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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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The objective of this project was to propose a means to improve aviation weather information, training procedures based on a human-centered systems approach. Methodology: cognitive analysis of pilot's tasks; trajectory-based approach to weather information; contingency planning support; and implications for improving weather information.
Ensuring safe separation between aircraft is a critical challenge in air traffic management, particularly in urban air mobility (UAM) environments where high traffic density and low altitudes require precise control. In these environments, conflicts often arise at the intersections of flight corridors, posing significant risks. We propose a tactical separation approach leveraging shared scheduling protocols, originally designed for Ethernet networks and operating systems, to coordinate access to these intersections. Using a decentralized Markov decision process framework, the proposed approach enables aircraft to autonomously adjust their speed and timing as they navigate these critical areas, maintaining safe separation without a central controller. We evaluate the effectiveness of this approach in simulated UAM scenarios, demonstrating its ability to reduce separation violations to zero while acknowledging trade-offs in flight times as traffic density increases. Additionally, we explore the impact of non-compliant aircraft, showing that while shared scheduling protocols can no longer guarantee safe separation, they still provide significant improvements over systems without scheduling protocols.
This paper provides major contributions in expanding the literature for membrane process design with critical mineral recovery applications and showcasing the importance of robust design techniques for reducing risks of underperformance in such systems. Here, a membrane process flowsheet featuring PrOMMiS membrane models for recovering lithium/cobalt from spent batteries is showcased, uncertainty in membrane sieving and localized fouling are considered, and robust designs are obtained using the PyROS toolset. This paper is intended for a general audience of researchers working in critical minerals, membranes, and optimization related areas.
This document contains five papers on coping with ice formation during the operation of aircraft. The first paper uses a pilot survey to identify the desired attributes of future information systems for aircraft icing. The second paper investigates the influence of potential remote ice-detection system features on pilot decision making. The third paper investigates the effectiveness of aviation weather forecasting along aircraft trajectories. The fourth paper applied a human-centered systems analysis to the adverse aircraft weather encounter problem in order to identify desirable functions of weather and icing information. The objective of the fifth paper, a viewgraph presentation, is to propose means to improve aviation weather information, training, and procedures based on a human-centered systems approach.
Design philosophies used in the L-1011 aircraft to provide protection against rotor fragments include: (1) incorporating into the rotor design features that tend to promote small fragments if failure occurs; (2) containing the fragments within the engine shell or greatly reducing the energy content of those fragments that are eventually uncontained; (3) shielding vulnerable elements or systems with heavy structural members that tend to stop or deflect high velocity fragments; and (4) incorporating redundant and/or backup systems into the basic design and separating these systems so as to minimize the probability that more than one system will be damaged by an uncontained rotor fragment. Some of the design features that were incorporated into the Rolls-Royce RB211 engine are discussed, and two in-service experiences are considered in order to illustrate the practical operation of these features.
The aim was to obtain visual and infrared lightcurves of Pluto-Charon mutual eclipse event lightcurves and to analyze them to derive models of the Pluto-Charon system, including separations, relative sizes, some orbital parameters, system density, and an albedo map of the hemisphere of Pluto facing Charon. Researchers obtained observations of Pluto-Charon mutual events with the Palomar 1.5 and 5-meter, Kitt Peak 1.3-meter, and NASA Infrared Telescope Facility (IRTF) 3-meter telescope. IRAS survey observations of Pluto were combined with the results of eclipse models to show that the thermal flux observed by IRAS cannot be explained using the standard thermal model for atmospherless solar system bodies but can be explained if Pluto behaves as an isothermal body, e.g., as would be the case if it had a thermally significant atmosphere (Tedesco et al., 1987). A water frost spectrum of Charon was obtained (Buie et al., 1987) and IR lightcurves of two asteroids were used to demonstrate that their visual lightcurves were due primarily to their irregular shapes (Lebofsky et al., 1988.
