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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 811 records · Page 45
All sourcesNASA NTRSDOE OSTI
NASA NTRS1989

Radiation Effects on Flow Characteristics in Combustion Chambers

A JANNAF sponsored workshop was held to discuss the importance and role of radiative heat transfer in rocket combustion chambers. The potential impact of radiative transfer on hardware design, reliability, and performance was discussed. The current state of radiative transfer prediction capability in CFD modeling was reviewed and concluded to be substantially lacking in both the physical models used and the radiative property data available. There is a clear need to begin to establish a data base for making radiation calculations in rocket combustion chambers. A natural starting point for this effort would be the NASA thermochemical equilibrium code (CEC).

Brewster, M. Q.↗
NASA NTRS1991

TEXSYS - A large scale demonstration of model-based real-time control of a Space Station subsystem

A hybrid approach to qualitative and temporal reasoning, using a device-oriented model-based representation in conjunction with both consistency-based and classification diagnosis methods, can be effectively used to monitor and control a complex electromechanical system. An example of this approach is given in some recent tests of the Thermal Expert System (TEXSYS) in control of the Boeing Aerospace Thermal Bus System (BATBS), a prototype two-phase Space Station Freedom thermal bus. The constraints of realtime performance and changing target hardware led to significant changes in the initial approach, including a reduction in the use of deep structural reasoning and the addition of temporal reasoning capabilities. TEXSYS test results show the successful completion of both nominal control and fault recovery actions with the BATBS.

Glass, B. J.↗
NASA NTRS1992

Parallel simulation today

This paper surveys topics that presently define the state of the art in parallel simulation. Included in the tutorial are discussions on new protocols, mathematical performance analysis, time parallelism, hardware support for parallel simulation, load balancing algorithms, and dynamic memory management for optimistic synchronization.

Nicol, David↗
NASA NTRS1991

Process and assembly plans for low cost commercial fuselage structure

Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization.

Willden, Kurtis↗
NASA NTRS1992

Assembly and integration of the Space Station Freedom ECLSS

The assembly and integration of the SSF elements and systems throughout the build-up sequence are addressed focusing on ECLSS hardware interfaces and stage performance. The ECLSS encompasses six subsystems which provide temperature and humidity control, atmospheric control and supply, atmospheric revitalization, water recovery and management, waste management, and the fire detection and protection.

Gould, M. J.↗
NASA NTRS1993

The Iridium (tm) system: Personal communications anytime, anyplace

The Iridium system is designed to provide handheld personal communications between diverse locations around the world at any time and without prior knowledge of the location of the personal units. This paper provides an overview of the system, the services it provides, its operation, and an overview of the commercial practices and relatively high volume satellite production techniques which will make the system cost effective. A constellation of 66 satellites will provide an orbiting, spherical-shell, infrastructure for this global calling capability. The satellites act as tall cellular towers and allow convenient operation for portable handheld telephones. The system will provide a full range of services including voice, paging, data, geolocation, and fax capabilities. Motorola is a world leader in the production of high volume, high quality, reliable telecommunications hardware. One of Iridium's goals is to apply these production techniques to high reliability space hardware. Concurrent engineering, high performance work teams, advanced manufacturing technologies, and improved assembly and test methods are some of the techniques that will keep the Iridium system cost effective. Mobile, global, flexible personal communications are coming that will allow anyone to call or receive a call from/to anyplace at anytime. The Iridium system will provide communications where none exist today. This connectivity will allow increased information transfer, open new markets for various business endeavors, and in general increase productivity and development.

Hatlelid, John E.↗
NASA NTRS1998

Space Tissue Loss Configuration B (STL-B)

The goal of these experiments was to determine the effect of microgravity on the early development of the fish medaka. There were two objectives for this flight series. The primary objective was to assess the effects of microgravity on different stages of development and to ascertain whether the relevant developmental questions can be addressed at the gross morphological level or if the issues involve more subtle questions about regulation at the molecular and cellular levels. The secondary objective was the assessment of the utility of flight hardware with the capabilities to perform embryological studies. We have been able to take advantage of the flight testing phase of the STL-B hardware to also study the effects of microgravity on the early development of the fish, Medaka. Our initial studies involved monitoring the early Medaka development and raising flight embryos for breeding. Images of the developing embryos were collected either via video which was either taken by the astronauts or broadcast to Earth. Sample video images were digitized and stored on a hard drive resident within the on-board STL-B unit. Embryos were fixed at specific intervals, returned to Earth and are being analyzed for the timing and location of molecular events associated with controlling the morphological pattern for the onset of adult structures.

