Personal CO2 Monitor (PCO2M) - In-flight Evaluation of the 2x2015 Technology Demonstration

The management of carbon dioxide (CO2) levels in the habitable volume of crewed spacecraft has proven to be a challenging task. Because of vehicle and mission constraints, the goal is to strike a balance between a CO2 environment crew can function within and vehicle resources needed to maintain that CO2 environment. A key aspect to achieving such a balance is an understanding of the behavior of anthropogenic CO2 in a close-loop environment in microgravity. To this end, a wearable CO2 monitor was recently developed and flown as a technology demonstration on-board the International Space Station (ISS). The Personal CO2 Monitor (PCO2M), designed and built by the WEAR Lab (Wearable Electronics Application and Research Lab) at NASA Johnson Space Center, provides the capability of measuring CO2 concentrations as a statically deployed sensor or as a crew-worn sensor. Although the science objectives of the technology demonstration were to assess wearability principles and demonstrate an in-house designed Modular Wearable Architecture Base Board for potential application to other wearable sensors, the crew-worn sessions also provided surveys of CO2 levels in various areas of ISS. An attempt was made to correlate the crew-worn PCO2M data, as well as CO2 data from the Major Constituents Analyzer (MCA), to crew activities performed while wearing the devices. This paper will discuss the PCO2M system, in-flight usage, and findings from the technology demonstration.