Op-Ed: Growing marigolds on the Moon- the economics of space colonies

The return to the Moon has a few problems to solve before lunar colonies are viable. One of them is the fact that payloads take up space on spacecraft. Food and water are bulky items, so it makes sense that some sort of self support is viable.

Scientists with the European Space Agency have been working with plants and lunar-like soil, trying to find ways of growing plants without fertilizer. In effect, the idea is a natural growth system. That’s not easy. Early efforts didn’t do too well. The plants did, however, do a lot better when bacteria were introduced into their growth medium, releasing nutrients from the soil. The Moon isn’t the only hostile environment the scientists have to deal with. The idea hasn’t done too well with ESA management, either, one of whom is quoted as saying the idea was “science fiction”. Nice to know ESA management has been paying attention to the last few decades of space research. It has been done before, and it is viable. Fortunately, the scientists haven’t been put off, and are piecing together a sort of DIY life support system. The BBC:

Bernard Foing, a senior scientist with the European Space Research and Technology Centre (Estec) in the Netherlands, believes growing plants on the Moon would be a useful as a tool to learn how life adapts to lunar conditions, and as a practical aid to establishing manned bases.

“We would bring a system of water circulation and recovery, which is also the type of system that in any case you want to develop when you are going to manufacture a primitive sort of life support system,” he told BBC News.

“So it is also a kind of ‘technological breadboard' for maintaining a simple life form in an extreme environment.”

This isn’t just “breadboard”, it’s bread and butter. Hauling materials from Earth will be prohibitively expensive, and a logistics comedy, until much better payload/thrust ratios are achieved. A tomato, sent to the Moon, could cost hundreds of dollars in real cost. Tomato seeds and bacteria, with efficient water usage, however, could produce a tomato that doesn’t cost a fortune. The scientists have got it right, economically. Anything which can be done locally on a space station or lunar base is going to be a lot more cost effective, and save space on supply runs. In terms of food, it could save a lot of space, and a lot of heartburn for the poor souls figuring out the supply schedule. ESA might like to take the time to teach their management to use calculators, and show them some research from the 1970s, or maybe even after then, so they have some idea what they’re talking about.

In principle, putting self-contained pieces of kit with seeds and nutrients on the Moon and giving them a supply of water and an artificial atmosphere would be little different from growing them on space stations, which has been done several times; although outside Earth's protective magnetic field they would be subject to higher levels of radiation.

This is sort of correct. Basic hydroponics would do, because hydro uses far less water, and almost anything can be used as a growth medium. Using bacteria improves the biological efficiency of the growth cycle, because the soil bacteria create nutrients for the plants by their biological actions. (The BBC article apparently considers that to be new information. The Agricultural Revolution happened about 10,000 years ago. Somebody really should tell the Beeb about it, so they don’t feel left out.) As for radiation, the plants can’t take unshielded radiation anyway, and obviously won’t be grown outdoors. Filters reflecting harmful wavelengths would do, and it’s not difficult technology, once you know what you’re supposed to be shielding against. Humans eat a lot of food, relative to their own weight, and use a lot of water. Space colonies of any sort can’t be totally dependent on supplies from Earth for staples. It wouldn’t work. It would also seriously distort the supply chain, using up capacity which could be devoted to more useful things than interplanetary spuds.