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At least 937 records · Page 52

Aerospace reliability applied to biomedicine.

An analysis is presented that indicates that the reliability and quality assurance methodology selected by NASA to minimize failures in aerospace equipment can be applied directly to biomedical devices to improve hospital equipment reliability. The Space Electric Rocket Test project is used as an example of NASA application of reliability and quality assurance (R&QA) methods. By analogy a comparison is made to show how these same methods can be used in the development of transducers, instrumentation, and complex systems for use in medicine.

Lalli, V. R.↗

Evaluation of the electrochemical O2 concentrator as an O2 compressor

A program was successfully completed to analytically and experimentally evaluate the feasibility of using an electrochemical oxygen (O2) concentrator as an O2 compressor. The electrochemical O2 compressor (EOC) compresses 345 kN/sq m (50 psia) O2 generated on board the space vehicle by the water electrolysis subsystem (WES) in a single stage to 20,700 kN/sq m (3000 psia) to refill spent extravehicular equipment O2 bottles and to eliminate the need for high pressure O2 storage. The single cell EOC designed, fabricated, and used for the feasibility testing is capable of being tested at O2 pressures up to 41,400 kN/sq m (6000 psia). A ground support test facility to test the EOC cell was designed, fabricated, and used for the EOC feasibility testing. A product assurance program was established, implemented, and maintained which emphasized safety and materials compatibility associated with high pressure O2 operation. A membrane development program was conducted to develop a membrane for EOC application. Data obtained using a commercially available membrane were used to guide the development of the membranes fabricated specifically for an EOC. A total of 15 membranes were fabricated.

Marshall, R. D.↗

SEPS mission and system integration/interface requirements for the space transportation system

Earth escape mission requirements on Solar Electric Propulsion System (SEPS), and the interface definition and planned integration between SEPS, user spacecraft, and other elements of the STS. Emphasis is placed on the Comet rendezvous mission, scheduled to be the first SEPS user. Interactive SEPS interface characteristics with spacecraft and mission, as well as the multiple organizations and inter-related development schedules required to integrate the SEPS with spacecraft and STS, require early attention to definition of interfaces in order to assure a successful path to the first SEPS launch in July 1985

Cork, M. J.↗

Tandem-Mirror Ion Source

Improved ion source produces beam of ions at any kinetic energy from 1 to 1,000 eV, with little spread in energy or angle. Such ion beams useful in studies of surface properties of materials, surface etching, deposition, and development of plasma-diagnostic instrumentation. Tandemmirror ion source uses electrostatic and magnetic fields to keep electrons in ionization chamber and assure uniform output ion beam having low divergence in energy and angle.

Biddle, A.↗

Space Station payload accommodations

Accommodating a multitude of diverse payloads on the Space Station base and its platforms requires an early definition of payload candidates to assure an adequate assessment of payload requirements. The task of interpreting the payload requirements, translating them into Station design requirements, and developing the processes and procedures to accommodate and integrate the user onto the Station is the function of the NASA Space Station Program Office Utilization and Operations Group. This paper describes the Space Station assembly sequence, time-phased payload accommodations, and the unique research environment provided by the Space Station.

Hemmerdinger, Louis↗

Reusable ultralight personnel carrier (RUPC)

Attention is given to a personnel-carrying space vehicle concept developed to minimize the cost of access to LEO. The RUPC could provide alternate access to Space Station Freedom (SSF) for six passengers per flight. It can also bring and return small amounts of cargo, up to and including one SSF double rack. These capabilities are ideal for utilization flights during man-tended operations at SSF and for crew rotation during permanently manned periods. The RUPC is a reusable conical reentry vehicle and disposable adapter with propulsion and power subsystems. Avionics subsystem benefit from advanced low-power high-performance microelectronics developed for both the civilian and military space sectors. The RUPC core cabin concept has growth potential for other applications, including assured crew return, ground-launched crew rescue, delivery and retrieval of SSF cargo, and crew cabin for flights to the moon.

