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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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At least 469 records · Page 26

Laser space rendezvous and docking system study continuation

Investigations were made of a configuration for a spaceborne laser radar (ladar) to meet the requirements for rendezvous and docking with a cooperative object in synchronous orbit. An analysis was completed of laser phase locking techniques, while experimental verification was made of pulse repetition frequency and resonant scanning control loops. Data measurements on a satellite mock-up were also made. The investigation supports the original contention that a rendezvous and docking ladar can be configured to offer a cost effective and reliable solution to envisioned space missions.

Adelman, S.↗

Extended performance solar electric propulsion thrust system study. Volume 5. Capacitor-diode voltage multiplier: Technology evaluation

A 1-kW capacitor-diode voltage multiplier (CDVM) was designed, fabricated and tested to demonstrate the power of feasibility of high power CDVM's and to verify the analytical techniques that had been used to predict the performance characteristics of a 6-kw CDVM. High efficiency (96.2%), a low ratio of component weight to power (0.55 kg/kW), and low output ripple voltage (less than 1%, peak to peak) were obtained during the operation of a 1-kW CDVM various input line, load current, and load fault conditions.

Martinelli, R. M.↗

OAST Space Systems Studies Review Meeting

The agenda from the OAST review meeting is presented. Some of the following topics were reviewed in detail: (1) space utilization; (2) space transportation and (3) science and exploration.

Sadin, S. R.↗

Characteristics of future air cargo demand and impact on aircraft development: A report on the Cargo/Logistic Airlift Systems Study (CLASS) project

Current domestic and international air cargo operations are studied and the characteristics of 1990 air cargo demand are postulated from surveys conducted at airports and with shippers, consignees, and freight forwarders as well as air, land, and ocean carriers. Simulation and route optimization programs are exercised to evaluate advanced aircraft concepts. The results show that proposed changes in the infrastructure and improved cargo loading efficiencies are as important enhancing the prospects of air cargo growth as is the advent of advanced freighter aircraft. Potential reductions in aircraft direct operating costs are estimated and related to future total revenue. Service and cost elasticities are established and utilized to estimate future potential tariff reductions that may be realized through direct and indirect operating cost reductions and economies of scale.

Whitehead, A. H., Jr.↗

Cargo Logistics Airlift Systems Study (CLASS). Volume 4: Future requirements of dedicated freighter aircraft to year 2008

The 1978 fleet operations are extended to the year 1992, thus providing an evaluation of current aircraft types in meeting the ensuing increased market demand. Possible changes in the fleet mix and the resulting economic situation are defined in terms of the number of units of each type aircraft and the resulting growth in operational frequency. Among the economic parameters considered are the associated investment required by the airline, the return on investment to the airline, and the accompanying levels of cash flow and operating income. Against this background the potential for a derivative aircraft to enter fleet operations in 1985 is defined as a function of payload size and as affected by 1980 technology. In a similar manner, the size and potential for a new dedicated 1990 technology, freighter aircraft to become operational in 1995 is established. The resulting aircraft and fleet operational and economic characteristics are evaluated over the period 1994 to 2008. The impacts of restricted growth in operational frequency, reduced market demand, variations in aircraft configurations, and military participation, are assessed.

Burby, R. J.↗

Turboprop Cargo Aircraft Systems study, phase 1

The effects of advanced propellers (propfan) on aircraft direct operating costs, fuel consumption, and noiseprints were determined. A comparison of three aircraft selected from the results with competitive turbofan aircraft shows that advanced turboprop aircraft offer these potential benefits, relative to advanced turbofan aircraft: 21 percent fuel saving, 26 percent higher fuel efficiency, 15 percent lower DOCs, and 25 percent shorter field lengths. Fuel consumption for the turboprop is nearly 40 percent less than for current commercial turbofan aircraft. Aircraft with both types of propulsion satisfy current federal noise regulations. Advanced turboprop aircraft have smaller noiseprints at 90 EPNdB than advanced turbofan aircraft, but large noiseprints at 70 and 80 EPNdB levels, which are usually suggested as quietness goals. Accelerated development of advanced turboprops is strongly recommended to permit early attainment of the potential fuel saving. Several areas of work are identified which may produce quieter turboprop aircraft.

Muehlbauer, J. C.↗

Advanced turboprop cargo aircraft systems study

Parametric studies were conducted to define the effects of advanced propeller (propfan) characteristics on aircraft direct operating costs, fuel consumption, and noiseprints. Selected propfan aircraft realized 21-percent fuel savings and 15-percent lower DOCs relative to advanced turbofan aircraft. While both the propfan and turbofan aircraft satisfied current federal noise regulations, the propfan aircraft had smaller noiseprints at 90-EPNdB noise levels but larger noiseprints at lower noise levels. Several techniques for reducing the propfan aircraft noiseprints were explored; some of these contribute substantial reductions in noiseprint areas. Also, a propfan aircraft for the C-X role was studied.

Muehlbauer, J. C.↗

Integrated command, control communication and computation system study

The study was conducted in three phases: a functional requirements phase; a functional architecture phase; and a design plan phase. The major emphasis was on the functional architecture phase and the approaches used for its functional hierarchy, operations concept, and interfaces.

Source record↗

Advanced Multipurpose Rendezvous Tracking System Study

Rendezvous and docking (R&D) sensors needed to support Earth orbital operations of vehicles were investigated to determine the form they should take. An R&D sensor must enable an interceptor vehicle to determine both the relative position and the relative attitude of a target vehicle. Relative position determination is fairly straightforward and places few constraints on the sensor. Relative attitude determination, however, is more difficult. The attitude is calculated based on relative position measurements of several reflectors placed in a known arrangement on the target vehicle. The constraints imposed on the sensor by the attitude determination method are severe. Narrow beamwidth, wide field of view (fov), high range accuracy, and fast random scan capability are all required to determine attitude by this method. A consideration of these constraints as well as others imposed by expected operating conditions and the available technology led to the conclusion that the sensor should be a cw optical radar employing a semiconductor laser transmitter and an image dissector receiver.

Laurie, R. J.↗