How to Grow Plants in Space

01If you think about going into space, if you have humans, you need to provide life support.

02Humans need oxygen, we need food, we need clean water.

03Through photosynthesis, plants can generate oxygen, they can remove carbon dioxide, they're always evaporating water so you can help them in purifying water if you design the systems, and of course if you choose food crops, you can grow food.

04But they're sort of less tangible things that could be really important.

05If you see things, other earthly organisms like plants, the smells, the odors, they're living things, you watch them grow, you get a sense of time.

06These could be important in terms of the crew's well-being and mental health and things like that.

07This is something that's innate to our being.

08It's part of the human condition.

09This is NASA's Curious Universe.

10Our universe is a wild and wonderful place.

11I'm your host, Patti Boyd, and in this podcast, NASA is your tour guide.

12You might be familiar with the idea of astronaut food.

13Prepared meals and snacks we send up to space to feed our explorers.

14But NASA scientists are also figuring out how to grow our own food in space so we can supplement those prepackaged portions.

15There's a whole lab at Kennedy Space Center devoted to it.

16The plant processing area studies what astronauts need to stay happy and healthy, and what specialized habitats, tools, and even plants we can use to garden in space.

17So when we look at astronauts' health and performance, really the first line of defense for crew health is their food system.

18My name is Ralph Fritchie, and I'm the space crop and exploration food system project manager for NASA, and I'm based out of the Kennedy Space Center in Florida.

19Ralph helps run the laboratory devoted to plants in space.

20Right now, all our cosmic gardening is done on board the International Space Station.

21Ralph and his team are working hard right here on Earth so that we can eventually take plants beyond, onto our next great journeys through the solar system.

22When I talk about long-duration exploration missions, especially to Mars, the food that we take with us has a shelf life, just like food that you get in a store on Earth, and we start to see degradation after about a year and a half on certain key nutrients.

23We may lose a little bit of flavor, texture, as well.

24When I look at crop production, that is a way to provide fresh nutrients.

25We try to target the specific areas that we think the prepackaged food system might begin to show some negative effects with, and that gives something fresh for the crew.

26It has aromas, smells, sensations, textures that you don't necessarily get in the prepackaged diet.

27The space crop production team is small and mighty, taking on the exciting challenges of sustaining life in space with the power of plants.

28My name is Joya Massa, and I'm a project scientist in space crop production at Kennedy Space Center.

29So I'm a plant scientist by training.

30The first step in any scientific process is asking questions.

31And when we think about how to grow crops in space, there are a lot of questions to consider.

32How do we grow the plants really well?

33How do we water the plants under different gravity levels?

34That's a really big challenge, actually.

35Figuring out what crops are going to meet the needs of different missions, and which crops are suitable for space.

36So we have to test a lot of different crops and see how they grow, and try to imagine how they'll grow in space.

37Understanding the ecosystem and the humans, the plants, the microorganisms going on in these closed spacecraft.

38And then, of course, there's all the human factors.

39Understanding how people and plants interact, how plants might be important for their psychological or behavioral health on these long missions.

40What activities they want to do with the plants, and which plants we should grow for them at which specific times and how many.

41So there's a lot of different factors that we think about.

42Trying to kind of answer these gaps and challenges is really our goal.

43This plant research lab is maybe not what you might picture when you think of a NASA laboratory.

44It's a big area full of all kinds of lush greenery and plant-growing technology.

45And they study lots of kinds of plants, from fruits and vegetables to flowers and vines.

46Joya, could you take us on a bit of a tour?

47So our lab is in the Space Station Processing Facility, which is a pretty big building at Kennedy Space Center that was originally designed to test out all of the different parts of the space station.

48We now have a space crop production area, which consists of kind of a big open area.

49And you go in through these really tall doors.

50I think they're about 12 feet tall.

51And we have these actually beautiful artwork on the doors.

52There's one with Earth and kind of a cornucopia and a rocket launching.

53The second one is the space station.

54The third door is the lunar surface with a depiction of a lunar surface greenhouse.

