Search NASA⌕ Search

SEARCH · Search NASA

Results for “technical analysis”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Tug rendezvous and docking with a spacecraft - A remote manned approach

The development and use of a visual simulator for remote-manned rendezvous and docking utilizing frame-by-frame, slow-scan, low-light-level TV (LLLTV) was conceived and initiated in mid-1974. The effort was limited to modification, checkout, and validation of simulator hardware specific to this task, to the development of simulation (digital computer) software, and technical support to several rendezvous and docking simulation studies. Analysis and simulation has shown that LLLTV, such as would be required for satellite inspection, could provide a suitable acquisition sensor for a remote manned rendezvous/docking subsystem. A manned, remote simulation has demonstrated its feasibility during the terminal rendezvous and docking phases. Should this approach prove fully adequate in subsequent detailed simulation studies and tests, an order-of-magnitude cost savings can be obtained for early rendezvous and docking operations.

Hurley, M. J.↗
NASA NTRS1996

NASA Research Announcement Phase 1 Report and Phase 2 Proposal for the Development of a Power Assisted Space Suit Glove Assembly

In July of 1996, ILC Dover was awarded Phase 1 of a contract for NASA to develop a prototype Power Assisted Space Suit glove to enhance the performance of astronauts during Extra-Vehicular Activity (EVA). This report summarizes the work performed to date on Phase 1, and details the work to be conducted on Phase 2 of the program. Phase 1 of the program consisted of research and review of related technical sources, concept brainstorming, baseline design development, modeling and analysis, component mock-up testing, and test data analysis. ILC worked in conjunction with the University of Maryland's Space Systems Laboratory (SSL) to develop the power assisted glove. Phase 2 activities will focus on the design maturation and the manufacture of a working prototype system. The prototype will be tested and evaluated in conjunction with existing space suit glove technology to determine the performance enhancement anticipated with the implementation of the power assisted joint technology in space suit gloves.

Cadogan, Dave↗
NASA NTRS1997

Lessons learned studying design issues for lunar and Mars settlements

In a study of lunar and Mars settlement concepts, an analysis was made of fundamental design assumptions in five technical areas against a model list of occupational and environmental health concerns. The technical areas included the proposed science projects to be supported, habitat and construction issues, closed ecosystem issues, the "MMM" issues (mining, material processing, and manufacturing), and the human elements of physiology, behavior, and mission approach. Four major lessons were learned. First it is possible to relate public health concerns to complex technological development in a proactive design mode, which has the potential for long-term cost savings. Second, it became very apparent that prior to committing any nation or international group to spending the billions to start and complete a lunar settlement, over the next century, that a significantly different approach must be taken from those previously proposed, to solve the closed ecosystem and "MMM" problems. Third, it also appears that the health concerns and technology issues to be addressed for human exploration into space are fundamentally those to be solved for human habitation of the Earth (as a closed ecosystem) in the 21st century. Finally, it is proposed that ecosystem design modeling must develop new tools, based on probabilistic models as a step up from closed circuit models.

Life Support Systems↗
NASA NTRS2007

Technical Findings, Lessons Learned, and Recommendations Resulting from the Helios Prototype Vehicle Mishap

The Helios Prototype was originally planned to be two separate vehicles, but because of resource limitations only one vehicle was developed to demonstrate two missions. The vehicle consisted of two configurations, one for each mission. One configuration, designated HP01, was designed to operate at extremely high altitudes using batteries and high-efficiency solar cells spread across the upper surface of its 247-foot wingspan. On August 13, 2001, the HP01 configuration reached an altitude of 96,863 feet, a world record for sustained horizontal flight by a winged aircraft. The other configuration, designated HP03, was designed for long-duration flight. The plan was to use the solar cells to power the vehicle's electric motors and subsystems during the day and to use a modified commercial hydrogen-air fuel cell system for use during the night. The aircraft design used wing dihedral, engine power, elevator control surfaces, and a stability augmentation and control system to provide aerodynamic stability and control. At about 30 minutes into the second flight of HP03, the aircraft encountered a disturbance in the way of turbulence and morphed into an unexpected, persistent, high dihedral configuration. As a result of the persistent high dihedral, the aircraft became unstable in a very divergent pitch mode in which the airspeed excursions from the nominal flight speed about doubled every cycle of the oscillation. The aircraft s design airspeed was subsequently exceeded and the resulting high dynamic pressures caused the wing leading edge secondary structure on the outer wing panels to fail and the solar cells and skin on the upper surface of the wing to rip away. As a result, the vehicle lost its ability to maintain lift, fell into the Pacific Ocean within the confines of the U.S. Navy's Pacific Missile Range Facility, and was destroyed. This paper describes the mishap and its causes, and presents the technical recommendations and lessons learned for improving the design, analysis, and testing methods and techniques required for this class of vehicle.

