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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 721 records · Page 40
All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Stacking the odds in favor of a space propulsion jackpot

When faced with a variety of technical options to solve a problem, program planners often try to identify one potential winner, then channel their resources into this option. The more scarce their resources are perceived to be, the more likely they are to fall into this trap of illogic. The real ideal solution could well be an optimum combination of options, not just one. Many propulsion opportunities are tantalizing solutions to the potentially high cost of travelling to other planets. Among these opportunities, nuclear thermal rockets (NTR), nuclear electric propulsion (NEP), and asteroid derived propellants stand out as high-payoff modest-challenge options, as near term as they are resolved to be made. But which to choose? Or should higher risk higher payoff technology be opted for, such as fusion? The approach advocated here, technoflex, is one that addresses NTR, NEP, and asteroid propellants in harmony rather than in isolation. Technoflex is technology rich, and option flexible. Technoflex should cost roughly the same as a classic phased technology elimination approach. The synergistic benefits amongst these three options, how they can be efficiently pursued together, and how they can fit with longer range technologies are stressed. Even if no single option reaches its highest expectations, the combinations of any two partial winners would still give big dividends. These combinations are cheap propellants in space, dual mode high thrust/low thrust, or versatile propellant NTR. The triple payoff is excellent, even if all three options would pan out below expectations. If only one option reaches its potential, it could make the other two still worth their investment. If all three options meet full expectations, the triple payoff is a space propulsion jackpot which makes concern about the initial investment ludicrous as well as open up the solar system to expedient exploration.

Willoughby, Alan J.↗
NASA NTRS1990

Economic consequences of commercial space operations

The potential economic benefits generated from increased industry involvement and investment in space activities and the subsequent cost implications are discussed. A historical overview of commercial industry involvement in space is given and sources of new economic growth in space are discussed. These include communications satellites, small satellites, positioning and navigation services, space transportation and infrastructure, remote sensing, and materials processing in space such as the manufacturing of protein crystals and zeolites. Macroeconomic trends and principles such as limits on technology trade, eased restrictions on international joint ventures, foreign investments in U.S. firms, and increased foreign competition are discussed. Earth observations and mapping are considered. Opportunities for private sector involvement in building space infrastructure and space transportation are highlighted.

Stone, Barbara A.↗
NASA NTRS1990

A proposal for risk sharing in the development of a lunar oxygen plant

The production of lunar oxygen for use in a NASA lunar outpost program could provide a profitable investment for nongovernment development, savings for government, and an initiation of a new resource of capital financing for space industrialization. A joint endeavor to share development risks between government and nongovernment investment is proposed, based on some early assessments of technical and financial feasibility for the project. Successful initial negotiations between government and nongovernment investors can establish the requirements for financing the project with private funds.

Duke, Michael B.↗
NASA NTRS1991

Advanced techniques and technology for efficient data storage, access, and transfer

Advanced techniques for efficiently representing most forms of data are being implemented in practical hardware and software form through the joint efforts of three NASA centers. These techniques adapt to local statistical variations to continually provide near optimum code efficiency when representing data without error. Demonstrated in several earlier space applications, these techniques are the basis of initial NASA data compression standards specifications. Since the techniques clearly apply to most NASA science data, NASA invested in the development of both hardware and software implementations for general use. This investment includes high-speed single-chip very large scale integration (VLSI) coding and decoding modules as well as machine-transferrable software routines. The hardware chips were tested in the laboratory at data rates as high as 700 Mbits/s. A coding module's definition includes a predictive preprocessing stage and a powerful adaptive coding stage. The function of the preprocessor is to optimally process incoming data into a standard form data source that the second stage can handle.The built-in preprocessor of the VLSI coder chips is ideal for high-speed sampled data applications such as imaging and high-quality audio, but additionally, the second stage adaptive coder can be used separately with any source that can be externally preprocessed into the 'standard form'. This generic functionality assures that the applicability of these techniques and their recent high-speed implementations should be equally broad outside of NASA.

