Criteria

Text:
Sector:
Display:

Results

Viewing 1 to 30 of 746
1999-10-19
Technical Paper
1999-01-5659
R. Kruk, N. Link, L. Reid, S. Jennings
The Enhanced/Synthetic Vision System (E/SVS) is a Technology Demonstrator (TD) project supported by the Chief, Research and Development of the Canadian Department of National Defence. E/SVS displays an augmented visual scene to the pilot that includes three separate image sources: a synthetic computer - generated terrain image; an enhanced visual image from an electro-optical sensor (fused as an inset); and aircraft instrument symbology, all displayed to the pilot on a Helmet Mounted Display (HMD). The synthetic component of the system provides a 40 degree vertical by 80 degree horizontal image of terrain and local features. The enhanced component digitizes imagery from electro-optic sensors and fuses the sensor image as an inset (20 degrees by 25 degrees) within the synthetic image. Symbology can be overlaid in any location within the synthetic field-of-view and may be head, aircraft, target or terrain referenced.
2011-10-04
Technical Paper
2011-36-0256
Sérgio Roberto Ferreira Machado, Marcelo de Oliveira e Souza
Avionics Systems are increasingly used to perform safety-critical functions at high altitudes. But their increasing capacity and concentration of memory and logics leads to more frequent occurrences of single event upsets, especially in high altitudes. In this work we discuss the effects and mitigation of single event upsets on avionics systems to help in developing future requirements. To do that we initially present the concepts of radiation environment of the atmosphere, radiation induced errors, single event upsets, etc. Then, we discuss some of their effects on avionic systems and ways of mitigation. Finally, we discuss provisions to demand the adoption of such mitigation measures, and their sufficiency. This will help in developing future requirements to accomplish the objectives of a safe operation of civil transportation aircraft.
2004-11-16
Technical Paper
2004-01-3236
Sandro Aparecido Baldacim, Nivaldo Cristofani, Carlos do Nascimento Santos, José Rui Lautenschlager
Lightning is a high voltage and high current phenomenon and it originates by build up of electrical charge in the air or, more commonly, in clouds. It is constituted of an electric current peak of short duration (0,5 ms) and high intensity (200 kA), followed by a low intensity (400 A) but high duration (1s) periods. The lightning effects in aircraft can be divided in two groups: direct effects (physical effects such as melting, rupture, damage of surfaces and structures due to conduction of lightning current or high power magnetic force) and indirect effects (electromagnetic fields generating levels of transient voltage and current on interconnecting wiring and cable leads within the equipment circuits eventually damaging internal components).
2011-06-13
Technical Paper
2011-38-0041
Douglas Spangenberg, Patrick Minnis, William Smith, Fu-Lung Chang
Cloud properties retrieved from satellite data are used to diagnose aircraft icing threat in single layer and multilayered ice-over-liquid clouds. The algorithms are being applied in real time to the Geostationary Operational Environmental Satellite (GOES) data over the CONUS with multilayer data available over the eastern CONUS. METEOSAT data are also used to retrieve icing conditions over western Europe. The icing algorithm's methodology and validation are discussed along with future enhancements and plans. The icing risk product is available in image and digital formats on NASA Langley ‘s Cloud and Radiation Products web site, http://www-angler.larc.nasa.gov.
2012-10-02
Technical Paper
2012-36-0519
Sergio Roberto Ferreira Machado, Marcelo Lopes de Oliveira e Souza
Avionics Systems are increasingly used to perform safety-critical functions at high altitudes. But their increasing capacity and concentration of memory and logics leads to more frequent occurrences of single event upsets, especially in high altitudes. In this work we discuss the process of eliciting and validating requirements to handle single events upsets in avionic systems. To do that we initially summarize and update the concepts of radiation environment of the atmosphere, radiation induced errors, single event upsets, etc. presented in a previous paper. Then, we discuss some of their effects on avionic systems and ways of mitigation, reported in the literature. Finally, we discuss provisions to demand the adoption of such mitigation measures, and their sufficiency by transforming them into requirements, according to recommendations of compliance described in standards as SAE ARP 4754A and RTCA DO-254.
