A Real-Life Space Botanist Comments On the Potato Garden In 'The Martian' (cnet.com)

MarkWhittington writes: In the hit movie, The Martian, stranded astronaut Mark Watney famously survives on Mars by creating a potato garden using Martian soil mixed in with composted human excrement. According to a story in CNET, NASA believes that the movie is on the right track as far as astronauts growing their own food on long-duration space missions. However, some caveats exists concerning how the film depicted space agriculture.

Comments

We've grown plants in regolith simulant.

[tlambert]

We've grown plants in regolith simulant.

So it's not like we don't already know that the answer is "yes".

http://journals.plos.org/ploso...

Re:Martian soil is like toxic....

[Rei]

It's like you didn't even listen to the parent.

Martian regolith contains perchlorates. It's toxic. We're not talking about nutrient levels. It's up to 2% by mass perchlorate ion. Perchlorates are rocket fuel. Literally, they've actually considered harvesting them to make propellant on Mars. They're also quite toxic, impeding thyroid function at a couple dozen parts per million quantity in water. They're toxic to plants too.

You can't just, like in the book, take some martian regolith, take some manure, sprinkle on some dirt for bacteria (which was BTW a pointless step given the crop choice and the bacteria already present in the manure), mix it all together and call it a growth medium. First you have to bake the regolith to break down the perchlorates. Then you have to rinse it to remove the extra salts. Then if you have a reverse osmosis system you could add the water back in. There's still no guarantees then that it'd be fertile/have all of the needed nutrients in approximately the right ratios, but at least it's not guaranteed to be a health hazard to both you and your plants.

Re:Martian soil is like toxic....

[frank249]

Perchlorates may lead to health problems but likely not deadly. According to some groups, perchlorate affects only the thyroid gland. Because it is neither stored nor metabolized, any effects of perchlorate on the thyroid gland are fully reversible. Some other studies suggest that perchlorate may have pulmonary toxic effects as well. In this article it is mentioned that exposure could be managed. As for using the soil for agriculture, there are several technologies can remove perchlorate, via treatments ex situ and in situ. Ex situ treatments include ion exchange using perchlorate-selective or nitrite-specific resins, bioremediation using packed-bed or fluidized-bed bioreactors, and membrane technologies via electrodialysis and reverse osmosis. In ex situ treatment via ion exchange, contaminants are attracted and adhere to the ion exchange resin because such resins and ions of contaminants have opposite charge. It may be beneficial to process it. Researchers have proposed a biochemical approach for the removal of perchlorate from Martian soil that would not only be energetically cheap and environmentally friendly, but could also be used to obtain oxygen both for human consumption and to fuel surface operations. In any event, precautions will have to be taken but the presence of perchlorates in the soil does not appear to be 'show stopper' at this point.