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Dunbar, W. G.

Publications and source records attributed to Dunbar, W. G..

9 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1984

High voltage requirements and issues for the 1990's

The development of high-power high-voltage space systems will require advances in power generation and processing. The systems must be reliable, adaptable, and durable for space mission success. The issues, which must be resolved in order to produce a high power system, are weight and volume reduction of components and modules and the creation of a reliable high repetition pulse power processor. Capacitor energy density must be increased by twice the present capacity and packaging must be reduced by a factor of 10 to 20 times. The packaging must also protect the system from interaction with the natural space environment and the induced environment, produced from spacecraft systems and environment interaction.

Dunbar, W. G.↗
NASA NTRS1982

High voltage distribution and grounding in high power spacecraft

Many space missions proposed for the time period from 1985 to 2000 will require large spacecraft to support the onboard loads. In some cases, large electrical power systems will be needed to supply the electrical/electronic equipment loads. These electronic systems will be used for communications, radar, and experimental equipment for aid to earth's overcrowded communication systems, exploration of new energy resources, space exploration, and eventually to supplement terrestrial electric power utilities. For the near term (1985-1990), some of these systems have power levels to 50 kW. The long-term programs, 1990 to post-2000, could possibly have demands in the order of multimegawatts. The problems which have to be solved to construct the required high-voltage power supply systems are considered. Data and conceptual designs generated are found to indicate that grounding and bonding for high power systems can be accomplished in spacecraft by using either manual or automatic joining of the structural members.

Dunbar, W. G.↗
NASA NTRS1981

High voltage cabling for high power spacecraft

Studies by NASA have shown that many of the space missions proposed for the time period 1980 to 2000 will require large spacecraft structures to be assembled in orbit. Large antennas and power systems up to 2.5 MW size are predicted to supply the electrical/electronic subsystems, solar electric subsystems, solar electric propulsion, and space processing for the near-term programs. Platforms of 100 meters/length for stable foundations, utility stations, and supports for these multi-antenna and electronic powered mechanisms are also being considered. This paper includes the findings of an analytic and conceptual design study for large spacecraft power distribution, and electrical loads and their influence on the cable and connector requirements for these proposed large spacecraft.

Dunbar, W. G.↗
NASA NTRS1980

Ground/bonding for Large Space System Technology (LSST)

The influence of the environment and extravehicular activity remote assembly operations on the grounding and bonding of metallic and nonmetallic structures is discussed. Grounding and bonding philosophy is outlined for the electrical systems and electronic compartments which contain high voltage, high power electrical and electronic equipment. The influence of plasma and particulate on the system was analyzed and the effects of static buildup on the spacecraft electrical system discussed. Conceptual grounding bonding designs are assessed for capability to withstand high current arcs to ground from a high voltage conductor and electromagnetic interference. Also shown were the extravehicular activities required of the space station and or supply spacecraft crew members to join and inspect the ground system using manual on remote assembly construction.

Dunbar, W. G.↗
NASA NTRS1980

Cables and connectors for Large Space System Technology (LSST)

The effect of the environment and extravehicular activity/remote assembly operations on the cables and connectors for spacecraft with metallic and/or nonmetallic structures was examined. Cable and connector philosophy was outlined for the electrical systems and electronic compartments which contain high-voltage, high-power electrical and electronic equipment. The influence of plasma and particulates on the system is analyzed and the effect of static buildup on the spacecraft electrical system discussed. Conceptual cable and connector designs are assessed for capability to withstand high current and high voltage without danger of arcs and electromagnetic interference. The extravehicular activites required of the space station and/or supply spacecraft crew members to join and inspect the electrical system, using manual or remote assembly construction are also considered.

Dunbar, W. G.↗
NASA NTRS1980

Large space systems technology electronics: Data and power distribution

The development of hardware technology and manufacturing techniques required to meet space platform and antenna system needs in the 1980s is discussed. Preliminary designs for manned and automatically assembled space power system cables, connectors, and grounding and bonding materials and techniques are reviewed. Connector concepts, grounding design requirements, and bonding requirements are discussed. The problem of particulate debris contamination for large structure spacecraft is addressed.

Dunbar, W. G.↗
NASA NTRS1973

Skylab high voltage electrical/electronic systems corona assessment.

Six significant design parameters which must be considered in the corona assessment include the operating voltage, radio frequency power, the 'pressure times spacing' relation, operating temperature, gases and contaminants in the environment, and configuration and field gradients. An equipment and experiments survey is presented, giving attention to corona-free equipment and equipment requiring detailed investigations.

Dunbar, W. G.↗