SEARCH · Engineering Papers
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
The results of a series of tests to determine the effect of internal pressure on the buckling load of a thin cylinder under an applied torque indicated that internal pressure raises the shear buckling stress. The experimental results were analyzed with the aid of previously developed theory and a simple interaction formula was derived. (author)
An analysis has been made by the NACA of the effects of heat and compressibility in the flow through the internal systems of aircraft. Equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.
At the request of the Army Air Forces, Materiel Command, tests were made in the two-Dimensional low-turbulence tunnel of a mode l submitted by Bell Aircraft Corporation as the tip section of the wing of the xp-63 airplane. " The model was a NACA 66, 2x-2l6 a = 0.6 airfoil section of 50-inch chord and made of dural according to standard sheet-metal practice. The model was fitted for an internal-balance aileron with a tab and a Frise type aileron. Several alterations of the skirts and balance on the internal- balance aileron were tested to obtain the various aerodynamic characteristics of the aileron.
Three-dimensional sidewall-compression scramjet inlets with leading-edge sweeps of 30 deg and 70 deg were tested in the Langley Hypersonic CF4 Tunnel at a Mach number of 6 and a free-stream ratio of specific heats of 1.2. The parametric effects of leading-edge sweep, cowl position, contraction ratio, and Reynolds number were investigated. The models were instrumented with static pressure orifices distributed on the sidewalls, baseplate, and cowl. Schlieren movies were made of selected tunnel runs for flow visualization of the entrance plane and cowl region. Although these movies could not show the internal flow, the effect of the internal flow on the external flow was evident by way of spillage. The purpose is to provide a preliminary data release for the investigation. The models, facility, and testing methods are described, and the test matrix and a tabulation of tunnel runs are provided. Line plots highlighting the stated parametric effects and a representative set of schlieren photographs are presented without analysis.
In 1992, the International Space University (ISU) held its Summer Session in Kitakyushu, Japan. This paper summarizes and expands upon some aspects of space solar power and space transportation that were considered during that session. The issues discussed in this paper are the result of a 10-week study by the Space Solar Power Program design project members and the Space Transportation Group to investigate new paradigms in space propulsion and how those paradigms might reduce the costs for large space programs. The program plan was to place a series of power satellites in Earth orbit. Several designs were studied where many kW, MW, or GW of power would be transmitted to Earth or to other spacecraft in orbit. During the summer session, a space solar power system was also detailed and analyzed. A high-cost space transportation program is potentially the most crippling barrier to such a space power program. At ISU, the focus of the study was to foster and develop some of the new paradigms that may eliminate the barriers to low cost for space exploration and exploitation. Many international and technical aspects of a large multinational program were studied. Environmental safety, space construction and maintenance, legal and policy issues of frequency allocation, technology transfer and control and many other areas were addressed. Over 120 students from 29 countries participated in this summer session. The results discussed in this paper, therefore, represent the efforts of many nations.
The first International Telemedicine/Disaster Medicine Conference was held in Dec. 1991. The overall purpose was to convene an international, multidisciplinary gathering of experts to discuss the emerging field of telemedicine and assess its future directions; principally the application of space technology to disaster response and management, but also to clinical medicine, remote health care, public health, and other needs. This collection is intended to acquaint the reader with recent landmark efforts in telemedicine as applied to disaster management and remote health care, the technical requirements of telemedicine systems, the application of telemedicine and telehealth in the U.S. space program, and the social and humanitarian dimensions of this area of medicine.
