First, Astronaut Scott Kelly grew (yummy) lettuce aboard the International Space Station (ISS). Now, he has successfully grown a batch of zinnia flowers, NASA announced over the weekend.
First food, then beauty. Of course, the zinnia plant was not chosen specifically for its beauty, but it can’t hurt to have pretty flowers onboard.
“The zinnia plant is very different from lettuce,” said NASA’s Trent Smith, Veggie project manager. “It is more sensitive to environmental parameters and light characteristics. It has a longer growth duration between 60 and 80 days. Thus, it is a more difficult plant to grow, and allowing it to flower, along with the longer growth duration, makes it a good precursor to a tomato plant.”
From bad to good
In December, it didn’t look like NASA was going to achieve this milestone. The zinnia leaves were starting to bend down and curl, which can indicate flooding in the roots, and excess water was gathering on the leaves’ edges—both clear signs of plant stress.
Smith decided to toggle the fan from low to high, as the above plant stressors indicated reduced air flow through the veggie facility. However, that only added to the problem—combine high humidity with wet surfaces, and you have prime real estate for mold to grow.
On Dec. 22, Kelly, who was now overseeing the veggie experiment, donned a dust mask for safety and cut away the molded plant tissue and sanitized the plant surfaces. The fans continued at a high speed in hopes of keeping the chamber dry and mold growth at bay.
Yet again, a new problem arose from these circumstances. On Christmas Eve, Kelly reported that he thought the fans were drying out the plants too much, and they needed more water. NASA’s ground support team informed Kelly that the next scheduled watering was not until Dec. 27, to which Kelly responded that would be too late.
And so, Kelly became the first autonomous gardener aboard the ISS. He was given basic guidelines for the care of zinnias, while putting judgment capabilities fully into his hands.
Shortly after the Christmas holiday, two plants died and were clipped off, while the other two continued to thrive. Then, on Saturday, Jan. 16, Kelly shared the above photo of the zinnia flower on his Twitter account with the caption “First ever flower grown in space makes its debut.” The next day, he shared this:
A learning experience
While it may have been stressful at the time, all the bad that happened to the zinnia plant in December was not for naught. The dead, moldy plant tissue that Kelly snipped was stored in the onboard -80° laboratory freezer so that it could be returned to Earth and studied. Additionally, the two plants that displayed stress and died off while the other two grew were also clipped and stowed in the freezer for further studying back on Earth.
In fact, Smith said, the experience drives home what science experiments are all about: finding what doesn’t work, and figuring out how to solve it. For crews on the way to Mars, scientists need to know what would happen if crops experienced drought, flooding, mold growth or other challenges. Would the practices of cutting away dead tissue and sanitizing plants work? How does changing the watering schedule affect the growth? How can crew members be given more opportunities to take charge in the gardening process?
Even if the flowers didn’t bloom, NASA would have learned a lot from what seems like a failure, but is really an opportunity to learn more about growing plants in microgravity. The pretty flowers are almost just a bonus at this point. For now, NASA continues to closely monitor the zinnia crop and are following Kelly’s lead for care based on his observations.
According to NASA, more crops for Veggie are heading to the orbiting laboratory aboard SpaceX-8. The Veg-03 run will include two sets of Chinese cabbage, and one set of red romaine lettuce. In 2018, there are plans to launch dwarf tomato seeds to the space station. Smith said the lessons learned from growing zinnia flowers will be critical in the process of growing tomatoes, a fellow flowering plant.