Search NASA⌕ Search

SEARCH · Search NASA

Results for “design standards”

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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Evaluating the Stability of NASA's Space Launch System with Adaptive Augmenting Control

NASA's baseline Space Launch System (SLS) flight control system (FCS) design includes an adaptive augmenting control (AAC) component that modifies the attitude control system response to provide the classical gain-scheduled control architecture with additional performance and robustness. The NASA Engineering and Safety Center (NESC) teamed with the Space Launch System (SLS) Program to perform a comprehensive assessment of the stability and robustness of the FCS with AAC. This paper provides an overview of the approach, specific analysis techniques, and outcomes that were particularly relevant for the SLS Program. Multiple analysis techniques that specifically target the nonlinear AAC were commissioned as part of this assessment, which was completed outside of the Program's standard design analysis cycle. The following analyses were included, with each technique adding its own valuable insights: Lyapunov-based stability analysis, classical stability analysis with static AAC gain variations, circle criterion-based analysis of the FCS with a time-varying element, time-domain stability margin assessment, Monte Carlo simulations with expanded dispersions, and an extensive set of stressing cases. Several of the completed analyses focused on determining whether the inclusion of AAC introduced risk to the FCS, while others quantified the benefits of the adaptive augmentation.

Tannen S Vanzwieten↗
NASA NTRS2004

Spacecraft Fire Suppression: Testing and Evaluation

The objective of this project is the testing and evaluation of the effectiveness of a variety of fire suppressants and fire-response techniques that will be used in the next generation of spacecraft (Crew Exploration Vehicle, CEV) and planetary habitats. From the many lessons learned in the last 40 years of space travel, there is common agreement in the spacecraft fire safety community that a new fire suppression system will be needed for the various types of fire threats anticipated in new space vehicles and habitats. To date, there is no single fire extinguishing system that can address all possible fire situations in a spacecraft in an effective, reliable, clean, and safe way. The testing conducted under this investigation will not only validate the various numerical models that are currently being developed, but it will provide new design standards on fire suppression that can then be applied to the next generation of spacecraft extinguishment systems. The test program will provide validation of scaling methods by conducting small, medium, and large scale fires. A variety of suppression methods will be tested, such as water mist, carbon dioxide, and nitrogen with single and multiple injection points and direct or distributed agent deployment. These injection methods cover the current ISS fire suppression method of a portable hand-held fire extinguisher spraying through a port in a rack and also next generation spacecraft units that may have a multi-point suppression delivery system built into the design. Consideration will be given to the need of a crew to clean-up the agent and recharge the extinguishers in flight in a long-duration mission. The fire suppression methods mentioned above will be used to extinguish several fire scenarios that have been identified as the most relevant to spaceflight, such as overheated wires, cable bundles, and circuit boards, as well as burning cloth and paper. Further testing will be conducted in which obstructions and ventilation will be added to represent actual spacecraft conditions (e.g., a series of cards in a card rack).

Abbud-Madrid, Angel↗
NASA NTRS1998

An Investigation of Reliability Models for Ceramic Matrix Composites and their Implementation into Finite Element Codes

The development of modeling approaches for the failure analysis of ceramic-based material systems used in high temperature environments was the primary objective of this research effort. These materials have the potential to support many key engineering technologies related to the design of aeropropulsion systems. Monolithic ceramics exhibit a number of useful properties such as retention of strength at high temperatures, chemical inertness, and low density. However, the use of monolithic ceramics has been limited by their inherent brittleness and a large variation in strength. This behavior has motivated material scientists to reinforce the monolithic material with a ceramic fiber. The addition of a second ceramic phase with an optimized interface increases toughness and marginally increases strength. The primary purpose of the fiber is to arrest crack growth, not to increase strength. The material systems of interest in this research effort were laminated ceramic matrix composites, as well as two- and three- dimensional fabric reinforced ceramic composites. These emerging composite systems can compete with metals in many demanding applications. However, the ongoing metamorphosis of ceramic composite material systems, and the lack of standardized design data has in the past tended to minimize research efforts related to structural analysis. Many structural components fabricated from ceramic matrix composites (CMC) have been designed by "trial and error." The justification for this approach lies in the fact that during the initial developmental phases for a material system fabrication issues are paramount. Emphasis is placed on demonstrating feasibility rather than fully understanding the processes controlling mechanical behavior. This is understandable during periods of rapid improvements in material properties for any composite system. But to avoid the ad hoc approach, the analytical methods developed under this effort can be used to develop rational structural design protocols.

