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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS1985

Fiber optics for propulsion control systems

In aircraft systems with digital controls, fiberoptics has advantages over wire systems because of its inherent immunity to electromagnetic noise (EMI) and electromagnetic pulses (EMP). It also offers a weight benefit when metallic conductors are replaced by optical fibers. To take full advantage of the benefits of optical waveguides, passive optical sensors are also being developed to eliminate the need for electrical power to the sensor. Fiberoptics may also be used for controlling actuators on engine and airframe. In this application, the optical fibers, connectors, etc. will be subjected to high temperature and vibrations. This paper discussed the use of fiberoptics in aircraft propulsion systems together with the optical sensors and optically controlled actuators being developed to take full advantage of the benefits which fiberoptics offers. The requirements for sensors and actuators in advanced propulsion systems are identified. The benefits of using fiberoptics in place of conventional wire systems are discussed as well as the environmental conditions under which the optical components must operate.

Baumbick, R. J.↗
NASA NTRS2020

Electromagnetic Compatibility Considerations for International Space Station Payload Developers

The International Space Station (ISS) is a laboratory for scientific research, innovative technology development, and global education. The ISS provides a number of facilities and platforms for payload developers and investigators to conduct biological, microgravity, and Earth and space observation science, as well as for performing technology development. Due to the unique nature of the ISS vehicle and its electrical power and data systems, achieving electromagnetic compatibility (EMC) with the vehicle requires special considerations by the payload developer. The ISS electromagnetic interference (EMI) requirements and test methods are based on MIL-STD-461, “Electromagnetic Emissions and Susceptibility Requirements for the Control of Electromagnetic Interference”, Revision C, and MIL-STD-462, “Electromagnetic Interference Characteristics, Measurement of,” respectively. The low source impedance of the test setup requires special considerations when designing or selecting EMI power filters and switched mode power supplies. Many filters, suited for later revisions of MIL-STD-461, will result in non-compliant designs. ISS electrical power system power quality requirements, imposed to protect the stability of the system, can also affect EMI filter design. The selection and use of commercial-off-the-shelf (COTS) equipment for ISS applications requires special considerations to meet both EMC and crew safety requirements. Furthermore, the ISS environment can provide unique immunity challenges; if the payload developer ignores these challenges, the result is a possible loss of science or impact to technology demonstration. The ISS provides a unique opportunity for the science and technology development community. However, in order to be successful, the payload developer must incorporate special EMC considerations, many of which will be presented.

McCollum, Matthew↗
NASA NTRS1998

Flight Tests on a Fiber Optic Temperature Sensor

For aircraft engine control, one key parameter to detect on an airplane is the exhaust gas temperature (EGT). Presently, thermocouples are used to perform this measurement. These electrical sensors perform adequately; however, fully utilizing the benefits of optical sensors requires replacing electrical architectures with optical architectures. Part of this requires replacing electrical sensors with optical sensors, such as the EGT sensor chosen for these tests. The objective of the development and testing of this prototype sensor system was to determine the feasibility of operating an optical sensor in a hostile aircraft environment. The fiber optic sensor system was developed to measure temperatures from 20C to 600C in an aircraft environment and was utilized to monitor the EGT of an OV-10D aircraft engine. The sensor has successfully flown over 50 hours and proven to be immune to surface deterioration of the optical element (located inside the sensor head) and able to withstand and operate in normal and sustained severe flight conditions where forces on the airplane exceeded 4 g's. Potential commercial uses for this sensor include monitoring temperature for aeropropulsion system control, military vehicle and naval engine control, conventional and nuclear power plant monitoring and industrial plan monitoring where EMI issues are critical.

Tuma, Margaret L.↗
NASA NTRS1999

RF Bonding Investigation: The Effects of a Space Environment on Coatings

Coatings are commonly used in the aerospace industry for corrosion control of metals. The impedance of these coatings can reduce the effectiveness of EMI filters. This paper documents the effects of a space environment on a variety of coatings applied to electrical bonding surfaces. Nickel plating, anodizing, and chemical conversion coatings of alodine and iridite are investigated. The test fixture is designed to simulate a feed-through filter in a metal chassis. The filter insertion loss will be shown as a function of frequency and coating.

