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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 595 records · Page 33
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

A system for the simulation and evaluation of satellite communication networks

With the emergence of a new era in satellite communications brought about by NASA's thrust into the Ka band with multibeam and onboard processing technologies, new and innovative techniques for evaluating these concepts and systems are required. To this end, NASA, in conjunction with its extensive program for advanced communications technology development, has undertaken to develop a concept for the simulation and evaluation of a complete communications network. Incorporated in this network will be proof of concept models of the latest technologies proposed for future satellite communications systems. These include low noise receivers, matrix switches, baseband processors, and solid state and tube type high power amplifiers. To accomplish this, numerous supporting technologies must be added to those aforementioned proof of concept models. These include controllers for synchronization, order wire, and resource allocation, gain compensation, signal leveling, power augmentation, and rain fade and range delay simulation. Taken together, these will be assembled to comprise a system capable of addressing numerous design and performance questions. The simulation and evaluation system as planned will be modular in design and implementation, capable of modification and updating to track and evaluate a continuum emerging concepts and technologies.

Bagwell, J. W.↗
NASA NTRS2003

The Building Blocks of Materials: Gathering Knowledge at the Molecular Level

Two start-up positions were created within SD46 to pursue developments in the rapidly expanding areas of biomineralization and nano-technology. As envisioned by Dr. Sandor Lehoczy, the new laboratories to be developed must have the capacity to investigate not only processes associated with the self-assembly of molecules but also the examination of self-assembled structures. For these purposes, laboratories capable of performing the intended function, particularly light scattering spectroscopy and atomic force microscopy were created. What follows then are recent advances arising from the development of these new laboratories. With the implementation of the Atomic Force Microscopy Facility, examples of investigations that determine a correlation between the molecular structure of materials and their macroscopic physical properties are provided. In addition, examples of investigations with particular emphasis on the physical properties of protein crystals, at the molecular level, and subsequent macroscopic characteristics are as provided. Finally, progress in fabrication of technology at the nano-scale levels at the developmental stage is also presented.

Source record↗
NASA NTRS1989

Advanced tracking systems design and analysis

The results of an assessment of several types of high-accuracy tracking systems proposed to track the spacecraft in the National Aeronautics and Space Administration (NASA) Advanced Tracking and Data Relay Satellite System (ATDRSS) are summarized. Tracking systems based on the use of interferometry and ranging are investigated. For each system, the top-level system design and operations concept are provided. A comparative system assessment is presented in terms of orbit determination performance, ATDRSS impacts, life-cycle cost, and technological risk.

Potash, R.↗
NASA NTRS1990

Smart built-in test

The work which built-in test (BIT) is asked to perform in today's electronic systems increases with every insertion of new technology or introduction of tighter performance criteria. Yet the basic purpose remains unchanged -- to determine with high confidence the operational capability of that equipment. Achievement of this level of BIT performance requires the management and assimilation of a large amount of data, both realtime and historical. Smart BIT has taken advantage of advanced techniques from the field of artificial intelligence (AI) in order to meet these demands. The Smart BIT approach enhances traditional functional BIT by utilizing AI techniques to incorporate environmental stress data, temporal BIT information and maintenance data, and realtime BIT reports into an integrated test methodology for increased BIT effectiveness and confidence levels. Future research in this area will incorporate onboard fault-logging of BIT output, stress data and Smart BIT decision criteria in support of a singular, integrated and complete test and maintenance capability. The state of this research is described along with a discussion of directions for future development.

Richards, Dale W.↗
NASA NTRS1990

High-power xenon ion thrusters

Steady state performance characteristics for a 25-cm diameter laboratory-model xenon ion thruster operating over the power range from 1.8 to 6.8 kW are described. Performance data are also presented for a similar 30-cm diameter thruster operated over the 1.4 to 11.1 kW power range. For each of the two thrusters, thermal characteristics, discharge-chamber performance data, overall thruster performance data, and beam-current density profiles are presented. A high level of performance and stability over a wide range of input power is demonstrated for the two thrusters. It is concluded that there appears to be no technological obstacles in the way of developing flight-design thrusters that operate in the 5- to 10-kW power range for near-term applications to orbit raising.

Beattie, J. R.↗
NASA NTRS1990

New accelerometers under development

The commercial viability of the Space Station requires that it provide a micro-g, or submicro-g environment to users. This represents significant improvement over existing systems. Attainment of the lowest micro-g levels requires isolation systems. Passive and active systems have been evaluated. Best performance is achieved using active approaches where accelerometer sensors close feedback loops. Two emerging accelerometer technologies are presented that have promise for meeting performance goals while achieving reductions of package size, weight, and power. The technologies addressed are Honeywell's design concept for an optical cavity locking accelerometer and the recent development of an integrated silicon accelerometer for government applications.