2012-10-22
Technical Paper
2012-01-2230
Yeong-Ren Lin, Yang Hu, Lei Zhou, David Woodburn, Thomas Wu, Louis C. Chow, Quinn Leland
In the aviation community, there is a high priority to develop all-electric aircraft. Electro-mechanical actuation systems would replace traditional, large, heavy and difficult-to-maintain hydraulic actuation systems. This movement from hydraulic actuation to electrical actuation enhances the flexibility to integrate redundancy and emergency system in future military aircraft. Elimination of the hydraulic fluid removes the possibility of leakage of corrosive hydraulic fluid and the associated fire hazard, as well as environmental concerns. The switch from hydraulic to electrical actuation provides additional benefits in reduced aircraft weight, improved survivability and improved maintainability. The heat load in an electro-mechanical actuation (EMA) is highly transient and localized in nature; therefore a phase change material could be embedded in the heat generating components to store peak heat load.
2012-10-22
Technical Paper
2012-01-2149
James Harrington
Many avionics and aircraft equipment manufacturers use DO-160 [Ref. 1] Section 22 to test their equipment for indirect effects of lightning without understanding why they are testing to specific values. Many aircraft manufacturers struggle with determining the level of indirect lightning that will be acceptable for their vehicle and what level of requirements they need to pass down to the avionics and aircraft equipment manufacturers. Organizations like SAE and RTCA, Inc. work to collect data on lightning and spend countless hours assimilating the information and developing documents to help engineers use the information. They struggle with knowing what data is pertinent and how it will be received and used by the engineering community.
2012-10-22
Technical Paper
2012-01-2133
Laurent Moss, Hubert Guerard, Gary Dare, Guy Bois
This paper presents an Electronic System-Level (ESL) methodology and framework for the system specification, design space exploration, performance analysis, and hardware/software implementation of aerospace electronic systems subject to Quality of Results (QoR) constraints such as execution time, communication rate, technology, as well as Size, Weight and Power (SWaP). In particular, we show how SWaP constraints could be converted into bounds on the target hardware platform, how several potential architectures could be devised for the system, how each potential architecture and mapping could be evaluated for performance, hardware resource usage and power taking into account the impact of Triple Modular Redundancy (TMR), and how a selected architecture could be exported as a hardware/software Register-Transfer Level (RTL) implementation.
2014-09-30
Technical Paper
2014-36-0306
Rafael Navarenho de Souza, Leonardo Navarenho de Souza Fino
Abstract This paper describes how new transistors layouts can mitigate failures Induced by atmospheric radiation, focusing on the total ionizing dose (TID) effects. By conducting an experimental comparative study of the TID effects between the Metal-Oxide-Semiconductor Field Effect Transistor (MOSFET) manufactured with new layouts proposals and the standard layout (Conventional), for devices exposed to 10 keV X-ray irradiation using a Shimadzu XRD-7000 equipment, this paper suggests a new approach of layouts to have a better performance in radiation environment with low cost impact, lower power consumption, more speed and they could keep robustness and reliability.
2014-09-30
Technical Paper
2014-36-0297
Leonardo Navarenho de Souza Fino, Rafael Navarenho de Souza
Abstract The detailed study of cosmic ray's influence is recent, as well as the invention of the transistor. Ionizing particles from space that focus on silicon integrated circuits (IC) can cause many undesirable effects. These particles are mainly from solar activity, and can be classified into two basic groups: charged particles, e.g, electrons, protons or heavy ions, and electromagnetic radiation (photons), as X-rays, Gamma -rays, or Ultraviolet (UV) light. When they collide in an IC, these energetic particles cause a current pulse, which can affect the correct functioning of the device. These electronic circuits have become increasingly susceptible to the effects of radiation, due to miniaturization, thus increasing the incidence of failures.
1955-01-01
Technical Paper
550295
George Grabowski
DEVELOPMENT of an explosion- and fire-suppression system is described here. The system consists of two components, a detector and a capsule, which are placed in the volume to be protected. The explosions encountered in aircraft fuel tanks can be started by either high- or low-energy ignition sources, necessitating a wide range of detection times. Therefore, three types of explosion detectors have been designed, two visual, and one pressure rate of rise. Each of these detectors has a particular advantage, making it possible to meet any requirement for a particular installation. When ignition occurs, the detector senses the explosion, causing an electric current to flow to the capsule. This sets off an explosive charge, which supplies the force to burst the capsule and disperse the suppressing agent. Of the many fire-extinguishing agents that have been studied, the new halogenated compounds have been found to present the most desirable characteristics.
