Greenhouses and Life Support (Earth as a Classroom

NASA artist's concept from the mid-1980s of a Mars base equipped with greenhouses

So far, humans have only visited another world (the Moon) a half a dozen times. The longest visit to the lunar surface was three days. On short trips like these, you can afford to bring all the supplies you need - air, food, water, etc. and leave things behind when you are done with them. And of course, the trip home only takes several days.

However, when humans begin to return to the Moon and build a base there and then visit other worlds such as Mars for even longer periods, they will have to be a little smarter and re-use much of what they have brought with them. Trips to Mars will be many months long, and people will be living on the Martian surface for as long - if not longer.

Life support systems are designed to provide humans with a comfortable and safe environment within which to live and work in space. While it is not a cozy as living on Earth, when done properly, it can be very comfortable. Since long duration space missions will need to cut back on weight (supplies) astronauts will need to recycle things and use them again and again.

Image: Cosmonaut Valery G. Korzun, Expedition Five mission commander, checks a plant growth experiment in the Zvezda Service Module on the International Space Station (ISS).

Right now, recycling of air, water, and waste is being done aboard the International Space Station. But no one grows any food there - yet. Some plant growth experiments have been conducted on the International Space Station and before that, aboard Russia's Mir space station. But in order for astronauts to be able to live for longer periods on Mars, many engineers and scientists believe that they will need to grow some of their food.

Of course, as is the case on Earth, plants also contribute to the recycling of air, water, and waste. So, the best possible plan for living on Mars will probably include a greenhouse, which grows some food and helps to recycle the air and water astronauts need to survive.

There is one final benefit to having a greenhouse as part of your base on the Moon or Mars: to remind you of home. It may seem silly when you can go outside and roll in the green grass under a blue sky. But imagine what it would be like when you can't do that for a long, long time.

Image: Greenhouse technician Rob Taylor relaxes in a hammock at the McMurdo greenhouse, Antarctic Sun/NSF

Living in the Antarctica is like living on a Mars base in many ways. One of the most popular places to hang out are the small greenhouses that have been established. Many people take lunch breaks to go in these small green places, lie in a hammock, and listen to their iPod. They emerge refreshed and ready to continue with the day's work.

The Haughton-Mars Project seeks to use the isolated and harsh environment on Devon Island as a "planetary analog" - a place on Earth that is similar in some (but not all) ways to the conditions we will find elsewhere in our solar system. Once important condition is isolation and harsh physical conditions - and Devon Island has both factors - in great supply!

Image: Arthur Clarke Mars Greenhouse - north side - showing propane tanks used for heating system.

If a greenhouse can be designed to work - without human interaction - for long periods of time - it should be able to provide important lessons to the engineers who will design such systems for actual use on the moon and Mars. Many mission plans call for things such as habitats, rovers, greenhouses, to be left on Mars for long periods between visits by humans. Those things need to be able to operate on their own - either in contact by satellite from Earth or, if something happens to that communication link, on their own using only the computers and sensors that are on Mars.

Image: plant growth trays inside the Arthur Clarke Mars Greenhouse

The greenhouse structure that was built on Devon Island is not a exact prototype of what we will build on another planet - with one very important exception: how we control it and how it works on its own when no one is around. Other researchers are working on the best materials to use for a greenhouse, how to build something on Mars, etc. Right now, our interest is how to get that future advanced greenhouse (whatever it looks like) to work as part of a planetary exploration mission. Controlling such a greenhouse is one of the more important questions that need to be answered.

Our task was to build a greenhouse on cold, remote Devon Island that acted as if it were sitting on the surface of the Moon or Mars. This greenhouse needed to be self-sufficient in terms of power, computers, and have the ability to grow and support plants with no one on hand to help - just as we will one day need to do on the moon and Mars.

This painting originally appeared in "The Exploration of Space" by Sir Arthur C. Clarke, published in 1951. Captioned in this book as "The Martian Base", the painting was done by Leslie Carr after a drawing by R.A. Smith. Reprinted Courtesy of Sir Arthur C. Clarke.

Sir Arthur C. Clarke, a noted science and science fiction author who wrote about growing plants on Mars more than 50 years ago, has generously allowed us to use his name on this experimental greenhouse and is following its progress with great enthusiasm.

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