Modeling Carbon Gain and Plant Growth of Lettuce (Lactuca sativa) under Ethylene and Hypobaric Environments for NASA Advanced Life Support (ALS) Systems, Poster Board #206

Hypobaria (low total atmospheric pressure) is essential in sustainable, energy-efficient plant production systems for long-term space exploration and human habitation on the Moon and Mars. There are also important engineering, safety and materials handling advantages of growing plants under hypobaric conditions, including reduced atmospheric leakage from extraterrestrial base environments. It is important to predict or model plant growth and edible biomass production for human consumption during space exploration. Net daily carbon gain (CDG) was used to model plant growth rate and mass balance in our low pressure plant growth system (LPPG) designed for a NASA life support system. There was a linear correlation between accumulated CDG and measured total plant, leaf and root dry mass. Edible fresh mass can also be predicted from the model. The model could fit hypobaric and hypoxic environments with ethylene scrubbed or allowed to accumulate. We evaluated the model via analysis between direct measurements and modeled data. There was a highly significant linear relationship between modeled and measured data indicating that errors can be predicted from the LPPG system.