Clark, B. C., III↗

Teaching, learning, and planetary exploration

The progress accomplished in the first five months of the three-year grant period of Teaching, Learning, and Planetary Exploration is presented. The objectives of this project are to discover new education products and services based on space science, particularly planetary exploration. An Exploration in Education is the umbrella name for the education projects as they are seen by teachers and the interested public. As described in the proposal, our approach consists of: (1) increasing practical understanding of the potential role and capabilities of the research community to contribute to basic education using new discoveries; (2) developing an intellectual framework for these contributions by supplying criteria and templates for the teacher's stories; (3) attracting astronomers, engineers, and technical staff to the project and helping them form productive education partnerships for the future, (4) exploring relevant technologies and networks for authoring and communicating the teacher's stories; (5) enlisting the participation of potential user's of the teacher's stories in defining the products; (6) actually producing and delivering many educationally useful teacher's stories; and (7) reporting the pilot study results with critical evaluation. Technical progress was made by assembling our electronic publishing stations, designing electronic publications based on space science, and developing distribution approaches for electronic products. Progress was made addressing critical issues by developing policies and procedures for securing intellectual property rights and assembling a focus group of teachers to test our ideas and assure the quality of our products. The following useful materials are being produced: the TOPS report; three electronic 'PictureBooks'; one 'ElectronicArticle'; three 'ElectronicReports'; ten 'PrinterPosters'; and the 'FaxForum' with an initial complement of printed materials. We have coordinated with planetary scientists and astronomers both at the technical and policy level to assure the efficiency and ultimate utility of these efforts to derive educational benefits from the space science and exploration program as a whole.

Brown, Robert A.↗

A prototype Crew Medical Restraint System (CMRS) for Space Station Freedom

The Crew Medical Restrain System (CMRS) is a prototype system designed and developed for use as a universally deployable medical restraint/workstation on Space Station Freedom (SSF), the Shuttle Transportation System (STS), and the Assured Crew Rescue Vehicle (ACRV) for support of an ill or injured crewmember requiring stabilization and transportation to Earth. The CMRS will support all medical capabilities of the Health Maintenance Facility (HMF) by providing a restraint/interface system for all equipment (advance life support packs, defibrillator, ventilator, portable oxygen supply, IV pump, transport monitor, transport aspirator, and intervenous fluids delivery system) and personnel (patient and crew medical officers). It must be functional within the STS, ACRV, and all SSF habitable volumes. The CMRS will allow for medical capabilities within CPR, ACLS and ATLS standards of care. This must all be accomplished for a worst case transport time scenario of 24 hours from SSF to a definitive medical care facility on Earth. A presentation of the above design prototype with its subsequent one year SSF/HMF and STS/ACRV high fidelity mock-up ground based simulation testing will be given. Also, parabolic flight and underwater Weightless Test Facility evaluations will be demonstrated for various medical contingencies. The final design configuration to date will be discussed with future space program impact considerations.

Johnston, S. L.↗

Design and Testing of a One-Third Scale Soyuz TM Descent Module Spartan Conversion Project Super Loki Instrumentation

The 1992-1993 senior Aerospace Engineering Design class continued work on the post landing configurations for the Assured Crew Return Vehicle. The Assured Crew Return Vehicle will be permanently docked to the space station fulfilling NASA's commitment of Assured Crew Return Capability in the event of an accident or illness aboard the space station. The objective of the project was to give the Assured Crew Return Vehicle Project Office data to feed into their feasibility studies. Three design teams were given the task of developing models with dynamically and geometrically scaled characteristics. Groups one and two combined efforts to design a one-third scale model of the Russian Soyuz TM Descent Module, and an on-board flotation system. This model was designed to determine the flotation characteristics and test the effects of a rigid flotation and orientation system. Group three designed a portable water wave test facility to be located on campus. Because of additional funding from Thiokol Corporation, testing of the Soyuz model and flotation systems took place at the Offshore Technology Research Center. Universities Space Research Association has been studying the use of small expendable launch vehicles for missions which cost less than 200 million dollars. The Crusader2B. which consists of the original Spartan first and second stage with an additional Spartan second stage and the Minuteman III upper stage is being considered for this task. University of Central Florida project accomplishments include an analysis of launch techniques, a modeling technique to determine flight characteristics, and input into the redesign of an existing mobile rail launch platform.

Anderson, Loren A.↗

Nondestructive Evaluation Methodologies Developed for Certifying Composite Flywheels

Manufacturing readiness of composite rotors and certification of flywheels depend in part on the maturity of nondestructive evaluation (NDE) technology for process optimization and quality assurance, respectively. At the NASA Glenn Research Center, the capabilities and limitations of x-ray-computed tomography and radiography, as well as advanced ultrasonics were established on NDE ring and rotor standards with electrical discharge machining (EDM) notches and drilled holes. Also, intentionally seeded delamination, tow break, and insert of bagging material were introduced in hydroburst-rings to study the NDE detection capabilities of such anomalies and their effect on the damage tolerance and safe life margins of subscale rings and rotors. Examples of possible occurring flaws or anomalies in composite rings as detected by NDE and validated by destructive metallography are shown. The general NDE approach to ensure the quality of composite rotors and to help in the certification of flywheels is briefly outlined.