Noll, Thomas E.↗
NASA NTRS2011

Space Transportation System Liftoff Debris Mitigation Process Overview

Liftoff debris is a top risk to the Space Shuttle Vehicle. To manage the Liftoff debris risk, the Space Shuttle Program created a team with in the Propulsion Systems Engineering & Integration Office. The Shutt le Liftoff Debris Team harnesses the Systems Engineering process to i dentify, assess, mitigate, and communicate the Liftoff debris risk. T he Liftoff Debris Team leverages off the technical knowledge and expe rtise of engineering groups across multiple NASA centers to integrate total system solutions. These solutions connect the hardware and ana lyses to identify and characterize debris sources and zones contribut ing to the Liftoff debris risk. The solutions incorporate analyses sp anning: the definition and modeling of natural and induced environmen ts; material characterizations; statistical trending analyses, imager y based trajectory analyses; debris transport analyses, and risk asse ssments. The verification and validation of these analyses are bound by conservative assumptions and anchored by testing and flight data. The Liftoff debris risk mitigation is managed through vigilant collab orative work between the Liftoff Debris Team and Launch Pad Operation s personnel and through the management of requirements, interfaces, r isk documentation, configurations, and technical data. Furthermore, o n day of launch, decision analysis is used to apply the wealth of ana lyses to case specific identified risks. This presentation describes how the Liftoff Debris Team applies Systems Engineering in their proce sses to mitigate risk and improve the safety of the Space Shuttle Veh icle.

Mitchell, Michael↗
NASA NTRS2014

Design Environment for Multifidelity and Multidisciplinary Components

One of the greatest challenges when developing propulsion systems is predicting the interacting effects between the fluid loads, thermal loads, and structural deflection. The interactions between technical disciplines often are not fully analyzed, and the analysis in one discipline often uses a simplified representation of other disciplines as an input or boundary condition. For example, the fluid forces in an engine generate static and dynamic rotor deflection, but the forces themselves are dependent on the rotor position and its orbit. It is important to consider the interaction between the physical phenomena where the outcome of each analysis is heavily dependent on the inputs (e.g., changes in flow due to deflection, changes in deflection due to fluid forces). A rigid design process also lacks the flexibility to employ multiple levels of fidelity in the analysis of each of the components. This project developed and validated an innovative design environment that has the flexibility to simultaneously analyze multiple disciplines and multiple components with multiple levels of model fidelity. Using NASA's open-source multidisciplinary design analysis and optimization (OpenMDAO) framework, this multifaceted system will provide substantially superior capabilities to current design tools.

Platt, Michael↗
NASA NTRS2016

NASA Collaborative Approach Mitigates Environmentally-Driven Obsolescence

National Aeronautics and Space Administration (NASA) missions, like Department of Defense (DoD) organizations, require the rigorous testing and qualification of critical materials. Obsolescence supply risks created by environmental requirements can affect the cost, schedule and performance of NASA missions and the resilience of critical infrastructure. The NASA Technology Evaluation for Environmental Risk Mitigation (TEERM) Principal Center helps to identify obsolescence supply risks driven by environmental requirements and works proactively with NASA Centers and Programs, the DoD, the European Space Agency (ESA) and other agencies and partners to identify and evaluate environmentally friendly alternatives. TEERM tracks environmental regulations, identifies the potential loss of material availability and works with NASA programs and Centers to evaluate potential impacts through a risk assessment approach. TEERM collaborative projects identify, demonstrate and evaluate commercially viable alternative technologies and materials. A major focus during the Space Shuttle Program was the need to replace ozone depleting substances that were used in spray foam and cleaning applications. The potential obsolescence of coatings containing hexavalent chromium and the risks associated with lead free solder were also of concern for the Space Shuttle and present ongoing risks to new programs such as the Space Launch System. One current project teams NASA and ESA in the evaluation and testing of individual coatings and coating systems as replacements for hexavalent chromium coatings in aerospace applications. The proactive, collaborative approach used by TEERM helps reduce the cost burden on any one team partner, reduces duplication of effort, and enhances the technical quality and overall applicability of the testing and analysis.

environmentall-driven obsolescence↗
NASA NTRS2018

The Design & Development of the Ocean Color Instrument Precision Superduplex Hybrid Bearing Cartridge

