Selection of a Total Organic Carbon Analyzer System for Exploration Missions

Monitoring the Total Organic Carbon (TOC) in spacecraft potable water will be of major importance in long-duration human space exploration. In-flight analysis of potable water produced from a regenerative water processor provides immediate feedback on the quality of reclaimed water for crew health as well as water processing system health monitoring. While the International Space Station (ISS) successfully employs a Total Organic Carbon Analyzer (TOCA) to complete these tasks, the device is too large for long-duration missions, especially when accounting for resupply needs. In addition, the water processing system does not directly integrate the current TOCA system to provide automated in-line water analysis. This paper reports on recent effort to develop the next generation TOCA designed for the unique requirements of an exploration-class mission. Following previous technology surveys and feasibility assessment, a number of breadboard systems were developed and tested for proof-of-concept and performance assessment at a system level. Each system was evaluated for feasibility against performance requirements. A trade study assessed the remaining candidates to find the most desirable system. This paper highlights the system architecture and performance of the top candidates. The selected system will continue maturation to a ground prototype followed by plans for technology demonstration on the ISS.