The sensor requirements for monitoring liquid phase parameters in Bioregenerative-Life-Support-Systems (BLSSs) for space application are reviewed. The requirement to measure many parameters over long time periods and at different nodes of Closed Ecological Systems, was determined. The demanding operational characteristics required of sensors for BLSS application were found to be very difficult to achieve with even state-of-the-art advanced chemical sensors, particularly biosensors. Flow-Injection-Analysis (FIA) was considered to represent the most appropriate interface technology for near-term application of these sensors. The recent emergence of Microsystems Technologies, and particularly Integrated Chemical Analysis Microsystems, are proposed as the means by which FIA, chemosensors and biosensors can be interfaced with space BLSSs in a flexible, modular and miniaturised format.