Engineering Perspectives of Growing Plants in Space

Plants are crucial to human existence. They provide a source of sustenance, nutrient recycling, atmospheric replenishment, water cycling, and physiological health for life on Earth as well as in space. The human spaceflight realm poses unique challenges for engineers who develop facilities to conduct plant experiments, grow crops, and design biology-based life support systems for off-Earth habitation. Fractional or microgravity strongly influences fluid and thermal management directly and indirectly in both the organisms themselves and their engineered life support facilities. Scarce resources such as mass, volume, power, crew involvement, and data must be minimized through all mission phases. The current spaceflight facilities vary in complexity from simple Petri dishes to closed-loop feedback-controlled chambers that regulate biologically relevant parameters such as photosynthetic illumination intensity and quality, diurnal cycle, temperature, relative humidity, moisture, atmospheric constituency, and even fractional gravity. Learning how to grow plants efficiently and effectively will become increasingly relevant as humans journey farther and farther out into the solar system.