55And then the fourth door is the Martian surface with a depiction of what a greenhouse on Mars may someday look like.

56The lab is broken up into sections for different areas and timelines of experimentation.

57In order to learn about various growing factors, scientists have to be able to control various aspects of plant growth, including things like temperature, humidity, carbon dioxide, light, and more.

58We have some very large controlled environment chambers, which look like really big coolers.

59We have an experiment with strawberries, and we're testing strawberries that grow from seed.

60And so you open the door of this chamber, and this smell of just strawberries fills the air.

61It's like you just wandered inside a carton of strawberries at the grocery store.

62We may have a chamber with herbs in there similarly, where we'll have, you know, basil or dill or mint.

63We've even tested some novel crops like kudzu and dandelion to see could these be good candidate for space.

64We've done a lot of work with leafy green crops, mustards and lettuces and bok choy and kale and Chinese cabbage.

65We also do a lot of work with a crop called microgreens, which are baby plants, essentially.

66Very, very small plants that are super nutritious, super flavorful.

67And we've tested a lot of tomatoes and peppers, and some of them grow really, really well.

68We want plants that are compact and high-yielding.

69Some just get too leggy, you know, their branches just grow everywhere, and they're just too big for the space environment.

70So we have to really grow them under our conditions of temperature, of high CO2, like we would find on the International Space Station, to see how they grow.

71We've been doing work in this area for, oh gosh, 30 years or more.

7225 years ago, we focused on larger-scale production systems with field crops, things like wheat and potatoes and soybeans.

73Now, I would say in the past 10 years, our focus has been more on supplemental food crops, like salad crops.

74That's Ray Wheeler, a plant physiologist with the Space Crop Team.

75Ray has been at NASA since 1988, and he's studied a lot of plants.

76Some are better suited for life in space than others.

77We do have sort of a checklist, you might say, of criteria.

78For example, we don't want really tall plants in space.

79You don't want to grow, say, an 8-foot-tall corn plant in space, because you just don't have that kind of room or volume.

80So we tend to think of shorter-growing plants, even dwarf varieties of things like tomatoes and peppers.

81If they're a salad or a supplemental crop, we target things like vitamins and antioxidants, things like that.

82You won't get a lot of calories, maybe, or protein out of a lettuce plant, but you can get fresh food that you add to the diet.

83You want them to taste good.

84You want them to be appealing in appearance.

85So those things are important if you're living in a confined space, like a space station or you're off to Mars.

86You want the astronauts and the crew to like the plants that they're eating.

87The standard thing you hear back is that they like things that are more spicy, more flavorful, because you kind of lose a little bit of that sensation.

88Living in space comes with a lot of challenges, and one of them is a lack of flavor.

89Astronauts have reported back that food is missing some of the punch we can find here on Earth.

90So scientists like Ralph think carefully about how to make their meals tastier.

91One of our most recent experiments was growing peppers in space, and the crew really liked them when they made tacos out of them.

92You're looking for flavorful items.

93You're looking for things that have some sensation.

94Part of what we do in the validation process is doing screening to make sure that people, even on the Earth, think that these things that we grow are flavorful.

95We don't want to bring something that's highly nutritious, but nobody wants to eat.

96We look for flavors that are pleasing, some that are intense, so that we can kind of work with the crew's palette in that spaceflight environment.

97But how do you grow plants in space?

98It's not exactly like a garden.

99There isn't a backyard to the International Space Station, after all.

100So engineers had to create special chambers for plants to thrive.

101Here's Ray.

102You need a plant growth chamber.

103That's a pretty broad, ambiguous term, but in essence, what it refers to is some containment or area where you can control the environment.

104You can provide light.

105And we typically use electric light sources like LEDs.

106You can manage the temperature if it's desirable to do that.

107You can manage the humidity.

108And then you have a system where you can allow the plant roots to establish.

109Maybe it's in a solid media.

110Maybe in the future it'll be in a hydroponic system for space.

111And then you can provide the water and the fertilizer and things that the plants need.

112So you sort of need all these basic, what are called controlled environment needs that you have to meet.

