You Can Grow Tomatoes from Seeds That Flew in Space!

Tomatosphere, a Space Station Explorers partner program, is looking forward to a big year. Through this award-winning, curriculum-driven free program, K–12 students investigate how the space environment affects tomato seeds’ germination and growth. More than 3 million students in North America have participated in Tomatosphere since 2001, and at least 24,000 classrooms in the U.S. and Canada expect to participate in 2017. Teachers can register at any time of year to receive seeds, and the main shipments of seeds are in the spring and summer.

Here’s how Tomatosphere works: Each registered class gets two packets of about 30-35 seeds each. One set of seeds spent time at the International Space Station and the other did not – but the class doesn’t know which is which. This “blind” experimental design helps minimize observers’ bias. If students knew which seeds had flown in space, they might over-interpret their observations because they expect those seeds to do something unusual.

Students plant and observe both sets of seeds for a few weeks, keeping track of how many seeds germinate. They submit their germination results to the Tomatosphere organizers, who reply by revealing which set of seeds flew in space. Each student receives a “Certificate of Participation” signed by the principal investigators of the project, Dr. Robert Thirsk (retired Canadian Space Agency astronaut) and Dr. Michael Dixon (University of Guelph, Canada). Scientists can access students’ reports and use the data for research.

After reporting their results, many students continue caring for their plants for weeks or months. At Saint Matthew Catholic School in Tennessee, teacher Julie Petcu described how one of her students continued nurturing his Tomatosphere seedling through the winter: “It matured into this huge plant bearing healthy fruits!” Students can harvest their tomatoes to eat, cook, or perhaps to prepare salsa – why not spice it up while you space it up? And they can collect the seeds from their tomatoes to plant a new crop. “Some students have even grown two or three plant generations from the original set of seeds!” said Ms. Petcu, who has participated in Tomatosphere for twelve years.

Teachers have enjoyed connecting Tomatosphere with a variety of school curricula with the help of free curriculum support materials. It builds on scientific practices such as recording observations, making measurements, analyzing and graphing data. Students get practice working on teams, too. Karen Lindsey, a teacher at Lake Orienta Elementary School in Florida, has grown Tomatosphere seeds with 25 classes in grades 3-5. She said, “I used the tomato plants to enhance my Living Things Unit, the scientific method, space exploration, research, and collaboration!”

The Tomatosphere seeds classrooms will receive in Spring 2017 traveled to and from the International Space Station on a Dragon cargo capsule as part of the SpaceX CRS-9 resupply mission. The seeds flew aboard the ISS from July 20 to August 25, 2016, a total of 36 days. While in orbit, the seeds were exposed to microgravityThe condition of perceived weightlessness created when an object is in free fall, for example when an object is in orbital motion. Microgravity alters many observable phenomena within the physical and life sciences, allowing scientists to study things in ways not possible on Earth. The International Space Station provides access to a persistent microgravity environment. (weightlessness) and above-average radiation levels. However, the seeds were not exposed to the freezing cold vacuum of space; they were in a storage area with Earth-like air pressure and temperature. The main difference between the space-flown seeds and the Earth-based seeds is that the space-flown seeds were weightless for a month. Is that enough to alter how the seeds grow? Doing the experiment is the best way to find out!