As a result of limited resources and tight fiscal constraints over the past several years, the defense and aerospace industries have experienced a downturn in business activity. The impact of fewer contracts being awarded has placed a greater emphasis for effectiveness and efficiency on industry contractors. It is clear that a reallocation of resources is required for America to continue to lead the world in space and technology. The key to technological and economic survival is the transforming of existing programs, such as the Space Shuttle Program, into more cost efficient programs so as to divert the savings to other NASA programs. The partnership between Rockwell International and NASA and their joint improvement efforts that resulted in significant streamlining and cost reduction measures to Rockwell International Space System Division's work on the Space Shuttle System Integration Contract is described. This work was a result of an established Cost Effectiveness Enhancement (CEE) Team formed initially in Fiscal Year 1991, and more recently expanded to a larger scale CEE Initiative in 1992. By working closely with the customer in agreeing to contract content, obtaining management endorsement and commitment, and involving the employees in total quality management (TQM) and continuous improvement 'teams,' the initial annual cost reduction target was exceeded significantly. The CEE Initiative helped reduce the cost of the Shuttle Systems Integration contract while establishing a stronger program based upon customer needs, teamwork, quality enhancements, and cost effectiveness. This was accomplished by systematically analyzing, challenging, and changing the established processes, practices, and systems. This examination, in nature, was work intensive due to the depth and breadth of the activity. The CEE Initiative has provided opportunities to make a difference in the way Rockwell and NASA work together - to update the methods and processes of the organizations. The future success of NASA space programs and Rockwell hinges upon the ability to adopt new, more efficient and effective work processes. Efficiency, proficiency, cost effectiveness, and teamwork are a necessity for economic survival. Continuous improvement initiatives like the CEE are, and will continue to be, vehicles by which the road can be traveled with a vision to the future.
This is the final report of the NASA Lewis SBIR Phase 2 Contract Number NAS3-25785, Multigrid Solution of Internal Flows Using Unstructured Solution Adaptive Meshes. The objective of this project, as described in the Statement of Work, is to develop and deliver to NASA a general three-dimensional Navier-Stokes code using unstructured solution-adaptive meshes for accuracy and multigrid techniques for convergence acceleration. The code will primarily be applied, but not necessarily limited, to high speed internal flows in turbomachinery.
Tests on a prototype engineering model of the Russian Mars 96 Rover were conducted by an international team in and near Death Valley in the United States in late May, 1992. These tests were part of a comprehensive design and testing program initiated by the three Russian groups responsible for the rover development. The specific objectives of the May tests were: (1) evaluate rover performance over different Mars-like terrains; (2) evaluate state-of-the-art teleoperation and autonomy development for Mars rover command, control and navigation; and (3) organize an international team to contribute expertise and capability on the rover development for the flight project. The range and performance that can be planned for the Mars mission is dependent on the degree of autonomy that will be possible to implement on the mission. Current plans are for limited autonomy, with Earth-based teleoperation for the nominal navigation system. Several types of television systems are being investigated for inclusion in the navigation system including panoramic camera, stereo, and framing cameras. The tests used each of these in teleoperation experiments. Experiments were included to consider use of such TV data in autonomy algorithms. Image processing and some aspects of closed-loop control software were also tested. A micro-rover was tested to help consider the value of such a device as a payload supplement to the main rover. The concept is for the micro-rover to serve like a mobile hand, with its own sensors including a television camera.
An investigation was conducted in the static test facility of the Langley 16-Foot Transonic Tunnel to evaluate the internal performance of a nonaxisymmetric convergent divergent nozzle designed to have simultaneous pitch and yaw thrust vectoring capability. This concept utilized divergent flap deflection for thrust vectoring in the pitch plane and flow-turning deflectors installed within the divergent flaps for yaw thrust vectoring. Modifications consisting of reducing the sidewall length and deflecting the sidewall outboard were investigated as means to increase yaw-vectoring performance. This investigation studied the effects of multiaxis (pitch and yaw) thrust vectoring on nozzle internal performance characteristics. All tests were conducted with no external flow, and nozzle pressure ratio was varied from 2.0 to approximately 13.0. The results indicate that this nozzle concept can successfully generate multiaxis thrust vectoring. Deflection of the divergent flaps produced resultant pitch vector angles that, although dependent on nozzle pressure ratio, were nearly equal to the geometric pitch vector angle. Losses in resultant thrust due to pitch vectoring were small or negligible. The yaw deflectors produced resultant yaw vector angles up to 21 degrees that were controllable by varying yaw deflector rotation. However, yaw deflector rotation resulted in significant losses in thrust ratios and, in some cases, nozzle discharge coefficient. Either of the sidewall modifications generally reduced these losses and increased maximum resultant yaw vector angle. During multiaxis (simultaneous pitch and yaw) thrust vectoring, little or no cross coupling between the thrust vectoring processes was observed.