Krome, Mark E.↗
DOE OSTI2024

Innovating the next generation of commercial smart building software

Nearly 30% of commercial building energy use is wasted due to equipment faults and HVAC controls problems. The result is increased emissions, compromised comfort and productivity, and less reliable coordination of building power needs with a clean grid. The energy impact alone represents $17 billion in potential savings. Today’s smart building software provides a robust solution to address these operational deficiencies. Energy management and information systems (EMIS) are saving up to 9% on average, with two-year paybacks. They are being incorporated into energy management processes, commissioning services, and utility programs. As effective as they are, two barriers prevent even deeper benefits; limited personnel to fix problems once they are identified, and the expense and time to manually implement changes in control systems. In partnership with the research community, the EMIS industry is developing new capabilities to overcome these barriers. Moving beyond siloed products for either fault detection and diagnostics, or optimal control, these new capabilities empower users to not only automatically identify faults, but also to push corrective action, and control improvements to their buildings. In this paper, several areas for enhancements are documented: ‘one-time’ correction of faults such as setpoints, schedules, and economizer lockouts; short-term active testing for automated proportional integral derivative (PID) loop tuning and functional testing; and continuous supervisory control for demand flexibility and year-round efficiency. Results are presented from a pair of partner implementations out of a dozen providers integrating these enhancements into their products, including field tests from across the country, and insights into operator acceptance and integration into operations and maintenance practices.

Casillas, Armando↗
NASA NTRS1984

Definition, analysis and development of an optical data distribution network for integrated avionics and control systems. Part 2: Component development and system integration

Fiber optic transmission is emerging as an attractive concept in data distribution onboard civil aircraft. Development of an Optical Data Distribution Network for Integrated Avionics and Control Systems for commercial aircraft will provide a data distribution network that gives freedom from EMI-RFI and ground loop problems, eliminates crosstalk and short circuits, provides protection and immunity from lightning induced transients and give a large bandwidth data transmission capability. In addition there is a potential for significantly reducing the weight and increasing the reliability over conventional data distribution networks. Wavelength Division Multiplexing (WDM) is a candidate method for data communication between the various avionic subsystems. With WDM all systems could conceptually communicate with each other without time sharing and requiring complicated coding schemes for each computer and subsystem to recognize a message. However, the state of the art of optical technology limits the application of fiber optics in advanced integrated avionics and control systems. Therefore, it is necessary to address the architecture for a fiber optics data distribution system for integrated avionics and control systems as well as develop prototype components and systems.

Yen, H. W.↗
NASA NTRS2014

Hexavalent Chrome Free Coatings for Electronics; Electromagnetic Interference (EMI) Shielding Effectiveness (SE)

The purpose of this testing is to determine the suitability of trivalent chromium conversion coatings that meet the requirements of MIL-DTL-5541, Type II, for use in applications where high-frequency electrical performance is important. This project will evaluate the ability of coated aluminum to form adequate EMI seals. Testing will assess performance of the trivalent chromium coatings against the known control hexavalent chromium MIL-DTL-5541 Type I Class 3 before and after they have been exposed to a set of environmental conditions. Performance will be assessed by evaluating shielding effectiveness (SE) test data from a variety of test samples comprised of different aluminum types and/or conversion coatings.

hexavalent chrome↗
NASA NTRS2002

On-Orbit Testing of the EO-1 Pulsed Plasma Thruster

The Pulsed Plasma Thruster (PPT) Experiment on the Earth Observing 1 (EO-1) spacecraft has demonstrated the capability of a new generation PPT to perform spacecraft attitude control. The PPT is a small, self-contained pulsed electromagnetic propulsion system capable of delivering high specific impulse (900-1200 s) and very small impulse bits (10-1000 microN-s) at low average power (4 to 100 W). EO-1 has a single PPT that can produce torque in the positive or negative pitch direction and replace the function of the spacecraft s pitch reaction wheel. The flight validation experiment was designed to demonstrate the ability of the PPT to provide precision pointing accuracy, response and stability, and to confirm that the thruster plume and EMI effects on the spacecraft and instruments were benign. The PPT has been successfully used for pitch attitude control accumulating over 26 hours of operational time with over 96,000 pulses. Thruster performance has been nominal and all spacecraft subsystems and instruments continue to show no detrimental effects from PPT operation.

Zakrzwski, Charles↗
NASA NTRS1977

Common approach to solving SGEMP, DEMP, and ESD survivability

System Generated Electromagnetic Pulse (SGEMP) and Dispersed Electromagnetic Pulse DEMP) are nuclear generated spacecraft environments. Electrostatic discharge (ESD) is a natural spacecraft environment resulting from differential charging in magnetic substorms. All three phenomena, though differing in origin, result in the same problem to the spacecraft and that is Electromagnetic Interference (EMI). A common design approach utilizing a spacecraft structural Faraday Cage is presented which helps solve the EMI problem. Also, other system design techniques are discussed which minimize the magnitude of these environments through control of materials and electrical grounding configuration.

