Description: NASA is investigating alternative carbon dioxide monitoring technologies to devices based on infrared absorption for space suit and PLSS development, to operate under conditions and geometries that current gas sensors cannot. In support of this effort, Intelligent Optical Systems (IOS) is developing an optical sensor probe to monitor carbon dioxide and humidity, which can operate in high humidity environments and directly report the partial pressure of the analyte of interest. For space and space training systems, these miniature sensor elements with remote optoelectronics give unmatched design flexibility for measurements in highly constrained volume systems such as the space suit. The proposed technology is particularly suitable for space suit and PLSS ground-based testing. For those applications, sensing patches perform non-intrusive monitoring of critical gas constituents and trace contaminants in space suits. Flexible sensor patches inside space suits are interrogated via optical fibers, which do not disturb the gas flow or the human subject. The technology will also provide a distributed measurement of the gases in the suit, and be able to access locations not accessible by any other sensor technology. The proposed Phase II Extended project will build on the knowledge gained in Phase II to optimize and streamline the process of calibrating and deploying the sensors. An on-site calibration unit will be developed and delivered to NASA so that the sensors can be shipped to the NBL up to a month before use, and calibrated in the days leading up to an NBL training event. The on-site calibrator will enable IOS to deliver 100 sensor pairs to the NBL to support 50 training events with two crew members using the NIOGS system simultaneously.

Benefits: - Monitoring physiological gases in space suits without compromising the pressure envelope. - Sensing can be performed both underwater and in a dry environment. - Compatible with ISS EMU and likely compatible with the xEMU space suit.

- Testing of suits for commercial space providers. - Non-invasive monitoring of dissolved gases in pipelines.