By Bob Granath
NASA’s Kennedy Space Center, Florida
Scientists and engineers are developing new hardware destined for the International Space Station to support experiments demonstrating how different organisms, such as plants, microbes or worms, develop under conditions of microgravity. Results from the Spectrum project will shed light on which living things are best suited for long-duration flights into deep space.
According to Dr. Scott Shipley, project engineer for Spectrum at NASA’s Kennedy Space Center in Florida, what make this system unique is it will allow scientists to observe how different genes are turned on and off while the organisms grow in space. In ground testing using plants, the device works by exposing the plants to different colors of light while a camera records fluorescent light emitted from the plants with time-lapse imagery.
In these experiments plant seeds are placed on agar gel (a jelly-like substance obtained from algae) in a Petri plate set up in the Spectrum unit. The seeds germinate and as the seedlings develop, they are exposed to any combination of red, green, blue, white or infrared light to investigate different aspects of their growth and physiology.
In a typical experiment, an astronaut will load a Petri plate with seeds into the Spectrum unit, the system then runs on an automatic script controlling temperature and changing the lights according to a desired program and the camera takes pictures about every hour. Scientists on Earth will receive regular photographs of the plants growing in the Petri plate. The results will shed light on how plants grow differently in the microgravity environment of space.
The Spectrum experiments will be important because genes control the physical and functional similarity between generations of plants. However, genes do not determine the structure of an organism alone. Environmental factors such as lighting and microgravity are other influences that can determine what types of plants are best suited for long spaceflights.
Recently, the team conducted a 14-day test with plant seedlings to evaluate whether the Spectrum prototype met NASA’s design specifications. At the end of the test, NASA managers and subject-matter experts conducted a critical design review to determine if the performance of the unit demonstrated it was ready for full-scale fabrication and assembly.
“There were a lot of smiles all around,” Shipley said. “The prototype passed the review and was judged to exceed all requirements. We also were given a ‘go’ to proceed with building the Spectrum unit.”
Aboard the space station, the flight version of Spectrum will be inserted into an EXpedite the PRocessing of Experiments for Space Station, or EXPRESS, rack. EXPRESS Racks support research aboard the station by providing structural interfaces, power, data and other elements needed to run science experiments.
Plans call for the flight unit to be launched to the space station aboard a commercial resupply services spacecraft.
“Our goal now is to have the Spectrum unit ready,” he said, “for a space station resupply mission in mid-to-late 2018.”