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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
NASA NTRS2005

Hydrazine inactivates bacillus spores

Planetary Protection places requirements on the maximum number of viable bacterial spores that may be delivered by a spacecraft to another solar system body. Therefore, for such space missions, the spores that may be found in hydrazine are of concern. A proposed change in processing procedures that eliminated a 0.2 um filtration step propmpted this study to ensure microbial contamination issue existed, especially since no information was found in the literature to substantiate bacterial spore inactivation by hydrazine.

Bacillus↗
NASA NTRS1972

The effects of various cure cycles upon the viability of Bacillus subtillis var. niger spores within solid propellant.

Saturethane solid propellant was used in all tests. The spore inoculum was evenly distributed in the propellant. Samples weighing approximately 5 g were aseptically removed, placed into curing ovens, and exposed to cure temperatures. Initial tests were conducted at 82 and 93 C. Analysis of the obtained data indicated that the survivor curves were not linear. Exposure of the inoculated propellant samples to 93 C reduced the initial population to less than 0.01% in about 20 hours. At 82 C, approximately 168 hours were required for a similar reduction. Tests involving curing temperatures of 105 and 115 C were also conducted. It is pointed out that changes in the mechanism of spore inactivation due to chemical and physical changes in the propellant could account for the nonlinear survivor curves obtained.

Brewer, W. A.↗
NASA NTRS1973

Postflight analyses of Bacillus thuringiensis organisms exposed to space flight conditions

Cultures of B. thuringiensis returned from space flight appeared to be normal to slightly affected adversely in their ability to produce three toxins that affect insects. In addition, it can be stated that B. thuringiensis spores are very resistant to ultraviolet irradiation at the individual wavelengths and energy levels previously described. Full sunlight, however, does have a detrimental effect on the viability of B. thuringiensis spores.

Wrenn, R. T.↗