NASA on LEDs.

LED Device Illuminates New Path to Space Technology Hall of Fame

Originating Technology/NASA Contribution

Studies have shown red LEDs are a viable light source for growing plants in space flight due to their small mass and volume, wavelength specificity, longevity, and safe operation.

Among NASA’s research goals is increased understanding of factors affecting plant growth, including the effects of microgravity. Impeding such studies, traditional light sources used to grow plants on Earth are difficult to adapt to space flight, as they require considerable amounts of power and produce relatively large amounts of heat. As such, an optimized experimental system requires much less energy and reduces temperature variance without negatively affecting plant growth results.
Light-emitting diodes, LEDs, are a light source for growing plants in space.

Studies have shown red LEDs are a viable light source for growing plants in space flight due to their small mass and volume, wavelength specificity, longevity, and safe operation.

Ronald W. Ignatius, founder and chairman of the board at Quantum Devices Inc. (QDI), of Barneveld, Wisconsin, proposed using light-emitting diodes (LEDs) as the photon source for plant growth experiments in space. This proposition was made at a meeting held by the Wisconsin Center for Space Automation and Robotics, a NASA-sponsored research center that facilitates the commercialization of robotics, automation, and other advanced technologies. The Wisconsin group teamed with QDI to determine whether an LED system could provide the necessary wavelengths and intensities for photosynthesis, and the resultant system proved successful. The center then produced the Astroculture3, a plant growth chamber that successfully incorporated this LED light source, which has now flown on several space shuttle missions.

NASA subsequently identified another need that could be addressed with the use of LEDs: astronaut health. A central concern in astronaut health is maintaining healthy growth of cells, including preventing bone and muscle loss and boosting the body’s ability to heal wounds—all adversely affected by prolonged weightlessness. Thus, having determined that LEDs can be used to grow plants in space, NASA decided to investigate whether LEDs might be used for photobiomodulation therapy (PBMT).

PBMT is an emerging medical and veterinary technique in which exposure to high-intensity, wavelength-specific light can stimulate or inhibit cellular function. PBMT modulates a body’s organelles—structures within a cell (e.g., mitochondria, vacuoles, and chloroplasts) that store food, discharge waste, produce energy, or perform other functions analogous to the role of organs in the body as a whole—with wavelength-specific photon energy to increase respiratory metabolism, reduce the natural inflammatory response, accelerate recovery of injury or stress at the cellular level, and increase circulation.