Two simulated spacecraft water systems are being used to evaluate the effectiveness of iodine for controlling microbial contamination within such systems. An iodine concentration of about 2.0 mg/L is maintained in one system by passing ultrapure water through an iodinated ion exchange resin. Stainless steel coupons with electropolished and mechanically-polished sides are being used to monitor biofilm formation. Results after three years of operation show a single episode of significant bacterial growth in the iodinated system when the iodine level dropped to 1.9 mg/L. This growth was apparently controlled by replacing the iodinated ion exchange resin, thereby increasing the iodine level. The second batch of resin has remained effective in controlling microbial growth down to an iodine level of 1.0 mg/L. Scanning electron microscopy indicates that the iodine has impeded but may have not completely eliminated the formation of biofilm. Metals analyses reveal some corrosion in the iodinated system after 3 years of continuous exposure. Significant microbial contamination has been present continuously in a parallel noniodinated system since the third week of operation. Although coupon scrapings show that fewer bacteria were recovered from the electropolished coupon sides, scanning electron microscopy shows that electropolishing does not offer a significant advantage.
Biofilm Formation and Control in a Simulated Spacecraft Water System: Three Year Results
Sae Technical Papers
International Conference On Environmental Systems ; 1992
1992-07-01
Conference paper
English
Metals , Bacteria , Biological sciences , Spacecraft , Steel , Resins , Microscopy , Water , Corrosion
Biofilm Formation and Control in a Simulated Spacecraft Water System: Two-Year Results
SAE Technical Papers | 1991
|Biofilm Formation and Control in a Simulated Spacecraft Water System: Interim Results
SAE Technical Papers | 1989
|Attitude Control Actuators for a Simulated Spacecraft
AIAA | 2011
|Attitude Control Actuators for a Simulated Spacecraft
British Library Conference Proceedings | 2011
|Three spacecraft formation control by means of electrostatic forces
Elsevier | 2015
|