Study of the Mariner Mars 66 spacecraft
Mariner Mars 66 spacecraft mission study - probabilities of successfully transmitting encounter TV science data, releasing capsule for Mars landing, and command systems logic
MISSION PLANNING↗
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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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A method for controlling parachute deployment conditions in simulated planetary environments.
NASA Planetary Entry Parachute Program /PEPP/, discussing method to control parachute deployment conditions in simulated planetary environments by radio command system
Murrow, H. N.↗
Rapid automatic sync acquisition via the telemetry and ranging channels.
Automatic synchronization acquisition of interplanetary flight command system by adjustment of ground code generator via telemetry
Anderson, T. O.↗
Random walk techniques in the solution of first order digital phase-locked loops
First order digital phase locked loops analysis for single channel command system, using random walk techniques
Holmes, J. K.↗
Hybrid carrier and modulation tracking loops.
The tracking loops presented herein exploit the coherency of the observed data sidebands at the carrier frequency for improvements in phase-coherent tracking, telemetry, and command system performance. The loop is motivated by one aspect of generalized harmonic analysis, viz., the so-called cross spectrum. The basic idea of the loop centers around using the power in the composite received signal (sidebands including cross-modulation components) to enhance the signal-to-noise ratio in the carrier tracking loop, thereby reducing the noisy reference loss and ultimately the subcarrier reference jitter, the symbol sync jitter, and the error probability of the data detector. The modulation from the extracted sidebands is removed in such a way that the coherence power in the data sidebands can be used for tracking at the carrier frequency.
Lindsey, W. C.↗
A concatenated coding scheme for extremely low error probabilities.
A coded command system is described which is capable of achieving extremely low error probabilities at moderate signal-to-noise ratios. Emphasis is placed on the implementation of the spaceborne portions of the system.
Stiffler, J. J.↗
Simulator evaluation of the flying qualities of externally blown flap and augmentor wing transport configurations
Concurrent simulations of powered-lift STOL transport aircraft having either an externally blown flap configuration or an augmentor wing configuration were conducted. The following types of simulators of varying sophistication were used: (1) a simple fixed-base simulation with a simple visual display, (2) a more complex fixed-base simulation using a realistic transport cockpit and a high-quality visual display, and (3) a six-degree-of-freedom motion simulator that had a realistic transport cockpit and a sophisticated visual display. The unaugmented flying qualities determined from these simulations were rated as unacceptable for both the externally blown flap and augmentor wing configurations. The longitudinal, lateral-directional, and single-engine-failure characteristics were rated satisfactory with extensive augmentation, including pitch and roll command systems, flight-path (or speed) augmentation, turn coordination, and effective yaw damping. However, the flare and landing characteristics from any approach glide-path angle in excess of 4 deg were rated as unsatisfactory but acceptable.
Kier, D. A.↗
A simple second-order digital phase-locked loop.
A simple second-order digital phase-locked loop has been designed for the Viking Orbiter 1975 command system. Excluding analog-to-digital conversion, implementation of the loop requires only an adder/subtractor, two registers, and a correctable counter with control logic. The loop considers only the polarity of phase error and corrects system clocks according to a filtered sequence of this polarity. The loop is insensitive to input gain variation, and therefore offers the advantage of stable performance over long life. Predictable performance is guaranteed by extreme reliability of acquisition, yet in the steady state the loop produces only a slight degradation with respect to analog loop performance.
Tegnelia, C. R.↗
Design definition study of NASA/Navy lift/cruise fan V/STOL aircraft. Volume 1: Summary report of Navy multimission aircraft
This report presents results of a study by the Rockwell International Corporation for the NASA Ames Research Center and the Naval Air Systems Command of promising Navy lift-cruise fan V/STOL aircraft for the 1980-1985 time period. The purpose of the study was to identify the likely technical and operating characteristics and technology requirements for the ultimate development of this type aircraft. The study focused on identifying aircraft individually optimized to perform the anti-submarine warfare, carrier onboard delivery, combat search and rescue, surveillance and surface attack missions, and a multi-purpose aircraft concept capable of performing all five missions at minimum total program cost. The configuration features the use of two 1.3 fan pressure ratio, single stage lift-cruise fans and three current design J97 gas generators with a high mounted high aspect ratio wing with winglets. The design missions can be performed at takeoff weights ranging from approximately 32,000 to 39,000 pounds. Top speed is 0.80 Mach number at sea level and 0.885 at altitude, Advanced composite structural technology and advanced subsystem concepts are employed. One basic fuselage design, with alternate bolt-in floor structures, meets all the mission requirements.
