Testing some of the challenges of transplanting plants to a new planet
The first human Martians will hopefully like their veggies. A lot of food for the first missions to Mars will likely be sealed, sterilized packets, similar to what’s eaten on the International Space Station today. While that does allow for a bit of improvisation, adding variety to astronauts’ diets is a concern, because people tend to eat better when they have options, rather than just eating the minimum calories to stay functional. One of the most attractive ways to add some fresh flavors to a person’s diet is to literally add some fresh food, grown by the astronauts themselves. Fresh produce has already been grown in space, but that doesn’t mean the first explorers on Mars will have an easy time setting up a salad bar.
Producing off-world produce
As any fledgling gardener has discovered, growing a garden of vegetables isn’t easy. Aside from pH and nutrient concerns particular to each breed of plant, astronauts on Mars will also have to deal with problems Earth-bound farmers have been able to take for granted, like gravity. As a smaller planet, Mars has less gravity than Earth, which is expected to affect how well water is saturated into the soil as well as how easily the plants can exchange carbon dioxide and oxygen with the air around them. They’ll likely retain more water in the end, growing slower than on their native planet. Beyond that lighting and the thin atmosphere in general mean that most plants will be grown in controlled greenhouses to try to make them feel as “at home” as possible.
Dangerous dirt
Hauling food and seeds to Mars will obviously be important, but loading rockets with large payloads of dirt probably isn’t going to happen. Once any starter soil is exhausted, the plants will have to use local nutrients and minerals in their growth, which raised concerns over how useful they’d ever be to astronauts. Martian soil has high amounts of heavy metals like cadmium, copper and lead, which might have made even the most beautiful tomatoes unsafe to eat if too much was absorbed into the produce. To test this, NASA used data from the many soil samples made on Mars to mix up some simulated soil here on Earth, then grew a batch of crops to see how much metal was soaked up.
Fortunately for our future salad-eating astronauts, these initial experiments suggest that the first Martian radishes will be safe to eat. Peas, rye, tomatoes and more were all successfully grown in the faux-Martian dirt, and the plants harvested don’t seem to be absorbing toxic levels of any of the metals. Since a central goal here is dietary variety, more crops are slated to be tested in the coming year. Yes, including potatoes.
In the mean time, knowing that astronauts will be looking forward to their Martian tomatoes will hopefully be motivating when my kids are reluctant to eat their veggies.
Source: Dutch crops grown on 'Mars' soil found safe to eat, Phys.org
