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Open-path Fourier transform infrared (OP-FTIR) spectrometry was evaluated for potential application to the measurement of contaminants in spacecraft air environments. OP-FTIR provides simultaneous, real-time quantification and confirmation of identity for most contaminants on the current Spacecraft Maximum Allowable Concentration (SMAC) list. In addition, the open-path measurement configuration provides characterization of an area rather than at a point. The dynamic composition and distribution of air contaminants throughout spacecraft air systems is measured without the need for multi-point sampling. These characteristics of open path FTIR make it a valuable method for spacecraft air characterization.

The feasibility of using open path Fourier transform infrared (OP-FTIR) spectrometry as an ambient air sensor on spacecraft was examined. OP-FTIR is a valuable monitoring technique because the sensor requires no sample preparation or separations and compositional information obtained is along a path rather than at a sampling point. OP-FTIR monitors and quantitates in real-time, offers high sensitivity, and detection is compound-specific. The data analysis, data reduction, and hardware requirements were investigated and potential applicability of chemometric methods and state-of-the-art commercial hardware systems were discussed.

A Portable Contamination/Leak Detector (PC/LD) is being developed for use by crew on Extravehicular Activity (EVA) to locate trace leaks from Space Station Freedom (SSF) systems and to monitor the surfaces of the Extravehicular Mobility Unit (EMU) for toxic contaminants being removed prior to ingress to the airlock. As with any trace level detector the background in which it operates has a significant impact on the operation and design of the instrument. The PC/LD operates in space vacuum and is sensitive to the composition and pressure which exists near the station. This paper describes the PC/LD mission, some data on the composition of ambient space environment and implications of that data on the PC/LD's design and usage.

An approach to the isolation and concentration of volatile organic compounds from a water sample prior to chemical analysis in a microgravity environment has been previously described (Reference 1). The Volatile Organics Concentrator (VOC) system was designed to attach to a gas chromatograph/mass spectrometer (GC/MS) for analysis of volatile organic compounds in water on Space Station Freedom. The VOC utilizes a primary solid sorbent for collection and concentration of the volatile compounds, transfer of the volatiles through a permeation dryer to a secondary solid sorbent, followed by thermal desorption of volatiles from the secondary sorbent onto a GC/MS system. Fabrications and preliminary testing of the VOC breadboard using a gas chromatography equipped with flame ionization detector has been previously described (Reference 2). These results have indicated that the VOC will meet or exceed the goals set for the program.

Initial efforts in the development of an EVA portable contamination detector (EVA PCD) for use by the EVA crew have resulted in the selection and preliminary testing of a concept based upon time-of-flight(TOF) mass spectrometry. The EVA PCD will be a compact, man-portable device intended for use in the ambient vacuum outside the Space Station. It will be used to monitor the surfaces of the EVA suits and mobility units for the presence of potentially toxic contaminants, such as hydrazine propellants and oxidizers, which might otherwise be inadvertently carried into the interior of the Station. The EVA PCD will also be used to locate small leaks of heat exchange fluids in the outer surface of the Station. This paper describes some key performance needs for the EVA PCD system, approaches taken to interpreting those needs, and some of the results of tradeoff analyses which led to the selection of the TOF concept. Some results from initial experimental tests of a TOF unit are presented.

An approach to the isolation and concentration of volatile organic compounds from a water sample prior to chemical analysis in a microgravity environment has been previously described (Reference 1). The Volatile Organics Concentrator (VOC) system was designed for attachment to a gas chromatograph/mass spectrometer (GC/MS) for analysis of the volatile organics in water on Space Station Freedom. The VOC concept utilizes a primary solid sorbent for collection and concentration of the the organics from water, with subsequent transfer using nitrogen gas through a permeation dryer tube to a secondary solid sorbent tube. The secondary solid sorbent is thermally desorbed to a gas chromatograph for separation of the volatiles which are detected using a mass spectrometer.

The process used to identify, select and design an approach to the isolation and concentration of volatile organic compounds from a water sample prior to chemical analysis in a microgravity environment is described. The Volatile Organics Concentrator (VOC) system described in this paper has been designed for attachment to a gas chromatograph/mass spectrometer (GC/MS) for analysis of volatile organics in water on Space Station. In this work, in order to rank the many identified approaches, the system was broken into three critical areas. These were gases, volatile separation from water and water removal/GC/MS interface. Five options involving different gases (or combinations) for potential use in the VOC and GC/MS system were identified and ranked. Nine options for separation of volatiles from the water phase were identified and ranked. Seven options for use in the water removal/GC column and MS interface were also identified and included in overall considerations.

The conditions of space environment, especially high vacuum, and the high degree of reliability required are two important aspects of the problem of lubrication for space vehicles. Experiments have been made using conventional designs to achieve high reliability, and a narrow gap seal with a calculated oil loss instead of a rubbing contact seal. Two systems are evolved from theoretical considerations derived from the kinetic theory of gases. The experiments have validated the usefulness of this approach.