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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

Nuclear Thermal Propulsion (NTP): A Proven Growth Technology for Human NEO/Mars Exploration Missions

The nuclear thermal rocket (NTR) represents the next "evolutionary step" in high performance rocket propulsion. Unlike conventional chemical rockets that produce their energy through combustion, the NTR derives its energy from fission of Uranium-235 atoms contained within fuel elements that comprise the engine s reactor core. Using an "expander" cycle for turbopump drive power, hydrogen propellant is raised to a high pressure and pumped through coolant channels in the fuel elements where it is superheated then expanded out a supersonic nozzle to generate high thrust. By using hydrogen for both the reactor coolant and propellant, the NTR can achieve specific impulse (Isp) values of ~900 seconds (s) or more - twice that of today s best chemical rockets. From 1955 - 1972, twenty rocket reactors were designed, built and ground tested in the Rover and NERVA (Nuclear Engine for Rocket Vehicle Applications) programs. These programs demonstrated: (1) high temperature carbide-based nuclear fuels; (2) a wide range of thrust levels; (3) sustained engine operation; (4) accumulated lifetime at full power; and (5) restart capability - all the requirements needed for a human Mars mission. Ceramic metal "cermet" fuel was pursued as well, as a backup option. The NTR also has significant "evolution and growth" capability. Configured as a "bimodal" system, it can generate its own electrical power to support spacecraft operational needs. Adding an oxygen "afterburner" nozzle introduces a variable thrust and Isp capability and allows bipropellant operation. In NASA s recent Mars Design Reference Architecture (DRA) 5.0 study, the NTR was selected as the preferred propulsion option because of its proven technology, higher performance, lower launch mass, versatile vehicle design, simple assembly, and growth potential. In contrast to other advanced propulsion options, no large technology scale-ups are required for NTP either. In fact, the smallest engine tested during the Rover program - the 25,000 lbf (25 klbf) "Pewee" engine is sufficient when used in a clustered engine arrangement. The "Copernicus" crewed spacecraft design developed in DRA 5.0 has significant capability and a human exploration strategy is outlined here that uses Copernicus and its key components for precursor near Earth object (NEO) and Mars orbital missions prior to a Mars landing mission. The paper also discusses NASA s current activities and future plans for NTP development that include system-level Technology Demonstrations - specifically ground testing a small, scalable NTR by 2020, with a flight test shortly thereafter.

Borowski, Stanley K.↗
NASA NTRS1964

Liquid rockets.

Liquid rocket propulsion systems examining performance and properties of propellant combinations and components of subsystems

PROPULSIVE EFFICIENCY↗
NASA NTRS1984

Laser propulsion

An introduction to thermal laser propulsion is presented. This form of rocket propulsion uses a laser beam from a remotely-located laser to heat a propellant gas, which is then expanded in a conventional way to produce thrust. This propulsion scheme has the potential for producing high specific impulse (greater than 1000 s) at moderate to high thrust (1000 lbs). Laser propulsion can thus fill a niche in propulsion for spaceflight missions which can be filled by no other practical scheme. The system analyses and some of the experimental and theoretical studies which have been performed are briefly reviewed. Production of thrust by a pulsed laser has been demonstrated on a laboratory scale at an Isp of 1000 s in hydrogen. While more work is needed, it seems apparent that laser propulsion has an important and unique capability which should be pursued, and should be considered for space missions in the 1990's and beyond.

Kemp, N. H.↗
NASA NTRS1998

1998 JANNAF Propulsion Meeting

This volume, the first of four volumes, is a collection of 40 unclassified/unlimited-distribution papers which were presented at the 1998 Joint Army-Navy-NASA-Air Force (JANNAF) Propulsion Meeting (JPM), held 15-17 July 1998 at the Cleveland Marriott Downtown at Key Center and the Celebreeze Federal Building in Cleveland, Ohio. The 1998 JPM was co-located with the 1998 American Institute of Aeronautics and Astronautics Joint Propulsion Conference. Specific subjects discussed include reusable liquid boosters, controllable solid propulsion, advanced propellants for the 2.75' rocket system, air-turbo-rocket propulsion, issues in gun propulsion, electric propulsion, liquid engine turbomachinery, and new liquid propulsion technology.

Eggleston, Debra S.↗
NASA NTRS1994

Space and transatmospheric propulsion technology

This report focuses primarily on Japan's programs in liquid rocket propulsion and propulsion for spaceplane and related transatmospheric areas. It refers briefly to Japan's solid rocket programs and to new supersonic air-breathing propulsion efforts. The panel observed that the Japanese had a carefully thought-out plan, a broad-based program, and an ambitious but achievable schedule for propulsion activity. Japan's overall propulsion program is behind that of the United States at the time of this study, but the Japanese are gaining rapidly. The Japanese are at the forefront in such key areas as advanced materials, enjoying a high level of project continuity and funding. Japan's space program has been evolutionary in nature, while the U.S. program has emphasized revolutionary advances. Projects have typically been smaller in Japan than in the United States, focusing on incremental advances in technology, with an excellent record of applying proven technology to new projects. This evolutionary approach, coupled with an ability to take technology off the shelf from other countries, has resulted in relatively low development costs, rapid progress, and enhanced reliability. Clearly Japan is positioned to be a world leader in space and transatmospheric propulsion technology by the year 2000.

