A fish tank brimming with urine is the first thing you see when you enter Jens Hauslage’s cramped office at the German space agency, DLR, near Cologne. It sits on a shelf by his desk, surrounded by the usual academic clutter of books, charts and scientific papers.
Rising from the centre of the tank are two transparent plastic cylindrical columns – around a metre in height. Spreading from the top of each tube is a bushy, healthy-looking tomato plant with green leaves, flowers and even a few bright red tomatoes.
“Are they edible?” I ask, half expecting to be told to stay well clear.
“Sure,” says Hauslage, a plant physiologist, casually twisting one of the tomatoes from its stem and handing over the euro-sized fruit.
I put it in my mouth. To be brutally honest, it’s not the nicest tomato I have ever tried: the skin is a little tough and the taste is slightly bitter. But it is, nevertheless, a healthy, edible tomato.
Despite Jeffersonian’s observation that gowing potatoes on Mars, in addition to feeding the Space Pigs, will result in Martian Tater-Tots wrapped in bacon, we humans require other nutrients. I’ve grown lettuce, and it’s not at all hard, so Martian BLTs are now possible.
Besides, the only two things I know how to do with urine are to either pour it down the drain/toilet or to set it out in shallow pans to evaporate the water so you can use the remainder to make black powder. And I don’t think that there will be much call for 18th Century musketry on the Red Planet.