Rice, Robert F.↗
NASA NTRS1992

Arrow 227: Air transport system design simulation

The Arrow 227 is a student-designed commercial transport for use in a overnight package delivery network. The major goal of the concept was to provide the delivery service with the greatest potential return on investment. The design objectives of the Arrow 227 were based on three parameters; production cost, payload weight, and aerodynamic efficiency. Low production cost helps to reduce initial investment. Increased payload weight allows for a decrease in flight cycles and, therefore, less fuel consumption than an aircraft carrying less payload weight and requiring more flight cycles. In addition, fewer flight cycles will allow a fleet to last longer. Finally, increased aerodynamic efficiency in the form of high L/D will decrease fuel consumption.

Bontempi, Michael↗
NASA NTRS1992

Deep space communications technology thrusts

The paper discusses the technology thrusts that are currently being developed for deep space missions as well as the expected dividends of these thrusts during the 1990's and beyond. Particular attention is given to Ka-band (32 GHz) development, channel coding, source coding, and optical communications. The ongoing development described here attempts to meet the telecommunications demands of future missions by stressing cooperative developments between ground networks and flight projects in order to optimize NASA's overall investment in solar system investment.

Yuen, Joseph H.↗
NASA NTRS1993

Improved ceramic slip casting technique

A primary concern in modern fluid dynamics research is the experimental verification of computational aerothermodynamic codes. This research requires high precision and detail in the test model employed. Ceramic materials are used for these models because of their low heat conductivity and their survivability at high temperatures. To fabricate such models, slip casting techniques were developed to provide net-form, precision casting capability for high-purity ceramic materials in aqueous solutions. In previous slip casting techniques, block, or flask molds made of plaster-of-paris were used to draw liquid from the slip material. Upon setting, parts were removed from the flask mold and cured in a kiln at high temperatures. Casting detail was usually limited with this technique -- detailed parts were frequently damaged upon separation from the flask mold, as the molded parts are extremely delicate in the uncured state, and the flask mold is inflexible. Ceramic surfaces were also marred by 'parting lines' caused by mold separation. This adversely affected the aerodynamic surface quality of the model as well. (Parting lines are invariably necessary on or near the leading edges of wings, nosetips, and fins for mold separation. These areas are also critical for flow boundary layer control.) Parting agents used in the casting process also affected surface quality. These agents eventually soaked into the mold, the model, or flaked off when releasing the case model. Different materials were tried, such as oils, paraffin, and even an algae. The algae released best, but some of it remained on the model and imparted an uneven texture and discoloration on the model surface when cured. According to the present invention, a wax pattern for a shell mold is provided, and an aqueous mixture of a calcium sulfate-bonded investment material is applied as a coating to the wax pattern. The coated wax pattern is then dried, followed by curing to vaporize the wax pattern and leave a shell mold of the calcium sulfate-bonded investment material. The shell mold is cooled to room temperature, and a ceramic slip is poured therein. After a ceramic shell of desired thickness has set up in the shell mold, excess ceramic slip is poured out. While still wet, the shell mold is peeled from the ceramic shell to expose any delicate or detailed parts, after which the ceramic shell is cured to provide a complete, detailed, precision ceramic article without parting lines.

Buck, Gregory M.↗
NASA NTRS1993

Future directions in flight simulation: A user perspective

Langley Research Center was an early leader in simulation technology, including a special emphasis in space vehicle simulations such as the rendezvous and docking simulator for the Gemini program and the lunar landing simulator used before Apollo. In more recent times, Langley operated the first synergistic six degree of freedom motion platform (the Visual Motion Simulator, or VMS) and developed the first dual-dome air combat simulator, the Differential Maneuvering Simulator (DMS). Each Langley simulator was developed more or less independently from one another with different programming support. At present time, the various simulation cockpits, while supported by the same host computer system, run dissimilar software. The majority of recent investments in Langley's simulation facilities have been hardware procurements: host processors, visual systems, and most recently, an improved motion system. Investments in software improvements, however, have not been of the same order.

Jackson, Bruce↗
NASA NTRS1994

Rapid prototype fabrication processes for high-performance thrust cells

The Thrust Cell Technologies Program (Air Force Phillips Laboratory Contract No. F04611-92-C-0050) is currently being performed by Rocketdyne to demonstrate advanced materials and fabrication technologies which can be utilized to produce low-cost, high-performance thrust cells for launch and space transportation rocket engines. Under Phase 2 of the Thrust Cell Technologies Program (TCTP), rapid prototyping and investment casting techniques are being employed to fabricate a 12,000-lbf thrust class combustion chamber for delivery and hot-fire testing at Phillips Lab. The integrated process of investment casting directly from rapid prototype patterns dramatically reduces design-to-delivery cycle time, and greatly enhances design flexibility over conventionally processed cast or machined parts.

