Considerations and philosophy of ground winds criteria formulation
Ground wind loading criteria for aerospace vehicle designing
AEROSPACE VEHICLE↗
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Results for “Design Philosophy”
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 requirement for designing analyzable space deployable structures
The applied technology satellite parabolic reflector subsystem is one of the first systems designed for space environment with limited terrestrial environmental ability. As a result, the complete performance of the system could not be demonstrated in a terrestrial environment without unacceptable design compromises. This problem was circumvented by developing a test philosophy which relied heavily on analysis to qualify and accept the flight hardware. The test program was successfully concluded and an optimized, low cost structure resulted. It is felt that this test and analysis philosophy can be applied to future space systems, resulting in substantial cost and schedule savings and a mission optimized system.
Woods, A. A., Jr.↗
Advanced data management design for autonomous telerobotic systems in space using spaceborne symbolic processors
The use of computers in autonomous telerobots is reaching the point where advanced distributed processing concepts and techniques are needed to support the functioning of Space Station era telerobotic systems. Three major issues that have impact on the design of data management functions in a telerobot are covered. It also presents a design concept that incorporates an intelligent systems manager (ISM) running on a spaceborne symbolic processor (SSP), to address these issues. The first issue is the support of a system-wide control architecture or control philosophy. Salient features of two candidates are presented that impose constraints on data management design. The second issue is the role of data management in terms of system integration. This referes to providing shared or coordinated data processing and storage resources to a variety of telerobotic components such as vision, mechanical sensing, real-time coordinated multiple limb and end effector control, and planning and reasoning. The third issue is hardware that supports symbolic processing in conjunction with standard data I/O and numeric processing. A SSP that currently is seen to be technologically feasible and is being developed is described and used as a baseline in the design concept.
Goforth, Andre↗
A semiconductor bridge ignited hot gas piston ejector
The topics are presented in viewgraph form and include the following: semiconductor bridge technology (SCB); SCB philosophy; technology transfer; simplified sketch of SCB; SCB processing; SCB design; SCB test assembly; 5 mJ SCB burst based on a polaroid photograph; micro-convective heat transfer hypothesis; SCB fire set; comparison of SCB and hot-wire actuators; satellite firing sets; logic fire set; SCB smart component; SCB smart firing set; semiconductor design considerations; and the adjustable actuator system.
Grubelich, M. C.↗
Sounding rocket and balloon flight safety philosophy and methodologies
NASA's sounding rocket and balloon goal is to successfully and safely perform scientific research. This is reflected in the design, planning, and conduct of sounding rocket and balloon operations. The purpose of this paper is to acquaint the sounding rocket and balloon scientific community with flight safety philosophy and methodologies, and how range safety affects their programs. This paper presents the flight safety philosophy for protecting the public against the risk created by the conduct of sounding rocket and balloon operations. The flight safety criteria used to implement this philosophy are defined and the methodologies used to calculate mission risk are described.
Beyma, R. J.↗
Operational Philosophy Concerning Manned Spacecraft Cabin Leaks
The last thirty years have seen the Space Shuttle as the prime United States spacecraft for manned spaceflight missions. Many lessons have been learned about spacecraft design and operation throughout these years. Over the next few decades, a large increase of manned spaceflight in the commercial sector is expected. This will result in the exposure of commercial crews and passengers to many of the same risks crews of the Space Shuttle have encountered. One of the more dire situations that can be encountered is the loss of pressure in the habitable volume of the spacecraft during on orbit operations. This is referred to as a cabin leak. This paper seeks to establish a general cabin leak response philosophy with the intent of educating future spacecraft designers and operators. After establishing a relative definition for a cabin leak, the paper covers general descriptions of detection equipment, detection methods, and general operational methods for management of a cabin leak. Subsequently, all these items are addressed from the perspective of the Space Shuttle Program, as this will be of the most value to future spacecraft due to similar operating profiles. Emphasis here is placed upon why and how these methods and philosophies have evolved to meet the Space Shuttle s needs. This includes the core ideas of: considerations of maintaining higher cabin pressures vs. lower cabin pressures, the pros and cons of a system designed to feed the leak with gas from pressurized tanks vs. using pressure suits to protect against lower cabin pressures, timeline and consumables constraints, re-entry considerations with leaks of unknown origin, and the impact the International Space Station (ISS) has had to the standard Space Shuttle cabin leak response philosophy. This last item in itself includes: procedural management differences, hardware considerations, additional capabilities due to the presence of the ISS and its resource, and ISS docking/undocking considerations with a cabin leak occurring. The paper also offers a look at how different equipment configurations on future spacecraft impact the previously defined cabin leak operational philosophy and includes additional operational methods and considerations that result due to various configurations. The intent is to showcase these various considerations and highlight the variability they allow. The paper concludes with a selection of the author s personal observations from a spacecraft operator's point of view and recommendations with the goal of improving the design and operations of future spacecraft.