Ling, D.↗
NASA NTRS2005

UWB EMI To Aircraft Radios: Field Evaluation on Operational Commercial Transport Airplanes

Ultrawideband (UWB) transmitters may soon be integrated into a wide variety of portable electronic devices (PEDs) that passengers routinely carry on board commercial airplanes. Airlines and the FAA will have difficulty controlling passenger use of UWB transmitters during flights with current airline policies and existing wireless product standards. The aeronautical community is concerned as to whether evolving FCC UWB rules are adequate to protect legacy and emerging aeronautical radio systems from electromagnetic interference (EMI) from emerging UWB products. To address these concerns, the NASA Office of Space Communications and Chief Spectrum Managers assembled a multidisciplinary team from NASA LaRC, NASA JPL, NASA ARC, FAA, United Airlines, Sky West Airlines, and Eagles Wings Inc. to carry out a comprehensive series of tests aimed at determining the nature and extent of any EMI to aeronautical communication and navigation systems from UWB devices meeting FCCapproved and proposed levels for unlicensed handheld transmitters.

Oria, A. J.↗
NASA NTRS2011

Monitoring Spacecraft Telemetry Via Optical or RF Link

A patent disclosure document discusses a photonic method for connecting a spacecraft with a launch vehicle upper-stage telemetry system as a means for monitoring a spacecraft fs health and status during and right after separation and deployment. This method also provides an efficient opto-coupled capability for prelaunch built-in-test (BIT) on the ground to enable more efficient and timely integration, preflight checkout, and a means to obviate any local EMI (electromagnetic interference) during integration and test. Additional utility can be envisioned for BIT on other platforms, such as the International Space Station (ISS). The photonic telemetry system implements an optical free-space link with a divergent laser transmitter beam spoiled over a significant cone angle to accommodate changes in spacecraft position without having to angle track it during deployment. Since the spacecraft may lose attitude control and tumble during deployment, the transmitted laser beam interrogates any one of several low-profile meso-scale retro-reflective spatial light modulators (SLMs) deployed over the surface of the spacecraft. The return signal beam, modulated by the SLMs, contains health, status, and attitude information received back at the launch vehicle. Very compact low-power opto-coupler technology already exists for the received signal (requiring relatively low bandwidths, e.g., .200 kbps) to enable transfer to a forward pass RF relay from the launch vehicle to TDRSS (Tracking and Data Relay Satellite System) or another recipient. The link would be active during separation and post-separation to monitor spacecraft health, status, attitude, or other data inventories until attitude recovery and ground control can be re-established. An optical link would not interfere with the existing upper stage telemetry and beacon systems, thus meeting launch vehicle EMI environmental constraints.

Fielhauer, K. B.↗
NASA NTRS2013

Small Radioisotope Power System Testing at NASA Glenn Research Center

In April 2009, NASA Glenn Research Center (GRC) formed an integrated product team (IPT) to develop a Small Radioisotope Power System (SRPS) utilizing a single Advanced Stirling Convertor (ASC) with passive balancer. A single ASC produces approximately 80 We making this system advantageous for small distributed lunar science stations. The IPT consists of Sunpower, Inc., to provide the single ASC with a passive balancer, The Johns Hopkins University Applied Physics Laboratory (JHUAPL) to design an engineering model Single Convertor Controller (SCC) for an ASC with a passive balancer, and NASA GRC to provide technical support to these tasks and to develop a simulated lunar lander test stand. The single ASC with a passive balancer, simulated lunar lander test stand, and SCC were delivered to GRC and were tested as a system. The testing sequence at GRC included SCC fault tolerance, integration, electromagnetic interference (EMI), vibration, and extended operation testing. The SCC fault tolerance test characterized the SCCs ability to handle various fault conditions, including high or low bus power consumption, total open load or short circuit, and replacing a failed SCC card while the backup maintains control of the ASC. The integrated test characterized the behavior of the system across a range of operating conditions, including variations in cold-end temperature and piston amplitude, including the emitted vibration to both the sensors on the lunar lander and the lunar surface. The EMI test characterized the AC and DC magnetic and electric fields emitted by the SCC and single ASC. The vibration test confirms the SCCs ability to control the single ASC during launch. The extended operation test allows data to be collected over a period of thousands of hours to obtain long term performance data of the ASC with a passive balancer and the SCC. This paper will discuss the results of each of these tests.

