Survival of soil bacteria during prolonged desiccation
Survival of soil bacteria during prolonged desiccation
Alexander, M.↗
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Survival of Antarctic desert soil bacteria exposed to various temperatures and to three years of continuous medium-high vacuum
Survival of Antarctic dessert soil bacteria exposed to various temperatures and to three years of continuous medium-high vacuum
Cameron, R. E.↗
Spacecraft component survivability during entry into the Jovian atmosphere
Investigation of survivability of spacecraft components during entry of Jupiter atmosphere to determine probability of biological contamination
Swenson, B. L.↗
Survival of a Jovian atmospheric probe
Thermal control, pressure survival and structural tradeoffs of Jovian atmospheric probe for mission parametric studies
Schelden, B. G.↗
Survival of microorganisms in a simulated Martian environment
Simulated Martian environment effects on terrestrial microorganisms survival
Fraser, S. J.↗
An emergency survival suit
A thermally insulative inflatable garment designed specifically as a lightweight low storage volume emergency suit for subzero weather survival is reported. Testing confirms that the inflatable suit design satisfies the objectives for a subject standing at rest with environmental temperatures down to -450 F if the garment is inflated with Freon.
Curtis, D. L.↗
Survival of bacterial isolates exposed to simulated Jovian trapped radiation belt electrons and solar wind protons
With missions to Jupiter, the spacecraft will be exposed for extended duration to solar wind radiation and the Jovian trapped radiation belt. This study is designed to determine the effect of these radiation environments on spacecraft bacterial isolates. The information can be used in the probability of contamination analysis for these missions. A bacterial subpopulation from Mariner Mars 1971 spacecraft (nine sporeforming and three nonsporeforming isolates) plus two comparative organisms, Staphylococcus epidermidis ATCC 17917 and a strain of Bacillus subtilis var. niger, were exposed to 2-, 12-, and 25-MeV electrons at different doses with simultaneous exposure to a vacuum of 0.0013 N/sqm at 20 and -20 C. The radioresistance of the subpopulation was dependent on the isolate, dose, and energy of electrons. Temperature affected the radioresistance of only the sporeforming isolates. Survival data indicated that spores were reduced approximately 1 log/1500 J/kg, while nonsporeforming isolates (micrococci) were reduced 1.5 to 2 logs/1500 J/kg with the exception of an apparent radioresistant isolate whose resistance approached that of the spores. The subpopulation was found to be less resistant to lower energy than to higher energy electrons.
Taylor, D. M.↗
The Effect of Temperature on the Survival of Microorganisms in a Deep Space Vacuum
A space molecular sink research facility (Molsink) was used to evaluate the ability of microorganisms to survive the vacuum of outer space. This facility could be programmed to simulate flight spacecraft vacuum environments at pressures in the .1 nanotorr range and thermal gradients (30 to 60 C) closely associated to surface temperatures of inflight spacecraft. Initial populations of Staphylococcus epidermidis and a Micrococcus sp. were reduced approximately 1 log while exposed to -105 and 34 C, and approximately 2 logs while exposed to 59 C for 14 days in the vacuum environment. Spores of Bacillus subtilis var. niger were less affected by the environment. Initial spore populations were reduced 0.2, 0.3, and 0.8 log during the 14-day vacuum exposure at -124, 34, and 59 C, respectively.
Hagen, C. A.↗
Cold sea survival.
Two prototype three-man life rafts were evaluated during the winter months in Arctic waters off Kodiak Island, Alaska, to assess potential survival problems and determine tolerance limits. Each raft incorporated thermal characteristics specifically designed for cold water. Water and air temperatures varied from 0 to +2 C and -5 to +4 C respectively. All subjects were removed upon reaching subjective tolerance. The results showed that none of the clothing assemblies was adequate to maintain a person in comfort even with dry boarding. No significant biochemical shifts in the blood or urine were found. The TUL raft was found to be superior in its thermal characteristics and afforded better subject protection. General tolerance for cold water immersion, wet and dry, and cold water raft exposures are depicted graphically, based on previously reported data.
Veghte, J. H.↗
Survival, profits and resource utilization
The intertwining of CAB regulation and airline operations makes it impossible to use operating and financial data from the regulated airlines to determine the extent to which regulation affects costs. The essentially nonregulated, but otherwise, similar, intrastate airlines operating wholly within California (and thus beyond the CAB's jurisdiction) provide a benchmark with which to compare the performance of regulated airlines and thus measure the effects of CAB regulation. This comparison, shows that the nonregulated environment within California has been a much sterner disciplinarian of airline operations than the regulated environment of interstate air transportation. Issues of survival, profits, efficiency, fares, and the impacts of CAB regulation on costs are examined.
