Search NASA⌕ Search

SEARCH · Search NASA

Results for “transportation system”

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.

At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1994

Potential impacts of advanced aerodynamic technology on air transportation system productivity

Summaries of a workshop held at NASA Langley Research Center in 1993 to explore the application of advanced aerodynamics to airport productivity improvement are discussed. Sessions included discussions of terminal area productivity problems and advanced aerodynamic technologies for enhanced high lift and reduced noise, emissions, and wake vortex hazard with emphasis upon advanced aircraft configurations and multidisciplinary solution options.

Bushnell, Dennis M.↗
NASA NTRS1995

Advanced transportation system studies technical area 2(TA-2): Heavy lift launch vehicle development: Executive summary - volume 1

The purpose of the TA-2 contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. This document is part of the final report for the TA-2 contract. The final report consists of three volumes: Volume 1 is the Executive Summary, Volume 2 is Technical Results, and Volume 3 is Program Cost Estimates. The document-at-hand, Volume 1, provides a summary description of the technical activities that were performed over the entire contract duration, covering three distinct launch vehicle definition activities: heavy-lift (300,000 pounds injected mass to low Earth orbit) launch vehicles for the First Lunar Outpost (FLO), medium-lift (50,000-80,000 pounds injected mass to low Earth orbit) launch vehicles, and single-stage-to-orbit (SSTO) launch vehicles (25,000 pounds injected mass to a Space Station orbit).

McCurry, J.↗
NASA NTRS1995

Advanced transportation system studies technical area 2 (TA-2): Heavy lift launch vehicle development: Program Cost estimates - volume 3

The purpose of the TA-2 contract was to provide advanced launch vehicle concept definition and analysis to assist NASA in the identification of future launch vehicle requirements. Contracted analysis activities included vehicle sizing and performance analysis, subsystem concept definition, propulsion subsystem definition (foreign and domestic), ground operations and facilities analysis, and life cycle cost estimation. The basic period of performance of the TA-2 contract was from May 1992 through May 1993. No-cost extensions were exercised on the contract from June 1993 through July 1995. This document is part of the final report for the TA-2 contract. The final report consists of three volumes: Volume 1 is the Executive Summary, Volume 2 is Technical Results, and Volume 3 is Program Cost Estimates. The document-at-hand, Volume 3, provides a work breakdown structure dictionary, user's guide for the parametric life cycle cost estimation tool, and final report developed by ECON, Inc., under subcontract to Lockheed Martin on TA-2 for the analysis of heavy lift launch vehicle concepts.

McCurry, J. B.↗
NASA NTRS1995

Advanced Transportation System Studies Technical Area 2 (TA-2) Heavy Lift Launch Vehicle Development Contract: Technical Results - Volume 2

The sections in this report include: Single Stage to Orbit (SSTO) Design Ground-rules; Operations Issues and Lessons Learned; Vertical-Takeoff/Landing Versus Vertical-Takeoff/Horizontal-Landing; SSTO Design Results; SSTO Simulation Results; SSTO Assessment Results; SSTO Sizing Tool User's Guide; SSto Turnaround Assessment Report; Ground Operations Assessment First Year Executive Summary; Health Management System Definition Study; Major TA-2 Presentations; First Lunar Outpost Heavy Lift Launch Vehicle Design and Assessment; and the section, Russian Propulsion Technology Assessment Reports.

Source record↗
NASA NTRS1997

Advanced Transportation Systems, Alternate Propulsion Subsystem Concepts

An understanding of the basic flow of of the subject hybrid model has been gained through this series of testing. Changing injectors (axial vs. radial) and inhibiting the flow between the upstream plenum and the CP section changes the basic flow structure, as evidenced by streamline and velocity contour plots. Numerous shear layer structures were identified in the test configurations; these structures include both standing and traveling vortices which may affect combustion ion stability. Standing vortices may play a role in the heat addition process as the oxidizer enters the motor, while traveling vortices may be instability mechanisms in themselves. Finally, the flow visualization and LVD measurements give insight into determining the effects of flow induced shear layers.