DeSimpelaere, Edward↗
Human factors of flight-deck checklists: The normal checklist
Although the aircraft checklist has long been regarded as the foundation of pilot standardization and cockpit safety, it has escaped the scrutiny of the human factors profession. The improper use, or the non-use, of the normal checklist by flight crews is often cited as the probable cause or at least a contributing factor to aircraft accidents. An attempt is made to analyze the normal checklist, its functions, format, design, length, usage, and the limitations of the humans who must interact with it. The development of the checklist from the certification of a new model to its delivery and use by the customer are discussed. The influence of the government, particularly the FAA Principle Operations Inspector, the manufacturer's philosophy, the airline's culture, and the end user, the pilot, influence the ultimate design and usage of this device. The effects of airline mergers and acquisitions on checklist usage and design are noted. In addition, the interaction between production pressures and checklist usage and checklist management are addressed. Finally, a list of design guidelines for normal checklists is provided.
Degani, Asaf↗
Servicing operations for the SIRTF Observatory at the Space Station
This paper describes the servicing requirements, plans, and proposed Space Station-based servicing operations for the Space Infrared Telescope Facility (SIRTF) Observatory. SIRTF is a cryogenically-cooled, long-life, one meter class space telescope which will be operated by NASA as a free-flying observatory for infrared astronomy, in the mid-1990's. To achieve its 5-year lifetime requirement (10 year goal), SIRTF must be replenished periodically with cryogenic helium and have its life-limited modular subsystems replaced; capability for contingency repair of warm components will also be provided in the Observatory design. A general description of the SIRTF Observatory is given, including options for the support systems (spacecraft). The overall servicing philosophy and plans are addressed with scheduling and needed support elements described. A proposed Space Station-based servicing scenario is described, including orbital transfer, servicing and checkout operations. A detailed description and timeline for liquid helium replenishment operations is provided, including a conceptual design and technology development program for the cryogenic helium transfer dewar (tanker). Finally, a preliminary SIRTF spares/logistics philosophy is outlined, including tradeoffs to be considered.
Wiltsee, Christopher B.↗
Cyber-Informed Engineering for Design and Operations
Pursuant to the National Cyber-Informed Engineering (CIE) Strategy published in 2022, INL is leading the development of philosophy and practices to identify and mitigate the inherent risks of digital technology by including cybersecurity as a core element of engineering risk management. This presentation will provide an overview of why we need CIE and what it is, a discussion of the major implications of CIE for electric power systems design and operations, and an update on significant milestones and resources from the CIE program.
24 POWER TRANSMISSION AND DISTRIBUTION↗
Materials for high-density electronic packaging and interconnection
Electronic packaging and interconnections are the elements that today limit the ultimate performance of advanced electronic systems. Materials in use today and those becoming available are critically examined to ascertain what actions are needed for U.S. industry to compete favorably in the world market for advanced electronics. Materials and processes are discussed in terms of the final properties achievable and systems design compatibility. Weak points in the domestic industrial capability, including technical, industrial philosophy, and political, are identified. Recommendations are presented for actions that could help U.S. industry regain its former leadership position in advanced semiconductor systems production.
