Thermal spore exposure vessels (TSEVs) are laboratory containers designed for use in measuring rates of death or survival of microbial spores at elevated temperatures. A major consideration in the design of a TSEV is minimizing thermal mass in order to minimize heating and cooling times. This is necessary in order to minimize the number of microbes killed before and after exposure at the test temperature, so that the results of the test accurately reflect the effect of the test temperature.
A typical prototype TSEV (see figure) includes a flat-bottomed stainless-steel cylinder 4 in. (10.16 cm) long, 0.5 in. (1.27 cm) in diameter, having a wall thickness of 0.010±0.002 in. (0.254±0.051 mm). Microbial spores are deposited in the bottom of the cylinder, then the top of the cylinder is closed with a sterile rubber stopper. Hypodermic needles are used to puncture the rubber stopper to evacuate the inside of the cylinder or to purge the inside of the cylinder with a gas. In a typical application, the inside of the cylinder is purged with dry nitrogen prior to a test.
During a test, the lower portion of the cylinder is immersed in a silicone-oil bath that has been preheated to and maintained at the test temperature. Test temperatures up to 220 °C have been used. Because the spores are in direct contact with the thin cylinder wall, they quickly become heated to the test temperature.
This work was done by Robert A. Beaudet, Michael Kempf, and Larry Kirschner of Caltech for NASA’s Jet Propulsion Laboratory.
NPO-41091
This Brief includes a Technical Support Package (TSP).
Thermal Spore Exposure Vessels
(reference NPO-41091) is currently available for download from the TSP library.
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Overview
The document is a Technical Support Package from NASA’s Jet Propulsion Laboratory (JPL) concerning the Thermal Spore Exposure Vessel (TSEV), identified by NTR Number 41091. It is part of NASA Tech Briefs, which disseminate information about aerospace-related developments that have potential technological, scientific, or commercial applications.
The TSEV is designed to facilitate research into the effects of thermal exposure on spores, which can be crucial for understanding microbial survival in extreme environments, such as those encountered in space exploration. This technology could have implications for astrobiology, planetary protection, and the study of life in extreme conditions.
The document emphasizes the importance of compliance with U.S. export regulations, indicating that the information may contain proprietary data from Caltech/JPL. It also provides contact information for further assistance, including the NASA Scientific and Technical Information (STI) Program Office, which offers additional resources and publications related to research and technology in this area.
The Technical Support Package serves as a resource for researchers and industry professionals interested in the applications of the TSEV technology. It highlights NASA's commitment to sharing advancements that could benefit a wider audience beyond aerospace, fostering innovation and collaboration in various fields.
Overall, the document encapsulates NASA's efforts to promote technological advancements and partnerships through the dissemination of research findings, while also ensuring that proprietary information is protected and that users are aware of their responsibilities regarding the use of this information.
