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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 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
NASA NTRS1972

Composites - Lighter and cheaper.

Composite engineering materials have two distinct parts, including the load-bearing filaments and the matrix. Fibers can range from glass to boron and graphite. Matrix constituents include epoxies for lower temperatures and metals for higher temperatures. Composites appear as tape or combined with metal in structural shapes. The increased use of composites will reduce over-all per pound manufacturing costs. Two major deterrents to further application of composites in advanced commercial transports include a shortage of cost-effective structural design concepts and a lack of confidence in the life characteristics. A program has been outlined by NASA that will, if implemented, provide considerable in-service life experience with structural components on commercial transports.

Goble, R. L.↗
NASA NTRS1975

Preliminary estimates of operating costs for lighter than air transports

Presented is a preliminary set of operating cost relationships for airship transports. The starting point for the development of the relationships is the direct operating cost formulae and the indirect operating cost categories commonly used for estimating costs of heavier than air commercial transports. Modifications are made to the relationships to account for the unique features of airships. To illustrate the cost estimating method, the operating costs of selected airship cargo transports are computed. Conventional fully buoyant and hybrid semi-buoyant systems are investigated for a variety of speeds, payloads, ranges, and altitudes. Comparisons are made with aircraft transports for a range of cargo densities.

Smith, C. L.↗
NASA NTRS1975

Structural materials research for lighter-than-air systems

Inflatable systems have widespread applications in military, government, and industrial sectors. Improvements in inflatable materials have followed each salient advancement in textiles. The new organic fiber, Kevlar, is a recent and most significant advancement that justified reexamination of old and new inflatable materials' applications. A fertile frontier exists in integrating Kevlar with various other material combinations, in optimization of geometric features, and in selection of thermomechanical characteristics' compatibility with the environment. Expectations regarding Kevlar have been justified by the performance of two experimental materials. Styrene-butadiene-styrene block copolymers appear promising as a constituent adhesive for low temperature applications. Biaxial testing for both strength and material elastic properties is a technology area needing greater awareness and technology growth along with improved facilities. Because of dramatic materials' advancements, inflatable systems appear to be moving toward an increased position in tomorrow's aerospace industry.

Alley, V. L., Jr.↗
NASA NTRS1975

An assessment of lighter than air technology

The workshop on LTA is summarized. The history and background are reviewed. The workshop reports for the following working groups are presented: policy, market analysis, economics, operations, and technology.

Vittek, J. F., Jr.↗
NASA NTRS1975

Preliminary estimates of operating costs for lighter than air transports

A preliminary set of operating cost relationships are presented for airship transports. The starting point for the development of the relationships is the direct operating cost formulae and the indirect operating cost categories commonly used for estimating costs of heavier than air commercial transports. Modifications are made to the relationships to account for the unique features of airships. To illustrate the cost estimating method, the operating costs of selected airship cargo transports are computed. Conventional fully buoyant and hybrid semi-buoyant systems are investigated for a variety of speeds, payloads, ranges, and altitudes. Comparisons are made with aircraft transports for a range of cargo densities.

Smith, C. L.↗
NASA NTRS1975

Market assessment in connection with lighter than air

A review of the marketability of the airship is given, and the relative energy consumption and speed potential of the airship is compared to other modes and guidelines to areas of initial development are also provided, together with a brief historical review.

Wood, J. E. R.↗
NASA NTRS1975

Lighter than air: A look at the past, a look at the possibilities

A brief history of the flight by LTA including the development of the zeppelin is presented. Safety and economy are discussed along with power requirements and production techniques. The problem of ground handling facilities for very large airships are briefly mentioned.

Shea, W. F.↗
NASA NTRS1975

Environic implications of lighter than air transportation

The advent of any new system of transportation must now be reviewed in the physical context and texture of the landscape. Henceforward, all transportation systems will be considered in respect of their effects upon the environment to ensure that they afford an environic asset as well as provide an economic benefit. The obligations which now confront the buoyancy engineers are emphasized so that they may respond to these ethical and environic urgencies simultaneously with routine technical development.