Source record↗
Space Vehicle Powerdown Philosophies Derived from the Space Shuttle Program
In spaceflight, electrical power is a vital but limited resource. Almost every spacecraft system, from avionics to life support systems, relies on electrical power. Since power can be limited by the generation system s performance, available consumables, solar array shading, or heat rejection capability, vehicle power management is a critical consideration in spacecraft design, mission planning, and real-time operations. The purpose of this paper is to capture the powerdown philosophies used during the Space Shuttle Program. This paper will discuss how electrical equipment is managed real-time to adjust the overall vehicle power level to ensure that systems and consumables will support changing mission objectives, as well as how electrical equipment is managed following system anomalies. We will focus on the power related impacts of anomalies in the generation systems, air and liquid cooling systems, and significant environmental events such as a fire, decrease in cabin pressure, or micrometeoroid debris strike. Additionally, considerations for executing powerdowns by crew action or by ground commands from Mission Control will be presented. General lessons learned from nearly 30 years of Space Shuttle powerdowns will be discussed, including an in depth case-study of STS-117. During this International Space Station (ISS) assembly mission, a failure of computers controlling the ISS guidance, navigation, and control system required that the Space Shuttle s maneuvering system be used to maintain attitude control. A powerdown was performed to save power generation consumables, thus extending the docked mission duration and allowing more time to resolve the issue.
Willsey, Mark↗
Robonaut 2 - The First Humanoid Robot in Space
NASA and General Motors have developed the second generation Robonaut, Robonaut 2 or R2, and it is scheduled to arrive on the International Space Station in late 2010 and undergo initial testing in early 2011. This state of the art, dexterous, anthropomorphic robotic torso has significant technical improvements over its predecessor making it a far more valuable tool for astronauts. Upgrades include: increased force sensing, greater range of motion, higher bandwidth and improved dexterity. R2 s integrated mechatronics design results in a more compact and robust distributed control system with a faction of the wiring of the original Robonaut. Modularity is prevalent throughout the hardware and software along with innovative and layered approaches for sensing and control. The most important aspects of the Robonaut philosophy are clearly present in this latest model s ability to allow comfortable human interaction and in its design to perform significant work using the same hardware and interfaces used by people. The following describes the mechanisms, integrated electronics, control strategies and user interface that make R2 a promising addition to the Space Station and other environments where humanoid robots can assist people.
Diftler, M. A.↗
Exact constraints and appropriate norms in machine-learned exchange-correlation functionals
Machine learning techniques have received growing attention as an alternative strategy for developing general-purpose density functional approximations, augmenting the historically successful approach of human-designed functionals derived to obey mathematical constraints known for the exact exchange-correlation functional. More recently, efforts have been made to reconcile the two techniques, integrating machine learning and exact-constraint satisfaction. We continue this integrated approach, designing a deep neural network that exploits the exact constraint and appropriate norm philosophy to de-orbitalize the strongly constrained and appropriately normed (SCAN) functional. The deep neural network is trained to replicate the SCAN functional from only electron density and local derivative information, avoiding the use of the orbital-dependent kinetic energy density. The performance and transferability of the machine-learned functional are demonstrated for molecular and periodic systems.
Artificial neural networks↗
A small missions program for investigation of near-earth asteroids
Current studies are examining the feasibility and possible content of the Discovery Program, a series of 'Explorer-class' missions to planetary targets. Organized as a multi-layer program with constant funding, the Discovery Program would support lower cost exploration opportunities that are missed in the new start procedure for larger missions. One approach to such a program is to focus on rendezvous missions to several near-Earth asteroids to characterize basic properties of this group of objects. A sample program is presented that visits six different targets over twelve years, using direct low energy trajectories; some of these are newly identified. Each flight in the program delivers a payload capable of addressing science objectives within the expected budget and programmatic constraints of small planetary missions. The key to satisfying the constraints is a disciplined program management philosophy, consistently applied over the entire program, that makes extensive use of hardware designs developed for other programs.
