Computation of structural modes of a rollout array spacecraft for attitude control study
Structural modes required to determine interaction between attitude control system and flexible deployed solar electric spacecraft
Weiner, E. O.↗
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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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AM baseband telemetry techniques
Techniques and circuits used in designing AM highly flexible telemetry system comprising single sideband/double sideband/constant bandwidth compatible system - space application
Clubb, J. J.↗
Development of a collapsible reinforced cylindrical space observation window
Existing material technology was applied to the development of a collapsible transparent window suitable for manned spacecraft structures. The effort reported encompasses the evaluation of flame retardants intended for use in the window matrix polymer, evaluation of reinforcement angle which would allow for a twisting pantographing motion as the cylindrical window is mechanically collapsed upon itself, and evaluation of several reinforcement embedment methods. A fabrication technique was developed to produce a reinforced cylindrical space window of 45.7 cm diameter and 61.0 cm length. The basic technique involved the application of a clear film on a male-section mold; winding axial and girth reinforcements and vacuum casting the outer layer. The high-strength transparent window composite consisted of a polyether urethane matrix reinforced with an orthogonal pattern of black-coated carbon steel wire cable. A thin film of RTV silicone rubber was applied to both surfaces of the urethane. The flexibility, retraction system, and installation system are described.
Khan, A. Q.↗
Effects of structural flexibility on entry vehicle control systems
Control system/structure interactions of space vehicles during planetary and earth entry were investigated with principal emphasis on atmospheric entry and aerodynamic deceleration to subsonic speeds
Source record↗
Flexible format, computer accessed telemetry system
With this system, it is possible to sample and generate two or more simultaneous formats; one can be transmitted to ground station in real time, and other is stored for later transmission. Sensor output comparison data, plus information to control format, compression algorithm, and allowable degree of sensor activity, are stored in memory.
Easton, R. A.↗
Computer techniques used for some enhancements of ERTS images
The JPL VICAR image processing system has been used for the enhancement of images received from the ERTS for the Arizona geology mapping experiment. This system contains flexible capabilities for reading and repairing MSS digital tape images, for geometric corrections and interpicture registration, for various enhancements and analyses of the data, and for display of the images in black and white and color.
Billingsley, F. C.↗
Implementation experiences of NASTRAN on CDC CYBER 74 SCOPE 3.4 operating system
The implementation of the NASTRAN system on the CDC CYBER 74 SCOPE 3.4 Operating System is described. The flexibility of the NASTRAN system made it possible to accomplish the change with no major problems. Various sizes of benchmark and test problems, ranging from two hours to less than one minute CP time were run on the CDC CYBER SCOPE 3.3, Univac EXEC-8, and CDC CYBER SCOPE 3.4. The NASTRAN installation deck is provided.
Go, J. C.↗
Experimentally determined stiffness and damping of an inherently compensated air squeeze-film damper
Values of damping and stiffness were determined experimentally for an externally pressurized, inherently compensated, compressible squeeze-film damper up to excitation frequencies of 36,000 cycles per minute. Experimental damping values were higher than theory predicted at low squeeze numbers and less than predicted at high squeeze numbers. Experimental values of air film stiffness were less than theory predicted at low squeeze numbers and much greater at higher squeeze numbers. Results also indicate sufficient damping to attenuate amplitudes and forces at the critical speed when using three dampers in the flexible support system of a small, lightweight turborotor.
Cunningham, R. E.↗
Circular earth orbits attainable with fixed two-impulse expendable tug
The performance of solid rocket motors in expendable stages as an alternative concept for Shuttle interim upper stage applications is assessed from the standpoint of mission flexibility. The system comprises two stages and a payload, released from a circular Shuttle orbit at 160 naut miles altitude. The stages are sized to deliver a given payload mass to synchronous equatorial orbit. Only nonreturn missions are considered. A parametric sweep was made with small increments of pitch and yaw to compute the possible transfer orbits with an apogee greater than 160 naut miles. At several points on each transfer orbit the possibility of attaining a circular orbit with the second burn impulse of 6000 fps was assessed. Constraints on the vertical component of the second impulse and on the total velocity after firing determine the pitch angle for second burn. Results indicate a fixed two-impulse system designed to place a payload into synchronous equatorial orbit from the Shuttle orbit can deliver the payload mass into any lower circular orbit at any inclination within about 30 deg of the Shuttle orbit. The only apparent disadvantage of the system is an inability to achieve circular orbits above geosynchronous altitudes with the design payload.