FAA Modernization and Reform Act of 2012 mandates UAS integration in the NAS by 2015. Operators must be able to safely maneuver UAS to maintain separation and collision avoidance. Delegated Separation is defined as the transfer of responsibility for maintaining separation between aircraft or vehicles from the air navigation service provider to the relevant flight operator, and will likely begin in sparsely trafficked areas before moving to more heavily populated airspace. As UAS operate primarily in areas with lower traffic density and perform maneuvers routinely that are currently managed through special handling, they have the advantage of becoming an early adopter of delegated separation. This experiment will examine if UAS are capable of performing delegated separation in 5 nm horizontal and 1000 ft vertical distances under two delegation conditions. In Extended Delegation, ATC are in charge of identifying problems and delegating to pilot identification and implementation of the solution and monitoring. In Full Delegation, the pilots are responsible for all tasks related to separation assurance: identification of problems and solutions, implementation and monitoring.
A control system concept is presented that produces proportional control of yaw moment for the space shuttle from early entry to Mach 2 with only software modifications of the vehicle. It uses separate deflections of the inboard and outboard elevon surfaces and is evaluated, by determining the maximum static yawing moment available by considering the deflection limits of the elevon surfaces. A proportional moment slightly in excess of that produced by the most effective reaction control system (RCS) jet for yaw control can be obtained. In addition to the static moment study, a control law is designed which is intended to produce desired flying qualities.
A drug detecting apparatus which includes a chromatographic system for separating particular substances from a sample solution passed through it is described. A source of radiation causes the substance to emit fluorescent radiation as it moves through the chromatographic system. An optical system spectrally separates the fluorescent radiation according to wavelength and for focusing particular portions of the separated spectrum through an exit aperture. A photodetector which is responsive to the radiation passing through the exit aperture develops an electrical signal commensurate with the intensity of the radiation. The electrical signal is recorded to provide an indication of certain characteristics of the substance.
This purpose of this contract study task was to investigate the State of the Art in Gas Separation Technologies utilized for separating air into both nitrogen and oxygen gases for potential applications on commercial aircraft. The intended applications included: nitrogen gas for fuel tank inerting, cargo compartment fire protection, and emergency oxygen for passenger and crew use in the event of loss of cabin pressure. The approach was to investigate three principle methods of gas separation: Hollow Fiber Membrane (HFM), Ceramic Membrane (CM), and liquefaction: Total Atmospheric Liquefaction of Oxygen and Nitrogen (TALON). Additional data on the performance of molecular sieve pressure swing adsorption (PSA) systems was also collected and discussed. Performance comparisons of these technologies are contained in the body of the report.
On 2 July 2019, the NASA Ascent Abort 2 flight took place off the Florida coast to test the emergency systems to separate the Orion Crew Module (CM) from the future Space Launch System rocket in the event of a malfunction. During this high-altitude test, instrumentation data was recorded on twelve customized buoyant Ejectable Data Recorders (EDRs) and subsequently jettisoned from the CM in mid-air. Upon release, the EDRs activated their GPS-Iridium beacon systems and began transmitting Short Burst Data (SBD) messages via the Iridium satellite network to relay their individual location and system health information. To locate, track and retrieve each EDR from the ocean surface in real-time, multiple open-source programming tools (Python and Linux shells) were developed for parsing the incoming Iridium binary SBD messages. For this, a Linux laptop was used to receive the Iridium-generated emails containing the SBD messages and autonomously execute the parsing tools. The received SBD data contained location, timestamp and health status information that was translated, saved, and subsequently used for simultaneously generating a continuously updated color-coded tabular display summary and unique KML files used with Google Earth to track their locations. Once their locations were known, dedicated recovery vessels retrieved all EDRs from the ocean. An additional tool was also developed in order to generate 5- and 10-minute geolocation predictions for each EDR by deriving the displacement distance, elapsed time, displacement heading and velocity based on the latest known information available. The recovery vessels were also tracked with the use of a separate commercial GPS beacon system. After jettison, 67% of the EDRs transmitted valid data by the time they were retrieved from the ocean. However, the real-time information presented by the plotting tool allowed for the ready depiction of EDR dispersal patterns and reference drift trajectories, which contributed to the recovery of all twelve EDRs and the AA-2 flight data. Lastly, the available data showed that the distance between the software’s reported drift/predicted locations and the recovery locations did not exceed 38 meters, therefore demonstrating the advantages of this software tool for supporting real-time tracking and recovery efforts of beacon devices.