A comparative study of two different incompressible Navier-Stokes algorithms for solving an unsteady, incompressible, internal flow problem is performed. The first algorithm uses an artificial compressibility method coupled with upwind differencing and a line relaxation scheme. The second algorithm uses a fractional step method with a staggered grid, finite volume approach. Unsteady, viscous, incompressible, internal flow through a channel with a constriction is computed using the first algorithm. A grid resolution study and parameter studies on the artificial compressibility coefficient and the maximum allowable residual of the continuity equation are performed. The periodicity of the solution is examined and several periodic data sets are generated using the first algorithm. These computational results are compared with previously published results computed using the second algorithm and experimental data.
The U.S. domestic and international regulatory and policy milestones since 1982, when NASA filed its petition with the Federal Communications Commission (FCC) to establish the U.S. domestic Mobile Satellite Service (MSS), are described. In 1985, the FCC proposed to establish MSS services and allocate spectrum for such service. In 1986, the FCC allocated L-band spectrum for MSS. In 1987, at the Mobile World Administrative Radio Conference (MOB WARC-87), despite U.S., Canadian, and Mexican efforts, the WARC did not adopt a multi-service, generic MSS allocation. In 1989, the FCC licensed the first MSS system. After two decisions by the U.S. Court of Appeals, the FCC's licensing actions remain intact. The FCC also has permitted Comsat to provide international aeronautical and land MSS via the Inmarsat system. Inmarsat, however, may not serve the domestic U.S. market. In 1991, the FCC accepted applications for MSS systems, most of which were non-geostationary proposals, for operation in the Radiodetermination Satellite Service (RDSS) bands, and the VHF and UHF bands. In 1992, the FCC proposed rules for non-geostationary MSS systems and applied a negotiated rulemaking procedure to each. Also in 1992, the U.S. position for flexibility in existing MSS bands and for additional worldwide MSS allocations was adopted in large part at the 1992 World Administrative Radio Conference (WARC-92).
The Global Energy and Water Cycle Experiment (GEWEX) represents the World Climate Research Program activities on clouds, radiation, and land-surface processes. The goal of the program is to reproduce and predict, by means of suitable models, the variations of the global hydrological regime and its impact on atmospheric and oceanic dynamics. However, GEWEX is also concerned with variations in regional hydrological processes and water resources and their response to changes in the environment such as increasing greenhouse gases. In fact, GEWEX contains a major new international project called the GEWEX Continental-scale International Project (GCIP), which is designed to bridge the gap between the small scales represented by hydrological models and those scales that are practical for predicting the regional impacts of climate change. The development and use of coupled mesoscale-hydrological models for this purpose is a high priority in GCIP. The objectives of GCIP are presented.
Throughout the 1980s, ESA and the space agencies of Canada, Germany, France, Japan, and the U.S. have pursued cooperative projects bilaterally and multilaterally to prepare for, and to respond to, opportunities in space life sciences research previously unapproachable in scale and sophistication. To cope effectively with likely future space research opportunities, broad, multilateral, coordinated strategic planning is required. Thus, life scientists from these agencies have allied to form the International Space Life Sciences Strategic Planning Working Group. This Group is formally organized under a charter that specifies the purpose of the Working Group as the development of an international strategic plan for the space life sciences, with periodic revisions as needed to keep the plan current. The plan will be policy-, not operations-oriented. The Working Group also may establish specific implementation teams to coordinate multilateral science policy in specific areas; such teams have been established for space station utilization, and for sharing of flight equipment.
In order to identify potential multi-cultural and multinational problems for future International Space Station Freedom crew, a crew debrief questionnaire was developed for U.S. astronauts who flew on shuttle missions with one or more crew members from other countries. Methods: From 1981-90, a total of 20 U.S. astronauts flew on international space missions. Debriefs were mailed to all 20 with instructions not to identify themselves or their specific mission. The debrief focused primarily on preflight training and post flight incidents of misunderstanding, miscommunication, and interpersonal friction among crewmembers. Astronauts were also asked to rate the impact of the incident to the mission (low, medium, high). Results: Ten astronauts responded, but only nine responses were able to be scored, for a return rate of 45 percent. 42 incidents were reported, 9 in the preflight period, 26 inflight, and 7 in the postflight period. Most of the incidents were rated at a low or medium impact, but 5 of the inflight incidents were rated at a 'high' mission impact. A number of causes for the problems were listed, and are discussed. Conclusions: The debrief respondents provide useful and timely recommendations on preflight training which might help facilitate the integration of multinational crews and prevent multi-cultural or multinational factors from interfering with mission operations.
