Mars mission
The current episode of the ETH Podcast is about a researcher who wants to develop an ecosystem for astronauts on a space station or inhabitants of a Mars base.

ETH researcher Grace Crain thinks on a galactic scale. She is hoping to develop an ecosystem that could provide food, drinking water and clean air to astronauts on a space station or to the inhabitants of a Moon or Mars base. In this ETH podcast, she explains why she chooses to use human urine and faeces to fertilise her plants.
Comments
What a fascinating endeavor! I do wonder about the possibility of Earth-based applications of Grace's work. It seems that, with some tweaks and scaling up, these techniques could especially aid water-starved and food-deprived areas here on Earth. (And Grace, the student is now the teacher!)