Source record↗
NASA NTRS1998

Tether Transportation System Study

The projected traffic to geostationary earth orbit (GEO) is expected to increase over the next few decades. At the same time, the cost of delivering payloads from the Earth's surface to low earth orbit (LEO) is projected to decrease, thanks in part to the Reusable Launch Vehicle (RLV). A comparable reduction in the cost of delivering payloads from LEO to GEO is sought. The use of in-space tethers, eliminating the requirement for traditional chemical upper stages and thereby reducing the launch mass, has been identified as such an alternative. Spinning tethers are excellent kinetic energy storage devices for providing the large delta vee's required for LEO to GEO transfer. A single-stage system for transferring payloads from LEO to GEO was proposed some years ago. The study results presented here contain the first detailed analyses of this proposal, its extension to a two-stage system, and the likely implementation of the operational system.

Bangham, M. E.↗
NASA NTRS1998

Friction Stir Weld Tooling Development for Application on the 2195 Al-Cu-Li Space Transportation System External Tank

Friction Stir Welding (FSW) is a new and innovative solid-state joining process which can be applied to difficult-to- weld aluminum alloys. However, the large forces involved with the process have posed a production tooling challenge. Lockheed Martin Michoud Space Systems has overcome many of these challenges on the Super Lightweight External Tank (ET) program. Utilizing Aluminum-Copper-Lithium alloy 2195 in the form of plate and extrusions, investigations of FSW process parameters have been completed. Major loading mechanisms are discussed in conjunction with deflection measurements. Since the ET program is a cryogenic application, a brief comparison of cryogenic material properties with room temperature material properties is offered for both FSW and fusion welds. Finally, a new approach to controlling the FSW process from a load perspective is introduced. Emphasis will be put on tooling development, as well as the impact of tooling design and philosophy on Friction Stir Weld success probability.

Loftus, Zachary↗
NASA NTRS2000

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystem Concepts

The Alternate Propulsion Subsystem Concepts contract had seven tasks defined for this report. The tasks were: F-1A Restart Study, J-2S Restart Study, Propulsion Database Development, SSME Upper Stage Use, CERs for Liquid Propellant Rocket Engines, Advanced Low Cost Engines, and Tripropellant Comparison Study. The detailed study results, with the data to support the conclusions from various analyses, are being reported as a series of five separate Final Task Reports. Consequently, this volume only reports the required programmatic information concerning Computer Aided Design Documentation, and New Technology Reports. A detailed Executive Summary, covering all the tasks, is also available as Volume I of this report.

Levack, Daniel J. H.↗
NASA NTRS2000

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystems Concepts: Program Cost Estimates - Volume 3

The objective of this contract was to provide definition of alternate propulsion systems for both earth-to-orbit (ETO) and in-space vehicles (upper stages and space transfer vehicles). For such propulsion systems, technical data to describe performance, weight, dimensions, etc. was provided along with programmatic information such as cost, schedule, needed facilities, etc. Advanced technology and advanced development needs were determined and provided. This volume separately presents the various program cost estimates that were generated under three tasks: the F- IA Restart Task, the J-2S Restart Task, and the SSME Upper Stage Use Task. The conclusions, technical results , and the program cost estimates are described in more detail in Volume I - Executive Summary and in individual Final Task Reports.

Levack, Daniel J. H.↗
NASA NTRS2000

Advanced Transportation System Studies. Technical Area 3: Alternate Propulsion Subsystem Concepts: Executive Summary - Volume 1

