Development of a Water Quality Monitor for Space Station Freedom Life Support System

In Space Station Freedom, the water supply will be a closed loop system. Humidity condensate from the cabin and waste hygiene water including urine are to be reclaimed for potable and hygiene uses. Close monitoring of the water quality is mandatory to ensure crew health. The 30-year utilization planned for SS Freedom requires careful planning for water processing and monitoring systems.

Perkin-Elmer is developing a Water Quality Monitor (WQM) for the Environmental Control and Life Support System (ECLSS) being developed by the Boeing Aerospace & Electronics Company.* The WQM will monitor impurities in both potable and hygiene water samples. The WQM consists of

1. 1)
   a high performance liquid chromatograph/ion chromatograph system to measure inorganics, phenols, and carboxylic acids,
2. 2)
   a gas chromatograph/mass spectrometer to quantitate volatile organics,
3. 3)
   a UV/VIS spectrometer to measure color, turbidity, and iodine,
4. 4)
   a mercury analyzer to detect mercury in the low parts per billion region,
5. 5)
   a total organic carbon analyzer to give indication of the total carbon level,
6. 6)
   a sensor assembly to monitor pH, conductivity, and temperature,
7. 7)
   a bacterial module to detect the bacterial growth, and
8. 8)
   a sampling system to acquire sample and distribute reagents.

The WQM will be packaged into three chassis occupying a single rack. It is being designed for automated operation with minimal crew involvement.

This paper will present the method development and the trade-off studies leading toward the WQM conceptual design. Since most of the WQM instruments have not previously been used in space, special considerations regarding microgravity operation will be discussed.