1954-01-01
Technical Paper
540212
W. P. BUSH
1947-01-01
Technical Paper
470141
HARVEY L. HANSBERRY
1948-01-01
Technical Paper
480038
M. M. NEWMAN
Summary The modern all-metal transport airplane is in general inherently well protected from lightning damage. The metal surface of the airplane forms an inherent safe path for lightning currents around occupants and equipment in the interior. Certain external elements such as movable control surfaces, plastic sections, and outside antennas require protection against lightning. Therefore a thorough knowledge of the character of the lightning discharge and its various effects is of importance. This paper gives an introductory brief discussion of the nature of the lightning discharge phenomena and possible effects on aircraft.
1949-01-01
Technical Paper
490068
A. W. WUERKER
2007-07-09
Technical Paper
2007-01-3142
Michael S. Roberts, Mary E. Hummerick, Sharon L. Edney, Patricia A. Bisbee, Michael R. Callahan, Sandy Loucks,, Karen D. Pickering, John C. Sager
This work describes the microbiological assessment and materials compatibility of a silver-based biocide as an alternative to iodine for the Crew Exploration Vehicle (CEV) and future spacecraft potable water systems. In addition to physical and operational anti-microbial counter-measures, the prevention of microbial growth, biofilm formation, and microbiologically induced corrosion in water distribution and storage systems requires maintenance of a biologically-effective, residual biocide concentration in solution and on the wetted surfaces of the system. Because of the potential for biocide depletion in water distribution systems and the development of acquired biocide resistance within microbial populations, even sterile water with residual biocide may, over time, support the growth and/or proliferation of bacteria that pose a risk to crew health and environmental systems.
2009-07-12
Technical Paper
2009-01-2337
James R. Gaier
Activation of the surfaces of lunar regolith particles can occur through interactions with solar electromagnetic radiation, solar and galactic particle radiation and micrometeoroid bombardment. An attempt has been made to quantify the relative importance of each of those effects. The effects of these activated surfaces may be to enhance the adhesion and toxicity of the particles. Also key to the importance of activation is the lifetimes of activated states in various environments which is controlled by their passivation rate as well as their activation rate. Although techniques exist to characterize the extent of activation of particles in biological system, it is important to be able to quantify the activation state on the lunar surface, in ground-test vacuum systems, and in habitat atmospheres as well.
2009-07-12
Technical Paper
2009-01-2574
Sumitaka Tachikawa, Akira Ohnishi, Kan Matsumoto, Yasuyuki Nakamura, Akira Okamoto
The Smart Radiation Device (SRD) is a new type of thermal control material for spacecraft. By changing its emissivity without using electrical instruments or mechanical parts, the SRD decreases the temperature variation of the applied place. The SRD changes its emissivity physically depending on its temperature. The drawback of the SRD is its high solar absorptance. In order to reduce the solar absorptance while keeping its emissivity variation, the wide band filter was designed for the SRD. The function of the wide band filter is to reflect sunlight and to transmit infrared light. The SRD with the wide band filter is called as the Smart Radiation Device with Multi-layer films (SRDM) and the target value of its solar absorptance is 0.13.
2009-07-12
Technical Paper
2009-01-2575
Emile Haddad, Roman V. Kruzelecky, Brian Wong, Wes Jamroz, Mohamed Soltani, Moushab Benkahoul, Mohamed Chaker, Philippe Poinas
MPB has developed advanced technologies based on smart radiator thin-film tiles (SRTs) employing V1−x−yMxNyOn, for the passive dynamic thermal control of space structures and payloads. The SRT has passed successfully the major ground tests and validated its performance for extended use in the harsh space environment, with a target of up to 15 years GEO, in preparation for a flight demonstration of this technology This paper describes the optimization of MPB's smart radiator and its validation of an efficient thermal control with the tuneability of thermo-optical properties. The thermal control of satellites is a critical subsystem that impacts on the performance and longevity of space payloads. MPB has developed advanced smart radiator devices (SRDs) for passive, dynamic thermal control of space structures and payload. The SRDs employ a nano-engineered, thin-film structure based on V1−x−yMxNyOn. Dopants, M and N, tailor the transition temperature of the IR emittance.
