If we want to grow food on Mars, we need to practice enclosed gardening on Earth
An interview with Dr. Bruce Bugbee, director of the plants, soils and climate department at Utah State University, who has been growing plants in harsh environments for the past two decades, working closely with NASA.
(This interview has been edited and condensed for easier reading.)
Q: In the movie, “The Martian,” the fictional Mars astronaut Mark Watney, played by Matt Damon, grows a crop of potatoes in order to stay alive. But how close is this kind of space gardening to reality?
A: Yes. In principle, we have got all the systems in place to go to Mars and to grow food on Mars. There is not anything that we would say, ‘Wow, we have no clue how to do this.’ We do know how to do everything. The challenge is practicing and making the commitment to do it, both of those are big. We could make a system on the ground. We could put those same eight people in a closed system on the ground and run it. And simulate Martian atmospheres and make sure that we have the regenerative parts correct and that there isn’t anything we are missing. Practicing is what I call it. Demonstrating that we can really do it.
Q: There is a Mars simulation under way in Hawaii, with six people enclosed in a dome for a year, but that experiment’s primary focus is on crew psychology. Has an enclosed food-growing experiment been done yet?
A: NASA first started thinking about space biology as soon as we put astronauts into space in the 1960s. It was immediately apparent then, if you could get some photosynthesis going up there, whether from algae or plants, they will recycle air. Even in the ’50s and ’60s, NASA was working with growing algae in space, not to provide food but to provide oxygen. That led to studies growing food, starting in the ’80s.
In the ’90s, people went into Biosphere 2 in Arizona. It was a privately funded thing, actually by a Texas oil millionaire named Ed Bass. A project by a group of eight people to build a big glass dome that was gas-tight and they would go in there and live in there for two years to recycle their own gases and grow their own food. It was sort of a cult thing, but they had advisors. And their advisors said you are not ready to do this. You need to do this test and that test, and what they did was fire the advisors.
They went ahead and did it anyway. They made it. They ran out of oxygen. They had to have oxygen pumped in. There were some things, that had they been in space, they wouldn’t have made it two years.
We were pretty involved with them, helping them grow more food because they were starving. They lost a lot of weight, all of them. They weren’t able to grow as much food as they needed. They did have stored food. But then they got into big issues of how much of this stored food should we eat? They were noticeably very thin when they came out after two years.
NASA distanced themselves from it. It was a leap to try to do this. I always said I admire them for just going for it, even though they really weren’t ready to do it. But they said we are tired of waiting, we are just going to go.
Q: What is the hardest thing about growing plants in a space environment?
A: In space there is minimal gravity. It is not zero gravity. It is what we call microgravity. So that is a challenge. Water doesn’t move the way it would on Earth. There are a lot of differences that you have to think through and work through. But as far as we know that lack of gravity affects people a lot more than it affects plants.
The second issue is this aspect of closure. How small can a closed-loop system be, and still recycle all of our waste and keep everything in balance? And that is a fascinating question. Could you put a bubble over your house, your yard, and call somebody up and get a big rocket and head off into space? How big would your yard have to be to do that? How big would your water buffers have to be? To me that is a bigger challenge than the microgravity. We don’t have a good idea of how big our space colony has to be in order to be stable.
Q: Could astronauts compost in space, and could all the plants die off suddenly the way they do in “The Martian” story?
A: It is not that difficult to compost. You would never put raw sewage on plants, but you could compost it, and it gets to high temperature and kills the harmful bacteria and breaks down a lot of the bad stuff, then you have compost which is really good.
In the book he has a system that he talks about, that he can split CO2 back into oxygen, and also split water to get oxygen out of that. And it is possible to do those things, to help keep the gases in balance.
There was some kind of puncture where he loses pressure and all of the potato plants die. The way that happened, if there was that much if a drop in pressure, yes they would all die. NASA has tested that, the effect of rapid pressure changes.
Q: What about the water? How much would you need, and how much could you make?
A: That is a huge question, because it is recycled, so how big does your storage have to be? We don’t have a really good idea of the minimum amount of water you would need to have a buffer. The smaller the storage tank, the more risky it is.
The amount of water you would recycle out of the atmosphere is thousands of times more than the recycling of the urine. Because it just evaporates especially if you are growing plants, it just evaporates from the plants.