113Plants need certain factors to grow, including water, light, carbon dioxide, and nutrients like nitrogen, potassium, and phosphorus.

114But without the regular patterns of day and night on Earth, Joia and her team have found that space plants need extra attention and can reap interesting benefits from manufactured sunlight.

115Plants are incredibly responsive to light.

116And as lighting technology has advanced, we can now use the ability to give a very specific color pattern of lights to change how plants grow.

117You can use the colors of light to impact how much the plant grows, how fast it grows, how big it is, how nutritious it is, perhaps, how the flavor of the plant changes, and even how the plant responds to disease.

118The facilities in Kennedy's plant research lab are only half of the equation.

119The other major laboratory for studying these plants is on board the International Space Station.

120So NASA's plant biologists test as much as they can on the ground and then send their experiments on a rocket up to space.

121With limited room to transport cargo up to the astronauts, let alone grow it on station, it can be tricky deciding what to send.

122The first thing you do is what's called a science verification test.

123So that's really testing the science in NASA's hardware for the first time.

124See how the plants grow, how long should the experiment run for, you know, when are the tomatoes going to be ripe?

125Like if you're doing a really early rehearsal for a play.

126Then, once you've answered all those questions, you develop crew procedures and a very clear plan of what you want to do on space flight.

127Once you have that plan and you have these procedures, we run the next step, which is called an experiment verification test.

128This is your full up dress rehearsal for flight.

129This is your practice of the play the day before opening with all your costumes on and everything.

130Once you get all the way through that process, you get approval to go to flight.

131You basically build up two sets of whatever you need.

132One set launches to the space station.

133The other set stays on the ground.

134And when the astronauts have time to do your experiment on the space station, we start the same experiment on the ground.

135And we run it usually a day or two later, just so we can make sure we do everything that the astronauts did.

136So we get data down directly from space station on the environment that the plants are in, the temperature, the humidity, everything that's on space station, so that we can mimic the space station environment, except for the gravity.

137At the very end, you'll get samples back from space.

138You'll get photos, all the data back.

139And you as a scientist can compare.

140We'll look at the chemistry of the plants and see how much potassium is in the lettuce and how much calcium and iron and magnesium.

141We want to understand the food safety.

142Was that lettuce different bacterially or fungally than the lettuce that were growing on the ground?

143So those are the types of questions we ask and how we learn answers that can get us to the next steps for crop production.

144By controlling nearly everything except gravity and location, scientists like Joya can zero in on the effects of space and microgravity on plant biology.

145That's why they run the experiment twice, to try and keep everything else the same.

146And according to Ray, there are a couple major differences about growing the same plants on Earth and in space.

147There's no gravitational orientation for plants in space.

148We do know that plants have evolved in a gravity environment just like humans.

149So the stems, the shoots as they're called botanically, tend to grow up.

150They grow away from the direction of gravity.

151And roots tend to grow down.

152You don't have that in space.

153Plants also respond to the direction of light.

154For example, if you put a plant on your windowsill, it kind of bends toward the window.

155That's a light-driven response.

156And so in the absence of gravity, we use light to orient the leaves and the stems.

157The roots, you just sort of contain, and you let them grow in the medium or however you're containing them because they don't really have any clues.

158They will go where water is, and so you can use that.

159There are other mysteries of space that are impacting plants, ones we're still trying to figure out solutions to.

160There's more radiation in space.

161So, you know, there's subtle things like that you have to pay attention to.

162Right now, all of the resources astronauts have on the space station were brought there from Earth.

163But there might be a time in the future when we return to the moon or journey to Mars and can use some of the natural resources there for food production.

164This is called in situ, or on-the-ground gardening, and it could be a possibility once we know more about these future farm sites.

165When you get to Mars, is there water ice?

166That would be a huge asset if there were.

167We know Mars has carbon dioxide.

168Plants need carbon dioxide, so you have both carbon and oxygen, you know, in terms of elements.

169So those would be available.

170Can you get some nutrients and fertilizer?

171Maybe.

172From some of the surface rubble and regolith?

