Advances in spacesuits are required to support the ISS and future human exploration. Spacesuit development and ground-based testing tasks require sensing and analytical instrumentation for characterizing and validating prototypes. While miniature thermosensors measure reliably at low cost, and can be incorporated all around spacesuit prototypes, incorporating gas sensors at locations of interest inside a spacesuit has been a significant challenge in particular for human subject tests because of the size and cost of available instrumentation. The sensor probes and cables must not restrict the suit or human subjects' mobility, and must not disturb the gas flow. Intelligent Optical System proposes to develop luminescence-based sensing patches for non-intrusive monitoring of critical life support gas constituents and potential trace contaminants in spacesuits. Flexible sensitive patches inside prototype spacesuits will be interrogated via optical fibers, and will not disturb the gas flow or the human subject. This will give suit engineers great flexibility for choosing multiple sensing points, fitting the sensor elements into the spacesuit, and cost effectively relocating the sensor elements as desired.