Duffy, Stephen F.↗
NASA NTRSDate not supplied

Abrstract - OnePlace Redesign Spring 2020 Internship

The project I worked on was the OnePlace Redesign. In that, I converted the OnePlace home page to the Service Portal to match NASA OnePlace’s current application design standards, I was able to allow users to easily find applications in OnePlace and I was able to allow users to easily find and request OnePlace services (new app development, new knowledge base, etc.). It was a major accomplishment to be able to remodel a website that soon the entire Langley center that uses OnePlace will use. The website was made through ServiceNow’s Service Portal, and I organized the applications like never before, allowed a clear styling to applications a user does not have access to and/or are new applications, browsing of applications with clear button divisions, and allowing for different options depending if app is accessible or not, with proper error checking in place and very-well documented code. It was amazing to incorporate all this logic into one widget so that whoever wants to utilize this feature has no trouble at all to do so. The 3 most important things I learned were being able to do this work within ServiceNow, as it is such an important enterprise platform for CRM and boosting the connected workforce of NASA, incorporate built-in APIs from ServiceNow Glide Records to connect Server Scripts to Client Scripts and HTML, and be able to use agile to get another experience of managing work capacity with stories, and having proper communication with the team if every feature is done correctly and steps for continuing forward. The part that I enjoyed the most was the training I did for ServiceNow and I freedom I had to experiment to see how to structure the Service Portal. I was not tied down, and I believe this allowed for a better outcome of the product. As part of the internship, I created a very in-depth design document with the help of my team to document the project goals before it was started and technical documentation (including the design document) summarizing the final result of the product in terms of the new features added and the explanation of the logic thoroughly so that anyone can understand the project easily. The technical documentation will be published as a Knowledge Article within OnePlace Knowledge Base documentation.

Ariel Wald↗
NASA NTRS1972

Manufacture and quality control of interconnecting wire harnesses, Volume 3

The document covers interconnecting wire harnesses defined in the design standard, including type 6, enclosed in TFE heat shrink tubing; and type 7, flexible armored. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

Source record↗
NASA NTRS1972

Manufacturing and quality control of interconnecting wire harnesses, Volume 4

The document covers interconnecting wire harnesses defined in the design standard, including type 8, flat conductor cable. Volume breadth covers installations of groups of harnesses in a major assembly and the associated post installation inspections and electrical tests. Knowledge gained through experience on the Saturn 5 program coupled with recent advances in techniques, materials, and processes was incorporated into this document.

Source record↗
NASA NTRS1972

Solar array cost reduction.

The costs regarding solar power systems are considered, giving attention to the total system cost index for the power system as a function of solar array area, and the recurring cost per square foot for the solar array versus the total area flight arrays built for each project. It is found that the costs decrease as production volume increases. Design standardization together with improvements in solar cell and array technology show promise of reducing costs. A long range program has been started to improve substantially the efficiency of silicon cells. Efficiencies approaching 20% are theoretically possible. One obstacle to cost reduction is that the volume of production required to satisfy the space program is not enough to justify a high degree of mechanization or automation.