A high precision, high-resolution Ocean Color Imaging (OCI) instrument is under development for the Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission which requires a pair of medium speed mechanisms to scan the ocean surface continuously. The design of the rotating telescope (RT) mechanism operating at 360 RPM and the half-angle mirror (HAM) mechanism synchronized at 180 RPM was concern for maintaining pointing precision over the required life and continuous operations. An effort was undertaken with the manufacturer to design and analyze a special bearing configuration to minimize axial and radial runout, minimize torque, and maintain nominal contact stresses and stiffness over the operating temperature range and to maximize life. The bearing design, development effort, analysis and testing will be discussed as will the technical challenges that this specific design imposed upon the mechanism engineers. Bearing performance, runout as achieved and verified during encoder installation and operating torque will be described.

mechanism↗
NASA NTRS2025

PACE Water Resources: Demonstrating the Use of NASA's PACE Hyperspectral Ocean Color Instrument Data for Enhanced Coastal Management

This project developed tools to support the future use of Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) hyperspectral imagery in water resource monitoring and research by NASA DEVELOP teams and members of the PACE applications community. We sought to address a need for support in processing and visualizing hyperspectral PACE Ocean Color Instrument (OCI) data among researchers and decision-makers working in coastal water quality management and harmful algal bloom (HAB) monitoring. To supplement the day of simulated PACE imagery available, we used Aqua MODIS earth observations with Level 3 processing from March 2022 to build a Python graphical user interface (GUI) for visualizing ocean biogeochemical parameters relevant to the early detection and monitoring of HABs. We used simulated PACE OCI Level 2 data derived from the Python Top of Atmosphere Simulation Tool (PyTOAST) to build Jupyter Notebooks for band subset and selection. The Level 3 PACE Viewer components support users with quick visualizations as well as the creation of geoTIFFs and time-series. The Level 2 Jupyter Notebooks address users’ concerns over the volume and complexity of hyperspectral imagery. The PACE Viewer is useful for visual inspection and netCDF data processing but should not be used for geospatial analysis. Once PACE launches, this tool will alleviate the technical burdens of working with hyperspectral data and support the early detection and monitoring of HABs using PACE satellite imagery.

Python Top of Atmosphere Simulation Tool↗
NASA NTRS2024

Survey of Methods for Assessing Safety Compliance of sUAS BVLOS Operations

To ensure the safety of small Unmanned Aircraft System (sUAS) Beyond Line of Sight (BVLOS) operations in the National Airspace System (NAS), the FAA offers a guideline on how sUAS operators can demonstrate compliance with FAA rules, including regulations, advisory circulars, policy statements, and acceptable means of compliance (AMOC), using a formal and top-down approach. According to FAA Advisory Circular 23.2010-1, the AMOC refers to “one method, but not the only method, to show compliance with a regulatory requirement.” It is common for regulations to include a performance and safety standard rather than a detailed design or operation requirement, which allows for flexibility in fulfilling the regulatory requirements while still achieving a predetermined level of safety. This technical report explores existing frameworks for sUAS BVLOS safety analysis. It begins by discussing how sUAS BVLOS operations can be strategically deconflicted and then discusses their hazards. The next step is to establish safety assessment methods commonly used by the aviation industry and the FAA, illustrate how these methods can be applied to several safety-critical air traffic systems, and list collision models that the FAA and industry use. This investigation documents the processes for assessing safety risks in sUAS BVLOS operations and will allow sUAS BVLOS operations to be assessed for safety compliance more efficiently.

sUAS BVLOS Operations↗
NASA NTRS2011

Rolling-Element Fatigue Testing and Data Analysis - A Tutorial

In order to rank bearing materials, lubricants and other design variables using rolling-element bench type fatigue testing of bearing components and full-scale rolling-element bearing tests, the investigator needs to be cognizant of the variables that affect rolling-element fatigue life and be able to maintain and control them within an acceptable experimental tolerance. Once these variables are controlled, the number of tests and the test conditions must be specified to assure reasonable statistical certainty of the final results. There is a reasonable correlation between the results from elemental test rigs with those results obtained with full-scale bearings. Using the statistical methods of W. Weibull and L. Johnson, the minimum number of tests required can be determined. This paper brings together and discusses the technical aspects of rolling-element fatigue testing and data analysis as well as making recommendations to assure quality and reliable testing of rolling-element specimens and full-scale rolling-element bearings.

