Operating and maintenance instructions for AFLIR refrigeration system X3180089-100
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Londre, F. M.↗
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Digital Data Recording System (DDRS) operating and maintenance manual
The digital data recording system (DDRS) was designed, fabricated, tested, and delivered. This unit is the interface between the synthetic aperture radar (SAR) and the recording system. The SAR data are formatted in the DDRS for data processing on the ground.
Griffin, C. R.↗
Advanced solar concentrator mass production, operation, and maintenance cost assessment
The object of this assessment was to estimate the costs of the preliminary design at: production rates of 100 to 1,000,000 concentrators per year; concentrators per aperture diameters of 5, 10, 11, and 15 meters; and various receiver/power conversion package weights. The design of the cellular glass substrate Advanced Solar Concentrator is presented. The concentrator is an 11 meter diameter, two axis tracking, parabolic dish solar concentrator. The reflective surface of this design consists of inner and outer groups of mirror glass/cellular glass gores.
Niemeyer, W. A.↗
The 747 primary flight control systems reliability and maintenance study
The major operational characteristics of the 747 Primary Flight Control Systems (PFCS) are described. Results of reliability analysis for separate control functions are presented. The analysis makes use of a NASA computer program which calculates reliability of redundant systems. Costs for maintaining the 747 PFCS in airline service are assessed. The reliabilities and cost will provide a baseline for use in trade studies of future flight control system design.
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On the generation and maintenance of turbulence in the interstellar medium
The broad spectrum of turbulent motions observed in the interstellar medium may be produced by the shearing action of differential galactic rotation. A steady state eddy distribution is maintained as energy cascades down the eddy hierarchy to smaller-scale motions. The characteristic decay time for interstellar turbulence is found to be 50-billion yr. Objections frequently raised against the presence of long-lived turbulent motions in the interstellar medium are therefore invalid, since these arguments usually presuppose that there is no source of fresh turbulent energy.
Fleck, R. C., Jr.↗
Operations and maintenance manual for the linear accelerator (sled)
The Linear Accelerator, a sliding chair which is pulled along a stationary platform in a horizontal axis is described. The driving force is a motor controlled by a velocity loop amplifier, and the mechanical link to the chair is a steel cable. The chair is moved in forward and reverse directions as indicated by the direction of motor rotation. The system operation is described with emphasis on the electronic control and monitoring functions. Line-by-line schematics and wire lists are included.
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Reusable Rocket Engine Maintenance Study
Approximately 85,000 liquid rocket engine failure reports, obtained from 30 years of developing and delivering major pump feed engines, were reviewed and screened and reduced to 1771. These were categorized into 16 different failure modes. Failure propagation diagrams were established. The state of the art of engine condition monitoring for in-flight sensors and between flight inspection technology was determined. For the 16 failure modes, the potential measurands and diagnostic requirements were identified, assessed and ranked. Eight areas are identified requiring advanced technology development.
Macgregor, C. A.↗
Specific SPS construction studies: Operations and maintenance
Surface as well as in-space operations of the solar power satellite program are addressed. The primary end products of SPS industrial enterprise are shown SPS and its ground receiving antenna every six months; and (3) construction of electric cargo orbital transfer vehicles. The production of photovoltaic cells and solar blankets is also considered.
Miller, K. H.↗
Electric propulsion: Synergy of orbit transfer and maintenance
Electric propulsion systems for transferring large payload masses to geosynchronous Earth orbits and providing accurate on-orbit stationkeeping are evaluated. Orbit boosting, inclination change, attitude control, stationkeeping, relocation, disposal, and power sharing on orbits using electric propulsion are compared with the use of chemical propulsion.
Zafran, S.↗
Phase linear interferometer experiment maintenance and calibration manual
This manual describes the necessary procedures for assuring continuous lightning sferics data collection at Marshall Space Flight Center. The phase linear interferometer experiment is under evaluation as a candidate RF sensor to support the space based optical lightning mapper system.
Goodman, S. J.↗
The role of communications, socio-psychological, and personality factors in the maintenance of crew coordination
The influence of group dynamics on the capability of aircraft crew members to make full use of the resources available on the flight deck in order to maintain flight safety is discussed. Instances of crewmembers withholding altimeter or heading information from the captain are cited as examples of domineering attitudes from command pilots and overconscientiousness on the parts of copilots, who may refuse to relay information forcefully enough or to take control of the aircraft in the case of pilot incapacitation. NASA studies of crew performance in controlled, simulator settings, concentrating on communication, decision making, crew interaction, and integration showed that efficient communication reduced errors. Acknowledgements served to encourage correct communication. The best crew performance is suggested to occur with personnel who are capable of both goal and group orientation. Finally, one bad effect of computer controlled flight is cited to be the tendency of the flight crew to think that someone else is taking care of difficulties in threatening situations.