Stancati, M. L.↗
Integrated Modeling Tools for Thermal Analysis and Applications
Integrated modeling of spacecraft systems is a rapidly evolving area in which multidisciplinary models are developed to design and analyze spacecraft configurations. These models are especially important in the early design stages where rapid trades between subsystems can substantially impact design decisions. Integrated modeling is one of the cornerstones of two of NASA's planned missions in the Origins Program -- the Next Generation Space Telescope (NGST) and the Space Interferometry Mission (SIM). Common modeling tools for control design and opto-mechanical analysis have recently emerged and are becoming increasingly widely used. A discipline that has been somewhat less integrated, but is nevertheless of critical concern for high precision optical instruments, is thermal analysis and design. A major factor contributing to this mild estrangement is that the modeling philosophies and objectives for structural and thermal systems typically do not coincide. Consequently the tools that are used in these discplines suffer a degree of incompatibility, each having developed along their own evolutionary path. Although standard thermal tools have worked relatively well in the past. integration with other disciplines requires revisiting modeling assumptions and solution methods. Over the past several years we have been developing a MATLAB based integrated modeling tool called IMOS (Integrated Modeling of Optical Systems) which integrates many aspects of structural, optical, control and dynamical analysis disciplines. Recent efforts have included developing a thermal modeling and analysis capability, which is the subject of this article. Currently, the IMOS thermal suite contains steady state and transient heat equation solvers, and the ability to set up the linear conduction network from an IMOS finite element model. The IMOS code generates linear conduction elements associated with plates and beams/rods of the thermal network directly from the finite element structural model. Conductances for temperature varying materials are accommodated. This capability both streamlines the process of developing the thermal model from the finite element model, and also makes the structural and thermal models compatible in the sense that each structural node is associated with a thermal node. This is particularly useful when the purpose of the analysis is to predict structural deformations due to thermal loads. The steady state solver uses a restricted step size Newton method, and the transient solver is an adaptive step size implicit method applicable to general differential algebraic systems. Temperature dependent conductances and capacitances are accommodated by the solvers. In addition to discussing the modeling and solution methods. applications where the thermal modeling is "in the loop" with sensitivity analysis, optimization and optical performance drawn from our experiences with the Space Interferometry Mission (SIM), and the Next Generation Space Telescope (NGST) are presented.
Milman, Mark H.↗
The role of failure/problems in engineering: A commentary of failures experienced - lessons learned
The written version of a series of seminars given to several aerospace companies and three NASA centers are presented. The results are lessons learned through a study of the problems experienced in 35 years of engineering. The basic conclusion is that the primary cause of problems has not been mission technologies, as important as technology is, but the neglect of basic principles. Undergirding this is the lack of a systems focus from determining requirements through design, verification, and operations phases. Many of the concepts discussed are fundamental to total quality management (TQM) and can be used to augment this product enhanced philosophy. Fourteen principles are addressed with problems experienced and are used as examples. Included is a discussion of the implication of constraints, poorly defined requirements, and schedules. Design guidelines, lessons learned, and future tasks are listed. Two additional sections are included that deal with personal lessons learned and thoughts on future thrusts (TQM).
Ryan, R. S.↗
Flight Deck Design of a Hybrid Turbine/Electric Passenger Aircraft
NASA is exploring the development of a 180-passenger subsonic single engine aft turbine aircraft, The aft turbine provides electric power in a hybrid design to wing mounted electric engines, creating a highly efficient, high-bypass-ratio fan equivalent. The SUbsonic Single Aft eNgine (SUSAN) aircraft is being developed as a sustainable subsonic regional aircraft that seeks to reduce emission levels by 50% in the next few decades. Pilot-in-the-loop studies were conducted at the NASA Langley Research Center in Hampton, Virginia, to explore the flight deck design for the hybrid electric aircraft. Following modern trends in commercial aircraft flight decks with full time augmented controls and a quiet and dark philosophy, single throttle and simplified engine displays were developed for the SUSAN aircraft. The aircraft includes a single aft mounted turbine engine and 16 wing mounted electric fans. The final design was developed from feedback received during an earlier pilot-in-the-loop study where one, two, and three throttles were tested in standard airline operations, including various failures of the turbine and electric engines. Current flight deck designs normally provide control inceptors for each propulsion engine and an engine display for all primary aircraft engine parameters. With full time augmentation expected, a single throttle control with autothrottle always engaged, even during failures, is desired. Augmentation of flight controls using distributed thrust also requires full time control of the electric engines using automation. Additionally, electric engine thrust is augmented during climb based on battery state of charge. Thrust augmentation changes faster than human reaction time and therefore requires full-time automation. A pilot-in-the-loop study was conducted at the NASA Langley Research Center in Hampton, Virginia, to test the final design of the single throttle with simplified engine displays. Fourteen airline pilots evaluated the single throttle and engine display concept. Electric engine failures included one, four symmetric, and eight non-symmetric electric engine failures. The turbine engine was evaluated for complete and partial failure during critical phases of flight to include takeoff as well as enroute. Unexpected go-arounds increase workload and require significant throttle manipulation. Go-arounds were included to ensure the single throttle was usable for all phases of flight. Failures during takeoff required a return to the departure field and failures enroute required a diversion except for one and four electric engine failures as these failures did not affect aircraft flyability or range. There are currently no Part 25 aircraft certified with hybrid systems or electric engines with batteries as emergency propulsion. For turbine engine failures in the SUSAN aircraft design, range is limited to 30 minutes at full power. Battery state of charge and battery health displays were developed and tested for usability and to determine how well they supported pilot decisions for alternate airports during emergency diversions. Novel displays using shape and color were developed to provide immediate feedback when state of charge became critical. This paper details the pilot study including pilot feedback supporting the potential for increased automation and a single throttle control. Detailed recommendations are provided for a novel single throttle control and additional pilot controls to support selection of engines during start, shutdown, and engine troubleshooting procedures. This design deviates significantly from current practice of providing throttles for each propulsion engine. Engine display recommendations are provided based on pilot feedback during a guided post-evaluation interview. Battery state of charge and battery health display recommendations were collected from all airline crews. The simplified engine displays design was rated excellent as measured with a usability scale. Quantitative metrics include airspeed tracking, time to complete checklists, time to make diversion decisions and the quality of the diversion decision. Recommendations for future studies are documented with supporting research and current observations about upcoming flight deck certifications.