Vlcek, Brian L.↗
NASA NTRS1999

Experimental and Numerical Analysis of Structural Acousticcontrol Interior Noise Reduction

The research results contained in this technical report were performed under the NASA grant entitled "Experimental and Numerical Structural Acoustic Control for Interior Noise Reduction". The report is based essentially on partial progress of the Ph.D. dissertation prepared by Jeffrey S. Bevan under direct guidance of Dr. Chuh Mei. The document presents a finite element formulation and control of sound radiated from cylindrical panels embedded with piezoceramic actuators. The extended MIN6 shallow shell element is fully electrical-structural coupled. A piezoelectric modal actuator participation (PMAP) is defined which indicates the actuator performance to each of the offending modes. Genetic algorithm is also employed to validate the sensor and actuator locations determined by the PMAP criteria. The work was conducted at the Department of Aerospace Engineering, Old Dominion University. Mr. Travis L. Turner, Structural Acoustics Branch, NASA Langley Research Center is the technical monitor.

Mei, Chuh↗
NASA NTRS2015

Analysis of Fluorinated Polyimides Flown on the Materials International Space Station Experiment

This Technical Memorandum documents the results from the Materials on International Space Station Experiment (MISSE) series involving fluorinated polyimide films analyzed at NASA Marshall Space Flight Center. These films may be used in thermal control, sunshield, solar sail, solar concentrator, and other lightweight polymer film applications. Results include postflight structural integrity, visual observations, determination of atomic oxygen erosion yield, and optical property changes as compared to preflight values.

Finckenor, M. M.↗
NASA NTRSDate not supplied

Space Shuttle Program Dual Docked Operations

Due to the ever-increasing visiting vehicle traffic to and from the International Space Station (ISS) during mated Orbiter/ISS missions, it became apparent to both the ISS Program (ISSP) and the Space Shuttle program (SSP) that there would arise occasions where a visiting vehicle docking and/or undocking could overlap when the Space Shuttle Orbiter was docked to the ISS, referred to as Dual Docked Operations (DDO). The primary concerns were that plumes from the visiting vehicles would cause contamination, corrosion, and erosion to Space Shuttle surfaces and present a toxicity hazard to ground personnel when processing the Space Shuttle after landing. This potential conflict provided the genesis for evaluating risk mitigations to gain maximum flexibility for managing potential visiting vehicle traffic to and from the ISS and to maximize launch and landing opportunities for all visiting vehicles. The overarching goal of this effort was to assess the viability and readiness of the SSP to protect for DDO on any given mission. To assess the viability of performing DDO, the ISSP delivered plume particle fluence (i.e., number of particles per unit area) and contamination deposition based on the visiting vehicle’s proximity operations to the SSP for evaluation. This paper summarizes the concept definition, studies, and analysis results generated by the SSP, ISSP, and Mission Operations Directorate (MOD) for implementing DDO involving the Orbiter and Russian vehicles (RVs). Discussion and results presented herein represent a generic assessment of the SSP and ISSP integrated safety and technical evaluations of DDO involving the Orbiter and RVs. Mission-specific analysis and operational impacts were conducted flight-by-flight as they arose.

Launch vehicles↗
NASA NTRS2011

A NASA Applied Spaceflight Environments Office Concept

The National Aeronautics and Space Administration (NASA) is launching a bold and ambitious new space initiative. A significant part of this new initiative includes exploration of new worlds, the development of more innovative technologies, and expansion our presence in the solar system. A common theme to this initiative is the exploration of space beyond Low Earth Orbit (LEO). As currently organized, NASA does not have an Agency-level office that provides coordination of space environment research and development. This has contributed to the formation of a gap between spaceflight environments knowledge and the application of this knowledge for multi-program use and for use outside NASA. This paper outlines a concept to establish a NASA-level Applied Spaceflight Environments (ASE) office that will provide coordination and funding for sustained multi-program support in three technical areas that have demonstrated these needs through customer requests. These technical areas are natural environments characterization and modeling, materials and systems analysis and test, and operational space environments modeling. Additionally the ASE office will serve as an entry point of contact for external users who wish to take advantage of data and assets associated with space environments, including space weather. This paper will establish the need for the ASE, discuss a concept for organizational structure and outline the scope in the three technical areas.

Spann, James F.↗
NASA NTRS2002

Sources of Variability in Chlorophyll Analysis by Fluorometry and High-Performance Liquid Chromatography in a SIMBIOS Inter-Calibration Exercise

The purpose of this technical report is to provide current documentation of the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) Project activities, NASA Research Announcement (NRA) research status, satellite data processing, data product validation, and field calibration. This documentation is necessary to ensure that critical information is related to the scientific community and NASA management. This critical information includes the technical difficulties and challenges of validating and combining ocean color data from an array of independent satellite systems to form consistent and accurate global bio-optical time series products. This technical report is not meant as a substitute for scientific literature. Instead, it will provide a ready and responsive vehicle for the multitude of technical reports issued by an operational project. This particular document focus on the variability in chlorophyll pigment measurements resulting from differences in methodologies and laboratories conducting the pigment analysis.

VanHeukelem, Laurie↗