Hunt, K.↗
NASA NTRS1995

AMCC casting development, volume 2

PCC successfully cast and performed nondestructive testing, FPI and x-ray, on seventeen AMCC castings. Destructive testing, lab analysis and chemical milling, was performed on eleven of the castings and the remaining six castings were shipped to NASA or Aerojet. Two of the six castings shipped, lots 015 and 016, were fully processed per blueprint requirements. PCC has fully developed the gating and processing parameters of this part and feels the part could be implemented into production, after four more castings have been completed to ensure the repeatability of the process. The AMCC casting has been a technically challenging part due to its size, configuration, and alloy type. The height and weight of the wax pattern assembly necessitated the development of a hollow gating system to ensure structural integrity of the shell throughout the investment process. The complexity in the jacket area of the casting required the development of an innovative casting technology that PCC has termed 'TGC' or thermal gradient control. This method of setting up thermal gradients in the casting during solidification represents a significant process improvement for PCC and has been successfully implemented on other programs. The alloy, JBK75, is a relatively new alloy in the investment casting arena and required our engineering staff to learn the gating, processing, and dimensional characteristics of the material.

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NASA NTRS1994

An overview of the Software Engineering Laboratory

This report describes the background and structure of the SEL organization, the SEL process improvement approach, and its experimentation and data collection process. Results of some sample SEL studies are included. It includes a discussion of the overall implication of trends observed over 17 years of process improvement efforts and looks at the return on investment based on a comparison of total investment in process improvement with the measurable improvements seen in the organization's software product.

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NASA NTRS1995

Space Science for the 21st Century: The Space Science Enterprise Strategic Plan

Throughout its history, the U.S. Space Science technologies program has been enormously productive. Its accomplishments have rewritten the textbooks. But now, the economic environment has changed dramatically. The Nation's scientific and technological goals are being reexamined and redefined.And the social contract between the scientific community and the Federal Government is being rewritten. There is an expectation that the American public should receive more direct benefits from its investment in science and technology. This Strategic Plan reflects this new paradigm. It presents a carefully selected set of new scientific initiatives that build on past accomplishments to continue NASA's excellence in Space Science. At the same time, it responds to fiscal constraints by defining a new approach to planning, developing, and operating Space Science missions. In particular, investments in new technologies will permit major scientific advances to be made with smaller, more focused, and less costly missions. With the introduction of advanced technologies, smaller does not have to mean less capable. The focus on new technologies also provides and opportunity for the Space Science program to enhance its direct contribution to the country's economic base. At the same time, the program can build on public interest to strengthen its contributions to education and scientific literacy. With this plan we are taking the first steps toward shaping the Space Science program of the 21st century. In doing so, we face major challenges. It will be a very different program than might have been envisioned even a few years ago. But it will be a program that remains at the forefront of science, technology, and education. We intend to continue rewriting the textbooks.

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NASA NTRS1995

NAS Experiences of Porting CM Fortran Codes to HPF on IBM SP2 and SGI Power Challenge

Current Connection Machine (CM) Fortran codes developed for the CM-2 and the CM-5 represent an important class of parallel applications. Several users have employed CM Fortran codes in production mode on the CM-2 and the CM-5 for the last five to six years, constituting a heavy investment in terms of cost and time. With Thinking Machines Corporation's decision to withdraw from the hardware business and with the decommissioning of many CM-2 and CM-5 machines, the best way to protect the substantial investment in CM Fortran codes is to port the codes to High Performance Fortran (HPF) on highly parallel systems. HPF is very similar to CM Fortran and thus represents a natural transition. Conversion issues involved in porting CM Fortran codes on the CM-5 to HPF are presented. In particular, the differences between data distribution directives and the CM Fortran Utility Routines Library, as well as the equivalent functionality in the HPF Library are discussed. Several CM Fortran codes (Cannon algorithm for matrix-matrix multiplication, Linear solver Ax=b, 1-D convolution for 2-D datasets, Laplace's Equation solver, and Direct Simulation Monte Carlo (DSMC) codes have been ported to Subset HPF on the IBM SP2 and the SGI Power Challenge. Speedup ratios versus number of processors for the Linear solver and DSMC code are presented.