Merkle, Charles↗
NASA NTRS2001

Engineering the Future of Full-Scale Propulsion Testing

Year 2000 has been an active one for rocket propulsion testing at the NASA John C. Stennis Space Center. This paper highlights several major test facilites for large-scale propulsion devices, and summarizes the varied nature of the recent test projects conducted at the Stennis Space Center (SSC) such as the X-33 Aerospike Engine, Ultra Low Cost Engine (ULCE) thrust chamber program, and the Hybrid Sounding Rocket (HYSR) program. Further, an overview of relevant engineering capabilities and technology challenges in conducting full-scale propulsion testing are outlined.

Ryan, H. M.↗
NASA NTRS2007

NASA Hypersonic Propulsion: Overview of Progress from 1995 to 2005

Hypersonic propulsion work supported by the United States National Aeronautics and Space Administration had a primary focus on Space Transportation during the period from 1995 to 2005. The framework for these advances was established by policy and pursued with substantial funding. Many noteworthy advances were made, highlighted by the pinnacle flights of the X-43. This paper reviews and summarizes the programs and accomplishments of this era. The accomplishments are compared to the goals and objectives to lend an overarching perspective to what was achieved. At least dating back to the early days of the Space Shuttle program, NASA has had the objective of reducing the cost of access to space and concurrently improving safety and reliability. National Space Transportation Policy in 1994 coupled with a base of prior programs such as the National Aerospace Plane and the need to look beyond the Space Shuttle program set the stage for NASA to pursue Space Transportation Advances. Programs defined to pursue the advances represented a broad approach addressing classical rocket propulsion as well as airbreathing propulsion in various combinations and forms. The resulting portfolio of activities included systems analysis and design studies, discipline research and technology, component technology development, propulsion system ground test demonstration and flight demonstration. The types of propulsion systems that were pursued by these programs included classical rocket engines, "aerospike" rocket engines, high performance rocket engines, scram jets, rocket based combined cycles, and turbine based combined cycles. Vehicle architectures included single and two stage vehicles. Either single types of propulsion systems or combinations of the basic propulsion types were applied to both single and two stage vehicle design concepts. Some of the propulsion system design concepts were built and tested at full scale, large scale and small scale. Many flight demonstrators were conceptually defined, fewer designed and some built and one flown to demonstrate several technical advancements including propulsion. The X-43 flights were a culmination of these efforts for airbreathing propulsion. During the course of that period, there was a balance of funding and emphasis toward rocket propulsion but still very substantial airbreathing propulsion effort. The broad objectives of these programs were to both advance and test the state of the art so as to provide a basis for options to be pursued for broad space transportation needs, most importantly focused on crew carrying capability. NASA cooperated with the Department of Defense in planning and implementation of these programs to make efficient use of objectives and capabilities where appropriate. Much of the work was conducted in industry and academia as well as Government laboratories. Many test articles and data-bases now exist as a result of this work. At the conclusion of the period, the body of work made it clear that continued research and technology development was warranted, because although not ready for a NASA system development decision, results continued to support the promise of air-breathing propulsion for access to space.

Cikanek, Harry A., III↗
NASA NTRS2006

Cryogenic Cooling for Myriad Applications-A STAR Is Born

Cryogenics, the science of generating extremely low temperatures, has wide applicability throughout NASA. The Agency employs cryogenics for rocket propulsion, high-pressure gas supply, breathable air in space, life support equipment, electricity, water, food preservation and packaging, medicine, imaging devices, and electronics. Cryogenic liquid oxygen and liquid hydrogen systems are also replacing solid rocket motor propulsion systems in most of the proposed launch systems, a reversion to old-style liquid propellants. In the late 1980s, NASA wanted a compact linear alternator/motor with reduced size and mass, as well as high efficiency, that had unlimited service life for use in a thermally driven power generator for space power applications. Prior development work with free-piston Stirling converters (a Stirling engine integrated with a linear actuator that produces electrical power output) had shown the promise of that technology for high-power space applications. A dual use for terrestrial applications exists for compact Stirling converters for onsite combined heat and power units. The Stirling cycle is also usable in reverse as a refrigeration cycle suitable for cryogenic cooling, so this Stirling converter work promised double benefits as well as dual uses. The uses for cryogenic coolers within NASA abound; commercial applications are similarly wide-ranging, from cooling liquid oxygen and nitrogen, to cryobiology and bio-storage, cryosurgery, instrument and detector cooling, semiconductor manufacturing, and support service for cooled superconducting power systems.