Wald, Jerry↗
NASA NTRS1999

Demonstrating the Performance Benefits of the Strutjet RBCC for Space Launch Architectures

The Rocket Based Combined Cycle (RBCC) engine synergistically combines the best elements of airbreathing and rocket propulsion to benefit a wide range of future reusable launch vehicles (RLV). Aerojet's Strutjet RBCC offers high Isp during mid-phase acceleration, and high thrust for boost and final ascent phases. The result is a relatively low gross weight vehicle that reduces thrust requirements compared with all-rocket solutions. Relative to combination propulsion systems, the integrated propulsive elements of the Strutjet reduce engine weight and complexity. This paper will summarize the results of tests demonstrating our latest hydrogen-fueled Strutjet RBCC engine performance, including inlet operability and performance over a range of conditions, sea level static and Mach 2.4 rocket thrust augmentation, ramjet and scramjet performance, combined scramjet/rocket performance at Mach 8, and ascent mode rocket performance. These tests have significantly advanced the technology readiness of the Strutjet engine and substantiate the performance benefits of RBCC engines for reusable launch vehicle applications. A companion paper provides a focus on Strutjet as a basis for advanced air and space architecture, covering hydrogen and hydrocarbon fuels and cooled structures.

Siebenhaar, Adam↗
NASA NTRS2007

Integration and Testing Challenges of Small, Multiple Satellite Missions: Experiences From The Space Technology 5 Project

This brief presentation describes the mechanical and electrical integration activities and environmental testing challenges of the Space Technology 5 (ST5) Project. Lessons learned during this process are highlighted, including performing mechanical activities serially to gain efficiency through repetition and performing electrical activities based on the level of subsystem expertise available.

Sauerwein, Timothy A.↗
NASA NTRS2010

Hypervelocity Impact Performance of Open Cell Foam Core Sandwich Panel Structures

Open cell metallic foam core sandwich panel structures are of interest for application in spacecraft micrometeoroid and orbital debris shields due to their novel form and advantageous structural and thermal performance. Repeated shocking as a result of secondary impacts upon individual foam ligaments during the penetration process acts to raise the thermal state of impacting projectiles ; resulting in fragmentation, melting, and vaporization at lower velocities than with traditional shielding configurations (e.g. Whipple shield). In order to characterize the protective capability of these structures, an extensive experimental campaign was performed by the Johnson Space Center Hypervelocity Impact Technology Facility, the results of which are reported in this paper. Although not capable of competing against the protection levels achievable with leading heavy shields in use on modern high-risk vehicles (i.e. International Space Station modules), metallic foam core sandwich panels are shown to provide a substantial improvement over comparable structural panels and traditional low weight shielding alternatives such as honeycomb sandwich panels and metallic Whipple shields. A ballistic limit equation, generalized in terms of panel geometry, is derived and presented in a form suitable for application in risk assessment codes.

Ryan, S.↗
NASA NTRS2011

Virtual Sensor Test Instrumentation

Virtual Sensor Test Instrumentation is based on the concept of smart sensor technology for testing with intelligence needed to perform sell-diagnosis of health, and to participate in a hierarchy of health determination at sensor, process, and system levels. A virtual sensor test instrumentation consists of five elements: (1) a common sensor interface, (2) microprocessor, (3) wireless interface, (4) signal conditioning and ADC/DAC (analog-to-digital conversion/ digital-to-analog conversion), and (5) onboard EEPROM (electrically erasable programmable read-only memory) for metadata storage and executable software to create powerful, scalable, reconfigurable, and reliable embedded and distributed test instruments. In order to maximize the efficient data conversion through the smart sensor node, plug-and-play functionality is required to interface with traditional sensors to enhance their identity and capabilities for data processing and communications. Virtual sensor test instrumentation can be accessible wirelessly via a Network Capable Application Processor (NCAP) or a Smart Transducer Interlace Module (STIM) that may be managed under real-time rule engines for mission-critical applications. The transducer senses the physical quantity being measured and converts it into an electrical signal. The signal is fed to an A/D converter, and is ready for use by the processor to execute functional transformation based on the sensor characteristics stored in a Transducer Electronic Data Sheet (TEDS). Virtual sensor test instrumentation is built upon an open-system architecture with standardized protocol modules/stacks to interface with industry standards and commonly used software. One major benefit for deploying the virtual sensor test instrumentation is the ability, through a plug-and-play common interface, to convert raw sensor data in either analog or digital form, to an IEEE 1451 standard-based smart sensor, which has instructions to program sensors for a wide variety of functions. The sensor data is processed in a distributed fashion across the network, providing a large pool of resources in real time to meet stringent latency requirements.

