Description: As called out in the NASA Technical Roadmap (TA7), in-orbit or deep space-based plant growth systems are of interest to NASA as part of fundamental space research and for ensuring supply of fresh produce to the crew for sustainable human spaceflight. Ethylene gas is a natural plant metabolite and phytohormone. In enclosed spaceship settings, ethylene build-up can be deleterious to plants. Thus, there is a need to monitor ethylene in real-time, sensitively, reversibly and effectively. State of the art technology is limited in terms of portability and ability for in-situ measurements with desired selectivity and sensitivity. To close this technology gap, InnoSense LLC (ISL) will continue developing a space-compatible, Polymer Nanowire based ethylene Monitor or PNet-Mon (TM). In Phase I, ISL fabricated a compact breadboard PNet-Mon device that demonstrated response to ppb levels of ethylene with immunity to interfering metabolites. In Phase II, ISL will optimize fabrication of the reversible sensor, develop prototype hardware having NASA-relevant footprint. The PNet-Mon prototype will be evaluated rigorously first under laboratory conditions. We have teamed with a prime contractor for testing the prototype in Advanced Plant Habitat (APH) system with the goal of integrating PNet-Mon with APH system for delivery to NASA.

Benefits: PNet-Mon is intended for use in plant growth systems and chambers in space. Once integrated into NASA systems, PNet-Mon will provide vital quantitative information, in situ, about the ethylene gas levels. The rugged, compact, and portable sensor will detect ethylene at parts per billion levels. This is critical in enclosed space settings. Successful ethylene monitoring will enable efficient crop management and prevent spoilage. PNet-Mon will be compatible with size, power and sensitivity requirements of NASA for long-term human spaceflight missions.

In addition to supporting human spaceflight missions, PNet-Mon will prove to be a valuable tool for any greenhouse, food processing, storage and distribution facility. The benefits of integrating PNet-Mon into any produce/crop supply chain would be of great interest to the industry as it could improve product quality and marketability generating lower production costs. By monitoring ethylene gas, the optimal harvest time and/or storage time/conditions can be determined. Thus, producers can achieve optimal quality and ripeness. PNet-Mon supply chain integration can help prevent produce spoilage caused by undesired levels of ethylene gas.