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Conditions and results of tensile tests of 26 Inconel 718 and four cryoformed stainless steel specimens are presented. Conclusions determine maximum safe hydrogen operating pressure for cryogenic pressure vessels and provide definitive information concerning flaw growth characteristics under the most severe temperature and pressure conditions
Information is given regarding experimental heat-transfer data compiled for the turbulent flow of hydrogen within straight, electrically heated, round cross section tubes. Tube materials, test conditions, parameters studied, and generalized conclusions are presented.
This report attempts to indicate the current status of Space Shuttle cargo handling analysis. It is intended for use by the various organizations operating in support of the Space Shuttle effort who are investigating problems not necessarily affected by the frequent configuration and approach changes imposed on the primary task team and contractor personnel. The various studies have been analyzed and the results interwoven with the results of in-house efforts. The problems involved in orbital docking, payload extraction and transfer, cargo handling, and special-purpose missions are discussed and some tentative conclusions and recommendations are presented. This report has been reviewed and approved for release by the MSFC Shuttle Task Team. However, no statements made herein should be interpreted as position statements with respect to the Space Shuttle, the direction of future efforts, or intended methods of operation. This document reflects the view of the author, following analysis of the data available, and should not be construed as an official recommendation.
This report continues studies on cells made with low temperature (<400degC) single-cycle, lithium diffusion schedules. Measurements of concentration of lithium at the back surface showed that C(sub S) changes with time consisting of a build-up to a maximum value (above 10(exp 17) cm(exp -3)) with gradual decrease at longer diffusion times. Using the estimated C(sub S) values, theoretical lithium profiles were calculated. The calculated concentration near the PN junction was higher than those measured by the capacitance voltage (C-V) technique. The calculated concentration gradients were one-seventh of those measured by C-V methods. Both the concentration and its gradient were proportional to C(sub S). Estimates of C(sub S) obtained by extrapolating from C-V measured values of concentration and gradient near the PN junction, showed a decrease in C(sub S) for longer diffusion times. This fact supported the trend observed in Shipment C-13, where,, at longer times, the spread in values of V(sub oc), lithium concentration, and gradient became greater. The general conclusion was that the I-V characteristics were well controlled, with good cell output, but for longer diffusion times the lithium concentration gradient could have wider spread. The work described has led to greater insight into the lithium distribution dependence on the surface conditions. The surface conditions could be changed by varying the method used to apply lithium. Vacuum evaporation of lithium shows promise, and another exhaustive test of this method is in progress. Shipment C-13 is summarized, and the succeeding lots (C-14, C-15) are described. It is felt that improved monitoring of cell properties is at hand, and that the control of cell fabrication processes has advanced to where the effects of subtle differences in lithium distribution can now be seen. Evaluation is continuing on the best method to scale up the fabrication steps. A different sequence of fabrication is planned for Shipments C-14 and C-15.
Spectroscopic search for water on Mars during 1963-1970, summarizing conclusions concerning quantity and variations with location, season and from year to year
High resolution accelerometer measurements in the altitude region 140 to 300 km from a satellite in a near-polar orbit during a period of extremely high geomagnetic activity indicate that Joule heating is the primary source of energy for atmospheric heating associated with geomagnetic activity. This conclusion is supported by the following observational evidence: (1) There is an atmospheric response in the auroral zone which is nearly simulataneous with the onset of geomagnetic activity, with no significant response in the equatorial region until several hours later; (2) The maximum heating occurs at geographic locations near the maximum current of the auroral electrojet; and (3) There is evidence of atmospheric waves originating near the auroral zone at altitudes where Joule heating would be expected to occur. An analysis of atmospheric response time to this heat shows time delays are apparently independent of altitude but are strongly dependent upon geomagnetic latitude.
Eleven photographs were taken of the L sub 4 earth-moon libration region during the Gemini 12 mission. The objective was to investigate the possible existence of clouds or particles of dust orbiting the earth in the L sub 4 region by the use of photographic techniques. No identifiable data were found in the first sequence of five photographs. Star field images could be recognized in two photographs of the second sequence of pictures. A light flare, of unknown source but possibly caused by light refraction from the window of the spacecraft, was recorded in both pictures. A reconstructed star field region (as photographed) is shown Isodensitraces of the two recognizable star fields were made; however, no conclusive results were obtained.
A tri-axis flux-gate magnetometer was used on four Gemini spacecraft for determination of the magnitude and direction of the local geomagnetic field with respect to the spacecraft. Conclusions derived from the data are not only important to the proton-electron spectrometer experiment, but also are of significance to any directional charged particle experiments that may be conducted. Even though the Gemini spacecraft was not clean magnetically, the data could be reduced to a form that supplied directional information on the magnetic field in relation to the spacecraft. Stray fields were the result of spacecraft structure, not the result of current flows that were produced within the spacecraft electrical systems. Efforts were made to reduce spacecraft stray fields and to facilitate the acquisition of more accurate data.
