Humidity is a critical variable for monitoring and control on extended duration missions because it can affect the operation and efficiency of closed loop life support systems. Humidity sensors are needed for real-time process control over the critical O2, H2, and CO2 gas streams in the system. Sensors with the right combination of performance, size, low power consumption, and durability for this application are not available. Synkera proposes to develop an advanced microsensor for humidity, which takes advantage of an innovative combination of nanomaterials and ceramic MEMS technology to meet the need for reliable and accurate humidity process control sensors for spacecraft. In Phase I, we will demonstrate the feasibility of integrating the elements described above to prepare a stable and accurate sensor, which will advance the technology from TRL 3 to 4. Then, in Phase II and beyond, we will work with an ECLSS prime contractor to develop space-qualified prototypes that are commercially viable for NASA and third-party applications and to integrate these sensors within NASA's closed loop life support systems.