Baaklini, George Y.↗

Development of NASA's Accident Precursor Analysis Process Through Application on the Space Shuttle Orbiter

Accident Precursor Analysis (APA) serves as the bridge between existing risk modeling activities, which are often based on historical or generic failure statistics, and system anomalies, which provide crucial information about the failure mechanisms that are actually operative in the system. APA docs more than simply track experience: it systematically evaluates experience, looking for under-appreciated risks that may warrant changes to design or operational practice. This paper presents the pilot application of the NASA APA process to Space Shuttle Orbiter systems. In this effort, the working sessions conducted at Johnson Space Center (JSC) piloted the APA process developed by Information Systems Laboratories (ISL) over the last two years under the auspices of NASA's Office of Safety & Mission Assurance, with the assistance of the Safety & Mission Assurance (S&MA) Shuttle & Exploration Analysis Branch. This process is built around facilitated working sessions involving diverse system experts. One important aspect of this particular APA process is its focus on understanding the physical mechanism responsible for an operational anomaly, followed by evaluation of the risk significance of the observed anomaly as well as consideration of generalizations of the underlying mechanism to other contexts. Model completeness will probably always be an issue, but this process tries to leverage operating experience to the extent possible in order to address completeness issues before a catastrophe occurs.

Maggio, Gaspare↗

Comparison of Image Restoration Methods for Lunar Epithermal Neutron Emission Mapping

Orbital measurements of neutrons by the Lunar Exploring Neutron Detector (LEND) onboard the Lunar Reconnaissance Orbiter are being used to quantify the spatial distribution of near surface hydrogen (H). Inferred H concentration maps have low signal-to-noise (SN) and image restoration (IR) techniques are being studied to enhance results. A single-blind. two-phase study is described in which four teams of researchers independently developed image restoration techniques optimized for LEND data. Synthetic lunar epithermal neutron emission maps were derived from LEND simulations. These data were used as ground truth to determine the relative quantitative performance of the IR methods vs. a default denoising (smoothing) technique. We review and used factors influencing orbital remote sensing of neutrons emitted from the lunar surface to develop a database of synthetic "true" maps for performance evaluation. A prior independent training phase was implemented for each technique to assure methods were optimized before the blind trial. Method performance was determined using several regional root-mean-square error metrics specific to epithermal signals of interest. Results indicate unbiased IR methods realize only small signal gains in most of the tested metrics. This suggests other physically based modeling assumptions are required to produce appreciable signal gains in similar low SN IR applications.

McClanahan, T. P.↗

A Fuel-Efficient Conflict Resolution Maneuver for Separation Assurance

Automated separation assurance algorithms are envisioned to play an integral role in accommodating the forecasted increase in demand of the National Airspace System. Developing a robust, reliable, air traffic management system involves safely increasing efficiency and throughput while considering the potential impact on users. This experiment seeks to evaluate the benefit of augmenting a conflict detection and resolution algorithm to consider a fuel efficient, Zero-Delay Direct-To maneuver, when resolving a given conflict based on either minimum fuel burn or minimum delay. A total of twelve conditions were tested in a fast-time simulation conducted in three airspace regions with mixed aircraft types and light weather. Results show that inclusion of this maneuver has no appreciable effect on the ability of the algorithm to safely detect and resolve conflicts. The results further suggest that enabling the Zero-Delay Direct-To maneuver significantly increases the cumulative fuel burn savings when choosing resolution based on minimum fuel burn while marginally increasing the average delay per resolution.

Bowe, Aisha Ruth↗

TPSAS-NF1676L-12354-DND

This work deals with performance properties of a dynamic traffic model, the Air Traffic Monotonic Lagrangian Grid (ATMLG), which can be used to evaluate new control strategies for conflict avoidance, separation assurance, and traffic management. The model is based on an algorithm and data structure called the Monotonic Lagrangian Grid (MLG), originally developed at NRL in the mid 1980s and since then used as an underpinning for various particle dynamics simulations. The MLG stores positions and other data needed to describe N moving objects, where N can be very large. The MLG algorithm involves sorting and ordering objects. A stationary grid is an alternative to the dynamic grid of MLG. Stationary grids can be attractive in that they do not require sorting. We investigate and report on the relative performances of air traffic simulations based on dynamic (MLG) and static (lat-long) grids.

