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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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Self-checking technique detects defective solid state modules used in electronic test and checkout instrumentation. A ten bit register provides failure monitor and indication for 1023 comparator circuits, and the automatic fault-isolation capability permits the electronic subsystems to be repaired by replacing the defective module.
Apollo rendezvous with command module active for rescue of lunar module
Module utilizes static water-feed electrolysis system and air-cooled fins to remove heat generated by cell inefficiencies. Module generates 0.15 pounds of oxygen and 0.0188 pounds of hydrogen at current density of 100 amps per square foot. Generator operates in aircraft, spacecraft, or submarine cabins.
Optical retrodirective modulator with focus spoiling reflector driven by modulation signal
When laser beam passes through electron plasma its frequency shifts by amount proportional to plasma density. This density varies with modulating signal resulting in corresponding modulation of laser beam frequency. Necessary apparatus is relatively inexpensive since crystals are not required.
The baseline experiment program is concerned with future space experiments and cover the scientific disciplines of astronomy, space physics, space biology, biomedicine and biotechnology, earth applications, materials science, and advanced technology. The experiments within each discipline are grouped into functional program elements according to experiments that support a particular area of research or investigation and experiments that impose similar or related demand on space station support systems. The experiment requirements on module subsystems, experiment operating modes and time profiles, and the role of the astronaut are discussed. Launch and rendezvous with the space station, disposal, and on-orbit operations are delineated. The operational interfaces between module and other system elements are presented and include space station and logistic system interfaces. Preliminary launch and on-orbit environmental criteria and requirements are discussed, and experiment equipment weights by functional program elements are tabulated.
The logistics requirements for the space station cargo, the initial buildup, and the 90 day resupply are presented, along with the conceptual selection for the orbiter crew accommodations and the GSS logistics system. Various module configurations are outlined; structural/mechanical, environmental, temperature, voice communication, and data bus subsystems are also reviewed. Ground operations and module prelaunch and launch operations are discussed, as well as logistics system interfaces for space shuttles and stations.
The design concepts and philosophies of the lunar module instrumentation subsystem are discussed along with manufacturing and systems integration. The experience gained from the program is discussed, and recommendations are made for making the subsystem more compatible and flexible in system usage. Characteristics of lunar module caution and warning circuits are presented.
Data presented in the appendices covers: (1) summary description of baseline power system; (2) revised thermal profile analysis; (3) design analysis of television monitor; (4) bioresearch module ground station support evaluation; (5) variable spin control analysis; and (6) bioresearch modules and work flow.
The research and applications modules (RAM) system is discussed. The RAM is a family of payload carrier modules that can be delivered to and retrieved from earth orbit by the space shuttle. The RAM's capability for implementing a wide range of manned and man-tended missions is described. The rams have evolved into three types; (1) pressurized RAMs, (2) unpressurized RAMs, and (3) pressurizable free-flying RAMs. A reference experiment plan for use as a baseline in the derivation and planning of the RAM project is reported. The plan describes the number and frequency of shuttle flights dedicated to RAM missions and the RAM payloads for the identified flights.
A paper describing the basic delta modulation systems studied was published. A second paper, describing the systems response to voice and video was presented at the International Communications Conference in June 1972, and a third paper describing several delta modulation systems used for voice and video is scheduled for presentation at the National Telecommunications Conference in December 1972.
Description of a multichannel PCM-PSK-PM modulation scheme called interplex which reduces cross-modulation loss and excess carrier reference power of conventional systems when the number of channels is small. In systems with equal channels, interplex is more efficient when the number of channels is not greater than four. The number of channels which can be combined efficiently with interplex increases if there are many low-power channels and only one high-power link. The scheme can be implemented in existing systems without significant hardware changes and appears to be suitable for use in a multichannel space-station telecommunications system.
Use of the molecular Stark effect in NH2D to modulate the 10.6-micron P(20) line of a CO2 laser, yielding a modulation depth of 40% from a 200-V/cm rms signal applied to a 19.7-cm gas cell external to the laser. NH2D was prepared by mixing ND3 and NH3. The absorption coefficient of the M = 4 Stark-split line was measured as a function of mixing ratio and pressure. The observed pressure-broadening coefficient was 32.5 MHz/torr.
The results of a computer search for the optimum type of bandpass filter for low-index angle-modulated signals are reported. The bandpass filters are discussed in terms of their low-pass prototypes. Only filter functions with constant numerators are considered. The pole locations for the optimum filters of several cases are shown in a table. The results are fairly independent of modulation index and bandwidth.
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.
The functional form of the modulation for the 11-year variation changed abruptly after the Forbush decrease of June 8, 1969. This change in the 11-year modulation suggests that this Forbush decrease was an integral part of the 11-year variation. Some details of the change as observed by neutron monitors and by spacecraft at low energies are discussed.
Two carriers transmit two high-power signals from single transmitter, each phase-modulated by subcarrier which, in turn, is modulated by data bits; switching between two carriers is alternated at high rate. Resulting composite signal is multiplied up to desired frequency and used to drive power amplifier which feeds transmitting antenna.
Wind tunnel pressure signatures measured at Mach 10.1 for model of the Apollo Command Module and at Mach numbers from 3.01 to 7.91 for two models of the Saturn launch configuration are presented. The signatures for the command module were obtained at roll angles ranging from 0 deg to 180 deg. A brief discussion of the extrapolation of strong pressure signatures is included in the report.