While it still seems like such a SF concept, it was proven in August 2015 that you can indeed grow lettuce in the microgravity environment of the International Space Station and consume it. And consume it, Expedition 45 crewmembers Scott Kelly, Kjell Lindgren and Kimiya Yui did!
Fast forward to the most recent phase in the “Veggie” experiment: growth round Veg-03 was started on October 25th, 2016, to test the modified water delivery system, and this time six lettuces were grown simultaneously, under the care of Expedition 50‘s newly minted Space Station Commander Shane Kimbrough.
Yet how do you grow lettuce–indeed, any vegetable–in space when the microgravity means you can’t just “water” the plants? And no, the answer does not requite astronaut feces, such as in The Martian. Instead, it calls for a nifty invention where the seed “wicks” water out of nutrient pillows each seed is attached to and germinated from.
Shane Kimbrough was the first to taste the lettuce grown from the latest growth experiment, using a repetitive harvest technique where only the tops of a selection of leaves are sliced off for him to eat, allowing the lettuce base to grow new leaves for subsequent consumption and science samples to be sent home to be tested. Each growth cycle takes approximately ten days.
“Testing this method on-orbit, after using it on the ground, is very exciting for us,” said Veggie Project Manager Nicole Dufour. “A repetitive harvest allows us to provide more food for both the crew and for science, so it’s a win-win.”
Since then the fifth crop has been harvested on the ISS, by Peggy Whitson, on February 17th, 2017–the first crop of Chinese cabbage ever grown. While most of it will be going back to Earth for scientific study, the crewmembers were able to enjoy some of it. Peggy’s stay on the ISS was extended by three months as she is now Expedition 51‘s Space Station Commander, allowing her to oversea the planting of a second round of Tokyo Bekana Chinese Cabbage, and as of April 3rd, the crew are already seeing sprouts.
So what does this mean for the future of space exploration? Everything. Scientists agree it helps morale and the physical health of the astronauts to be able to consume fresh food while away from Earth. Not only that, but it increases the probability of creating a renewable sustainable food supply while NASA continues to explore the feasibility of humanity moving to Mars, or beyond.
But what about the immediate future?
“I love gardening on Earth, and it is just as fun in space….” Peggy Whitson tweeted in early February. “I just need more room to plant more!”
And NASA apparently agrees. Later in Spring a second Veggie installation will be set up on the ISS, to provide side-by-side comparison experiments. And on the April 18th resupply mission is an experiment involving Arabidopsis, a small flowering plant as well as petri dishes to place within the Veggie facility. Arabidopsis is seen as the genetic model of the plant world, so the principle investigator, University of Florida’s Dr. Anna Lisa Paul, considers it the perfect specimen for performing genetic studies.
“These experiments will provide a key piece of the puzzle of how plants adjust their physiology to meet the needs of growing in a place outside their evolutionary experience,” Dr. Paul said. “And the more complete our understanding, the more success we will have in future missions as we take plants with us off planet.”
Now, when I read that quote, why can’t I help but think of The Day of the Triffids? Just how will the plants evolve to cope with microgravity? How will they adapt? With each advancement we make, the science fiction we extrapolate in books really does seem to becoming closer to reality. I can’t wait to find out what the future holds. How about you?