When Scott Kelly tweeted a picture of moldy leaves on the current crop of zinnia flowers aboard the International Space Station, it could have looked like the science was doomed. In fact, science was blooming stronger than ever. What may seem like a failure in systems is actually an exceptional opportunity for scientists back on Earth to better understand how plants grow in microgravity, and for astronauts to practice doing what they’ll be tasked with on a deep space mission: autonomous gardening.
“While the plants haven’t grown perfectly,” said Dr. Gioia Massa, NASA science team lead for Veggie, “I think we have gained a lot from this, and we are learning both more about plants and fluids and also how better to operate between ground and station. Regardless of final flowering outcome we will have gained a lot.”
The Veggie plant growth facility was installed on the orbiting laboratory in early May of 2014, and the first crop – ‘Outredgrous’ red romaine lettuce – was activated for growth. The first growth cycle faced some issues.
The second crop of the same lettuce was activated in early July by NASA astronaut Scott Kelly, and thanks to lessons learned from the first run, adjustments to watering and collecting imagery of the plants were made.
The next crop on the docket was a batch of zinnia flowers, but they weren’t selected for their beauty. They were chosen because they can help scientists understand how plants flower and grow in microgravity.
“The zinnia plant is very different from lettuce," said 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."