Space tool state-of-the-art, and considerations for future space tool-equipment design.
Tools and equipment for extra- and intravehicular activities in space and on lunar surface
Kubokawa, C. C.↗
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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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Magnetic gear backup
Backup clutch for magnetic gear operates only in case of slippage. Contacting a pin arrangement in the driven gear, the clutch provides extra force for continuing output. It does not interfere with normal, noncontact action.
Shefke, R. A.↗
Inexpensive automatic ranging for digital voltmeters and frequency counters
Seven integrated circuits incorporated at very low cost into frequency counters and digital voltmeters performing a voltage-to-frequency conversion permit automatic range changing. Extra decades are switched into and out of the counting chain as a function of the counter during the previous counting period.
Roller, R. F.↗
Ultra-long monostable multivibrator employing bistable semiconductor switch to allow charging of timing circuit Patent
Extra-long monostable multivibrator employing bistable semiconductor switch to allow charging of timing circuit
Libby, J. N.↗
A study of nitride devices for computer memory applications
Metal-nitride-oxide-silicon /MNOS/ capacitors act like metal-nitride-silicon /MNS/ capacitors with extra interface where sheet of charge can be stored in slow states. Flatband voltage shifts over a wide range by adjusting store charge density.
Raburn, W. D.↗
An information retrieval system for photographic data
Information retrieval system at Extra-terrestrial Photographic Information Center /EPIC/ for identification of extraterrestrial photographs from satellites and manned space explorations
Blum, B. I.↗
Photographic Study of Liquid-Oxygen Boiling and Gas Injection in the Injector of a Chugging Rocket Engine
High-speed motion pictures were taken of conditions in the injector liquid-oxygen cavity of an RL-10 rocket engine during throttled engine operation. Photographs were taken during operation of the engine in the chugging region as the helium gas was injected to stabilize combustion, during operation at rated thrust, and during transition into chugging conditions as the gas injection was discontinued. Results of the investigation indicate that, during chugging rocket operation of the RL-10 engine, a high population of fairly large bubbles formed and collapsed within the liquid-oxygen cavity at the same frequency as the chamber pressure oscillations. When gaseous helium was injected into the liquid-oxygen cavity, a fog rapidly spread over the entire field of view, and the system immediately became stable. The injection of gaseous helium at rated conditions produced a very slight increase in engine performance but not enough to produce a net gain in a typical mission payload with the extra equipment needed. The inherent low-frequency system instability associated with the fuel system at low thrust levels was reduced by injecting either gaseous helium or hydrogen. Complete stabilization was achieved in some cases, and a reduction in the severity of the oscillations in others. This was apparently due to the ·anchoring of the phase change front to the location of the gas injection.
Conrad, E. William↗
High-power microstrip RF switch
A microstrip-type single-pole double-throw (SPDT) switch whose RF and bias portions contain only a metallized alumina substrate and two PIN diodes has been developed. A technique developed to eliminate the dc blocking capacitors needed for biasing the diodes is described. These capacitors are extra components and could lower the reliability significantly. An SPDT switch fabricated on a 5.08 x 5.08 x 0.127-cm (2 x 2 x 0.050-in.) substrate has demonstrated an RF power-handling capability greater than 50 W at S-band. The insertion loss is less than 0.25 db and the input-to-off port isolation is greater than 36 db over a bandwidth larger than 30 MHz. The input voltage standing-wave ratio is lower than 1.07 over the same bandwidth. Theoretical development of the switch characteristics and experimental results, which are in good agreement with theory, are presented.
Choi, S. D.↗
Computer-assisted instruction in programming: AID
Lessons for training students on how to program and operate computers to and AID language are given. The course consists of a set of 50 lessons, plus summaries, reviews, tests, and extra credit problems. No prior knowledge is needed for the course, the only requirement being a strong background in algebra. A student manual, which includes instruction for operating the instructional program and a glossary of terms used in the course, is included in the appendices.
Friend, J.↗
Advantages of cryopumping with liquid hydrogen instead of helium refrigerators
Open loop hydrogen vaporizers and helium refrigerators are compared for operational complexity, installation and operating cost, and safety requirements. Data from two vacuum chambers using helium refrigerators are used to provide comparative data. In general, the use of hydrogen is attractive in the larger systems, even when extra safety precautions are taken. Emotional resistance to the use of hydrogen because of safety requirements is considered great. However, the experience gained in the handling of large quantities of cryogenics, particularly hydrogen and liquefied natural gases, should be considered in the design of open loop hydrogen cooling systems.
