urine is quite large and clunky (weighing up to 150 kg), and regularly needs replacing as it gets bunged up with unwanted molecules. But a Danish company says it has a sleeker bio-inspired solution: by filtering waste water so it's drinkable, the company wants to provide both astronauts and people in the developing world with easier access to clean water
Aquaporin Space Alliance, a collaboration between a Danish cleantech firm and aerospace company, has come up with a biomimetic "aquamembrane" kit that makes use of nanotechnology and proteins to produce fresh water. Aquaporin are proteins that control water supply in all living organisms. The Danish company's dinky "AquaMembrane" kit is made of aquaporin proteins on a hollow-fibre membrane.
What's cool about these membranes is that they let through water molecules, but an electrostatic charge makes sure that any unwanted ions, including salt, stay behind. This results in a process called forward-osmosis, where water continuously flows from one side of the membrane to the other.
Danish European Space Agency astronaut Andreas Morgensen will be testing three sets of the Aquamembrane kits for the first time when he jets up to the ISS in the Soyuz spacecraft in September. Morgensen will be charged with filtering three samples of dirty waste water of about 300 ml each. According to ESA's blogpost, he should end up with three Aquaporin-purified samples of 50 ml each, which will be analysed back on Earth later on in the year.
Astronauts, space engineers, and mission planners who have to deal with the tricky logistics of providing a fresh water supply in space hope this new tech could provide a smaller, lighter, and quieter water purification method. Back on Earth, the makers of the AquaMembrane also want to start mass producing them at the end of this year so that more people can have easier access to clean drinking water.