2009-07-12
Technical Paper
2009-01-2470
David Zuniga, Steven D. Hornung, Jon P. Haas, John C. Graf
Fire detection, post fire atmospheric monitoring, fire extinguishing, and post fire atmospheric cleaning are vital components of a spacecraft fire response system, Preliminary efforts focused on the technology evaluation of fire detection, post fire atmospheric monitoring and post fire cleanup systems under realistic conditions are described in this paper. While the primary objective of testing is to determine the performance of a smoke mitigation filter, supplemental evaluations measuring the smoke-filled chamber handheld Commercial Off The Shelf (COTS) atmospheric monitoring devices (combustion product monitors) are conducted. The test chamber consists of a 1.4 cubic meter (50 cu. ft.) volume containing a smoke generator.
2009-11-10
Technical Paper
2009-01-3276
Clint Baggerman, Mary McCabe, Dinesh Verma
It has been 30 years since the National Aeronautics and Space Administration (NASA) last developed a crewed spacecraft capable of launch, on-orbit operations, and landing. During that time, aerospace avionics technologies have greatly advanced in capability, and these technologies have enabled integrated avionics architectures for aerospace applications. The inception of NASA's Orion Crew Exploration Vehicle (CEV) spacecraft offers the opportunity to leverage the latest integrated avionics technologies into crewed space vehicle architecture. The outstanding question is to what extent to implement these advances in avionics while still meeting the unique crewed spaceflight requirements for safety, reliability and maintainability. Historically, aircraft and spacecraft have very similar avionics requirements. Both aircraft and spacecraft must have high reliability.
2009-11-10
Technical Paper
2009-01-3275
Roscoe C. Ferguson, Zulema Olivas
The purpose of the Space Shuttle Cockpit Avionics Upgrade project (1999 – 2004) was to reduce crew workload and improve situational awareness. The upgrade was to augment the Shuttle avionics system with new hardware and software. A major success of this project was the validation of the hardware architecture and software design. This was significant because the project incorporated new technology and approaches for the development of human rated space software. An early version of this system was tested at the Johnson Space Center for one month by teams of astronauts. The results were positive, but NASA eventually cancelled the project towards the end of the development cycle. The goal to reduce crew workload and improve situational awareness resulted in the need for high performance Central Processing Units (CPUs). The choice of CPU selected was the PowerPC family, which is a reduced instruction set computer (RISC) known for its high performance.
2009-07-12
Technical Paper
2009-01-2469
Gary W. Hunter, Paul S. Green berg, Jennifer C. Xu, Benjamin Ward, Darby Makel, Prabir Dutta, Chung-Chiun Liu
A fire in spacecraft or habitat supporting NASA's Exploration mission could jeopardize the system, mission, and/or crew. Given adequate measures for fire prevention, the hazard from a fire can be significantly reduced if fire detection is rapid and occurs in the early stages of fire development. The simultaneous detection of both particulate and gaseous products has been proven to rapidly detect fires and accurately distinguish between real fires and nuisance sources. This paper describes the development status of gaseous and particulate sensor elements, integrated sensor systems, and system testing. It is concluded that while development is still necessary, the fundamental approach of smart, miniaturized, multisensor technology has the potential to significantly improve the safety of NASA space exploration systems.
2009-07-12
Technical Paper
2009-01-2543
A. V. Shevade, M. A. Ryan, M. L. Homer, A. K. Kisor, K. S. Manatt, L. M. Lara
Simultaneous measurements were made for particle releases and off-gassing products produced by heating electrical wires. The wire samples in these experiments were heated to selected temperatures in a heating chamber and responses to vapor releases were recorded by the JPL Electronic Nose (ENose) and an Industrial Scientific ITX gas-monitor; particles released were detected by a TSI P-Trak particle counter. The temperature range considered for the experiment is room temperature (24−26°C) to 500 °C. The results were analyzed by overlapping responses from the ENose, ITX gas sensors and P-Trak, to understand the events (particle release/off-gassing) and sequence of events as a function of temperature and to determine qualitatively whether ENose may be used to detect pre-combustion event markers.
2009-07-12
Technical Paper
2009-01-2542
Brian M. Sutin, William Niu, George Steiner, William O'Hara, John F. Lewis
The Orion Crew Exploration Vehicle (CEV) requires a smoke detector for the detection of particulate smoke products as part of the Fire Detection and Suppression (FDS) system. The smoke detector described in this paper is an adaptation of a mature commercial aircraft design for manned spaceflight. Changes made to the original design include upgrading the materials and electronics to space-qualified components, and modifying the mechanical design to withstand launch and landing loads. The results of laboratory characterization of the response of the new design to test particles are presented.