Saini, Subhash↗
NASA NTRS1996

Recommendations for Technology Development and Validation Activities in Support of the Origins Program

The Office of Space Science (OSS) has initiated mission concept studies and associated technology roadmapping activities for future large space optical systems. The scientific motivation for these systems is the study of the origins of galaxies, stars, planetary systems and, ultimately, life. Collectively, these studies are part of the 'Astronomical Search for Origins and Planetary Systems Program' or 'Origins Program'. A series of at least three science missions and associated technology validation flights is currently envisioned in the time frame between the year 1999 and approximately 2020. These would be the Space Interferometry Mission (SIM), a 10-meter baseline Michelson stellar interferometer; the Next Generation Space Telescope (NGST), a space-based infrared optimized telescope with aperture diameter larger than four meters; and the Terrestrial Planet Finder (TPF), an 80-meter baseline-nulling Michelson interferometer described in the Exploration of Neighboring Planetary Systems (ExNPS) Study. While all of these missions include significant technological challenges, preliminary studies indicate that the technological requirements are achievable. However, immediate and aggressive technology development is needed. The Office of Space Access and Technology (OSAT) is the primary sponsor of NASA-unique technology for missions such as the Origins series. For some time, the OSAT Space Technology Program has been developing technologies for large space optical systems, including both interferometers and large-aperture telescopes. In addition, technology investments have been made by other NASA programs, including OSS; other government agencies, particularly the Department of Defense; and by the aerospace industrial community. This basis of prior technology investment provides much of the rationale for confidence in the feasibility of the advanced Origins missions. In response to the enhanced interest of both the user community and senior NASA management in large space optics, OSAT is moving to improve the focus of its sensor, spacecraft, and interferometer/telescope technology programs on the specific additional needs of the OSS Origins Program. To better define Origins mission technology and facilitate its development, OSAT and OSS called for a series of workshops with broad participation from industry, academia and the national laboratory community to address these issues. Responsibility for workshop implementation was assigned jointly to the two NASA field centers with primary Origins mission responsibility, the Goddard Space Flight Center and the Jet Propulsion Laboratory. The Origins Technology Workshop, held at Dana Point, California between June 4 and 6, 1996 was the first in the series of comprehensive workshops aimed at addressing the broad technological needs of the Origins Program. It was attended by 64 individuals selected to provide technical expertise relevant to the technology challenges of the Origins missions. This report summarizes the results of that meeting. A higher level executive summary was considered inappropriate because of the potential loss of important context for the recommendations. Subsequent to the Origins Technology Workshop and prior to publication of this report, NASA Headquarters reorganized the activities of the Of fice of Space Access and Technology. It appears likely that responsibility for the technology programs recommended in this document will move to the Office of Space Science.

Capps, Richard W.↗
NASA NTRS1998

1997 NASA Academy in Aeronautics

The NASA Academy in Aeronautics at the Dryden Flight Research Center (DFRC) was a ten-week summer leadership training program conducted for the first time in the summer of 1997. Funding was provided by a contract between DFRC and Purdue University. Mr. Lee Duke of DFRC was the contract monitor, and Professor Dominick Andrisani was the principal investigator. Five student research associates participated in the program. Biographies of the research associates are given in Appendix 1. Dominick Andrisani served as Dean of the NASA Academy in Aeronautics. NASA Academy in Aeronautics is a unique summer institute of higher learning that endeavors to provide insight into all of the elements that make NASA aeronautical research possible. At the same time the Academy assigns the research associate to be mentored by one of NASA!s best researchers so that they can contribute towards an active flight research program. Aeronautical research and development are an investment in the future, and NASA Academy is an investment in aeronautical leaders of the future. The Academy was run by the Indiana Space Grant Consortium at Purdue in strategic partnership with the National Space Grant College and Fellowship Program. Research associates at the Academy were selected with help from the Space Grant Consortium that sponsored the research associate. Research associate stipend and travel to DFRC were paid by the students' Space Grant Consortium. All other student expenses were paid by the Academy. Since the Academy at DFRC had only five students the opportunity for individual growth and attention was unique in the country. About 30% of the working time and most of the social time of the students were be spent as a "group" or "team." This time was devoted to exchange of ideas, on forays into the highest levels of decision making, and in executing aeronautical research. This was done by interviewing leaders throughout the aerospace industry, seminars, working dinners, and informal discussions. The other 70% of the working time was spent working on the technical research project with the engineering mentors. Abstracts of those projects are given in Appendix 4.