autothrottle↗
Flight Deck Design of a Hybrid Turbine/Electric Passenger Aircraft
NASA is exploring the development of a 180-passenger subsonic single engine aft turbine aircraft, The aft turbine provides electric power in a hybrid design to wing mounted electric engines, creating a highly efficient, high-bypass-ratio fan equivalent. The SUbsonic Single Aft eNgine (SUSAN) aircraft is being developed as a sustainable subsonic regional aircraft that seeks to reduce emission levels by 50% in the next few decades. Pilot-in-the-loop studies were conducted at the NASA Langley Research Center in Hampton, Virginia, to explore the flight deck design for the hybrid electric aircraft. Following modern trends in commercial aircraft flight decks with full time augmented controls and a quiet and dark philosophy, single throttle and simplified engine displays were developed for the SUSAN aircraft. The aircraft includes a single aft mounted turbine engine and 16 wing mounted electric fans. The final design was developed from feedback received during an earlier pilot-in-the-loop study where one, two, and three throttles were tested in standard airline operations, including various failures of the turbine and electric engines. Current flight deck designs normally provide control inceptors for each propulsion engine and an engine display for all primary aircraft engine parameters. With full time augmentation expected, a single throttle control with autothrottle always engaged, even during failures, is desired. Augmentation of flight controls using distributed thrust also requires full time control of the electric engines using automation. Additionally, electric engine thrust is augmented during climb based on battery state of charge. Thrust augmentation changes faster than human reaction time and therefore requires full-time automation. A pilot-in-the-loop study was conducted at the NASA Langley Research Center in Hampton, Virginia, to test the final design of the single throttle with simplified engine displays. Fourteen airline pilots evaluated the single throttle and engine display concept. Electric engine failures included one, four symmetric, and eight non-symmetric electric engine failures. The turbine engine was evaluated for complete and partial failure during critical phases of flight to include takeoff as well as enroute. Unexpected go-arounds increase workload and require significant throttle manipulation. Go-arounds were included to ensure the single throttle was usable for all phases of flight. Failures during takeoff required a return to the departure field and failures enroute required a diversion except for one and four electric engine failures as these failures did not affect aircraft flyability or range. There are currently no Part 25 aircraft certified with hybrid systems or electric engines with batteries as emergency propulsion. For turbine engine failures in the SUSAN aircraft design, range is limited to 30 minutes at full power. Battery state of charge and battery health displays were developed and tested for usability and to determine how well they supported pilot decisions for alternate airports during emergency diversions. Novel displays using shape and color were developed to provide immediate feedback when state of charge became critical. This paper details the pilot study including pilot feedback supporting the potential for increased automation and a single throttle control. Detailed recommendations are provided for a novel single throttle control and additional pilot controls to support selection of engines during start, shutdown, and engine troubleshooting procedures. This design deviates significantly from current practice of providing throttles for each propulsion engine. Engine display recommendations are provided based on pilot feedback during a guided post-evaluation interview. Battery state of charge and battery health display recommendations were collected from all airline crews. The simplified engine displays design was rated excellent as measured with a usability scale. Quantitative metrics include airspeed tracking, time to complete checklists, time to make diversion decisions and the quality of the diversion decision. Recommendations for future studies are documented with supporting research and current observations about upcoming flight deck certifications.
autothrottle↗