Plant growth will be an important part of future space exploration as NASA plans for long-duration missions to the moon. Astronauts may be able to grow plants on the moon to supplement their meals.
But there's a lot to learn about how astronauts might grow plants on the moon. Students are helping NASA explore lunar plant growth through NASA's Engineering Design Challenge: Lunar Plant Growth Chamber. The challenge calls on elementary, middle and high school students to design, build and evaluate lunar plant growth chambers. The project supports NASA's goal of attracting and retaining students in science, technology, engineering and mathematics disciplines.
Third-graders at Oak Hills Terrace Elementary School are among the thousands of students participating in the challenge. Oak Hills Terrace is a NASA Explorer School in San Antonio, Texas.
Oak Hills teacher Heidi Poffinbarger taught students about the spaceflight environment astronauts will encounter as they travel to the moon or other planets. They studied how living things, such as astronauts and plants, survive in space and how liquids act in microgravity.
Poffinbarger focused mostly on how water acts in space, helping students understand that water poured on a plant in space will not fall onto the soil like it does on Earth. Instead, the water will bounce off the soil and break into smaller water droplets. "If water reacted that way in space, what would we need to do to prevent it from doing that (when growing plants) in space?" Poffinbarger asked students.
After understanding how water behaves in space, students were ready to begin the challenge. The class was divided into four groups. Each team is designing and building their own plant growth chamber.
The groups first designed a water system for their plant growth chambers. Students had a lot of different ideas, Poffinbarger said. Eight-year-old Logan said his group had so many ideas they couldn't figure out which one to do.
Each person in the group came up with a design. The groups discussed all of their ideas and decided on one official watering system per group, Poffinbarger said. "The groups are very different in their designs. They (the students) were loud, but they weren't too loud because they wanted their design to be kept secret."
One water system uses a syringe to push air and water into a tube in the soil. Another design uses a water-filled sponge placed under the soil. A string around the sponge is pulled tight to squeeze the water out of the sponge and into the soil.
Another group came up with the idea of putting water into the chamber and then turning the entire chamber upside down so that the water would go into the soil. The fourth design works much like an IV. A large syringe attached to a bag of water squeezes air into the bag. This process causes the water to push out through a tube in the soil.
"They have just been so creative in this," Poffinbarger said. "It's been interesting watching them, seeing what they come up with."
She said the most unusual idea so far has been to turn the chamber upside down for watering. "I never would have thought of that. I don't know if it's going to work. They're a bright group, and I'm sure they're going to think of something that will make it work."
To construct their chambers, students used aluminum foil, yarn, sponges, plastic food containers, masking tape, plastic water bottles, plant holders, drinking straws and syringes. Students learned about circuits and electricity, and incorporated an artificial light source into their chambers.
Students said the designing and building phase of the project was hard but fun. One student, Daniel, said constructing the chamber was the hardest part, but his group worked together to solve the problems they were having. Another student, Evan, had trouble with the circuit for his group's light source. "Others helped me out and gave me ideas," he said.
All teams will be using a special clay-pellet soil that absorbs moisture better than regular soil. Poffinbarger said the soil is the same as that used in plant growth experiments in space. "We want to make this situation as much as it would be like up there (in space) as we could," Poffinbarger said.
The groups are currently testing their designs, which is an important part of the engineering design process. After testing, students may have to redesign or modify certain elements of their chamber. "They know they're going to have to go back and make changes to it," Poffinbarger said. "They keep saying they have this feeling they've left something out."
Once the chambers are complete, the third-graders will turn their experiment over to the kindergarten classes to test. The kindergartners will plant cinnamon basil seeds that flew in space on the STS-118 space shuttle mission in the chambers. They will also plant seeds that did not fly in space. The kindergartners will take care of the plants using instructions from the third-graders about how much and how often to water the plants and how often to expose them to light.
"We've discussed that a lot," Poffinbarger said. "How much water is it going to need? How much light? ... A lot of them are saying even (watering) once a day is too much. They don't have the concept of that yet, so that's going to be what we discuss as soon as we get their water systems working."
Students will use a data table to document the date the seeds are planted and the date the plants germinate. They will also measure and chart the plants' growth. The students will be looking at which seeds grow faster -- space-flown seeds or the control seeds. They will also determine which plant growth chamber performed the best, based on which chamber produced the most plant growth.
Poffinbarger said her students are very interested in finding out which chamber design is the best. "The kids are into the engineering aspect and learning things that I didn't know third-graders were able to learn at this age," she said.
NASA Engineering Design Challenge: Lunar Plant Growth Chamber
STS-118 Shuttle Mission
NASA Explorer Schools →
NASA Education Web site →
Heather R. Smith/NASA Educational Technology Services Team