C Kaplan↗

TPSAS-NF1676L-12301-DND

This work deals with performance properties of a dynamic traffic model, the Air Traffic Monotonic Lagrangian Grid (ATMLG), which can be used to evaluate new control strategies for conflict avoidance, separation assurance, and traffic management. The model is based on an algorithm and data structure called the Monotonic Lagrangian Grid (MLG), originally developed at NRL in the mid 1980s and since then used as an underpinning for various particle dynamics simulations. The MLG stores positions and other data needed to describe N moving objects, where N can be very large. The MLG algorithm involves sorting and ordering objects. A stationary grid is an alternative to the dynamic grid of MLG. Stationary grids can be attractive in that they do not require sorting. We investigate and report on the relative performances of air traffic simulations based on dynamic (MLG) and static (lat-long) grids.

Carolyn Kaplan↗

Automated Airspace Management: Concept, Development, and Testing

For many decades, researchers at NASA Ames Research Center have worked to make the air-transportation system more efficient, predictable, and effective. Since about 2005 one important aspect of this research has been the development of an autonomous system for air-traffic control. This system, known as the Autoresolver, is designed to perform most of the roles that air-traffic controllers perform including ensuring separation between aircraft, creating routes around weather and other avoidance volumes, and sequencing and scheduling aircraft across points in space. The recent, rapid expansion of new aircraft operations and types, including urban air mobility aircraft and small unmanned aerial systems, have only increased the need for highly automated systems to control the predicted traffic demand. This talk will focus on the development of the Autoresolver - from concept to testing. It will also discuss the National Airspace (NAS) Digital Twin simulation platform, created to facilitate rapid testing and improvement of the algorithm and with the hope of proving the automation in a high-fidelity environment. An open question that will be discussed is how to ensure that the system-level emergent behavior of independently developed autonomous algorithms is what is desired.

autonomy↗

Assessing Several Non-Traditional Data Sources for Value in Aviation Safety

The NASA System-Wide Safety (SWS) project and its predecessor projects have been developing Machine Learning (ML) algorithms for commercial aviation safety for many years. These algorithms have been applied to Flight Operations Quality Assurance (FOQA); radar track data (e.g., Threaded Track); and safety reports, including Aviation Safety Reporting System (ASRS) and Aviation Safety Action Plan (ASAP). SWS is working with partners to get access to other data that air carriers provide, such as maintenance data, and has been assisting carriers in working with other data, such as Line Operations Safety Audit (LOSA) data, using manual methods. However, the project has discussed whether there are other data that are not traditionally used in aviation safety analysis that may be useful. This paper discusses four sets of data and models that are not traditionally used in aviation safety but that have shown promise for such use. In the future, we plan to incorporate such data into ML algorithms to use with data that we have used before and determine the additional benefit that is actually achieved under different contexts from the inclusion of these non-traditional data sources.

Nikunj C. Oza↗

The Next Generation Radioisotope Thermoelectric Generator Project - Overview and Progress Status

The Next Generation Radioisotope Thermoelectric Generator (Next Gen RTG) Project is a spaceflight system project within NASA’s Radioisotope Power Systems (RPS) Program. The project, in partnership with the Idaho National Laboratory (INL) / Battelle Energy Alliance (BEA), will build and deliver an unfueled, flight qualified Radioisotope Thermoelectric Generator (RTG) system based on RPS Program needs. The Next Gen RTG Project aims to assure the availability of high-power, vacuum-rated RTGs to enable future deep space missions. The Project team is developing that capability through a multi-phase effort that leverages the heritage General Purpose Heat Source - RTG (GPHS-RTG) design and available legacy hardware. The Project’s primary aim is to re-establish the capability to manufacture a silicon germanium (SiGe) unicouple based thermoelectric converter and associated hardware with minimal changes to the heritage GPHS-RTG design. The project will also refurbish the GPHS-RTG Flight Unit #5 (F-5) located at INL and verify its compliance with heritage GPHS-RTG requirements. This paper will detail the project’s plans for the development of these systems. Management approaches, technical challenges, and risks will also be discussed.

Radioisotope↗