The National Aeronautics and Space Administration (NASA) Goddard Space Flight Center (GSFC) International Solar-Terrestrial Physics (ISTP) Program is committed to the development of a comprehensive, multi-mission ground data system which will support a variety of national and international scientific missions in an effort to study the flow of energy from the sun through the Earth-space environment, known as the geospace. A major component of the ISTP ground data system is an ISTP-dedicated Central Data Handling Facility (CDHF). Acquisition, development, and operation of the ISTP CDHF were delegated by the ISTP Project Office within the Flight Projects Directorate to the Information Processing Division (IPD) within the Mission Operations and Data Systems Directorate (MO&DSD). The ISTP CDHF supports the receipt, storage, and electronic access of the full complement of ISTP Level-zero science data; serves as the linchpin for the centralized processing and long-term storage of all key parameters generated either by the ISTP CDHF itself or received from external, ISTP Program approved sources; and provides the required networking and 'science-friendly' interfaces for the ISTP investigators. Once connected to the ISTP CDHF, the online catalog of key parameters can be browsed from their remote processing facilities for the immediate electronic receipt of selected key parameters using the NASA Science Internet (NSI), managed by NASA's Ames Research Center. The purpose of this paper is twofold: (1) to describe how the ISTP CDHF was successfully implemented and operated to support initially the Japanese Geomagnetic Tail (GEOTAIL) mission and correlative science investigations, and (2) to describe how the ISTP CDHF has been enhanced to support ongoing as well as future ISTP missions. Emphasis will be placed on how various project management approaches were undertaken that proved to be highly effective in delivering an operational ISTP CDHF to the Project on schedule and within budget. Examples to be discussed include: the development of superior teams; the use of Defect Causal Analysis (DCA) concepts to improve the software development process in a pilot Total Quality Management (TQM) initiative; and the implementation of a robust architecture that will be able to support the anticipated growth in the ISTP Program science requirements with only incremental upgrades to the baseline system. Further examples include the use of automated data management software and the implementation of Government and/or industry standards, whenever possible, into the hardware and software development life-cycle. Finally, the paper will also report on several new technologies (for example, the installation of a Fiber Data Distribution Interface network) that were successfully employed.
Space very long baseline interferometry (SVLBI) experiments using a TDRSS satellite have successfully demonstrated the capability of using spacecraft to extend the effective baseline length of VLBI observations beyond the diameter of the Earth, thereby improving the resolution for imaging of active galactic nuclei at centimeter wavelengths. As a result, two spacecraft dedicated to SVLBI, VSOP (Japan) and RadioAstron (Russia), are scheduled to be launched into high Earth orbit in 1996 and 1997. The success of these missions depends on the cooperation of the international community in providing support from ground tracking stations, ground radio telescopes, and correlation facilities. The timely exchange and monitoring of data among the participants requires a well-designed and automated international data transfer system. In this paper, we will discuss the design requirements, data types and flows, and the operational responsibilities associated with the SVLBI data transfer system.
International Space Station Alpha (ISSA) will accommodate a variety of user payloads investigating diverse scientific and technology disciplines on behalf of five international partners: Canada, Europe, Japan, Russia, and the United States. A combination of crew, automated systems, and ground operations teams will control payload operations that require complementary on-board and ground systems. This paper presents the current planning for the ISSA U.S. user payload operations concept and the functional architecture supporting the concept. It describes various NASA payload operations facilities, their interfaces, user facility flight support, the payload planning system, the onboard and ground data management system, and payload operations crew and ground personnel training. This paper summarizes the payload operations infrastructure and architecture developed at the Marshall Space Flight Center (MSFC) to prepare and conduct ISSA on-orbit payload operations from the Payload Operations Integration Center (POIC), and from various user operations locations. The authors pay particular attention to user data management, which includes interfaces with both the onboard data management system and the ground data system. Discussion covers the functional disciplines that define and support POIC payload operations: Planning, Operations Control, Data Management, and Training. The paper describes potential interfaces between users and the POIC disciplines, from the U.S. user perspective.