Wang, Roy↗
NASA NTRS2015

Soldier-Warfighter Operationally Responsive Deployer for Space

The Soldier-Warfighter Operationally Responsive Deployer for Space (SWORDS) project was a joint project between the U.S. Army Space & Missile Defense Command (SMDC) and NASA. The effort, lead by SMDC, was intended to develop a three-stage liquid bipropellant (liquid oxygen/liquid methane), pressure-fed launch vehicle capable of inserting a payload of at least 25 kg to a 750-km circular orbit. The vehicle design was driven by low cost instead of high performance. SWORDS leveraged commercial industry standards to utilize standard hardware and technologies over customized unique aerospace designs. SWORDS identified broadly based global industries that have achieved adequate levels of quality control and reliability in their products and then designed around their expertise and business motivations.

Davis, Benny↗
NASA NTRS2019

Overview of Electric Propulsion Projects at NASA Glenn Research Center

NASA Glenn Research Center (GRC) is currently leading the development of multiple electric propulsion systems to flight readiness. The Advanced Electric Propulsion System is a 12.5 kW Hall thruster system that is being developed by the Solar Electric Propulsion Technology Demonstration Mission (SEP TDM) project, under the sponsorship of the Space Technology Mission Directorate. NASA's Evolutionary Xenon Thruster-Commercial (NEXT-C) is 7 kW class gridded ion thruster system that being developed under the sponsorship of the Science Mission Directorate. NASA GRC is also providing electric propulsion discipline support to the Power and Propulsion Element and the Double Asteroid Redirection Test (DART) missions, which will be the first applications for these technologies, respectively. Lower technology readiness level (TRL) projects are underway for applications including CubeSats, small spacecraft and Mars exploration vehicles. Under the sponsorship of the Small Spacecraft Technology Program, NASA GRC has performed numerous independent verification and validation tests of CubeSat class electric propulsion systems in support of a growing number of small US businesses that are developing these systems. Lastly, three technology development efforts focused on 100 kW EP strings led by Aerojet Rocketdyne, Ad Astra and MSNW were recently completed.

Smith, Bryan K.↗
NASA NTRS1984

A system for the simulation and evaluation of satellite communication networks

With the emergence of a new era in satellite communications, brought about by NASA's thrust into the Ka band with multibeam and onboard processing technologies, new and innovative techniques for evaluating these concepts and systems are required. To this end, NASA, in conjunction with its extensive program for advanced communications technology development, has undertaken to develop a concept for the simulation and evaluation of a complete communications network. Incorporated in this network will be proof-of-concept models of the latest technologies proposed for future satellite communications systems. These include low noise receivers, matrix switches, baseband processors, and solid state and tube type high power amplifiers. To accomplish this, numerous supporting technologies must be added to those aforementioned proof-of-concept models. These include controllers for synchronization, order wire, resource allocation, gain compensation, signal leveling, power augmentation, and rain fade and range delay simulation. Taken together, these will be assembled to comprise a system capable of addressing numerous design and performance questions. The simulation and evaluation system, as planned, will be modular in design and implementation, capable of modification and updating to track and evaluate a continuum of emerging concepts and technologies. Previously announced in STAR as N84-13400

Bagwell, J. W.↗
NASA NTRS1991

Development of technology needs for the SEI TNIM network

A comparison of the salient features of the SEI with previous space exploration programs shows the need for a telecommunications, navigation and information management (TNIM) system level reoptimization. An approach is developed that takes the various candidate mission plans and decomposes them into architectural building blocks, many of which are common to several of the plans. Once identified, each of these blocks can then be parametrically examined with respect to performance benefit, cost, technology, and schedule risk tradeoffs. As the Space Exploration Initiative plan is established, these TNIM building blocks may be fused into an optimized system architecture.

Wachs, M. R.↗
NASA NTRS1983

A summary of EHV propulsion technology

While the battery used by an electric vehicle is the primary determinant of range, and to a lesser extent of performance, the design of the vehicle's propulsion system establishes its performance level and is the greatest contributor to its purchase price. Propulsion system weight, efficiency and cost are related to the specific combination of components used. Attention is given to the development status of the U.S. Department of Energy's Electric and Hybrid Vehicle Program, through which propulsion component and system design improvements have been made which promise weight savings of 35-50 percent, efficiency gains of 25 percent, and lower costs, when compared to the state of the art at the program's inception.