The Alternate Propulsion Subsystem Concepts contract had seven tasks defined that are reported under this contract deliverable. The tasks were: FAA Restart Study, J-2S Restart Study, Propulsion Database Development. SSME Upper Stage Use. CERs for Liquid Propellant Rocket Engines. Advanced Low Cost Engines, and Tripropellant Comparison Study. The two restart studies, F-1A and J-2S, generated program plans for restarting production of each engine. Special emphasis was placed on determining changes to individual parts due to obsolete materials, changes in OSHA and environmental concerns, new processes available, and any configuration changes to the engines. The Propulsion Database Development task developed a database structure and format which is easy to use and modify while also being comprehensive in the level of detail available. The database structure included extensive engine information and allows for parametric data generation for conceptual engine concepts. The SSME Upper Stage Use task examined the changes needed or desirable to use the SSME as an upper stage engine both in a second stage and in a translunar injection stage. The CERs for Liquid Engines task developed qualitative parametric cost estimating relationships at the engine and major subassembly level for estimating development and production costs of chemical propulsion liquid rocket engines. The Advanced Low Cost Engines task examined propulsion systems for SSTO applications including engine concept definition, mission analysis. trade studies. operating point selection, turbomachinery alternatives, life cycle cost, weight definition. and point design conceptual drawings and component design. The task concentrated on bipropellant engines, but also examined tripropellant engines. The Tripropellant Comparison Study task provided an unambiguous comparison among various tripropellant implementation approaches and cycle choices, and then compared them to similarly designed bipropellant engines in the SSTO mission This volume overviews each of the tasks giving its objectives, main results. and conclusions. More detailed Final Task Reports are available on each individual task.

Levack, Daniel J. H.↗
NASA NTRS2000

Transportation System Options For The Interstellar Probe Mission

NASA is considering a mission to explore near-interstellar space early in the next decade as the first step toward a vigorous interstellar exploration program. A key enabling technology for such an ambitious science and exploration effort is the development of propulsion systems capable of providing fast trip times. Advanced propulsion technologies that might support an interstellar precursor mission early in the next century include some combination of solar sails, nuclear electric propulsion systems, and aerogravity assists. For years, the scientific community has been interested in the development of solar sail technology to support exploration of the inner and outer planets. Progress in thin-film technology and the development of technologies that may enable the remote assembly of lar2e sails in space are only now maturing to the point where ambitious interstellar precursor missions can be considered. Electric propulsion is now being demonstrated for planetary exploration by the Deep Space I mission. The primary issues for it's adaptation to interstellar precursor applications include the nuclear reactor that would be required and the engine lifetime. A propulsion system concept for the proposed Interstellar Probe mission will be described for each.

Johnson, Charles Les↗
NASA NTRS2000

Financing the Airport of the Future: The Small Aircraft Transportation System

The objective of SATS is to reduce gridlock at hubs, reduce travel times, allow for personal control over travel, and anticipate demand shifts resulting from a migration from suburbs to rural places. The technology is presently available and economical to produce SATS aircraft. The public issue centers on the airports. SATS is a federal program, and many airports in the U.S. are under the control of local governments. The scope of the objective will require thousands of airports in rural and suburban areas to modify their infrastructure and increase their investment. Researchers at the University of Nebraska at Omaha (UNO), and others at other institutions, have prepared reports surveying the relevant issues of implementing SATS. Our UNO team focused on the issues of policy implementation, economic development, management, and finance specific to Nebraska. We are finding that these issues are similar to those in other states in our region and other rural states. This paper discusses how this investment might be financed.

Bartle, John R.↗
NASA NTRS2000

Small Aircraft Transportation System (SATS): A Collaborative Effort Between Nebraska EPSCoR and NASA Langley Research Center

Implementing SATS in Nebraska will require a number of changes, both technical and administrative. SATS will require major improvements in the infrastructure of Nebraska airports. Improving airport infrastructure so that it can accommodate SATS is first and most obvious goal. A second goal is to make airports financially sustainable over the long term with limited federal assistance. A third goal, closely related to the second, is to link the implementation of SATS with anticipated local economic growth. This can leverage local funds without tax increases, enhance the equity of the finance approach, improve planning of facility size, and reduce long-term per unit cost. Many of these goals are national issues, and presumably federal policy will determine how these goals are addressed. This study examines several financing options and discusses their ease of application to Nebraska's airports.