Source record↗
NASA NTRS1973

Detonation propulsion for high pressure environments

One limitation encountered by chemical rocket propulsion in high pressure planetary atmospheres is illustrated by the conflict between the dependence of specific impulse on the ratio of chamber pressure to ambient pressure and the dependence of the motor structural design on the difference between the pressures. This work proposes to resolve the difficulty by employing detonating propellant in which the high pressures necessary for efficient propulsion are developed over a short time and need not be contained statically. Experimental results are presented to substantiate this claim of relatively high performance, together with an analytical development that approximately describes the flow dynamics.

Varsi, G.↗
NASA NTRS1989

Advanced technology for future space propulsion systems

The NASA Project Pathfinder contains programs to provide technologies for future transfer vehicles including those powered by both advanced chemical and electric propulsion rockets. This paper discusses the Chemical Transfer Propulsion and Cargo Vehicle Propulsion elements of Pathfinder. The program requirements and goals for both elements are discussed, and technical activities which are planned or underway are summarized. Recent progress in programs which support or proceed the Pathfinder activities is detailed. In particular, the NASA Program for Advanced Orbital Transfer Vehicle Propulsion, which acted as the precursor for the Chemical Transfer Propulsion element of Pathfinder is summarized.

Diehl, Larry A.↗
NASA NTRS2012

Testing of the NASA Hypersonics Project Combined Cycle Engine Large Scale Inlet Mode Transition Experiment (CCE LlMX)

Status on an effort to develop Turbine Based Combined Cycle (TBCC) propulsion is described. This propulsion technology can enable reliable and reusable space launch systems. TBCC propulsion offers improved performance and safety over rocket propulsion. The potential to realize aircraft-like operations and reduced maintenance are additional benefits. Among most the critical TBCC enabling technologies are: 1) mode transition from turbine to scramjet propulsion, 2) high Mach turbine engines and 3) TBCC integration. To address these TBCC challenges, the effort is centered on a propulsion mode transition experiment and includes analytical research. The test program, the Combined-Cycle Engine Large Scale Inlet Mode Transition Experiment (CCE LIMX), was conceived to integrate TBCC propulsion with proposed hypersonic vehicles. The goals address: (1) dual inlet operability and performance, (2) mode-transition sequences enabling a switch between turbine and scramjet flow paths, and (3) turbine engine transients during transition. Four test phases are planned from which a database can be used to both validate design and analysis codes and characterize operability and integration issues for TBCC propulsion. In this paper we discuss the research objectives, features of the CCE hardware and test plans, and status of the parametric inlet characterization testing which began in 2011. This effort is sponsored by the NASA Fundamental Aeronautics Hypersonics project

Saunders, J. D.↗
NASA NTRS1971

Application of hybrid propulsion systems to planetary missions

The feasibility and application of hybrid rocket propulsion to outer-planet orbiter missions is assessed in this study and guidelines regarding future development are provided. A Jupiter Orbiter Mission was selected for evaluation because it is the earliest planetary mission which may require advanced chemical propulsion. Mission and spacecraft characteristics which affect the selection and design of propulsion subsystems are presented. Alternative propulsion subsystems, including space-storable bipropellant liquids, a solid/monopropellant vernier, and a hybrid, are compared on the basis of performance, reliability, and cost. Cost-effectiveness comparisons are made for a range of assumptions including variation in (1) the level of need for spacecraft performance (determined in part by launch vehicle injected mass capability), and (2) achievable reliability at corresponding costs. The results indicated that the hybrid and space-storable bipropellant mechanizations are competitive.

Don, J. P.↗
NASA NTRS1993

Integrated modular propulsion for launch vehicles

The paper proposes a modular approach to rocket propulsion which offers a versatile method for realizing the goals of low cost, safety, reliability, and ease of operation. It is shown that, using practical modules made up of only 4-6 individual elements, it is possible to achieve thrust levels of 2-3 mln lbf and more, using turbomachinery, thrust chambers, lines, and valves about the size of SSME hardware. The approach is illustrated by a LOX/LH2 configuration.

Knuth, William↗
NASA NTRS1974

Investigation of matter-antimatter interaction for possible propulsion applications

Matter-antimatter annihilation is discussed as a means of rocket propulsion. The feasibility of different means of antimatter storage is shown to depend on how annihilation rates are affected by various circumstances. The annihilation processes are described, with emphasis on important features of atom-antiatom interatomic potential energies. A model is developed that allows approximate calculation of upper and lower bounds to the interatomic potential energy for any atom-antiatom pair. Formulae for the upper and lower bounds for atom-antiatom annihilation cross-sections are obtained and applied to the annihilation rates for each means of antimatter storage under consideration. Recommendations for further studies are presented.

Morgan, D. L., Jr.↗