Foushee, H. C.↗
Care 3 phase 2 report, maintenance manual
CARE 3 (Computer-Aided Reliability Estimation, version three) is a computer program designed to help estimate the reliability of complex, redundant systems. Although the program can model a wide variety of redundant structures, it was developed specifically for fault-tolerant avionics systems--systems distinguished by the need for extremely reliable performance since a system failure could well result in the loss of human life. It substantially generalizes the class of redundant configurations that could be accommodated, and includes a coverage model to determine the various coverage probabilities as a function of the applicable fault recovery mechanisms (detection delay, diagnostic scheduling interval, isolation and recovery delay, etc.). CARE 3 further generalizes the class of system structures that can be modeled and greatly expands the coverage model to take into account such effects as intermittent and transient faults, latent faults, error propagation, etc.
Bryant, L. A.↗
Time maintenance of user clocks via the tracking and data relay satellite system
A system is described which uses the Tracking and Data Relay Satellite System (TDRSS) itself to compare the user satellite clock with a clock at the White Sands station that is referenced to Universal Time Coordinated (UTC). No command of the spacecraft by the system is required, and actual on-board clock corrections are made by the spacecraft control center at its discretion. Computer models were constructed using basic orbital parameters for user and TDRS satellites. With only first-order corrections and simple averaging techniques for constant clock rates, error measurement precision of better than one microsecond was obtained. More sophisticated computations should allow considerable improvement over this.
Whitworth, G.↗
Numerical experiments on the role of radiative processes in the development and maintenance of upper level clouds
A time-dependent, two-dimensional Eulerian model is presented whose purpose is to obtain more realistic parameterizations of extended high level cloudiness, and the results of a numerical experiment using the model are reported. The model is anelastic and the Bousinesque assumption is invoked. Unresolved subgrid scale processes are parameterized as eddy diffusion processes. Two phases of water are incorporated and equilibrium between them is assumed. The effects of infrared radiative processes are parametrically represented. Two simulations were conducted with identical initial conditions; in one of them, the radiation term was never turned on. The mean values of perturbation potential temperature at each level in the domain are plotted versus height after 15, 30, and 60 minutes of simulated time. The influence of the radiative term is seen to impose a cooling trend, leading to an increased generation of ice water and an increased generation of turbulent kinetic energy in the cloud layer.
Starr, D. O'C.↗
On the maintenance of the Marine boundary layer-free tropospheric gradient of transient tracers
A simple model of the marine boundary layer is used to arrive at a steady-state budget for trace gases in this layer. Five processes maintain the tracer balance in the layer. The first is a large-scale horizontal convergence of the tracer; the second is the pumping by clouds of the tracer out of the boundary layer into the free troposphere; the third is penetration by the tracer from the free troposphere into the marine boundary from compensating subsidence in the cloud-free air surrounding cumulus clouds; the fourth is sea surface emission or deposition of the tracer; and the fifth is in situ photochemical production or loss of the tracer within the marine boundary layer. The budget equation is used in deriving an expression for the mixing ratio difference between the two regions. A scale analysis suggests that the mixing ratio difference between the marine boundary layer and the free troposphere can be an order of magnitude smaller in disturbed weather conditions than in suppressed conditions, showing that the difference in chemical concentrations between the free troposphere and the marine boundary layer cannot be rationalized solely on the basis of chemical measurements.
Gidel, L. T.↗
On the establishment and maintenance of a modern conventional terrestrial reference system
The frame of the Conventional Terrestrial Reference System (CTS) is defined by an adopted set of coordinates, at a fundamental epoxh, of a global network of stations which contribute the vertices of a fundamental polyhedron. A method to estimate this set of coordinates using a combination of modern three dimensional geodetic systems is presented. Once established, the function of the CTS is twofold. The first is to monitor the external (or global) motions of the polyhedron with respect to the frame of a Conventional Inertial Reference System, i.e., those motions common to all stations. The second is to monitor the internal motions (or deformations) of the polyhedron, i.e., those motions that are not common to all stations. Two possible estimators for use in earth deformation analysis are given and their statistical and physical properties are described.
Bock, Y.↗
Maintenance of contamination sensitive surfaces on board long-term space vehicles
In the current age, highly sensitive instruments are being flown on spacecraft, and questions of contamination have become important. The present investigation is concerned with the available approaches which can provide long-term protection for contamination sensitive surfaces. Aspects and sources of spacecraft contamination are examined, taking into account materials outgassing, particulates, propulsion system interaction, overboard venting, man-made and cosmic debris, and atomic oxygen/ambient atmosphere interaction. Suitable protection approaches provided by current technology are discussed, giving attention to aperture covers, a possibility for a retractable cover design, gaseous purges, options for prolonging the lifetime of the thermal control system, and plume shields. Some new possibilities considered are related to an early warning system for excessive amounts of contamination, a molecular/wake shield, and the use of atomic oxygen.
Phillips, A.↗
Performance management system enhancement and maintenance
The research described in this report concludes a two-year effort to develop a Performance Management System (PMS) for the NCC computers. PMS provides semi-automated monthly reports to NASA and contractor management on the status and performance of the NCC computers in the TDRSS program. Throughout 1984, PMS was tested, debugged, extended, and enhanced. Regular PMS monthly reports were produced and distributed. PMS continues to operate at the NCC under control of Bendix Corp. personnel.
Cleaver, T. G.↗