Source record↗
NASA NTRS2002

Improvements in Thermal Protection Sizing Capabilities for TCAT: Conceptual Design for Advanced Space Transportation Systems

The Thermal Calculation Analysis Tool (TCAT), originally developed for the Space Systems Design Lab at the Georgia Institute of Technology, is a conceptual design tool capable of integrating aeroheating analysis into conceptual reusable launch vehicle design. It provides Thermal Protection System (TPS) unit thicknesses and acreage percentages based on the geometry of the vehicle and a reference trajectory to be used in calculation of the total cost and weight of the vehicle design. TCAT has proven to be reasonably accurate at calculating the TPS unit weights for in-flight trajectories; however, it does not have the capability of sizing TPS materials above cryogenic fuel tanks for ground hold operations. During ground hold operations, the vehicle is held for a brief period (generally about two hours) during which heat transfer from the TPS materials to the cryogenic fuel occurs. If too much heat is extracted from the TPS material, the surface temperature may fall below the freezing point of water, thereby freezing any condensation that may be present at the surface of the TPS. Condensation or ice on the surface of the vehicle is potentially hazardous to the mission and can also damage the TPS. It is questionable whether or not the TPS thicknesses provided by the aeroheating analysis would be sufficiently thick to insulate the surface of the TPS from the heat transfer to the fuel. Therefore, a design tool has been developed that is capable of sizing TPS materials at these cryogenic fuel tank locations to augment TCAT's TPS sizing capabilities.

Olds, John R.↗
NASA NTRS2001

Internal Flow Simulation of Enhanced Performance Solid Rocket Booster for the Space Transportation System

An enhanced performance solid rocket booster concept for the space shuttle system has been proposed. The concept booster will have strong commonality with the existing, proven, reliable four-segment Space Shuttle Reusable Solid Rocket Motors (RSRM) with individual component design (nozzle, insulator, etc.) optimized for a five-segment configuration. Increased performance is desirable to further enhance safety/reliability and/or increase payload capability. Performance increase will be achieved by adding a fifth propellant segment to the current four-segment booster and opening the throat to accommodate the increased mass flow while maintaining current pressure levels. One development concept under consideration is the static test of a "standard" RSRM with a fifth propellant segment inserted and appropriate minimum motor modifications. Feasibility studies are being conducted to assess the potential for any significant departure in component performance/loading from the well-characterized RSRM. An area of concern is the aft motor (submerged nozzle inlet, aft dome, etc.) where the altered internal flow resulting from the performance enhancing features (25% increase in mass flow rate, higher Mach numbers, modified subsonic nozzle contour) may result in increased component erosion and char. To assess this issue and to define the minimum design changes required to successfully static test a fifth segment RSRM engineering test motor, internal flow studies have been initiated. Internal aero-thermal environments were quantified in terms of conventional convective heating and discrete phase alumina particle impact/concentration and accretion calculations via Computational Fluid Dynamics (CFD) simulation. Two sets of comparative CFD simulations of the RSRM and the five-segment (IBM) concept motor were conducted with CFD commercial code FLUENT. The first simulation involved a two-dimensional axi-symmetric model of the full motor, initial grain RSRM. The second set of analyses included three-dimensional models of the RSRM and FSM aft motors with four-degree vectored nozzles.

Ahmad, Rashid A.↗
NASA NTRS1996

The Main Transport System in the Wheat Ear

The vascular system in the rachis, rachilla, and florets of the wheat ear was studied by direct microscopical observation of cleaned semi longitudinal sections. A periodic repetitive change of amphivasal and collateral phases was found along each main vascular bundle in the rachis. This change alternates between the two groups of main bundles and is related to the bilateral alternate arrangement of the spikelets on the rachis, so that a large amphivasal phase of the one group opposes the collateral phase of the other group. Ring-shaped tracheary inter-connections were observed mostly at the nodes. A similar system was found in the rachilla. There is a continuous uninterrupted tracheary connection between each of the florets and the rachis. A functional significance of the periodic changes observed has been suggested.

Stieber, Joseph↗
NASA NTRS1980

Space Transportation Systems, Aeronautics and Space Technology, Space and Terrestrial Applications, and Space Sciences

This report is prepared on an annual basis for the purposes of highlighting the fiscal year research and technology (R&T) activities. Its intent is to better inform the R&T Program Managers of significant accomplishments that promise practical and beneficial program application. The report is not inclusive of all R&T activities. The document is organized into two distinct sections: (1) a general summary of the major R&T activities in each program area, and (2) a description of significant individual completed activities and their results. This document will be updated November 1 of each year.

Source record↗