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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 145 records · Page 8

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NASA NTRS1977

Alternate aircraft fuels: Prospects and operational implications

The potential use of coal-derived aviation fuels was assessed. The studies addressed the prices and thermal efficiencies associated with the production of coal-derived aviation kerosene, liquid methane and liquid hydrogen and the air terminal requirements and subsonic transport performance when utilizing liquid hydrogen. The fuel production studies indicated that liquid methane can be produced at a lower price and with a higher thermal efficiency than aviation kerosene or liquid hydrogen. Ground facilities of liquefaction, storage, distribution and refueling of liquid hydrogen fueled aircraft at airports appear technically feasibile. The aircraft studies indicate modest onboard energy savings for hydrogen compared to conventional fuels. Liquid hydrogen was found to be superior to both aviation kerosene and liquid methane from the standpoint of aircraft engine emissions.

Witcofski, R. D.↗

NASA NTRS1977

Solar power satellite. System definition study. Part 1, volume 3: Construction, transportation and cost analyses

Concepts developed for both LEO and GEO construction of photovoltaic and thermal engine satellites are analyzed. Topics discussed include: satellite construction; crew scheduling; crew jobs and organizations; operator productivity rating; constructability rating; transportation systems for cargo launch, refueling operations, personnel transport, and orbit transfer; collision analysis, cost analysis, and radiation evironment and effects.

Source record↗

NASA NTRS1978

The application of dual fuel /JP-LH2/ for hypersonic cruise vehicles

The possibility of utilizing jet fuel (JP) stored primarily in the wings of hydrogen-fueled hypersonic cruise vehicles has been evaluated and compared to the performance of all hydrogen-fueled aircraft. Parametric investigations of wing loading, thrust-to-weight ratio, payload size and vehicle size are presented. Results indicate improvements in performance for a wide range of potential payload sizes, particularly when in-flight refueling of the JP fuel is considered as a means of increasing range and mission flexibility.

Weidner, J. P.↗

NASA NTRS1978

Fission and activation of uranium by fusion-plasma neutrons

Fusion-fission hybrid reactors are discussed in terms of two main purposes: to breed fissile materials (Pu 233 and Th 233 from U 238 or Th 232) for use in low-reactivity breeders, and to produce tritium from lithium to refuel fusion plasma cores. Neutron flux generation is critical for both processes. Various methods for generating the flux are described, with attention to new geometries for multiple plasma focus arrays, e.g., hypocycloidal pinch and staged plasma focus devices. These methods are evaluated with reference to their applicability to D-D fusion reactors, which will ensure a virtually unlimited energy supply. Accurate observations of the neutron flux from such schemes are obtained by using different target materials in the plasma focus.

Lee, J. H.↗

NASA NTRS1979

Gas core reactors for actinide transmutation

The preliminary design of a uranium hexafluoride actinide transmutation reactor to convert long-lived actinide wastes to shorter-lived fission product wastes was analyzed. It is shown that externally moderated gas core reactors are ideal radiators. They provide an abundant supply of thermal neutrons and are insensitive to composition changes in the blanket. For the present reactor, an initial load of 6 metric tons of actinides is loaded. This is equivalent to the quantity produced by 300 LWR-years of operation. At the beginning, the core produces 2000 MWt while the blanket generates only 239 MWt. After four years of irradiation, the actinide mass is reduced to 3.9 metric tonnes. During this time, the blanket is becoming more fissile and its power rapidly approaches 1600 MWt. At the end of four years, continuous refueling of actinides is carried out and the actinide mass is held constant. Equilibrium is essentially achieved at the end of eight years. At equilibrium, the core is producing 1400 MWt and the blanket 1600 MWt. At this power level, the actinide destruction rate is equal to the production rate from 32 LWRs.

