InnoSense LLC (ISL) proposes to develop a miniaturized, multi-analyte sensor for near real-time monitoring of analytes in the spacecraft environment. The proposed innovations will build on ISL's past NASA SBIR project to develop an oxygen sensor for aircraft fuel tanks and DOE funded project to develop a carbon dioxide sensor for unattended remote deployment. In this project ISL will incorporate the disparate sensors on a single chip and develop a space-worthy sensor array. Through iterative development, ISL will expand capabilities of the system to monitor chemical, microbial and particulate content in the spacecraft environment. The proposed Phase I studies will demonstrate the sensor array approach by detecting oxygen, carbon dioxide and moisture simultaneously at the low parts per million (ppm) levels with a signal to noise ratio (SNR) of at least 3. A prototype sensor array system will be constructed and field-tested during Phase II. To assure success of this project, InnoSense LLC has assembled an engineering team with a cumulative 80 person-years of experience in developing commercially viable optical sensor systems.