653 results on '"Aerospace"'
Search Results
2. X-ray backscatter sensing of defects in carbon fibre composite materials
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Nicholas Fox, Daniel O’Flynn, Chiaki Crews, Mark Sammons, Brian P. Allen, and Robert D. Speller
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Materials science ,Structural material ,Backscatter ,business.industry ,Nondestructive testing ,Acoustics ,Coupling (piping) ,Composite material ,Radiation ,business ,Aerospace ,Signal ,Beam (structure) - Abstract
X-ray backscatter (XBS) provides a novel approach to the field of non-destructive evaluation (NDE) in the aerospace industry. XBS is conducted by collecting the radiation which is scattered from a sample illuminated by a well-defined Xray beam, and the technique enables objects to be scanned at a sub-surface level using single-sided access, and without the requirement for coupling with the sample. Single-sided access is of particular importance when the objects of interest are very large, such as aircraft components. Carbon fibre composite materials are being increasingly used as a structural material in aircraft, and there is an increasing demand for techniques which are sensitive to the delaminations which occur in these composites as a result of both large impacts and barely visible impact damage (BVID). The XBS signal is greatly enhanced for plastics and lightweight materials, making it an ideal candidate for probing sub-surface damage and defects in carbon fibre composites. Here we present both computer modelling and experimental data which demonstrate the capability of the XBS technique for identifying hidden defects in carbon fibre.
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- 2017
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3. Consideration of materials for creating 3D printed space sensors and systems
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Jeremy Straub and Jacob Reimers
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Flexibility (engineering) ,3d printed ,business.industry ,Computer science ,Systems engineering ,Volume (computing) ,Orbit (dynamics) ,3D printing ,Space (commercial competition) ,Aerospace ,business - Abstract
Three-dimensional printing (also known as additive manufacturing) in space is a practical solution to reducing the mass and volume required for bringing materials into orbit and beyond. Materials can be launched in their raw form and transformed into the requisite parts and structures, as needed. This provides flexibility, allows structures to be designed to only support microgravity and allows sensing systems to be configured (and reconfigured) based on needs identified during the mission. This paper presents work undertaken to identify materials that are well-suited to in-space 3D printing. Materials commonly used for aerospace hardware were examined to assess their suitability.
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- 2017
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4. War-gaming application for future space systems acquisition: MATLAB implementation of war-gaming acquisition models and simulation results
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Hien T. Tran, Amanda Coons, Heather Barcomb, Paul Vienhage, William A. Black, Justin R. Kizer, Karel Marshall, Andy T. Guillen, Tien M. Nguyen, Blake A. Rogers, and James Yoh
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business.industry ,Computer science ,02 engineering and technology ,Space (commercial competition) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Corporation ,Computational science ,010309 optics ,0103 physical sciences ,Technical report ,Systems engineering ,0210 nano-technology ,Baseline (configuration management) ,Aerospace ,business ,MATLAB ,computer ,computer.programming_language - Abstract
The paper describes the MATLAB (MathWorks) programs that were developed during the REU workshop 1 to implement The Aerospace Corporation developed Unified Game-based Acquisition Framework and Advanced Game - based Mathematical Framework (UGAF-AGMF) and its associated War-Gaming Engine (WGE) models. Each game can be played from the perspectives of the Department of Defense Acquisition Authority (DAA) or of an individual contractor (KTR). The programs also implement Aerospace’s optimum “Program and Technical Baseline (PTB) and associated acquisition” strategy that combines low Total Ownership Cost (TOC) with innovative designs while still meeting warfighter needs. The paper also describes the Bayesian Acquisition War-Gaming approach using Monte Carlo simulations, a numerical analysis technique to account for uncertainty in decision making, which simulate the PTB development and acquisition processes and will detail the procedure of the implementation and the interactions between the games.
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- 2017
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5. Ricor's Nanostar water vapor compact cryopump: applications and model overview
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Rodney S. Harris, Tomer Tauber, Eli Aminov, Ilan Nachman, Boris Barak, Michael Kootzenko, and Dan Gover
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0301 basic medicine ,Materials science ,business.industry ,Nuclear engineering ,Evaporation ,Cryopump ,Sputter deposition ,03 medical and health sciences ,030104 developmental biology ,Getter ,Stirling cycle ,Aerospace ,business ,Gas compressor ,Water vapor - Abstract
Ricor Systems has developed a compact, single stage cryopump that fills the gap where GM and other type cryopumps can't fit in. Stirling cycle technology is highly efficient and is the primary cryogenic technology for use in IR, SWIR, HOT FPA, and other IR detector technology in military, security, and aerospace applications. Current GM based dual stage cryopumps have been the legacy type water vapor pumping system for more than 50 years. However, the typically large cryopanel head, compressor footprint, and power requirements make them not cost and use effective for small, tabletop evaporation / sputtering systems, portable analysis systems, and other systems requiring small volume vacuum creation from medium, high, and UHV levels. This single stage cryopump works well in-line with diffusion and molecular turbopumps. Studies have shown effective cooperation with non-evaporable getter technology as well for UHV levels. Further testing in this area are ongoing. Temperatures created by Stirling cycle cryogenic coolers develop a useful temperature range of 40 to 150K. Temperatures of approximately 100 K are sufficient to condense water and all hydrocarbons oil vapors.