Horsbrugh, P.↗
NASA NTRS1975

Special problems and capabilities of high altitude lighter than air vehicles

Powered LTA vehicles have historically been limited to operations at low altitudes. Conditions exist which may enable a remotely piloted unit to be operated at an altitude near 70,000 feet. Such systems will be launched like high altitude balloons, operate like nonrigid airships, and have mission capabilities comparable to a low altitude stationary satellite. The limited lift available and the stratospheric environment impose special requirements on power systems, hull materials and payloads. Potential nonmilitary uses of the vehicle include communications relay, environmental monitoring and ship traffic control.

Wessel, P. R.↗
NASA NTRS1979

Large lighter-than-air vehicles

The background of experience and the results achieved in building large airships are discussed. Two current applications are identified. These are in heavy vertical lift and in long endurance patrol. The most promising concepts for these missions include hybrid combinations of helicopters and aerostats and more conventional rigid types. These new approaches will require some technology development in aerodynamics and structures, but all vehicles will benefit from application of modern methods and materials.

Mayer, N. J.↗
NASA NTRS1979

A summary of lighter-than-air technology development and applications in the United States

Recent studies indicate the promise of advanced LTA vehicles that can carry heavy loads and be capable of vertical takeoff and landing. Such airships may be combinations of aerostats and helicopters or modern versions of more conventional aircraft. These latter types would not be competitive with high speed modern jet air transports on established routes, but they would have a role in special situations and as long-endurance Naval and coastal surveillance aircraft. The most attractive and immediate market for modern airships in the field of short-range and heavy lift.

Mayer, N. J.↗
NASA NTRS1993

Smaller, Lighter Magnetic Sector For Mass Spectrometer

Miniature, lightweight focal-plane magnetic sector of mass spectrometer (Mattauch-Herzog type) developed. Magnetic sector integral part of portable gas-chromatograph/mass spectrometer (GC/MS). Focal plane covers nominal range of 40 to 240 atomic mass units for 1-keV ion energy. System used for analyzing pollutants in field environments.

Sinha, Mahadeva P.↗
NASA NTRS1993

Lighter, More-Efficient Helicopter Transmissions

Improved gear system intended primarily for use in helicopter transmits torque from horizontal or nearly horizontal shafts of two engines to vertical output shaft supporting rotor. Apportions torques equally along multiple, redundant drive paths, reducing stresses on individual gear teeth, and enables one engine to continue to turn rotor when other engine fails. Design concept also applied to couple two airplane engines to set of propellers in such way both propellers turn as long as at least one engine operates.

Bossler, Robert B., Jr.↗
NASA NTRS2002

A Lighter-Than-Air System Enhanced with Kinetic Lift

A hybrid airship system is proposed in which the buoyant lift is enhanced with kinetic lift. The airship would consist of twin hulls in which the buoyant gas is contained. The twin hulls would be connected in parallel by a wing having an airfoil contour. In forward flight, the wing would provide kinetic lift that would add to the buoyant lift. The added lift would permit a greater payload/altitude combination than that which could be supported by the buoyant lift alone. The buoyant lift is a function of the volume of gas and the flight altitude. The kinetic lift is a function of the airfoil section, wing area, and the speed and altitude of flight. Accordingly there are a number of factors that can be manipulated to arrive at a particular design. Particular designs could vary from small, lightweight systems to very large, heavy-load systems. It will be the purpose of this paper to examine the sensitivity of such a design to the several variables. In addition, possible uses made achievable by such a hybrid system will be suggested.

Spearman, M. Leroy↗
NASA NTRS2015

Recent Space PV Concentrator Advances: More Robust, Lighter, and Easier to Track

Over the past three years, the authors have collaborated on several significant advances in space photovoltaic concentrator technology, including a far more robust Fresnel lens for sunlight concentration, improved color-mixing features for the lens to minimize chromatic aberration losses for next-generation 4-junction and 6-junction IMM cells, a new approach to suntracking requiring only one axis of rotation even in the presence of large beta angles (e.g., +/- 50 deg), a new waste heat radiator made of graphene, with 80-90% reduction in mass, and a new platform for deployment and support on orbit (SOLAROSA). These patent-pending advances are described in this paper.

concentrators↗