Jordan, W.↗
Effect of simulated lunar impact on the survival of bacterial spores.
In order to test the effect of impact on organisms, the survival of bacterial spores after being propelled at high velocity in Pyrex and plastic beads into crushed basalt was measured. The beads were fired into sterilized canisters by both a conventional powder and a light gas gun. Results indicate that at the minimum (2.4 km/sec) lunar capture velocity, the number of colony forming units (CFUs) decreased by five orders of magnitude, and at 5.5 km/sec, statistically a more probable capture velocity, no CFUs were found. The decrease in CFUs observed with increasing velocity indicates that the spores were most probably killed by the impact.
Whitfield, O.↗
Circadian timing of single daily 'meal' affects survival of mice
It is shown that the survival of young mice after abrupt restriction to a single 4-hr span of daily food accessibility can depend on the temporal placement of this feeding span in relation to the lighting regimen. Housing conditions are an important codeterminant of this response.
Nelson, W.↗
Survival probabilities for interstellar hydrogen flowing into the interplanetary system from far regions of the heliosphere
The expressions for 'survival' probabilities are presented for an atomic hydrogen particle moving on a trajectory from far regions of the heliosphere to the vicinity of the sun. Three 'destroying' processes have been considered; photoionization, charge transfer and electron ionization. The solar wind has been assumed to be a two-flux steady stream radially expanding with constant flow velocity. Recent profiles of solar-wind electron temperature have been used. The results can be useful for theoretical analyses as well as for analysis of spaceflight observations.
Kunc, J. A.↗
The survival of solar flare tracks in interplanetary dust silicates on deceleration in the earth's atmosphere
Pulse heating experiments on magnesium-rich olivine and pyroxene, two silicates often found in micrometeorites collected in the stratosphere, show that iron ion tracks remain detectable in the transmission electron microscope for temperature maxima up to approximately 600 C. Assuming thermal emissivities near unity, this implies that micrometeorites with surface densities above 1 mg/sq cm are likely to have their track record erased, and that tracks in reentrant or low-density micrometeorites smaller than 7 microns in size are likely to survive atmospheric entry.
Fraundorf, P.↗
A topology for computer networks with good survivability characteristics and low transmission delays between node computers
Various network topologies are developed which have not appeared in the literature before which result in minimum diameter graphs for computer networks having connectivity four. The topologies presented have good survivability characteristics and result in more topologies being available for computer network designers which achieve the minimum diameter resulting in small transmission delays.
Kelly, G. L.↗
Crustal radiogenic heat production and the selective survival of ancient continental crust
It is pointed out that the oldest terrestrial rocks have so far revealed no evidence of the impact phase of Earth evolution. This observation suggests that processes other than impact were dominant at the time of stabilization of these units. However, a use of the oldest terrestrial rocks as a sample of the early terrestrial crust makes it necessary to consider the possibility that these rocks may represent a biased sample. In the present study, the global continental heat flow data set is used to provide further evidence that potassium, uranium, and thorium abundances are, on the average, low in surviving Archean crust relative to younger continental crust. An investigation is conducted of the implications of relatively low crustal radiogenic heat production to the stabilization of early continental crust, and possible Archean crustal stabilization models are discussed.
Morgan, P.↗
Crustal radiogenic heat production and the selective survival of ancient continental crust
It is pointed out that the oldest terrestrial rocks have so far revealed no evidence of the impact phase of earth evolution. This observation suggests that processes other than impact were dominant at the time of stabilization of these units. However, a use of the oldest terrestrial rocks as a sample of the early terrestrial crust makes it necessary to consider the possibility that these rocks may represent a biased sample. In the present study, the global continental heat flow data set is used to provide further evidence that potassium, uranium, and thorium abundances are, on the average, low in surviving Archean crust relative to younger continental crust. An investigation is conducted of the implications of relatively low crustal radiogenic heat production to the stabilization of early continental crust, and possible Archean crustal stabilization models are discussed.
Morgan, P.↗
Optimization techniques applied to passive measures for in-orbit spacecraft survivability
Optimization techniques applied to passive measures for in-orbit spacecraft survivability, is a six-month study, designed to evaluate the effectiveness of the geometric programming (GP) optimization technique in determining the optimal design of a meteoroid and space debris protection system for the Space Station Core Module configuration. Geometric Programming was found to be superior to other methods in that it provided maximum protection from impact problems at the lowest weight and cost.
Mog, Robert A.↗