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- 2017
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6. Optical frequency domain reflectometry for aerospace applications
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Osgar John Ohanian, Emily H. Templeton, Matthew A. Davis, Dan Kominski, James W. Jeans, Naman Garg, J. R. Pedrazzani, Stephen T. Kreger, Matthew A. Castellucci, Nur Aida Abdul Rahim, and Noah Beaty
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Engineering ,Data acquisition ,business.industry ,Fiber optic sensor ,Data management ,Electronic engineering ,Synchronizing ,Structural health monitoring ,business ,Reflectometry ,Aerospace ,Domain (software engineering) - Abstract
Optical Frequency Domain Reflectometry (OFDR) is the basis of an emerging high-definition distributed fiber optic sensing (HD-FOS) technique that provides an unprecedented combination of resolution and sensitivity. We examine aerospace applications that benefit from HD-FOS, such as for defect detection, FEA model verification, and structural health monitoring. We describe how HD-FOS is used in applications spanning the full design chain, review progress with sensor response calibration and certification, and examine the challenges of data management through the use of event triggering, synchronizing data acquisition with control signals, and integrating the data output with established industry protocols and acquisition systems.
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- 2017
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7. Optical fiber sensor-based life cycling monitoring and quality assessment of carbon fiber reinforced polymer matrix composite structures
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S. Minakuchi and N. Takeda
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010302 applied physics ,Carbon fiber reinforced polymer ,Optical fiber ,Materials science ,business.industry ,Composite number ,Process (computing) ,Mechanical engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Temperature measurement ,law.invention ,law ,Fiber optic sensor ,0103 physical sciences ,0210 nano-technology ,Aerospace ,business ,Shrinkage - Abstract
Optical fiber sensors are very useful to monitor the internal strain and temperature in composites during manufacturing and assembly as well as in practical operations. The authors have been using both multi-point and distributed strain monitoring techniques to characterize the internal state of composite structures. This paper reports some recent developments of life cycle monitoring and quality control of aerospace composite structures. Specifically, distributed sensing for large-scaled parts, through-thickness strain monitoring for complex-shaped parts, and direction-dependent cure shrinkage monitoring are described, highlighting wide applicability of embedded optical fiber sensors for intelligent process monitoring and quality assessment of composite parts.
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- 2017
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8. Investigation of LEO environment exposure monitoring potential using embedded FBG sensors
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Chun-Gon Kim, Hyunseok Kwon, Yurim Park, and Pratik Shrestha
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Fiber gratings ,Damage detection ,business.industry ,Computer science ,Delamination ,02 engineering and technology ,021001 nanoscience & nanotechnology ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Low earth orbit ,Fiber Bragg grating ,Electronic engineering ,Structural health monitoring ,0210 nano-technology ,Aerospace ,business ,Reliability (statistics) - Abstract
Composite materials provide many advantages over conventional materials including metals, especially for space applications. However, composites have failure modes that are complex and difficult to identify, and various cracks and delamination are predominantly difficult to detect visually. In this regard, an effective method of monitoring the integrity of composite materials and structures exposed to hazardous space environments is necessary to ensure the long-term reliability of composite materials in aerospace applications. FBG sensors are advantageous for space applications due to their immunity to various environments. In this study, FBG sensors were used to investigate LEO environment exposure monitoring of CFRP.