The ionization and penetration power of various primary and secondary radiations that were present within the Gemini spacecraft was studied. This was accomplished by measurement of the contributions to dose according to profile, particle type, time, and position (location) within the spacecraft. Both active- and passive-dosimetry data collected in this experiment showed that no radiation hazard was associated with manned space operations within the Gemini spacecraft at altitudes as great as 310 kilometers in the South Atlantic anomaly region. This conclusion is warranted also by theoretical calculations.
Several tentative conclusions can be derived from the results of the synoptic terrain photography experiment, with particular reference to the results from the Gemini mission. The photographs are additional confirmation of the feasibility and value of orbital photographs for geology, geography, and oceanography. The photographs have proven to be of value in the study of the tectonic problems. Although vertical or near-vertical photography is superior to oblique photography, photographs from the Gemini 12 mission have proven that low oblique photographs, and even high oblique photographs, may be of value for certain situations. The oblique views of the Makran Range were useful substitutes for vertical photographs. Equivalent aerial coverage by vertical photographs would have necessitated a camera altitude of several hundred miles. The oblique views of the Sierra Madre Oriental have been used in the search for structures that are approximately normal to the horizon and are enhanced by the foreshortening because of the photograph.
An appendix of the supporting data leading to conclusions and recommendations for an effective intraurban transportation system from volumes 1, 2, and 3 is presented. The data are given in tables and graphs.
A description is given of the approach used in a study to identify and define engineering data for a spectrum of possible items and equipment comprising potential food systems. In addition, the material presented includes: (1) the study results containing the candidate concepts considered and technical data, performance characteristics, and sketches for each of the concepts by functional area; (2) human factors considerations for crew tasks; (3) shuttle supply interface requirements; (4) special food system study areas; and (5) recommendations and conclusions based on the study results.
Studies have been conducted to determine the influence of the tracking radar and data reduction technique on the accuracy of the meteorological measurements made in the 30 to 100 kilometer altitude region by the ROBIN passive falling sphere. A survey of accuracy requirements was made of agencies interested in data from this region of the atmosphere. In light of these requirements, various types of radars were evaluated to determine the tracking system most applicable to the ROBIN, and methods were developed to compute the errors in wind and density that arise from noise errors in the radar supplied data. The effects of launch conditions on the measurements were also examined. Conclusions and recommendations have been made concerning the optimum tracking and data reduction techniques for the ROBIN falling sphere system.
A flight computer functional executive design for the reusable shuttle is presented. The design is given in the form of functional flowcharts and prose description. Techniques utilized in the regulation of process flow to accomplish activation, resource allocation, suspension, termination, and error masking based on process primitives are considered. Preliminary estimates of main storage utilization by the Executive are furnished. Conclusions and recommendations for timely, effective software-hardware integration in the reusable shuttle avionics system are proposed.
Photography revealed the widespread and variable effects of southern corn leaf blight in Indiana. Three levels of severity of the infection could be discerned from good quality color and color infrared photography. As many as five severity levels appeared to be detectable and classifiable with multispectral scanner data and pattern recognition analysis. These conclusions are preliminary in nature, however, having been obtained from a limited amount of good quality scanner data collected over a small geographic area.
Investigations were undertaken to determine the properties of shallow aquifers and related features that influence electromagnetic energy, to determine how these properties can be detected remotely, and to establish remote sensing procedures for aiding in ground water mapping. The direct influence of aquifier characteristics on surface thermal contrasts is discussed. Conclusions reached for late summer, predawn missions were: (1) Dynamic thermal changes near the surface can be used for thermal infrared sensing to detect shallow aquifers in glacial drift. (2) Under ideal conditions, surface temperatures may be used to predict certain features related to the occurrence of shallow aquifers. (3) The timing of missions and the optimum meteorological conditions occurring prior to and during the mission are critical for night thermal missions. (4) Repetitive flights made under variable conditions provide additional evidence to verify the occurrence of shallow aquifers. (5) Imagery from this investigation, along with ERTS-simulated imagery, indicates the feasibility of applying ERTS A and B data to reconnaissance studies for detection of shallow aquifers.
The selection of a single blue band to quantitatively measure ocean chlorophyll is dependent upon the altitude and spectral bandwidth of the filter. These relationships are discussed, and the conclusion made that a blue band from 0.44 to 0.50 microns would best serve this oceanographic application.
A land use analysis of 18 selected census tracts in the Metropolitan Washington area using aerial photography was undertaken. A comparison of the results was made with comparable land use data from the Metropolitan Washington Council of Governments' Parcel File, and the results reported. Summary conclusions and recommendations for the use of photo-derived data in land use studies by COG are made.