Andrisani, Dominick, II↗
NASA NTRS1998

GCM Studies on the Interactions Between Photosynthesis and Climate at Diurnal to Decadal Time Scales

Transpiration, a major component of total evaporation from vegetated surfaces, is an unavoidable consequence of photosynthetic carbon fixation. Because of limiting soil moisture and competition for solar radiation plants invest most of their fixed carbon into structural and hydraulic functions (roots and stems) and solar radiation absorption (leaves). These investments permit individuals to overshadow competitors and provide for transport of water from the soil to the leaves where photosynthesis and transpiration occur. Often low soil moisture or high evaporative demand limit the supply of water to leaves reducing photosynthesis and thus transpiration. The absorption of solar radiation for photosynthesis and dissipation of this energy via radiation, heat, mass and momentum fluxes represents the link between photosynthesis and climate. Recognition of these relationships has led to the development of hydro/energy balance models that are based on the physiological ecology of photosynthesis. We discuss an approach to study vegetation-climate interactions using photosynthesis-centric models embedded in a GCM. The rate at which a vegetated area transpires and photosynthesizes is determined by the physiological state of the vegetation, its amount and its type. The latter two are specified from global satellite data collected since 1982. Climate simulations have been carried out to study how this simulated climate system responds to changes in radiative forcing, physiological capacity, atmospheric CO2, vegetation type and variable vegetation cover observed from satellites during the 1980's. Results from these studies reveal significant feedbacks between the vegetation activity and climate. For example, vegetation cover and physiological activity increases cause the total latent heat flux and precipitation to increase while mean and maximum air temperatures decrease. The reverse occurs if cover or activity'decreases. In general climate response of a particular region was dominated by local processes but we also find evidence that plausible climate-vegetation scenarios lead to changes in global atmospheric circulation and strong non-local influences in some cases.

Collatz, G. James↗
NASA NTRS1998

NASA Technology Plan 1998

This NASA Strategic Plan describes an ambitious, exciting vision for the Agency across all its Strategic Enterprises that addresses a series of fundamental questions of science and research. This vision is so challenging that it literally depends on the success of an aggressive, cutting-edge advanced technology development program. The objective of this plan is to describe the NASA-wide technology program in a manner that provides not only the content of ongoing and planned activities, but also the rationale and justification for these activities in the context of NASA's future needs. The scope of this plan is Agencywide, and it includes technology investments to support all major space and aeronautics program areas, but particular emphasis is placed on longer term strategic technology efforts that will have broad impact across the spectrum of NASA activities and perhaps beyond. Our goal is to broaden the understanding of NASA technology programs and to encourage greater participation from outside the Agency. By relating technology goals to anticipated mission needs, we hope to stimulate additional innovative approaches to technology challenges and promote more cooperative programs with partners outside NASA who share common goals. We also believe that this will increase the transfer of NASA-sponsored technology into nonaerospace applications, resulting in an even greater return on the investment in NASA.

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NASA NTRS1998

Technology Development Benefits and the Economics Breakdown Structure

This paper describes the construction and application of the EBS (Economics Breakdown Structure) in evaluating technology investments across multiple systems and organizations, illustrated with examples in space transportation technology. The United States Government (USG) has a long history of investing in technology to enable its missions. Agencies such as the National Aeronautics and Space Administration (NASA) and the Department of Defense (DoD) have evaluated their technology development programs primarily on their effects on mission performance and cost. More and more, though, USG agencies are being evaluated on their technology transfer to the commercial sector. In addition, an increasing number of USG missions are being accomplished by industry-led or joint efforts, where the USG provides technology and funding but tasks industry with development and operation of the mission systems.

Shaw, Eric J.↗