S11: Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

Monday, October 29, 2012: 9:30 AM
Michele N. Birmele1, Megan Morford2, Janicce Caro1, Gerard Newsham1, Michael Roberts1 and Ray Wheeler2, (1)ESC-850, Engineering Services Contract, Ksc, FL, (2)NE-S, NASA, Ksc, FL
Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems.  Requirements set by NASA puts limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control.  Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments.  Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (PCR) for microbial identification.  Additional research is being conducted on how to control for microbial contamination on a continual basis.  Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed.  This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.