This project investigated the use of a Centrifugal Particle Separation (CPS) system to improve the durability and operational reliability of outdoor heat exchangers in vapor-compression based heating, ventilation, air conditioning, and refrigeration (HVACR) systems. The developed method introduced a novel dust and fouling mitigation approach by integrating an ambient air pre-cleaner that employs centrifugal forces to remove particulate matter from incoming air before it reaches the heat exchanger. By reducing the accumulation of dust and debris on coil surfaces, the CPS system aims to lower maintenance requirements and extend equipment lifespan. The project specifically involves coupling a centrifugal air pre-cleaner with a single-zone ductless mini-split system and evaluating its effectiveness in maintaining cleaner coil surfaces. Additionally, the study examined the impact of CPS integration on system energy performance. Through controlled experimental testing and performance monitoring, this work seeks to validate CPS-based air pre-cleaning as a practical, efficient solution for mitigating outdoor coil dust accumulation and fouling in both residential and commercial HVACR applications.
Internal restraint system, composed of liquid filled garment and separate auxiliary system, for integrated restraint pressure suit for acceleration protection and thermal transport
The paper discusses the design of a higher harmonic blade pitch control system for flight testing on an OH-6A helicopter. Alternative designs for both the mechanical and electronic subsystems are also presented. Among the recommendations set forth are: (1) use electronic analog methods instead of FFT software, delegating spectral analysis and self testing to an Electronic Control Unit; (2) use a digital rather than analog computer for increased flexibility in solution processing; and (3) locate HHC actuators in the nonrotating system and separate these actuators from the primary control system. It is concluded that a target weight for a prototype control system would be less than 1% of design gross weight and the production weight of the future HHC system may be 0.5 of the weight of the aircraft.
A comparison of system performance is made for two possible system setups: (1) individual loads powered by separate solar cell sources; and (2) multiple loads powered by a common solar cell source. A proof for resistive loads is given that shows the advantage of a common source over a separate source photovoltaic system for a large range of loads. For identical loads, both systems perform the same.
NASDA has recently developed a new tracking and control system as a basis for future satellite mission operation. It is named type-I Space Operations and Data Systems (type-I SODS). The software of this system is separated into three parts: operation and control system, network system, and support and information system. The operation control system treats telemetry and command operations. The network system controls the communication line and ground station equipments to connect the satellite and the operation control system. The support and information system provides to other systems necessary information. JERS-1 which was launched in February of this year is the first satellite operated by type-l SODS. We explain the architecture and operation methods of this system using JERS-1 mission operations.
A flight evaluation of a Beech model 99 equipped with an attitude command control system incorporating separate surface stability augmentation (SSSA) was conducted to determine whether an attitude command control system could be implemented using separate surface controls, and to determine whether the handling and ride qualities of the aircraft were improved by the SSSA attitude command system. The results of the program revealed that SSSA is a viable approach to implementing attitude command and also that SSSA has the capability of performing less demanding augmentation tasks such as yaw damping, wing leveling, and pitch damping. The program also revealed that attitude command did improve the pilot rating and ride qualities of the airplane while flying an IFR mission in turbulence. Some disadvantages of the system included the necessity of holding aileron force in a banked turn and excessive stiffness in the pitch axis.
A method and apparatus for increasing the signal to noise ratio of a receiving facility for coherent frequency reception by arraying receiving systems using separate antennas for each, or one antenna for all systems are presented. One system is operated with a carrier tracking loop to provide a first local oscillator frequency for the first and all other systems arrayed, with individual tracking loops in all other systems operated at IF for tracking out any phase differences due to separate group delays using an adjustable phase shifter for a second reference to compensate for different group delays in the antenna and low noise amplifier of each of the other systems. The second IF output of all systems is summed into the first system. This technique may also be used when two systems are arrayed to an antenna designed for circular or linear polarization diversity reception to effectively provide the same signal to noise ratio for both polarized signal transmission channels that would result from matched polarization. An arrangement adapted to high rate telemetry reception is disclosed. With additional components, the same arrangement is adapted to provide low rate telemetry reception as well.