Schwartz, H. J.↗
NASA NTRS1978

Technology advancement of the electrochemical CO2 concentrating process

The overall objectives of the present program are to: (1) improve the performance of the electrochemical CO2 removal technique by increasing CO2 removal efficiencies at pCO2 levels below 400 Pa, increasing cell power output and broadening the tolerance of electrochemical cells for operation over wide ranges of cabin relative humidity; (2) design, fabricate, and assemble development hardware to continue the evolution of the electrochemical concentrating technique from the existing level to an advanced level able to efficiently meet the CO2 removal needs of a spacecraft air revitalization system (ARS); (3) develop and incorporate into the EDC the components and concepts that allow for the efficient integration of the electrochemical technique with other subsystems to form a spacecraft ARS; (4) combine ARS functions to enable the elimination of subsystem components and interfaces; and (5) demonstrate the integration concepts through actual operation of a functionally integrated ARS.

Schubert, F. H.↗
NASA NTRS2017

ADEPT SR-1 Flight Experiment

The ADEPT architecture represents a completely new approach for entry vehicle design using a high-performance carbon fabric to serve as the primary drag surface of the mechanically deployed decelerator and to protect the payload from hypersonic aerothermal heating during entry. The initial system-level development of the nano-ADEPT architecture will culminate in the launch of a 0.7-m deployed diameter ADEPT sounding rocket flight experiment. The SR-1 sounding rocket flight experiment is a critical milestone in the technology maturation plan for ADEPT and will generate performance data on in-space deployment and aerodynamic stability.

aeroshell↗
NASA NTRS2002

Advanced Engine Cycles Analyzed for Turbofans With Variable-Area Fan Nozzles Actuated by a Shape Memory Alloy

Advanced, large commercial turbofan engines using low-fan-pressure-ratio, very high bypass ratio thermodynamic cycles can offer significant fuel savings over engines currently in operation. Several technological challenges must be addressed, however, before these engines can be designed. To name a few, the high-diameter fans associated with these engines pose a significant packaging and aircraft installation challenge, and a large, heavy gearbox is often necessary to address the differences in ideal operating speeds between the fan and the low-pressure turbine. Also, the large nacelles contribute aerodynamic drag penalties and require long, heavy landing gear when mounted on conventional, low wing aircraft. Nevertheless, the reduced fuel consumption rates of these engines are a compelling economic incentive, and fans designed with low pressure ratios and low tip speeds offer attractive noise-reduction benefits. Another complication associated with low-pressure-ratio fans is their need for variable flow-path geometry. As the design fan pressure ratio is reduced below about 1.4, an operational disparity is set up in the fan between high and low flight speeds. In other words, between takeoff and cruise there is too large a swing in several key fan parameters-- such as speed, flow, and pressure--for a fan to accommodate. One solution to this problem is to make use of a variable-area fan nozzle (VAFN). However, conventional, hydraulically actuated variable nozzles have weight, cost, maintenance, and reliability issues that discourage their use with low-fan-pressure-ratio engine cycles. United Technologies Research, in cooperation with NASA, is developing a revolutionary, lightweight, and reliable shape memory alloy actuator system that can change the on-demand nozzle exit area by up to 20 percent. This "smart material" actuation technology, being studied under NASA's Ultra-Efficient Engine Technology (UEET) Program and Revolutionary Concepts in Aeronautics (RevCon) Program, has the potential to enable the next generation of efficient, quiet, very high bypass ratio turbofans. NASA Glenn Research Center's Propulsion Systems Analysis Office, along with NASA Langley Research Center's Systems Analysis Branch, conducted an independent analytical assessment of this new technology to provide strategic guidance to UEET and RevCon. A 2010-technology-level high-spool engine core was designed for this evaluation. Two families of low-spool components, one with and one without VAFN's, were designed to operate with the core. This "constant core" approach was used to hold most design parameters constant so that any performance differences between the VAFN and fixed nozzle cycles could be attributed to the VAFN technology alone. In this manner, the cycle design regimes that offer a performance payoff when VAFN's are used could be identified. The NASA analytical model of a performance-optimized VAFN turbofan with a fan pressure ratio of 1.28 is shown. Mission analyses of the engines were conducted using the notional, long-haul, advanced commercial twinjet shown. A high wing design was used to accommodate the large high-bypassratio engines. The mission fuel reduction benefit of very high bypass shape-memory-alloy VAFN aircraft was calculated to be 8.3 percent lower than a moderate bypass cycle using a conventional fixed nozzle. Shape-memory-alloy VAFN technology is currently under development in NASA's UEET and RevCon Programs.

Berton, Jeffrey J.↗