Porter, R. F.↗
Multiplexed fiber-optic transmission system
Digital, audio, and video data channels spanning 100 megahertz bandwidth are transmitted via single fiber-optical link. System is flexible by virtue of its plug-in modularity and optical patchboard that allows it to adjust to data and bandwidth changes.
Bell, C. H.↗
Flexible deployable-retractable space radiators
A lightweight flexible radiator system for on-orbit cooling of space payloads is described. The radiator is packaged as a compact unit which can be attached to a vehicle structure or hatch prior to or after launch. On-orbit, it is deployed to provide the radiating surface needed for a specific experiment. The unit is being independently developed and qualified as a heat rejection system which will be ready for any spacecraft or experiment, and which will not require significant structural and systems accommodation. Design details and thermal vacuum test results are presented.
Leach, J. W.↗
Coaxial isolator has versatile interface
Approach increases system-packaging flexibility. Isolators are constructed with removable connectors that can be changed to meet user's requirements. Technique reduces development scheduling problems. Isolators can be procured before package design is firm and then readily reconfigured to meet final design requirements. Changes to existing designs to incorporate removable connectors are minimal. Small adapter plates increase size modestly; weight increase is negligible.
Olsson, D. L.↗
Medical Information Management System
On-line interactive information processing system easily and rapidly handles all aspects of data management related to patient care. General purpose system is flexible enough to be applied to other data management situations found in areas such as occupational safety data, judicial information, or personnel records.
Alterescu, S.↗
Spacelab - A new tool for cooperative research
For work in earth orbit, the European Space Agency, ESA, in cooperation with NASA, has developed a flexible laboratory system called Spacelab, which will fit into the Space Shuttle. Spacelab will offer new possibilities for conducting research related to the behavior and properties of the neutral and ionized atmosphere. Up to 400 km altitude, the total payload weight will be in excess of 25,000 kg. The main advantages of Spacelab consist of high payload weight, power, the return of the instrumentation, and the availability of man for real-time operation of the equipment. Limitations are related to the local contamination, the restriction of mission duration to periods from one to four weeks, and limited altitudes and inclinations (for early missions). Spacelab is, therefore, not suited for many types of in-situ sensing, or for long-term monitoring. Attention is given to the proposed science program, passive observations, and chemical releases and active experiments.
Schmerling, E. R.↗
Control concepts for large space structures
A comprehensive program to develop the required control technology was started at Rockwell International's Space Division. A few of the concepts under consideration for attitude, figure, and vibration control of large, flexible space systems are highlighted. In addition, an overview of the Space Division's independent research and development (IR&D) is presented. The direction of the IR&D program was influenced by requirements for electro-optical systems, shuttle erectable structures and satellite power stations.
Quartararo, R. C.↗
Experiments on multiplane balancing using a laser for material removal
The modifications of a flexible rotor system for two-plane laser balancing is described. Experimental testing of the laser material removal method for balancing through the first bending critical speed was demonstrated. The test rig, optical configuration, and a neodymium glass laser system were assembled and calibrated for static and rotating material removal rates. The laser control computer program was combined with the influence coefficient balancing process, resulting in a completely automated data acquisition, laser, and balancing system. The laser system rotor was balanced through the first bending critical speed using the laser material removal procedure to apply trial weights and correction weights without stopping the rotor.
Demuth, R. S.↗
Large Area Crop Inventory Experiment (LACIE). Development of procedure M for multicrop inventory, with tests of a spring-wheat configuration
The author has identified the following significant results. An outgrowth of research and development activities in support of LACIE was a multicrop area estimation procedure, Procedure M. This procedure was a flexible, modular system that could be operated within the LACIE framework. Its distinctive features were refined preprocessing (including spatially varying correction for atmospheric haze), definition of field like spatial features for labeling, spectral stratification, and unbiased selection of samples to label and crop area estimation without conventional maximum likelihood classification.
Horvath, R.↗
Program documentation for the space environment test division post-test data reduction program (GNFLEX)
The Space Environment Test Division Post-Test Data Reduction Program processes data from test history tapes generated on the Flexible Data System in the Space Environment Simulation Laboratory at the National Aeronautics and Space Administration/Lyndon B. Johnson Space Center. The program reads the tape's data base records to retrieve the item directory conversion file, the item capture file and the process link file to determine the active parameters. The desired parameter names are read in by lead cards after which the periodic data records are read to determine parameter data level changes. The data is considered to be compressed rather than full sample rate. Tabulations and/or a tape for generating plots may be output.
Jones, L. D.↗