J.W. Anderson↗
Fluid flow analysis of a hot-core hypersonic wind-tunnel nozzle concept
A hypersonic-wind-tunnel nozzle concept which incorporates a hot-core flow surrounded by an annular flow of cold air offers a promising technique for maximizing the model size while minimizing the power required to heat the test core. This capability becomes especially important when providing the true-temperature duplication needed for hypersonic propulsion testing. Several two-dimensional wind-tunnel nozzle configurations that are designed according to this concept are analyzed by using recently developed analytical techniques for prediction of the boundary-layer growth and the mixing between the hot and cold coaxial supersonic airflows. The analyses indicate that introduction of the cold annular flow near the throat results in an unacceptable test core for the nozzle size and stagnation conditions considered because of both mixing and condensation effects. Use of a half-nozzle with a ramp on the flat portion does not appear promising because of the thick boundary layer associated with the extra length. However, the analyses indicate that if the cold annular flow is introduced at the exit of a full two-dimensional nozzle, an acceptable test core will be produced. Predictions of the mixing between the hot and cold supersonic streams for this configuration show that mixing effects from the cold flow do not appreciably penetrate into the hot core for the large downstream distances of interest.
Anders, J. B.↗
Spectral structure of the diffuse X-ray sky
A description of diffuse celestial X-ray flux is drawn from data taken by rocket borne detectors. It was concluded that the diffuse flux is intra- and extra-galactic in origin and is caused by Compton scattering of .052 rad black body photons of relativistic electrons leaking out of the galaxies.
Boldt, E. A.↗
A simple branch synchronizer for convolutional decoders.
A simple branch synchronizer for rate 1/3, constraint length five, nonsystematic convolutional code is described. The scheme derives the sync information from the received channel bits, thus avoiding the extra formatting of the sync data at the transmitter and receiver, and increasing the data rate. The synchronizer detects the proper sync bits for both the in-phase and phase ambiguous cases. The design is adaptable to nonsystematic codes of different constraint lengths.
Taqvi, S. Z. H.↗
Apollo 15 mission report.
Apollo 15 was the first of the 'J' Mission Series designed to conduct an extended scientific exploration of the moon, both from lunar orbit and on the surface. The powered descent into the Hadley-Apennine site is discussed. The major hardware innovation for the lunar exploration phase on Apollo 15 was the Lunar Roving Vehicle. Lunar orbit SIM operations are considered together with transearth coast extra-vehicular activity, and entry.
Scott, D. R.↗
Skylab status report.
The laboratory will be launched on Apr. 30, 1973, aboard a Saturn V vehicle. Approximately twenty-three and a half hours later the first crew will be launched in a command and service module aboard a Saturn IB launch vehicle. The laboratory will consist of modules. The orbital workshop (OWS) is made from the liquid oxygen and liquid hydrogen tanks of a Saturn S-IVB third stage. The OWS contains the living quarters and two experiments areas. The airlock sits on top of the OWS and contains the controls and hatch for the extra-vehicular activity.
Conrad, C., Jr.↗
Stability of plane Poiseuille flow with heat transfer.
Investigation of the influence of heat transfer on the stability of a plane Poiseuille flow iahnnl. The liquid flow is affected by the heat transfer through the variation in viscosity with temperature. Additional viscosity gradient terms are included in a modified Orr-Sommerfeld equation, and it is the presence of these terms which leads to a prediction of more unstable flows, for without the inclusion of these extra terms, the flow is stabilized. The results show that a temperature difference between the walls is always destabilizing and, in particular, a temperature difference between the walls of 100 F leads to a reduction in the critical Reynolds number from 7800 to 4600.
Potter, M. C.↗
A common solar electric upper stage for multi-mission applications.
The concept of using a solar-electric upper stage for multi-mission application is practical, economical, and versatile approach to space expMission capabilities include a Mercury orbiter, asteroid and comet rendezvous, a solar probe, and extra-ecliptic probe, and outer planet flybys and orbiters. The 17.5-kw vehicle has an injected mass of 1500 to 2500 kg and carries up to 500 kg of attached or separable payload packages. Mission characteristics, performance tradeoffs and a concepegn configuration are presented, and program plans, cost estimates and advanced technology requirements are identified.
Meissinger, H. F.↗
The structure of the magnetosphere as deduced from magnetospherically reflected whistlers
Very low frequency (VLF) electromagnetic wave phenomenon called the magnetospherically reflected (MR) whistler was investigated. VLF (0.3 to 12.5 kHz) data obtained from the Orbiting Geophysical Observatories 1 and 3 from October 1964 to December 1966 were used. MR whistlers are produced by the dispersive propagation of energy from atmospheric lightning through the magnetosphere to the satellite along ray paths which undergo one or more reflections due to the presence of ions. The gross features of MR whistler frequency-time spectrograms are explained in terms of propagation through a magnetosphere composed of thermal ions and electrons and having small density gradients across L-shells. Irregularities observed in MR spectra were interpreted in terms of propagation through field-aligned density structures. Trough and enhancement density structures were found to produce unique and easily recognizable signatures in MR spectra. Sharp cross-field density dropoff produces extra traces in MR spectrograms.
Edgar, B. C.↗