Bernatowicz, D. T.↗
NASA NTRS1972

Rocket Combustion Instability Suppression With Cavity Resonators

Properly tuned Helmholtz resonator damping devices are an effective method for eliminating high frequency combustion instability in rocket engine thrust chambers. A program was implemented with the objective of extending Helmholtz resonator theory to thrust chamber conditions to establish a standard design procedure. By using systematic cold-flow testing and hot firings, empirical design equations were formulated. An effort is currently underway to extend the design theory to other types of acoustical damping devices such as quarter-wave tubes and slots.

R H Counts↗
NASA NTRS1973

Systems approach to low cost payload design and operations

It is argued that the numerous factors governing the development and use of low-cost payload systems must be analyzed from a total systems viewpoint covering design, standardization, reuse, and refurbishment operations both in orbit and on the ground. Standardization of payloads for use with different transportation systems is shown to require extensive management studies involving cooperation between users and the technical community. Problems and potential solutions are identified in areas of orbital and ground-based refurbishment, and candidate vehicle systems are discussed for delivery, repair, replacement, and resupply of systems in orbit.

Moore, W. F.↗
NASA NTRS1973

Extraterrestrial solar energy and its possible variations

Values of the solar constant and solar spectrum have been adopted as design standards for NASA space vehicles and as engineering standards by IES/ASTM. High resolution spectral data for the UV and visible range, normalized to these standards have been derived. Applications of these results for weather analysis, air pollution, ozone production, and atmospheric energy exchange are reviewed. Indications of possible variations in solar energy, total and spectral, and their influence on the earth-atmosphere system are examined. Programs for future studies of these variations from satellites and high-altitude aircraft are discussed.

Thekaekara, M. P.↗
NASA NTRS1974

Fast response vanes for sensing flow patterns in helicopter rotor environment

Wind tunnel experiments were conducted on four small-scale flow-direction vanes for the determination of aerodynamic response. The tests were further extended to include a standard sized low-inertia vane currently employed in aircraft flight testing. The four test vanes had different aspect ratios and were about 35 percent of the surface area of the standard vane. The test results indicate satisfactory damping and frequency response for all vanes tested and compare favorably with the standard design.

Barna, P. S.↗
NASA NTRS1980

Advanced Gas Turbine Powertrain System Development Project

A progress report on the Advanced Gas Turbine Powertrain System Development Project being performed under contract from NASA Lewis is presented. The goals and objectives of the project are described noting that funds from the DOE, Office of Transportation Programs are used to sponsor the project. Among the demonstration objectives are attaining a fuel economy of 42.5 miles per gallon in a 1985 Pontiac Phoenix, multifuel capability, and emission levels within the federal standards. Design objectives examined include competitive reliability and life as well as competitive initial and life cycle costs. Finally, it is stressed that high risk and key elements in this advanced powertrain project are the development of ceramic turbine engine components and the aerodynamic development of small size turbine components.

Helms, H. E.↗
NASA NTRS1980

FBI fingerprint identification automation study: AIDS 3 evaluation report. Volume 9: Functional requirements

The current system and subsystem used by the Identification Division are described. System constraints that dictate the system environment are discussed and boundaries within which solutions must be found are described. The functional requirements were related to the performance requirements. These performance requirements were then related to their applicable subsystems. The flow of data, documents, or other pieces of information from one subsystem to another or from the external world into the identification system is described. Requirements and design standards for a computer based system are presented.

Source record↗
NASA NTRS1983

Grounding and fault protection of the SMUD PVI array

If large terrestrial photovoltaic (PV) power plants are to provide an economic source of generation, low-cost, reliable and easily maintainable systems must be developed. In addition, if the system is to be a central station powerplant owned and operated by an electric utility, the design must also be consistent with utility specifications and design standards. The particular solutions developed to address these issues, with regard to grounding and fault protection, for the first phase of the Sacramento Municipal Utility District's (SMUD) 100 mw(ac) PV powerplant are presented. This plant, known as PV1, is nominally rated at 1 mw(ac) and is scheduled to be in operation by the spring of 1984.

Rosen, D.↗