Vibration↗
NASA NTRS2020

Fault Propagation, EMI Propagation, and Fault Containment in Aerospace Systems

The occurrence of faults in aerospace system hardware and software have consequences ranging from minor effects to catastrophic effects, and such faults can directly affect the safety of hardware and personnel. There are many origins to fault conditions, and the hardware that is capable of still meeting its performance requirements after experiencing itself a fault is said to be fault tolerant. A fault tolerant hardware is capable of detecting, isolating, and recovering from a fault condition; and this is a subfield of control engineering. An aerospace system that has been shown to have electromagnetic compatibility (EMC) in all its subsystems and systems cannot induced faults caused by electromagnetic interference (EMI). It can be proposed that the presence of EMI (or lack of EMC) is analogous to a potential fault initiator and the effects can likewise range from minor to severe. This paper starts by addressing the consequences of hardware failure in aerospace systems from a fault perspective, because the design of fault tolerant system is a major endeavor in aerospace. To arrive to this goal the paper starts with the concepts of fault, fault propagation, and a new concept called fault containment region. The paper then proceeds to provide two very recent examples in the aircraft industry of fault propagation with catastrophic effects. The paper proceeds to introduce the concept of EMI fault containment and a brief introduction to another new concept called the EMI containment region. The paper proceeds with an example of EMI fault containment region. The paper ends with a lesson learned conclusions.

Perez, Reinaldo↗
NASA NTRS1979

High-voltage dc power processing thermal control and packaging techniques

The power processor operates in several modes, delivering up to 100 amperes of regulated electrical power, operating at input voltages to 375 volts with outputs controlled by an integral microprocessor. Several alternative packaging concepts are discussed and evaluated. High-voltage design applications, power stage interconnection and EMI considerations are also discussed. Preliminary thermal analyses were performed and the results presented for each conceptual approach with parametric study results given for the selected concept.

Chapter, J. J.↗
NASA NTRS1995

Marshall Space Flight Center Electromagnetic Compatibility Design and Interference Control (MEDIC) handbook

The purpose of the MEDIC Handbook is to provide practical and helpful information in the design of electrical equipment for electromagnetic compatibility (EMS). Included is the definition of electromagnetic interference (EMI) terms and units as well as an explanation of the basic EMI interactions. An overview of typical NASA EMI test requirements and associated test setups is given. General design techniques to minimize the risk of EMI and EMI suppression techniques at the board and equipment interface levels are presented. The Handbook contains specific EMI test compliance design techniques and retrofit fixes for noncompliant equipment. Also presented are special tests that are useful in the design process or in instances of specification noncompliance.

Clark, T. L.↗
NASA NTRS2005

Low cost environmental sensors for Spaceflight : NMP Space Environmental Monitor (SEM) requirements

An outstanding problem in spaceflight is the lack of adequate sensors for monitoring the space environment and its effects on engineering systems. By adequate, we mean low cost in terms of mission impact (e.g., low price, low mass/size, low power, low data rate, and low design impact). The New Millennium Program (NMP) is investigating the development of such a low-cost Space Environmental Monitor (SEM) package for inclusion on its technology validation flights. This effort follows from the need by NMP to characterize the space environment during testing so that potential users can extrapolate the test results to end-use conditions. The immediate objective of this effort is to develop a small diagnostic sensor package that could be obtained from commercial sources. Environments being considered are: contamination, atomic oxygen, ionizing radiation, cosmic radiation, EMI, and temperature. This talk describes the requirements and rational for selecting these environments and reviews a preliminary design that includes a micro-controller data logger with data storage and interfaces to the sensors and spacecraft. If successful, such a sensor package could be the basis of a unique, long term program for monitoring the effects of the space environment on spacecraft systems.

Galileo↗
NASA NTRS2005

Low Cost Environmental Sensors for Spaceflight: NMP Space Environmental Monitor (SEM) Requirements

An outstanding problem in spaceflight is the lack of adequate sensors for monitoring the space environment and its effects on engineering systems. By adequate, we mean low cost in terms of mission impact (e.g., low price, low mass/size, low power, low data rate, and low design impact). The New Millennium Program (NMP) is investigating the development of such a low-cost Space Environmental Monitor (SEM) package for inclusion on its technology validation flights. This effort follows from the need by NMP to characterize the space environment during testing so that potential users can extrapolate the test results to end-use conditions. The immediate objective of this effort is to develop a small diagnostic sensor package that could be obtained from commercial sources. Environments being considered are: contamination, atomic oxygen, ionizing radiation, cosmic radiation, EMI, and temperature. This talk describes the requirements and rational for selecting these environments and reviews a preliminary design that includes a micro-controller data logger with data storage and interfaces to the sensors and spacecraft. If successful, such a sensor package could be the basis of a unique, long term program for monitoring the effects of the space environment on spacecraft systems.