Source record↗
NASA NTRS1995

Development of the Fish Medaka in Microgravity

The goal of these experiments was to determine the effect of microgravity on the early development of the fish medaka. There were two objectives for this flight series. The primary objective was to assess the effects of microgravity on different stages of development and to ascertain whether the relevant developmental questions can be addressed at the gross morphological level or if the issues involve more subtle questions about regulation at the molecular and cellular levels. The secondary objective was the assessment of the utility of flight hardware with the capabilities to perform embryological studies. We have been able to take advantage of the flight testing phase of the STL-B hardware to also study the effects of microgravity on the early development of the fish, Medaka. Our initial studies involved monitoring the early Medaka development and raising flight embryos for breeding. Images of the developing embryos were collected either via video which was either taken by the astronauts or broadcast to Earth. Sample video images were digitized and stored on a hard drive resident within the on-board STL-B unit. Embryos were fixed at specific intervals, returned to Earth and are being analyzed for the timing and location of molecular events associated with controlling the morphological pattern for the onset of adult structures.

Wolgemuth, Debra J.↗
NASA NTRS1999

Mars In-Situ Propellant Production Precursor (MIP) Flight Demonstration Project: Overview

Strategic planning for human missions of exploration to Mars has conclusively identified in-situ propellant production (ISPP) as an enabling technology. A team of scientists and engineers from NASA's Johnson Space Center, Jet Propulsion Laboratory, and Lewis Research Center is preparing the MARS ISPP Precursors (MIP) Flight Demonstration. The objectives of MIP are to characterize the performance of processes and hardware which are important to ISPP concepts and to demonstrate how these processes and hardware interact with the Mars environment. Operating this hardware in the actual Mars environment is extremely important due to both uncertainties in our knowledge of the Mars environment as well as because of conditions that cannot be adequately simulated on Earth. The MIP Flight Demonstration is a payload onboard the MARS SURVEYOR Lander and will be launched in April 2001. MIP will be the first hardware to utilize the indigenous resources of a planet or moon. Its successful operation will pave the way for future robotic and human missions to rely on propellants produced using Martian resources as feedstock.

Kaplan, D. I.↗
NASA NTRS1999

Mars In-Situ Propellant Production Precursor (MIP) Flight Demonstration Project: Overview

Strategic planning for human missions of exploration to Mars has conclusively identified in-situ propellant production (ISPP) as an enabling technology. A team of scientists and engineers from NASA's Johnson Space Center, Jet Propulsion Laboratory, and Lewis Research Center is preparing the MARS ISPP PRECURSOR (MIP) Flight Demonstration. The objectives of MIP are to characterize the performance of processes and hardware which are important to ISPP concepts and to demonstrate how these processes and hardware interact with the Mars environment. Operating this hardware in the actual Mars environment is extremely important due to both uncertainties in our knowledge of the Mars environment as well as because of conditions that cannot be adequately simulated on Earth. The MIP Flight Demonstration is a payload onboard the MARS SURVEYOR Lander and will be launched in April 2001. MIP will be the first hardware to utilize the indigenous resources of a planet or moon. Its successful operation will pave the way for future robotic and human missions to rely on propellants produced using Martian resources as feedstock.

Kaplan, D. I.↗
NASA NTRS1998

Data Acquisition System(DAS) Sustaining Engineering

This paper presents general information describing the Data Acquisition System contract, a summary of objectives, tasks performed and completed. The hardware deliverables which are comprised of: 1) Two ground DAS units; 2) Two flight DAS units; 3) Logistic spares; and 4) Shipping containers are described. Also included are the data requirements and scope of the contract.

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NASA NTRS1999

NSTAR Ion Thrusters and Power Processors

The purpose of the NASA Solar Electric Propulsion Technology Applications Readiness (NSTAR) project is to validate ion propulsion technology for use on future NASA deep space missions. This program, which was initiated in September 1995, focused on the development of two sets of flight quality ion thrusters, power processors, and controllers that provided the same performance as engineering model hardware and also met the dynamic and environmental requirements of the Deep Space 1 Project. One of the flight sets was used for primary propulsion for the Deep Space 1 spacecraft which was launched in October 1998.

Bond, T. A.↗
NASA NTRS1999

The Mars In-Situ-Propellant-Production Precursor (MIP) Flight Demonstration

Strategic planning for human missions of exploration to Mars has conclusively identified insitu propellant production (ISPP) as an enabling technology. A team of scientists and engineers from NASA's Johnson Space Center, Jet Propulsion Laboratory, and Glenn Research Center is preparing the MARS ISPP PRECURSOR (MIP) Flight Demonstration. The objectives of MIP are to characterize the performance of processes and hardware that are important to ISPP concepts and to demonstrate how these processes and hardware interact with the Mars environment. Operating this hardware in the actual Mars environment is extremely important due to (1) uncertainties in our knowledge of the Mars environment, and (2) conditions that cannot be adequately simulated on Earth. The MIP Flight Demonstration is a payload onboard the MARS SURVEYOR Lander and will be launched in April 2001. MIP will be the first hardware to utilize the indigenous resources of a planet or moon. Its successful operation will pave the way for future robotic and human missions to rely on propellants produced using Martian resources as feedstock.

