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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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Use of higher plants as dosimeters during space flights - cytological approach to study of chromosomal aberrations, mitotic changes, and growth impairment
Lossless conversion of plane laser wave to plane wave of uniform irradiance, noting planoaspheric lenses method and aberrated lens system
Information content of photoelectric star images determined by background radiation, optical aberrations and photon noise, deriving equations for rms error
Program traces rays of light through optical systems consisting of up to 65 different optical surfaces and computes the aberrations. For design purposes, paraxial tracings with astigmation and third order tracings are provided.
The mode of satellite tracking adopted at the Goonhilly earth station is to steer the aerial primarily by means of predicted data computed from the satellite orbital parameters and to superimpose, during the passage of the satellite, corrections to remove any prediction errors or aberrations due the transmission path. Predictions have proved to be highly accurate for satellites having a high mass to projected area ratio orbiting at altitudes at which air drag is very small; hence the corrections are small and infrequent.
Zone plate free from chromatic aberration and application to three-color holography
Optical system designed by third order aberration theory is significantly improved by placing it into a ray deviation design program composed of two distinct computer programs. Tests were conducted on telescope systems, an ultraviolet relay lens, and a four lens corrector system.
Escherichia coli WWU multiauxotrophic revertants with nonsense suppression, noting role in aberrant morphology and in catabolizing thymidine for energy and carbon
Pre and postflight leukocyte chromosome aberration analyses of Gemini astronauts
S-4 human blood experiment during Gemini 2 flight, studying spaceflight ionizing radiation interaction effects on single and multiple break chromosome aberrations
Encircled energy calculation in optical systems with central obstruction, observing focus error, spherical aberration and central stop effects on image contrast
Hollow-cone illumination techniques, using an annular objective aperture located behind back focal plane of objective lens, increase image contrast and minimize chromatic aberrations.
The two parts of this experiment have resulted in proof that neither orbital space flight nor any of the stresses connected with it produced significant, unpredicted genetic damage, at least insofar as chromosomal-aberration production is a valid measure of this general type of effect. Furthermore, the Gemini 11 results lead to the conclusion that no synergistic effect exists between radiation and factors that are associated with space flight. No significant difference was found between dose-effect curves for survival or mutation induction of the inflight and ground-based samples irradiated on filters. Thus, like the blood experiment, this part of the experiment failed to result in data that were appropriate for confirmation of the apparent synergism that was observed in the Gemini 3 blood experiment. Also, the Nuerospora crassa experiment provided conclusive data that there is no difference in the genetic effects of irradiation during space flight and the genetic effects obtained in ground-based experiments. Both the Gemini 11 blood experiment and the Neurospora crassa experiment thus have failed to result in data confirmatory of the apparent synergism observed on the Gemini 3 mission.
The f1 Hewitt camera is a field flattened Schmidt system of 60cm aperture. The salient features of this equipment are briefly described. Details of the methods of plate measurement are then given. The plate reduction is carried out in two stages. The plate is first calibrated using the photogrammetric method. The formulae usually quoted have been extended to take account of the large distortion introduced by the field flattening lens. In the second stage, the satellite measurements are reduced to satellite positions corrected for refraction, aberration, and when necessary, phase.
Refinement of the relationship between the trajectory of Mariner 4 in its fly-by of Mars and the calculated location of a proposed Martian bow arising from interaction of the solar wind and the ionosphere by inclusion of aberration effects of the planet's motion about the sun. The modified theory indicates that the bow wave was crossed twice during a three-hour interval following the time of closest approach of Mariner 4 to Mars, instead of being missed slightly by the spacecraft as indicated in a previous paper in which the theory of this interaction was presented, and the solar wind was considered, for simplicity, to flow along the sun-Mars line. It is shown that the observed magnetic field changed abruptly at virtually the precise times of the shock crossings indicated by the theory. Although malfunction of the plasma probe prevents observational confirmation of these as shock crossings, this coincidence supports the recent suggestion of the magnetometer experimenters that a bow wave may have been traversed. It also supports the interpretation that the bow wave results from interaction of the solar wind with the ionosphere, and not with a weak planetary magnetic field.
Description of a new method which makes it possible to reduce drastically the resolution-limiting influence of chromatic aberration, and thus to obtain high-quality images, by selecting the image-forming electrons that have passed through a small annular zone of an objective lens. In addition, the manufacture of special objective-lens aperture diaphragms that are needed for this method is also described.
Explorer 33 and 35 magnetometers, on the western and eastern flanks of the earth's bow shock, respectively, observed the boundary concurrently between 0130 and 0430 UT, Oct. 30, 1968. Contrasting shock structures were recorded. Explorer 35 saw a quiet abrupt shock, whereas Explorer 33 saw an irregular noisy boundary with much upstream wave activity. The interplanetary field was roughly in the average archimedean spiral angle and was therefore approximately tangent to the shock at Explorer 35 and normal to the shock at Explorer 33. Gross motions and variable tilting of the aberrated shock probably contributed to the peculiar sequence of shock crossings at the two spacecraft. The observations support a model of the shock in which perpendicular and oblique collisionless structures coexist and form a nonuniform magnetosheath outer boundary.
Catoptric optical scanning system provides relatively fast line-scan rate for two-dimensional coverage. Rapid scan rates require low focal ratios between components and smallest possible masses. System is relatively free from monochromatic defects and chromatic aberrations.