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- 2017
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9. Development of an ultrasonic nondestructive inspection method for impact damage detection in composite aircraft structures
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Hyonny Kim, Margherita Capriotti, Hyunjung Kim, and F. Lanza di Scalea
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Damage detection ,Computer science ,business.industry ,Acoustics ,Composite number ,02 engineering and technology ,Penetration (firestop) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Shear (sheet metal) ,Transducer ,Nondestructive testing ,0103 physical sciences ,Outlier ,Ultrasonic sensor ,0210 nano-technology ,Aerospace ,business ,010301 acoustics - Abstract
High Energy Wide Area Blunt Impact (HEWABI) due to ground service equipment can often occur in aircraft structures causing major damages. These Wide Area Impact Damages (WAID) can affect the internal components of the structure, hence are usually not visible nor detectable by typical one-sided NDE techniques and can easily compromise the structural safety of the aircraft. In this study, the development of an NDI method is presented together with its application to impacted aircraft frames. The HEWABI from a typical ground service scenario has been previously tested and the desired type of damages have been generated, so that the aircraft panels could become representative study cases. The need of the aircraft industry for a rapid, ramp-friendly system to detect such WAID is here approached with guided ultrasonic waves (GUW) and a scanning tool that accesses the whole structure from the exterior side only. The wide coverage of the specimen provided by GUW has been coupled to a differential detection approach and is aided by an outlier statistical analysis to be able to inspect and detect faults in the challenging composite material and complex structure. The results will be presented and discussed with respect to the detection capability of the system and its response to the different damage types. Receiving Operating Characteristics curves (ROC) are also produced to quantify and assess the performance of the proposed method. Ongoing work is currently aimed at the penetration of the inner components of the structure, such as shear ties and C-frames, exploiting different frequency ranges and signal processing techniques. From the hardware and tool development side, different transducers and coupling methods, such as air-coupled transducers, are under investigation together with the design of a more suitable scanning technique.
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- 2017
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10. Fiber gratings strain sensor systems for composites and adhesive joints
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Ingrid Udd Scheel and Eric Udd
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PHOSFOS ,Optical fiber ,Materials science ,business.industry ,Acoustics ,Physics::Optics ,Sense (electronics) ,Electromagnetic interference ,law.invention ,Vibration ,Fiber Bragg grating ,law ,Fiber optic sensor ,Aerospace ,business - Abstract
Fiber Bragg grating (FBG) and other fiber optic based sensors have been used to sense environmental parameters for numerous applications including aerospace, oil and gas, civil structure health monitoring, mining, and medical. There are many benefits to using fiber optic based sensors over traditional electrical sensing methods. These advantages include: immunity to electromagnetic interference, high bandwidth, low loss, small, lightweight, and portability. New developments allow these physical measurements such as strain, temperature, pressure, vibration, and acoustics to be made at extremely fast speeds extending the capability of fiber optic sensor systems to monitor impacts and other rapid events.
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- 2017
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11. Shape sensing of inflatable aerospace structures with fiber optic curvature rosettes
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Justin Bond and Dryver R. Huston
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Surface (mathematics) ,0209 industrial biotechnology ,Riemann curvature tensor ,Optical fiber ,Materials science ,business.industry ,Physics::Optics ,02 engineering and technology ,Curvature ,law.invention ,Rosette (zoology) ,symbols.namesake ,020210 optoelectronics & photonics ,020901 industrial engineering & automation ,Inflatable ,Optics ,Fiber Bragg grating ,law ,0202 electrical engineering, electronic engineering, information engineering ,symbols ,Aerospace ,business - Abstract
The use of inflatable structures in aerospace applications is becoming increasingly widespread. Monitoring the inflation status and overall health of these inflatables requires an accurate means of shape sensing. This work reports on the application of local curvature sensing to establish global shape. The technique uses surface-attached Fiber Bragg Grating (FBG) curvature sensing rosettes consisting of three curvature-sensing FBG pairs. Presented will be methods of extracting values for the curvature tensor using the curvature-sensing rosette, along with experimental verification. By using such rosettes on an inflatable surface, the geometry of the inflatable can be monitored in real time.