Kaplan, D. I.↗
NASA NTRS1999

Analysis of MIR Condensate and Potable Water

Approximately fifty percent of the potable water supplied to the Russian cosmonauts, American astronauts, and other occupants of the current Russian Mir Space Station is produced by the direct recycle of water from humidity condensate. The remainder comes from ground supplied potable water that is delivered on a Progress resupply spacecraft, or processed fuel cell water transferred from the Shuttle. Reclamation of water for potable and hygiene purposes is considered essential for extended duration missions in order to avoid massive costs associated with resupplying water from the ground. The Joint U.S/Russian Phase 1 program provided the U.S. the first opportunity to evaluate the performance of water reclamation hardware in microgravity. During the Phase I program, the U.S. collected recycled water, stored water, and humidity condensate samples for chemical and microbial evaluation. This experiment was conducted to determine the potability of the water supplied on Mir, to assess the reliability of the water reclamation and distribution systems, and to aid in developing water quality monitoring standards for International Space Station.

Pierre, L. M.↗
NASA NTRS1999

Simulation of a Real-Time Local Data Integration System over East-Central Florida

The Applied Meteorology Unit (AMU) simulated a real-time configuration of a Local Data Integration System (LDIS) using data from 15-28 February 1999. The objectives were to assess the utility of a simulated real-time LDIS, evaluate and extrapolate system performance to identify the hardware necessary to run a real-time LDIS, and determine the sensitivities of LDIS. The ultimate goal for running LDIS is to generate analysis products that enhance short-range (less than 6 h) weather forecasts issued in support of the 45th Weather Squadron, Spaceflight Meteorology Group, and Melbourne National Weather Service operational requirements. The simulation used the Advanced Regional Prediction System (ARPS) Data Analysis System (ADAS) software on an IBM RS/6000 workstation with a 67-MHz processor. This configuration ran in real-time, but not sufficiently fast for operational requirements. Thus, the AMU recommends a workstation with a 200-MHz processor and 512 megabytes of memory to run the AMU's configuration of LDIS in real-time. This report presents results from two case studies and several data sensitivity experiments. ADAS demonstrates utility through its ability to depict high-resolution cloud and wind features in a variety of weather situations. The sensitivity experiments illustrate the influence of disparate data on the resulting ADAS analyses.

Case, Jonathan↗
NASA NTRS2000

Automatic Generation of Directive-Based Parallel Programs for Shared Memory Parallel Systems

The shared-memory programming model is a very effective way to achieve parallelism on shared memory parallel computers. As great progress was made in hardware and software technologies, performance of parallel programs with compiler directives has demonstrated large improvement. The introduction of OpenMP directives, the industrial standard for shared-memory programming, has minimized the issue of portability. Due to its ease of programming and its good performance, the technique has become very popular. In this study, we have extended CAPTools, a computer-aided parallelization toolkit, to automatically generate directive-based, OpenMP, parallel programs. We outline techniques used in the implementation of the tool and present test results on the NAS parallel benchmarks and ARC3D, a CFD application. This work demonstrates the great potential of using computer-aided tools to quickly port parallel programs and also achieve good performance.

Jin, Hao-Qiang↗
NASA NTRS2000

Automatic Generation of OpenMP Directives and Its Application to Computational Fluid Dynamics Codes

The shared-memory programming model is a very effective way to achieve parallelism on shared memory parallel computers. As great progress was made in hardware and software technologies, performance of parallel programs with compiler directives has demonstrated large improvement. The introduction of OpenMP directives, the industrial standard for shared-memory programming, has minimized the issue of portability. In this study, we have extended CAPTools, a computer-aided parallelization toolkit, to automatically generate OpenMP-based parallel programs with nominal user assistance. We outline techniques used in the implementation of the tool and discuss the application of this tool on the NAS Parallel Benchmarks and several computational fluid dynamics codes. This work demonstrates the great potential of using the tool to quickly port parallel programs and also achieve good performance that exceeds some of the commercial tools.

Yan, Jerry↗
NASA NTRS1998

Getting to the Point in Pinpoint Landing

Assisted by Langley Research Center's Small Business Technology Transfer (STTR) Program, IntegriNautics has developed a commercialized precision landing system. The idea finds its origins in Stanford University work on a satellite test of Einstein's General Theory of Relativity, where Stanford has designed a new high-performance altitude-determining hardware.

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