Q: What about his diet of potatoes, vitamins and protein bars? Is that realistic?
A: We have never tested a long-term diet like that for people. In an average day, we eat the products of maybe 1,000 different plants, and now we are going to reduce that to like, one? We would never just grow potatoes. We would grow rice and wheat to have some variety in the diet. And we would certainly grow tomatoes and lettuce to have some fresh food.
All the stories we hear from the astronauts, growing food in space is enormously appealing from a psychological standpoint. There have been stories of astronauts and cosmonauts that grew food in space but they became so connected with the plants they did not want to eat them. Part of it is a psychological connection to another living thing in space. It is interesting and it is not all that surprising. It is easy to imagine how that could happen.
Q: We recently learned of astronauts taking the first official bite of lettuce grown in space, but research on growing plants in space has been going on for a long time. Why is it taking so long for this to come to fruition, if I can say it that way?
A: The Russians have long been interested in regenerative life support. And they have had people living in closed systems in Russia. This is now a national science program in Russia, better planned and more organized with more backups.
In the United States, in my opinion, we are so concerned about the safety of people, we don’t even want to try. Something might go wrong and we are not ready. NASA is ultra cautious about the safety of people and that is exactly why they didn’t eat lettuce until a couple of weeks ago. The lettuce has been up there a long time. And the Russian cosmonauts have been eating it, for I don’t know, 10 years, because they didn’t have the same restrictions.
The general consensus is that the US astronauts were probably eating it too but they couldn’t admit to it. They weren’t supposed to eat it for safety concerns. There might be some microbiological contamination. They might get sick. When they finally got permission, it was after a lot of tests on the lettuce to demonstrate it wasn’t any different than lettuce grown on the ground. It was very safe. It was as safe as lettuce on the ground. But it was still news.
Q: What kind of research is going on toward growing plants and food in space?
A: The focus of my expertise and career has been growing plants in controlled environments, which often means a big growth chamber with electric lights and hydroponic culture — liquid and nutrients — so we say these plants never see the sun and they never touch the soil so it is a very controlled environment, and we study plant-environment interactions.
We have done a lot of ground based studies in closed environments on plants for NASA, regenerative life support systems where plants purify the water, provide oxygen and of course provide food to the people.
One of the things we are looking at now is colors of LEDs. They are getting more efficient now and we are upgrading our chamber up there (at the International Space Station) to LEDs, so what colors? And how much can you manipulate the plant by changing the colors over the life cycle?
Another one is fiberoptics to grow plants. Right now we have lots of solar cells and electric lights but we could use mirrors and fiberoptics, no batteries and just pass the sunlight right in to the plants. So that is an emerging technology that is not cost effective on the ground but it certainly could be in space.
Some plants can thrive in continuous light. They don’t need to sleep. But other plants absolutely have to sleep. Tomatoes are a classic example. They have to get eight hours of dark at night or they don’t grow well at all. But the space station orbits the Earth every 90 minutes. And 30 minutes of that is in the dark, in the shadow of the Earth. It gets 60 minutes of bright sunshine. So what does that do to plants? If we use fiberoptics, that is what we are going to have.
Q: NASA is spending billions on spaceships and rockets. How much is NASA spending on plant-growing technology?
A: If this were Donald Trump, it would be a penny falling out of his pocket. It is miniscule. He wouldn’t even notice. It is so little. It might be a few hundred thousand dollars. But given a budget of trillions that is pretty tiny.
Q: So somehow we have to convince NASA to put these into a real life practice on Earth, before we could know for sure we could do it on Mars, is that the idea?
A: Yes, but I wouldn’t say it is so much an issue of convincing NASA — they get as excited about these things as we do — it is a matter of funding priorities in the long term. We really need to convince the taxpayers that this is interesting and it is worth pursuing. Because NASA wants to do it if they have the budget.
We should be spending more on the science of living in space. I justify that by seeing the many tens of thousands of school kids who even to this day get excited about growing plants in their classrooms and the thought that they might go to space someday and they would have to grow food, what would that be like?
And frankly I think that speaks to that human interest in growing your own food. I think that is what fuels the incredible interest right now in urban agriculture. People do not want to be disconnected from their food production. They don’t want it growing mysteriously somewhere far away they want to see it growing in their cities and near their cities.
Kerry Sheridan is a science writer for Agence France-Presse.