New Millennium Program (NMP)↗
DOE OSTI2025

Packages of Distributed Energy Technologies Demonstrating Demand Flexibility at Community Scale

The combination of increased electric load growth across all sectors, deferred electrical infrastructure investment, and other factors resulting in variable electric power supply, has created technical challenges to maintaining a resilient and reliable grid. Many federal, regional, and local efforts are in play to modernize the electric grid, including advancing building technologies and distributed energy resources (DERs) that are utilizing smarter controls to become responsive to both occupant and grid needs. This report reviews ten pilot projects demonstrating how groups of buildings combined with behind-the-meter (BTM) DERs such as electric vehicle (EV) charging, battery storage, flexible HVAC and domestic hot water systems, and photovoltaic systems can reliably and cost effectively provide grid services. Each of the ten pilot projects aim to deliver both energy efficiency and demand flexibility (DF) while supporting load growth. The ten demonstration teams are piloting flexible DER packages across diverse communities of residential and commercial buildings to address a variety of regional grid needs. The outcomes of these pilot projects will be used to inform future scaling through utility program development. This paper characterizes the ten teams, showcasing the decision-making process used by each group to develop their packages (Section 2), the grid services they plan to deliver (Section 3), the types of DER packages selected for deployment within building sectors (Section 4) and trends between building sector, DER types, and grid services In order to achieve community scale benefits, the pilot projects must utilize aggregated control mechanisms for coordinating buildings and DERs together. Several types of coordinated control architectures have evolved amongst the teams, influenced by use type, existing market conditions, and integration type. Three coordinated controls architectures have been characterized, highlighting their use cases, benefits, challenges, and tradeoffs in their design. These insights can aid utilities, control vendors, and developers in scaling community-level energy systems (Paul, 2024). Ultimately, the technology packages selected by the ten teams will be coordinated to provide power system services, also known as grid services. Insights from these demonstrations will be useful for grid operators, regulators, aggregators and other stakeholders as they look to deploy demand flexible resources as grid services in the future. The grid services that each team is targeting for demonstration are described in Section 3 and Section 4. Methods for evaluating the grid services have been described in the paper Metrics for Evaluating Grid Service Provision from Communities of Grid-interactive and Efficient Buildings and other DER (MacDonald, 2023). To identify technology packages for demonstration, Section 2 shows that project teams used a range of analysis approaches, including building energy modeling, AMI data analysis, cost-benefit frameworks, and utility pilot data. Some teams emphasized technical modeling to quantify grid impacts and demand reduction potential, while others prioritized economic evaluations, stakeholder input, or exploratory pilots to inform deployment decisions. This diversity reflects the need to tailor selection methods to project goals, available data, and organizational context. Section 5 discusses trends between the DER technologies deployed and the grid service provisions from each team. Residential buildings (multifamily and single family) lean towards technologies that enhance energy efficiency (e.g. weatherization upgrades, smart thermostats) and onsite power generation integration (e.g. solar PV). Commercial building demonstrations prioritize technologies that ensure operational reliability (e.g. battery storage) and centralized energy management systems and optimization solutions. Teams that are deploying controllable storage-based technologies are more likely to provide grid services that require a near real-time response. Teams incorporating load shifting technologies like smart thermostats with HEMs are likely to include energy markets participation and customer bill management offerings. Campus demonstrations are adopting diverse sets of DERs to emphasize renewable generation, paired with centralized control. This section also describes technologies that were considered during project planning but ultimately excluded from final deployment. These demonstrations reveal that effective DER package design should be tailored to building type, customer segment, and construction vintage. Multifamily buildings benefit from centralized HVAC upgrades and supervisory controls, while single-family homes are well-suited for individualized technologies like solar, storage, and smart home energy monitors. Commercial and campus settings prioritize EMIS integration and load optimization. New construction enables cost-effective integration of DER-ready infrastructure, whereas retrofits require deployments aligned with owner and tenant value streams. For utility program planners, early coordination with developers and building owners, paired with segmented and modular program offerings, can improve adoption, scalability, and grid impact.

24 POWER TRANSMISSION AND DISTRIBUTION↗