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- 2017
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12. Impact resistant smart hybrid laminates
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Francesco Rizzo, Fulvio Pinto, and Michele Meo
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Absorption (acoustics) ,Materials science ,business.industry ,Automotive industry ,Mechanical engineering ,02 engineering and technology ,Shape-memory alloy ,021001 nanoscience & nanotechnology ,Smart material ,Specific strength ,Microcontroller ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Hybrid system ,0210 nano-technology ,Aerospace ,business - Abstract
The large diffusion of structural parts made of carbon fibres reinforced polymers (CFRP) in the aerospace and automotive sectors has highlighted the importance of developing hybrid multifunctional materials characterised by improved mechanical properties and coupled with non-structural features. Indeed, while due to their high specific strength and light weight, composite systems are characterised by very high mechanical properties in the in-plane direction, their intrinsic layered structure makes them very susceptible to low-velocity impacts resulting in Barely Visible Impact Damage (BVID) that can lead to the critical failure of primarily structures. Based on these premises, the development of a multifunctional hybrid system can overcome this drawback by tackling this issue from two different points of view, enhancing the total reliability of light-weight composite parts in order to improve fuel efficiency and optimise the footprint of new generation aero-structures. Indeed, by including an additional metallic phase within the structure of a traditional laminate it is possible to develop a smart multifunctional system in which the hybrid phase acts simultaneously as a reinforcement to enhance the out-of-plane properties of the material and as an intelligent embedded sensor system able to communicate information about the health status of the part and detect impact events or critical loads. This work is focused on the design, manufacturing and testing of a hybrid CFRP (H-CFRP) in which the hybridisation is obtained by including an array of Shape Memory Alloys (SMA) or Copper wires within the laminate. The electrical properties of the hybrid network is exploited to design a smart sensing system which can be interrogated to monitor the load distribution on the part and detect critical solicitations in critical points. The low-power system, controlled by an Arduino microcontroller, is able to monitor the integrity status of the part using each wire as a linear probe to scan complex structures at a certain frequency, measuring the local change in the electrical resistance from which it is possible to build a map of the stress distribution. The position of the metallic network along the laminate’s thickness was determined by analysing the response of different configurations of hybrid samples subjected to Low Velocity Impacts (LVI) in order to optimise the design of the H-CFRP and enhance the energy absorption. Using the same Arduinocontrolled Multiplex the smart wires array was exploited as heat source to scan the sample inner structure and monitoring the variation of the superficial apparent thermal variation with an Infra-Red (IR) Camera, a simulated delaminated area was detected.
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- 2017
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13. Online terahertz thickness measurement in films and coatings
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Irl N. Duling and Jeffrey S. White
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Terahertz radiation ,business.industry ,Computer science ,Bandwidth (signal processing) ,Optical power ,Laser ,law.invention ,Wavelength ,Optical coating ,law ,Electronic engineering ,Optoelectronics ,Process control ,Waveform ,Physical design ,business ,Aerospace - Abstract
Pulsed terahertz systems are currently being deployed for online process control and quality control of multi-layered products for use in the building products and aerospace industries. While many laboratory applications of terahertz can allow waveforms to be acquired at rates of 1 – 40 Hz, online applications require measurement rates of in excess of 100Hz. The existing technologies of thickness measurement (nuclear, x-ray, or laser gauges) have rates between 100 and 1000 Hz. At these rates, the single waveform bandwidth must still remain at 2THz or above to allow thinner layers to be measured. In the applications where terahertz can provide unique capability (e.g. multi-layer thickness, delamination, density) long-term stability must be guaranteed within the tolerance required by the measurement. This can mean multi-day stability of less than a micron. The software that runs on these systems must be flexible enough to allow multiple product configurations, while maintaining the simplicity required by plant operators. The final requirement is to have systems that can withstand the environmental conditions of the measurement. This might mean qualification in explosive environments, or operation in hot, wet or dusty environments. All of these requirements can put restrictions on not only the voltage of electronic circuitry used, but also the wavelength and optical power used for the transmitter and receiver. The application of terahertz systems to online process control presents unique challenges that not only effect the physical design of the system, but can also effect the choices made on the terahertz technology itself.
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- 2017
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14. Computer fluid dynamics (CFD) study of a micro annular gear pump
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Liviu-Constantin Stan and Ioan Calimanescu
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Engineering ,Process (engineering) ,business.industry ,Design tool ,Fluid dynamics ,Mechanical engineering ,Instrumentation (computer programming) ,Gear pump ,Computational fluid dynamics ,Micro technology ,business ,Aerospace - Abstract
Micro technology makes it possible to design products simply, efficiently and sustainably and at the same time, opens up the creation of new functionalities. The field of application of the micro annular gear pumps lies in analytical instrumentation, mechanical and plant engineering, chemical and pharmaceutical process engineering as well as in new markets like fuel cells or biotechnology, organic electronics or aerospace. The purpose of this paper is to investigate by using the powerful ANSYS 16 CFX module the hydrodynamic behavior of an 8/9 teeth annular gear pump. The solving of solids evolving inside fluids was very cumbersome until the advent of the Ansys immersed solid technology. By deploying this technology for very special topics like the CFD analysis of Micro annular gear pumps, credible and reliable results may be pulled leading thus the way for more in depth studies like geometrical a functional optimization of the existing devices. This paper is a valuable guide for the professionals working in the design field of micro pumps handing them a new and powerful design tool.
