Designing an Optimal Lighting Fixture for Extraterrestrial Crop Growth: Integrating Efficacy and Photobiology

Extraterrestrial crop growth will require the development of technologies that provide photons to drive photosynthesis. Light-emitting diode (LED) technology is the likely technology of choice due to 1) its inherent flexibility, and 2) its high efficiency. Here we describe two important considerations for the optimization of this system: photon efficacy (μmol of photons produced per joule of input electrical energy) and spectral effects on plant growth and development. With these two considerations, we suggest the design of an LED fixture for extraterrestrial crop growth that contains a 5:10:55:30 ratio of blue, green, red, and far-red photons (respectively). This would be achieved through phosphor-converted white, 660 nm red and 730 nm far-red LEDs