2009-07-12
Technical Paper
2009-01-2510
James R. Butz, Angel Abbud-Madrid
ADA Technologies, Inc. has designed and built a microgravity-tolerant portable fire extinguisher prototype for use in manned spacecraft and planetary habitats. This device employs Fine Water Mist (FWM) as the fire extinguishing agent, and is refillable from standard stores on long-duration missions. The design uses a single storage tank for minimal mass and volume. The prototype employs a dual-fluid atomizer concept where the pressurant gas (nitrogen) also enhances the water atomization process to generate a droplet size distribution in the optimum diameter range of 10 to 50 micrometers. The expanding discharge gas plume carries the mist to the immediate vicinity of the fire where its extensive surface area promotes high heat transfer rates. A series of 80 fire suppression tests was recently completed to evaluate design options for the hardware and validate performance on three representative fire scenarios.
2008-06-29
Technical Paper
2008-01-2152
Sumitaka Tachikawa, Akira Ohnishi, Yasuyuki Nakamura, Akira Okamoto
The Smart Radiation Device (SRD) is a new thermal control material that decreases the temperature variation by changing the emissivity without using electrical instruments or mechanical parts. The emissivity of the SRD changes physically depending on its temperatures. Bonded only to the external surface of the spacecrafts, the SRD controls the temperature. The drawback of the SRD is the high solar absorptance. The multi-layer film for SRD was designed in order to decrease the solar absorptance from 0.81 to less than 0.2 by putting multi-layer film on it and the optical performance of the Smart Radiation Device with Multi-layer film (SRDM) was evaluated.
2008-06-29
Technical Paper
2008-01-2136
David E. Williams
The International Space Station (ISS) Node 1 Environmental Control and Life Support (ECLS) System is comprised of five subsystems: Atmosphere Control and Supply (ACS), Atmosphere Revitalization (AR), Fire Detection and Suppression (FDS), Temperature and Humidity Control (THC), and Water Recovery and Management (WRM). This paper provides a summary of the Node 1 Emergency Response capability, which includes nominal and off-nominal FDS operation, off-nominal ACS operation, and off-nominal THC operation. These subsystems provide the capability to help aid the crew members during an emergency cabin depressurization, a toxic spill, or a fire. The paper will also provide a discussion of the detailed Node 1 ECLS Element Verification methodologies for operation of the Node 1 Emergency Response hardware utilized during the Node 1 Element Qualification phase.
2005-07-11
Technical Paper
2005-01-2831
G. De Angelis, F. F. Badavi, J. M. Clem, S. R. Blattnig, M. S. Clowdsley, J. E. Nealy, R. K. Tripathi, J. W. Wilson
In view of manned missions targeted to the Moon, for which radiation exposure is one of the greatest challenges to be tackled, it is of fundamental importance to have available a tool, which allows determination of the particle flux and spectra at any time and at any point of the lunar surface. With this goal in mind, a new model of the Moon’s radiation environment due to Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) has been developed. Primary particles reach the lunar surface, and are transported all throughout the subsurface layers, with backscattering patterns taken into account. The surface itself has been modeled as regolith and bedrock, with composition taken from the results of the instruments flown on the Apollo missions, namely on the Apollo 12 from the Oceanus Procellarum landing site. Subsurface environments like lava tubes have been considered in the analysis.
2005-07-11
Technical Paper
2005-01-2925
Lester A. Wilson, Stephen J. French, Michele Perchonok
Soybeans were chosen for lunar and planetary missions, where soybeans will be supplied in bulk or grown locally, due to their nutritive value and ability to produce oil and protein for further food applications. However, soybeans must be processed into foods prior to consumption. Wilson et al. (2003) raised questions about the influence of radiation (on germination and functional properties) that the soybeans would be exposed to during bulk storage prior to and during a Mars mission. The influence of radiation can be broken down into two components: the affect of surface pasteurization to ensure the astronauts safety from food-borne illnesses (HACCP, CCP), and the affect of the amount of radiation the soybeans receive during a Mars mission. Decreases in the amount of natural antioxidants, free radical formation, and oxidation-induced changes in the soybean will influence the nutritional value, texture, and quality of soyfoods.
Viewing 1 to 30 of 746

Filter

  • Range:
    to:
  • Year: