Mars One plans to provide 50 square meters of space for the first four to grow food in. Will it be enough? If we use an efficient hydroponics system, it can be. If you’re a serious lover of fresh oregano, thyme and mint, you can grow all the seasonings you’ll ever need in an area the size of a typical closet and have enough left over to give to friends. If you have spare space in your closet, you can grow a pretty good batch of mushrooms with the side benefit of the aromatic smell of the coffee used as a growing medium in your bedroom. Fifty square meters is about the size of a respectable garden plot. If you can grow enough tomatoes, peppers and basil to make as much spaghetti sauce as you think you’ll ever need in that space, a well-designed hydroponics system in the same space should be able to feed four settlers.
Not that it’s going to be easy. With the sun being less powerful on Mars than it is on Earth, the growing system will rely on a specialized kind of lighting that emits only the wavelengths that are actually used for photosynthesis. The system will require near-constant monitoring to ensure that the plants are getting the right blend of nutrients at the right levels and aren’t being affected by diseases. Occasionally the system could have a meltdown and tracking down the pinpoint leak that causes solution levels to plummet may well be like finding that one light bulb that causes your entire string of Christmas lights to malfunction.
Hydroponics In Space
NASA has done some research on hydroponics systems for space, including work currently being done at the University of Arizona’s Controlled Environment Agriculture Center with greenhouses in such exotic places as the geophysical south pole. It also operates a Prototype Lunar Greenhouse under a grant from NASA to study the requirements for providing a sustained vegetarian diet for astronauts in a closed environment.
Hydroponies in the Antarctic
A look inside the greenhouse at McMurdo Station
Another graduate student at Iowa State University performed a study on the best varieties (“cultivars”) of basil would do best in a hydroponics system. This is interesting because we want not just species that can do well in a cramped environment, but also varieties that can thrive in a hydroponics-based environment. Studies like these can help us choose the crops that are both nutritious enough to sustain the crew and thrive in a hydroponics system.
NASA Technology In Aeroponics
So, what type of hydroponics will we have on Mars? Some of the common types we have right here on Earth include:
- Aeroponics: A super-high-tech version of hydroponics with air as the primary growing medium. Essentially, the roots are suspended in midair and a timer activates a system that mists the roots with nutrients every few minutes. NASA studies have shown that plants grown using aeroponics and the disease-controlling agents in Organically Derived Colloidals can actually do pretty well in a microgravity environment. On Mars, aeroponics can be a highly efficient way to produce food in a limited space with fewer worries about plants being affected by soil-borne diseases. Drawbacks include the level of maintenance required to keep the timer, sprinklers and pumps functional and the root chambers cleaned along with the expense of the system.
- Drip Systems: This version of hydroponics systems again involves a timer to regularly add a nutrient solution to the base of each plant. It is very popular for widescale commercial applications. The Recovery Drip System may work better than the Non-Recovery Drip System for the sake of resource efficiency because the Recovery Drip System recycles unused nutrient solution and doesn’t require as precise of a timer. The Recovery Drip System does require monitoring for pH and nutrient levels.
- Ebb and Flow Systems regularly flood the root chambers with a nutrient solution and then drain the leftover solution back into a reservoir. This has the benefit of reducing wastage in the nutrient solution. Weaknesses include potential failures in the pump mechanism and timer. This version is customizable with the addition of grow rocks and gravel to the root chambers.
- Nutrient Film Technique (NFT) Systems make use of a steady flow of nutrients that is pumped into the chamber and drained back into the reservoir, eliminating the need for a timer. This is a fairly common system and usually makes use of plastic buckets with the roots dangling into the growing medium. The major disadvantages are mostly attributed to a poor design that causes flooding or waterlogging of roots, insufficient water levels, and breakdowns of equipment or the power supply.
- Water Culture Growing Systems are a very simple hydroponics system that uses Styrofoam platforms to hold the plants above the nutrient solution. The main advantage is its simplicity and ease of maintenance, with its main drawback being the limited number of plants that can be grown using this system. It is mostly used for growing lettuce.
- Wick Growing Systems are popular among beginning hydroponics hobbyists for their simplicity. It has no moving parts and the nutrient solution is drawn up into the grow tray using a wick. Wick systems can’t support plants that need a lot of water, such as tomatoes.
I favor using the aeroponics system despite the high maintenance cost, for the simple reason that you can get a lot of food in a limited space. Remember, we only have fifty square meters in which to grow food. That’s not even the size of a respectable apartment and there are going to be four hungry mouths to feed. So the hydroponics system will have to be a dependable model that makes the most efficient use of available resources.