SEARCH · Engineering Papers
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Motion induced errors in a tuned, flexure-mounted strapdown gyro are investigated. Analytic expressions are developed for errors induced by linear vibrations, angular motion, and detuning. Sensor-level errors (gyro drift rate) and system-level errors (navigation errors) that are stimulated by an actual dynamic motion environment are computed.
A practical laboratory technique is presented for evaluating the thermal characteristics of the diode/diode header combinations in terms of the diode spectrum and efficiency. Experimental data are presented verifying this technique for a GaALAs light emitting homojunction diode mounted on an oxygen-free high conductivity copper header.
Some of the test techniques used to evaluate the outgassing and contamination characteristics of prospective Apollo telescope mount (ATM) materials are reviewed. These include a screening test providing information on weight losses of materials, weights of their condensed outgas products, and white-light scattered by the condensed products. They also include an ultraviolet-region screening test and a comprehensive continuous in situ weight-loss test. Examples are presented of data obtained from each of the tests on various prospective ATM materials.
The theoretical derivation of the set of equations is discussed which is applicable to modeling the dynamic characteristics of aeroelastically-scaled models flown on the two-cable mount system in a 16 ft transonic dynamics tunnel. The computer program provided for the analysis is also described. The program calculates model trim conditions as well as 3 DOF longitudinal and lateral/directional dynamic conditions for various flying cable and snubber cable configurations. Sample input and output are included.
A contract for modernization of the Mount Wilson 60-inch telescope was awarded. Under this contract, the original hour angle and declination drives were replaced, digital coordinate readouts were added, a Cassegrain/ coude flip cage was built and installed, the telescope was completely rewired, a new control console was installed, and a coude spectrograph was completed. Extensive building modifications also were made to provide a working floor at mezzanine level for a computer and a coude observing room. These modifications and additions were completed by February 1970, and the telescope returned to regular and continuous use for stellar and planetary astronomy.
A detailed evaluation is presented of the Skylab Apollo Telescope Mount experiments performance throughout the eight and one-half month Skylab Mission. Descriptions and the objectives of each instrument are included. The anomalies experienced, the causes, and corrective actions taken are discussed. Conclusions, based on evaluation of the performance of each instrument, are presented. Examples of the scientific data obtained, as well as a discussion of the quality and quantity of the data, are presented.
A summary of the Apollo Telescope Mount (ATM) performance during the 8.5-month Skylab mission is presented. A brief description of each ATM system, system performance summaries, discussion of all significant ATM anomalies which occurred during the Skylab mission, and, in an appendix, a summary of the Skylab ATM Calibration Rocket Project (CALROC) are provided. The text is supplemented and amplified by photographs, drawings, curves, and tables. The report shows that the ATM not only met, but exceeded premission performance criteria, and that participation of man in space for this scientific investigation greatly enhanced the quality and quantity of the data attained.
The roll plane radiation patterns of on-aircraft antennas are analyzed using high frequency solutions. This is a basic study of aircraft-antenna pattern performance in which the aircraft is modelled in its most basic form. The fuselage is assumed to be a perfectly conducting elliptic cylinder with the antennas mounted near the top or bottom. The wings are simulated by arbitrarily many sided flat plates.
A technical history and management critique of the Skylab Apollo Telescope Mount (ATM) from initial conception through the design, manufacturing, testing and prelaunch phases is presented. A mission performance summary provides a general overview of the ATM's achievements in relationship to its design goals. Recommendations and conclusions applicable to hardware design, test program philosophy and performance, and program management techniques for the ATM with potential application to future programs are also discussed.
The primary mirror of a large (26-inch diameter aperture) solar telescope was made of glass ceramic and designed with an integral hub on the back of the center of the mirror. This permits heat from the mirror to radiate off its back to a nearby cold plate. To permit mounting without high stresses, the hub was ground down to a smooth cylindrical surface 3.5 inch in diameter. The ground surface was then acid-etched to remove 0.007 inch (on the diameter) by immersion for five minutes in a mixture of four parts 92% sulfuric acid and three parts 50% hydrofluoric acid. The acid etching removes microcracks from the ground Cer-Vit surface. An Invar sleeve was fabricated to fit over the hub with about 0.010 inch radial (0.020 inch diametral) clearance.
Information necessary for successful performance of the observer's function in the White Light Coronagraph portion of the Apollo Telescope Mount experiments is presented. The pre-flight, in-flight, and post-flight operations required to perform the S-052 experiment are described. A discussion of the scientific objectives of the experiment and a description of the hardware are provided.
Design and development of six gimballed star trackers for Skylab's Apollo Telescope Mount, which performed successfully on all three manned Skylab missions and accumulated a total usage time of approximately 3,500 hours, is described in terms of configurations, materials and construction, qualification testing, performance, and reliability characteristics. A brief program history and design changes incorporated during the life of the program are also discussed. Extensive drawings, block diagrams, and photographs are provided.
The Skylab Saturn Workshop Assembly was designed to expand the knowledge of manned earth orbital operations and accomplish a multitude of scientific experiments. The Apollo Telescope Mount (ATM), a module of the Skylab Saturn Workshop Assembly, was the first manned solar observatory to successfully observe, monitor, and record the structure and behavior of the sun outside the earth's atmosphere. The ATM contained eight solar telescopes that recorded solar phenomena in X-ray, ultraviolet, white light, and hydrogen alpha regions of the electromagnetic spectrum. In addition, the ATM contained the Saturn Workshop Assembly's pointing and attitude control system, a data and communication system, and a solar array/rechargeable battery power system. This document presents the overall ATM thermal design philosophy, premission and mission support activity, and the mission thermal evaluation. Emphasis is placed on premission planning and orbital performance with particular attention on problems encountered during the mission. ATM thermal performance was satisfactory throughout the mission. Although several anomalies occurred, no failure was directly attributable to a deficiency in the thermal design.
The concepts are discussed which are being considered and developed for surface-mounted wiring using flat conductor cable. Safety aspects, problems being encountered, and advantages are also discussed.
The Apollo Telescope Mount (ATM) containing eight telescopes that cover wavelengths ranging from 2 to 6563 A is described. These are a white light coronograph, an XUV coronal spectroheliograph, and XUV spectrograph, an X-ray spectrographic telescope, a UV scanning polychromator/spectroheliometer, an X-ray telescope, and two H-alpha telescopes. The purpose, performance, and characteristic features of each of these instruments are discussed. The extremely high quality of the transmitted data is noted, and solar photographs are presented.
The structure, physical properties of ejecta, ballistics, and growth of Northeast crater, a young pyroclastic cone that originated in 1911 near the summit of Mount Etna, Sicily, were studied in order to form a model of volcano cinder cone growth. Four stages of growth were discerned: (1) a simple cone; (2) a cone with an outward-dipping talus slope; (3) destruction of rounded rim by the inward migration of the upper edge of the talus pile; and (4) extension of limits of talus pile beyond the ballistic limit of ejecta trajectories. The model is used to predict the features of lunar and Martian cones, assuming that they erupted under conditions qualitatively similar to Etna's Northeast crater.
Mount includes metallic cup and support ring placed in mold fixture. Viscoelastic material is injected between these parts by means of large hypodermic needle. Circular projections on cup and ring extend into material and are kept in place without dependence on quality of adhesion between material and metal.
Mounting clamps attach polymeric film sample to thermomechanical analyzer. Using this technique, temperature at which polymer passes from relatively nonflexible or glasslike state to rubbery condition where it exhibits marked increase in flow properties is readily determined.