Microbial Monitoring and Disinfection aboard NASA Spacecraft

As NASA prepares for long-term missions aboard the International Space Station (ISS) and the eventual exploration of Mars, environmental factors such as the disinfection of potable water becomes increasingly important. During the space shuttle program, NASA's human exploration of space primarily had been limited to short-term missions and single-pass, easily cleaned water systems. Currently aboard ISS, potable water is supplied by transport of ground-filled portable containers, production from the space shuttle fuel cells, and regeneration of condensate collected in the Russian-built SRV-K. The interconnection of these systems is complex. In addition, the disinfection of potable water aboard ISS is achieved using either iodine or silver, depending on the water source. Monitoring potable water and other areas that affect the water system is accomplished using simple devices that must operate using limited power, volume, mass, and astronaut time. These devices must function in microgravity where liquid/gas phase separation is not guaranteed. Remediation of contaminated systems has historically been achieved using higher disinfectant concentrations. However, potential threats to crew health and the resistance of bacterial biofilms to disinfectants have limited the effectiveness of this approach. These and other concerns must be addressed as a new water recovery system aboard ISS is expected within the next four years and deep space missions are being designed.