Clement, J. D.↗

NASA NTRS1979

OTV orbital tanking systems

Orbital transfer of cryogenic propellants could benefit spacecraft and Orbital Transfer Vehicle (OTV) missions in the 1980s by supplying main propulsion, attitude control, or other fluid systems. The Space Shuttle can operate as a tanker when equipped with cryogenic propellant storage and orbital transfer systems. The key technologies are multilayer insulation, capillary propellant acquisition, zero-g gaging, orbital chilldown, and possibly large flight weight dewars. The technologies and operations could be realistically demonstrated using a Centaur that has been integrated with the Shuttle. Orbital refueling capability can enhance the usefulness of the whole Shuttle program

Heald, D. A.↗

NASA NTRS1980

Fog dispersion

A study of economically viable techniques for dispersing warm fog at commercial airports is presented. Five fog dispersion techniques are examined: evaporation suppression, downwash, mixing, seeding with hygroscopic material, thermal techniques, and charged particle techniques. Thermal techniques, although effective, were found to be too expensive for routine airport operations, and detrimental to the environment. Seeding or helicopter downwash are practical for small-scale or temporary fog clearing, but are probably not useful for airport operations on a routine basis. Considerable disagreement exists on the capability of charged particle techniques, which stems from the fact that different assumptions and parameter values are used in the analytical models. Recommendations resulting from the review of this technique are listed, and include: experimental measurements of the parameters in question; a study to ascertain possible safety hazards, such as increased electrical activity or fuel ignition during refueling operations which could render charged particle techniques impractical; and a study of a single charged particle generator.

Frost, W.↗

NASA NTRS1982

Orbiter based construction equipment

Many orbiter based activities need equipment to hold a payload steady while it is being worked on. This work may be construction, updating, repair, services, check out, or refueling operations in preparation for return to Earth. The Handling and Positioning Aid (HPA) is intended for use as general purpose equipment. The HPA provides a wide choice of work station positions, both immediately above the orbiter cargo bay and beyond. It can act in a primary docking role and, if required, can assist actively in the berthing process. From an analysis of ten reference missions, it was determined that two types of HPA mobility are needed; a tilt table, which simply swings out of the cargo bay, pivoting about an athwartships y axis, and an articulated arm. Illustration of the aid are provided.

Goodwin, C. J.↗

NASA NTRS1982

Capability of the manned maneuvering unit to support satellite servicing operations

Features, capabilities, and projected performances and missions of the Manned Maneuvering Unit (MMU) are described. A zero gravity, autonomous, six degree of freedom mobility system using gaseous nitrogen for propulsion, the MMU is equipped with jets for attitude and rotational control, 24 thrusters total, with each providing 7.5 N thrust. The unit is controled from hand controllers used by the pilot, in addition to an automatic attitude control using outputs from a gyroscope pack in the control electronics assembly. EVA periods of 6 hrs are possible with the 150 kg MMU and its fuel complement of 12 kg of gaseous N. Refueling is allowed through an Orbiter interface at the same location the MMU is stowed. The MMU has a delta-V capability of 20 m/sec, with a thrust duration of 7085 N-sec, implying the EVA suit limit will be reached before propellant can be exhausted. The results of various mission simulations for the MMU are reported.

Bergonz, F. H.↗

NASA NTRS1983

Searching for Clear-Air Turbulence

System for determining potential location and severity of clear-air turbulence based on passive microwave sensor. Horn antenna for prototype clearair-turbulence warning system rotatable through plus or minus 45 degrees. Permits safer more comfortable flights for commercial airplanes and enables safer inflight refueling for military airplanes.

Gary, B. L.↗

NASA NTRS1982

Fluids management technology

Various techniques and methods in fluid management are discussed. Propellant on-orbit transfer efficiency from the space shuttle orbiter to orbital transfer vehicle is discussed. Techniques such as refueling, residuals recovery and propellant storage are described.

Mcgee, J. M.↗

NASA NTRS1983

Flight test experience with pilot-induced-oscillation suppressor filters

Digital flight control systems are popular for their flexibility, reliability, and power; however, their use sometimes results in deficient handling qualities, including pilot-induced oscillation (PIO), which can require extensive redesign of the control system. When redesign is not immediately possible, temporary solutions, such as the PIO suppression (PIOS) filter developed for the Space Shuttle, have been proposed. To determine the effectiveness of such PIOS filters on more conventional, high-performance aircraft, three experiments were performed using the NASA F-8 digital fly-by-wire and USAF/Calspan NT-33 variable-stability aircraft. Two types of PIOS filters were evaluated, using high-gain, precision tasks (close formation, probe-and-drogue refueling, and precision touch-and-go landing) with a time delay or a first-order lag added to make the aircraft prone to PIO. Various configurations of the PIOS filter were evaluated in the flight programs, and most of the PIOS filter configurations reduced the occurrence of PIOs and improved the handling qualities of the PIO-prone aircraft. These experiments also confirmed the influence of high-gain tasks and excessive control system time delay in evoking pilot-induced oscillations.