173Maybe.

174Probably you'll have to take a lot of that with you and sort of prime the system, and maybe even with the water.

175You prime the system, but then you run it in a highly closed mode where you're recycling as much as you can.

176And so you create sort of a closed ecosystem.

177Mars and the moon are really the near-term objectives, and Mars is sort of the ultimate for now.

178There's interest in going to, say, some of the large moons of Jupiter, like Europa.

179There's very large moons in Jupiter, and they might have water ice, but you're going to have a lot less sunlight there.

180As a project manager, Ralph thinks about the long-term applications of these programs.

181How will crops be utilized?

182Or even necessary as we plan our next explorations into space?

183And how can we create food systems that allow us to travel even further from our home planet?

184On a mission to Mars, we're going to need something to supplement that cruise system.

185Early missions to the moon are just short in duration.

186We're not going to be there long enough that we were going to have to worry about doing any kind of food production.

187But then when I start talking about putting out bases or outposts, now I'm looking at how do I begin to cut the cord to earth.

188A big part of that will be food, because food and logistics that food requires, the support, that's a big part of the mass that I'm taking with me when I go places.

189So we want to be able to cut down on that.

190You really have to go knowing that you need to take care of yourself.

191Resupply is something that will be very challenging.

192You're not going to be able to go like we can now to the International Space Station.

193And so everything we do is to try to get to that point of what, from the food system perspective, can we grow and produce locally so that we don't have to rely on earth quite so much as we do now.

194Even on earth, we think a lot about the food we put in our bodies.

195The nutrients, the taste, and even the convenience.

196But one thing we might take for granted is how impactful our proximity to nature, to plants, to growing, thriving organisms, helps our day-to-day life.

197Up in space, on station or on another planet, we won't have that same connection to plants unless we create it.

198And already, scientists like Ralph, Ray, and Joya have seen the emotional difference a little bit of space gardening can make for our astronauts living and working far from home.

199A few years ago, we grew zinnias in space, not as a food crop, but as an example of what you would need for a flowering crop, like a tomato or a pepper.

200However, we had a problem.

201Power was cut off.

202And when power came back on, the lights came back on, all the indicators came back on.

203What didn't come back on were the fans.

204And we didn't know that.

205So the plants were very stressed, and they were showing all this weird growth.

206And then we got fungus.

207We got a call at four in the morning, you know, there's something funny growing on the plants.

208And we finally figured it all out.

209Scott Kelly was the astronaut at the time.

210He cleaned everything up, reset the fans, and he took over watering on his schedule.

211And then the zinnias that survived, and they didn't all survive, some died from the fungus, but the ones that survived actually started to flower.

212And it just went from being this stressful, difficult, really upsetting experience to being just wonderful.

213He made a bouquet for the final harvest, and he took these photos of this bouquet.

214And he was so happy with the flowers, and they were so important to him for his long mission.

215You know, he talked about them quite a lot.

216But being a part of that just made me feel like, wow, this is really important.

217And we're just, we're learning stuff every day.

218So I think it's a great, great thing to do.

219Special thanks to Daryl Nail, Lee J.

220Lockhart, and the Kennedy Space Center team.

221If you'd like to see Scott Kelly's floating zinnias, we've linked the photos at nasa.gov slash curiousuniverse.

222And remember, you can follow NASA's curious universe in your favorite podcast app to get a notification each time we post a new episode.

223What did you think about the movie The Martian?

224Is Matt Damon a good space farmer?

225In a way, we thank him for getting the publicity that he did for the whole idea, but how he went about it is just not something that would really work.

226Even from the standpoint of how potatoes would grow in that environment, they would be challenged to use Martian regolith or Martian soil and to grow like they did.

227There are chemical components of that material that just are not conducive to plant health and performance, let alone how you would fertilize them.

228That movie came out and the book came out right about the time that Veggie was really starting to do things where we were growing plants and astronauts were beginning to consume it.

229So it was one of those positive, perfect storms where everything came together at the right time.

230So it was a very good thing.

231So it was a very good thing.

232So it was a very good thing.