Robert L Cavage↗
Some research advances in computer graphics that will enhance applications to engineering design
Research in man/machine interactions and graphics hardware/software that will enhance applications to engineering design was described. Research aspects of executive systems, command languages, and networking used in the computer applications laboratory are mentioned. Finally, a few areas where little or no research is being done were identified.
Allan, J. J., III↗
The SAS-3 X-ray observatory
The experiment section of the Small Astronomy Satellite-3 (SAS-3) launched in May 1975 is an X-ray observatory intended to determine the location of bright X-ray sources to an accuracy of 15 arc-seconds; to study a selected set of sources over a wide energy range, from 0.1 to 55 keV, while performing very specific measurements of the spectra and time variability of known X-ray sources; and to monitor the sky continuously for X-ray novae, flares, and unexpected phenomena. The improvements in SAS-3 spacecraft include a clock accurate to 1 part in 10 billion, rotatable solar panels, a programmable data format, and improved nutation damper, a delayed command system, improved magnetic trim and azimuth control systems. These improvements enable SAS-3 to perform three-axis stabilized observations of any point on the celestial sphere at any time of the year. The description of the experiment section and the SAS-3 operation is followed by a synopsis of scientific results obtained from the observations of X-ray sources, such as Vela X-1 (supposed to be an accreting neutron star), a transient source of hard X-ray (less than 36 min in duration) detected by SAS-3, the Crab Nebula pulsar, the Perseus cluster of galaxies, and the Vela supernova remnant.
Mayer, W. F.↗
Bearing restoration by grinding
A joint program was undertaken by the NASA Lewis Research Center and the Army Aviation Systems Command to restore by grinding those rolling-element bearings which are currently being discarded at aircraft engine and transmission overhaul. Three bearing types were selected from the UH-1 helicopter engine (T-53) and transmission for the pilot program. No bearing failures occurred related to the restoration by grinding process. The risk and cost of a bearing restoration by grinding programs was analyzed. A microeconomic impact analysis was performed.
Hanau, H.↗
On-orbit checkout study
The spaceborne testing equipment carried by the orbiter and the measuring equipment onboard the satellite (telemetry) is tested to verify that each is operating satisfactorily. The satellite command system is also checked. Thermal stabilization with the satellite in the orbiter shadow is achieved in six to eight hours. Satellite subsystem tests are run, and thermal control by heaters is checked. Thermal stabilization with the satellite exposed to the sun (when the orbiter is in sunlight) is again achieved in an estimated six to eight hours. Subsystem tests are again run in the hot condition, and heat rejection tests are made.
Pritchard, E. I.↗
User's guide to SFTRAN/1100
Extensions and improvements were made to SFTRAN, a structured programming language. This language was implemented as a precompiler that translates from SFTRAN to FORTRAN. It was available to batch and conversational users of the UNIVAC 1100 computer system. The SFTRAN language and its use are described. In addition, conversational time-sharing system command subroutines were implemented that eliminated the complications of dealing with extra files and processing steps that the use of a precompiler would otherwise require. These command subroutines are reported, and their use is illustrated by examples.
Ford, W. F.↗
Application of multispectral radar and LANDSAT imagery to geologic mapping in death valley
Side-Looking Airborne Radar (SLAR) images, acquired by JPL and Strategic Air Command Systems, and visible and near-infrared LANDSAT imagery were applied to studies of the Quaternary alluvial and evaporite deposits in Death Valley, California. Unprocessed radar imagery revealed considerable variation in microwave backscatter, generally correlated with surface roughness. For Death Valley, LANDSAT imagery is of limited value in discriminating the Quaternary units except for alluvial units distinguishable by presence or absence of desert varnish or evaporite units whose extremely rough surfaces are strongly shadowed. In contrast, radar returns are most strongly dependent on surface roughness, a property more strongly correlated with surficial geology than is surface chemistry.
Daily, M.↗
Compiler validates units and dimensions
Software added to compiler for automated test system for Space Shuttle decreases computer run errors by providing offline validation of engineering units used system command programs. Validation procedures are general, though originally written for GOAL, a free-form language that accepts "English-like" statements, and may be adapted to other programming languages.
Levine, F. E.↗
Air Force satellite position management
The Space Act of 1958 identified the Department of Defense as responsible for conducting military operations in space. Subsequently, the United States Air Force was assigned to act as the DOD's executive agent for space. In addition, the Air Force is responsible for acquisition and launch of DOD space systems. Within the Air Force, space related roles and activities have been delegated to several subordinate organizations and agencies. The roles and responsibilities of agencies are still evolving. The Air Force has designated the Air Force System Command's Space Division as its office of primary responsibility for satellite position management. Spacecraft program offices at Space Division are required by regulation to include position management planning in both prelaunch and orbital phases of spacecraft development and operation.
Davis, R.↗