Innovations in LED Lighting for Reduced-ESM Crop Production in Space

Introduction: In controlled-environment crop production such as will have to be practiced at selfsustaining, crewed space bases, the single most energy-demanding aspect is electric lighting for plant growth, including energy costs for energizing lamps as well as for removing excess heat [1]. For multiple reasons, sunlight may not be a viable option as the sole source of crop lighting off-Earth. Traditional electric lamps for crop lighting also have numerous drawbacks for use in a space environment. A collaborative research venture between the Advanced Life Support Crops Group at the NASA Specialized Center of Research and Training in Advanced Life Support (the ALS NSCORT) and the Orbital Technologies Corporation (ORBITEC) has led to the development of efficient, reconfigurable LED lighting systems that will support crop growth in a space-based crewed habitat. The LED lighting arrays were based on previous proof-of-concept work with intracanopy fluorescent lamps [2]. The light sources use printedcircuit red and blue LEDs, which are individually tunable for a range of photosynthetic photon fluxes and photomorphogenic plant responses [3]. Initial lighting arrays have LED light engines that can be energized from the bottom upward when deployed in a vertical, intracanopy configuration, thereby allowing the illumination to be tailored for stand height throughout the cropping cycle (Fig. 1).