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Materials were selected for the European TD satellite with a view to avoiding contamination of its stellar ultraviolet telescopes. Materiels were selected using the micro-VCM technique, and some typical cases of materials evaluation are described. The cleanliness of the satellite was monitored during integration and test phases, and in particular during long duration thermal vacuum tests.
Design and fabrication of a mass spectrometer system for use as an atmospheric monitor by submarine is reported. The performance design goals are presented. The operation of the system is essentially automatic, providing continuous display of the partial pressures of the principal atmospheric constituents and a pushbutton update display of two freon trace contaminants. The freon update cycle takes 15 or 30 seconds, depending on which are measured. Trouble free, long term, reliable operation, and ease of maintenance are the primary system requirements. The requirement of the freon detection with high sensitivity and high resolution made redesign of the overall analyzer housing and magnet necessary.
Appendices containing equipment specifications and performance test data of the atmospheric contaminant sensor for submarines are presented.
A study was made of the spatial registration of fluoride and phosphate pollution parameters in central Florida by utilizing remote sensing techniques. Multispectral remote sensing data were collected over the area and processed to produce multispectral recognition maps. These processed data were used to map land areas and waters containing concentrations of fluoride and phosphate. Maps showing distribution of affected and unaffected vegetation were produced. In addition, the multispectral data were processed by single band radiometric slicing to produce radiometric maps used to delineate areas of high ultraviolet radiance, which indicates high fluoride concentrations. The multispectral parameter maps and radiometric maps in combination showed distinctive patterns, which are correlated with areas known to be affected by fluoride and phosphate contamination. These remote sensing techniques have the potential for regional use to assess the environmental impact of fluoride and phosphate wastes in central Florida.
Calculations of Mie scattering functions involved individual as well as mixed scattering of particles. In particular, computations were completed for a 15A particle and for particles subjected to incident light of ultraviolet wavelengths. Calculations of contaminant atmospheres for Gemini, Apollo, and Skylab considered leakage rates for the respective vehicles and the mass column density of the atmospheres surrounding them. Atmospheres for these vehicles have been computed for a uniform particle size distribution, and for a particle size distribution in which size varied.
Methods for analyzing atmospheric aerosols and particulate contaminants from natural and industrial sources are briefly described. Their development was spurred by interest in cosmic dust investigations. These methods make it possible to analyze individual particles ranging in size from 0.01 to 1000 microns for elemental and mineralogical content. The described methods include transmission electron microscopy, scanning electron microscopy, electron probe microanalysis, X-ray diffraction, optical mineralogy, and density measurement.
Analyses of biological substances and geochemical samples, of both terrestrial and extraterrestrial origin, are reported for amino acids at the 1-10 nanogram per gram level achieved by gas-liquid and ion-exchange chromatographic methods. These studies have shown that nanogram quantities of amino acids, present in water extracts of geochemical samples or in other samples of low amino acid concentration, can be successfully determined only if the researcher is well aware of the possible sources of contamination.
The modification of the Atmospheric Contaminant Sensor (ACS) to produce a carbon dioxide measuring capability is discussed. The modified instrument is described and the instructions for its operation and maintenance are included. Schematic diagrams and circuit drawings are included to clarify the text.
Current U.S. planetary quarantine standards based on international agreements require consideration of the probability of contamination (Pc) of the outer planets, Venus, Jupiter, Saturn, etc. One of the key parameters in estimation of the Pc of these planets is the probability of growth (Pg) of terrestrial microorganisms on or near these planets. For example, Jupiter and Saturn appear to have an atmosphere in which some microbial species could metabolize and propagate. This study includes investigation of the likelihood of metabolism and propagation of microbes suspended in dynamic atmospheres. It is directed toward providing experimental information needed to aid in rational estimation of Pg for these outer plants.
A theoretical analysis was performed to determine the effects of outgassing and waste dumping on the contamination field around an orbiting spacecraft. The spacecraft was assumed to be spherical in shape with the mass flow emitting uniformly from the spherical surface at a constant rate and in a D'Lambertian spatial distribution. The outflow of gases were assumed to be neutrally charged and of a single species with a molecular weight characteristic of a composite of the actual species involved in the mass flow. The theoretical analysis showed that, for outgassing only, less than 1.5 percent of the outgas products will return to the Skylab spacecraft as a result of intermolecular collisions. When the total mass flow from the spacecraft, including waste dumps and reaction control motor firings, was considered, it was estimated that about 30 percent will return to the spacecraft.
The changes are presented in spectral transmittance, and reflectance due to exposure of various optical materials to the exhaust plume of a 5-pound thrust bipropellant rocket. The engine was fired in a pulsed mode for a total exposure of 223.7 second. Spectral optical properties were measured in air before and after exposure to the exhaust plume in vacuum. The contaminating layer resulted in both absorption and scattering effects which caused changes as large as 30-50% for transmitting elements and 15% for mirrors in the near ultraviolet wavelengths. The changes in spectral properties of materials exposed to the exhaust plume for 44 and 223.7 seconds are compared and found to be similar.
Methods for analyzing and characterizing outgassing contaminants from such materials as RTV 501 potting compound and S 13 G paint are presented. Fractional distillation of a gross distillate from RTV 501 rubber was carried out and the distilled fractions examined as to their ultraviolet and infrared spectra by gas liquid chromatography. A sensitive technique for structural analysis and molecular identification was found to consist of a gas chromatography-mass spectroscopy system, which was determined to be economically unfeasible at present.
Analyses for Experiment T027, Contamination Measurement Sample Array (MSFC), to be used for evaluating the performance of the Skylab corrollary experiments under preflight, inflight, and post-flight conditions are presented. Experiment contingency plan workaround procedure and malfunction analyses are presented in order to assist in making the experiment operationally successful.
The contamination control program plan delineates the cleanliness requirements to be attained and maintained, and the methods to be utilized, in the fabrication, handling, test, calibration, shipment, pre-installation checkout and installation for the ultraviolet spectrometer experiment prototype, qualification and flight equipment.
A series of analyses for Experiment T027/S073, contamination measurement, photometer and gegenschein/zodiacal light (MSFC), to be used for evaluating the performance of the Skylab corollary experiments under preflight, inflight, and post-flight conditons is presented. Experiment contingency plan workaround procedure and malfunction analyses are presented in order to assist in making the experiment operationally successful.
A method for determining the quantity of buried contamination using solvents is presented. A nonsporocidal method with which high spore recoveries are achievable from silicone coatings and potting compounds was developed. An extension of the method to silicon potting compound RTV 60 is reported. It is stated that spores remain viable during chemical curing of silicone potting compounds and more than ninety percent of the spore population is recoverable by amine dissolution and proper plating techniques.
Six quartz crystal microbalance contamination monitors were flown on Skylab to monitor the deposition of material from spacecraft outgassing and from the rendezvous and docking maneuvers of the Command/Service Module. This report contains a quick-look analysis of the data from these units during the unmanned and manned portions of SL2.
Polymerized organic materials found in vacuum systems frequently contaminate the individual channels (which can be as small as 15 microns) of an oil-pumped channel electron multiplier array used as a vacuum UV- to visible-radiation conversion device. It is shown that exposure to an oxygen plasma is an effective means of decontaminating the channels, thereby restoring the sensitivity of the device.