Shafer, M. F.↗

NASA NTRS1983

An alternate concept for expanding man's presence in space

A logical next step after shuttle is a manned orbital service system (MOSS) consisting of a two-man crew module mated with a propulsion module. The resulting spacecraft would remain in low Earth orbit for months or years at a time conducting civil or military satellite servicing, experimental, or applications missions while being periodically supplied and refueled by Shuttle flights from the ground. The system would accumulate experience invaluable to the design of future large and more expensive spacecraft. Key features of the vehicle are versatility and mobility. With Centaur-type propulsion and a large payload, the MOSS could leave an initial orbit of 370 km (200 nmi) altitude and inclinations up to 56 deg, make a plane change of up to + or - 14 deg, reach altitudes to 5500 km (2970 nmi), and then return the payload to the original orbit altitude and inclination. Obviously, the size of the performance envelope varies with the payload and propulsion-unit selected. The MOSS can reach orbits and perform tasks not possible with Shuttle alone or with the much larger space stations currently being proposed.

Hook, W. R.↗

NASA NTRS1984

Flight test experience with pilot-induced-oscillation suppression filters

Shafer, M. F.↗

NASA NTRS1983

Space Station needs, attributes and architectural options: Summary briefing

Computerized data sorting and analysis techniques were used with a data base accumulated in over 20 years of space station studies to evaluate candidate missions and select a final model of 88 missions. The social, cultural, scientific, technical, and commercial benefits to be accrued from each mission were identified. Requirements were determined for satellite servicing; payload placement and retrieval; refueling; repair; testing; assembly; and construction. Missions drivers determined include crew, remote manipulating system, external parts, instrumentation, extravehicular activity/manned maneuvering unit, and voice/video equipment. User interest for commercial applications were determined. Variable architecture based on a modular concept with multi-use elements is proposed.

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NASA NTRS1983

Space station needs, attributes and architectural options study. Briefing material: Final review and executive summary

Advantages and disadvantages were assessed for configuration options for a modular 14' diameter space station, a modular aft cargo carrier and a shuttle derived vehicle. Early, intermediate, and mature configurations were defined as well as power requirements, heat rejection, hydrazine usage, and the external scavenging concept. Subsystems were analyzed for propulsion, attitude control, data processing, and communications. Areas of uncertainties, associated costs and benefits, and the cost by phase of the modular and shuttle derived vehicle configurations were identified. Technologies assessed included solar vs nuclear; gravity gradient vs active control; heat pipe radiators vs fluid loops; distributed processors vs centralized, and modular vs shuttle derived configuration. It was determined that the early space station architecture should include: (1) reusable OTV with aerobraking; (2) TMS with telepresence services; (3) OTV/TMS refueling and servicing capability; and (4) attached research laboratories for life sciences and materials processing.

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NASA NTRS1981

Manned geosynchronous mission requirements and systems analysis study extension

Turnaround requirements for the manned orbital transfer vehicle (MOTV) baseline and alternate concepts with and without a space operations center (SOC) are defined. Manned orbital transfer vehicle maintenance, refurbishment, resupply, and refueling are considered as well as the most effective combination of ground based and space based turnaround activities. Ground and flight operations requirements for abort are identified as well as low cost approaches to space and ground operations through maintenance and missions sensitivity studies. The recommended turnaround mix shows that space basing MOTV at SOC with periodic return to ground for overhaul results in minimum recurring costs. A pressurized hangar at SOC reduces labor costs by approximately 50%.

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NASA NTRS1984

Spacecraft servicing demonstration plan

A preliminary spacecraft servicing demonstration plan is prepared which leads to a fully verified operational on-orbit servicing system based on the module exchange, refueling, and resupply technologies. The resulting system can be applied at the space station, in low Earth orbit with an orbital maneuvering vehicle (OMV), or be carried with an OMV to geosynchronous orbit by an orbital transfer vehicle. The three phase plan includes ground demonstrations, cargo bay demonstrations, and free flight verifications. The plan emphasizes the exchange of multimission modular spacecraft (MMS) modules which involves space repairable satellites. Three servicer mechanism configurations are the engineering test unit, a protoflight quality unit, and two fully operational units that have been qualified and documented for use in free flight verification activity. The plan balances costs and risks by overlapping study phases, utilizing existing equipment for ground demonstrations, maximizing use of existing MMS equipment, and rental of a spacecraft bus.

Bergonz, F. H.↗