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- 2016
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15. Dimensional measurement of micro parts with high aspect ratio in HIT-UOI
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Shiyuan Zhao, Kunpeng Feng, Jiubin Tan, Junying Li, Hong Dang, Haoran Zhang, and Jiwen Cui
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Coupling ,Materials science ,Optical fiber ,business.industry ,Physics::Optics ,Collimated light ,Field (computer science) ,law.invention ,Optics ,Fiber Bragg grating ,law ,Dimensional metrology ,Electronic engineering ,Focus (optics) ,Aerospace ,business - Abstract
Micro parts with high aspect ratios have been widely used in different fields including aerospace and defense industries, while the dimensional measurement of these micro parts becomes a challenge in the field of precision measurement and instrument. To deal with this contradiction, several probes for the micro parts precision measurement have been proposed by researchers in Center of Ultra-precision Optoelectronic Instrument (UOI), Harbin Institute of Technology (HIT). In this paper, optical fiber probes with structures of spherical coupling(SC) with double optical fibers, micro focal-length collimation (MFL-collimation) and fiber Bragg grating (FBG) are described in detail. After introducing the sensing principles, both advantages and disadvantages of these probes are analyzed respectively. In order to improve the performances of these probes, several approaches are proposed. A two-dimensional orthogonal path arrangement is propounded to enhance the dimensional measurement ability of MFL-collimation probes, while a high resolution and response speed interrogation method based on differential method is used to improve the accuracy and dynamic characteristics of the FBG probes. The experiments for these special structural fiber probes are given with a focus on the characteristics of these probes, and engineering applications will also be presented to prove the availability of them. In order to improve the accuracy and the instantaneity of the engineering applications, several techniques are used in probe integration. The effectiveness of these fiber probes were therefore verified through both the analysis and experiments.
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- 2016
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16. A toolbox of metrology-based techniques for optical system alignment
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Raymond G. Ohl, John G. Hagopian, William L. Eichhorn, Kevin Redman, David A. Kubalak, Jerrod Young, Peter Blake, Joseph E. Hayden, Brent J. Bos, Kyle F. Mclean, Theodore Hadjimichael, Jeffrey S. Gum, Victor J. Chambers, Henry P. Sampler, Greg Wenzel, Joseph McMann, Phillip Coulter, and Samuel E. Hetherington
- Subjects
Optical alignment ,Spacecraft ,business.industry ,Computer science ,Optical instrument ,James Webb Space Telescope ,Astrophysics::Instrumentation and Methods for Astrophysics ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Toolbox ,law.invention ,Metrology ,010309 optics ,law ,0103 physical sciences ,Systems engineering ,0210 nano-technology ,business ,Aerospace ,Simulation - Abstract
The NASA Goddard Space Flight Center (GSFC) and its partners have broad experience in the alignment of flight optical instruments and spacecraft structures. Over decades, GSFC developed alignment capabilities and techniques for a variety of optical and aerospace applications. In this paper, we provide an overview of a subset of the capabilities and techniques used on several recent projects in a toolbox format. We discuss a range of applications, from small-scale optical alignment of sensors to mirror and bench examples that make use of various large-volume metrology techniques. We also discuss instruments and analytical tools.
- Published
- 2016
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17. Current status of the dual-frequency precipitation radar on the global precipitation measurement core spacecraft and the new version of GPM standard products
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Tomomi Nio, Toshio Iguchi, Kinji Furukawa, Riko Oki, Toshiyuki Konishi, Takeshi Masaki, and Takuji Kubota
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Spacecraft ,Meteorology ,business.industry ,Orbital mechanics ,Ku band ,law.invention ,Geography ,Satellite bus ,law ,Satellite ,Radar ,Aerospace ,business ,Global Precipitation Measurement ,Remote sensing - Abstract
The Dual-frequency Precipitation Radar (DPR) on the Global Precipitation Measurement (GPM) core satellite was developed by Japan Aerospace Exploration Agency (JAXA) and National Institute of Information and Communications Technology (NICT). The objective of the GPM mission is to observe global precipitation more frequently and accurately. The GPM core satellite is a joint product of National Aeronautics and Space Administration (NASA), JAXA and NICT. NASA developed the satellite bus and the GPM Microwave Imager (GMI), and JAXA and NICT developed the DPR. The inclination of the GPM core satellite is 65 degrees, and the nominal flight altitude is 407 km. The non-sunsynchronous circular orbit is necessary for measuring the diurnal change of rainfall. The DPR consists of two radars, which are Ku-band precipitation radar (KuPR) and Ka-band precipitation radar (KaPR). GPM core observatory was successfully launched by H2A launch vehicle on Feb. 28, 2014. DPR keeps its performances on orbit after launch. DPR products were released to the public on Sep. 2, 2014. JAXA is continuing DPR trend monitoring, calibration and validation operations to confirm that DPR keeps its function and performance on orbit. JAXA have started to provide new version (Version 4) of GPM standard products on March 3, 2016. Various improvements of the DPR algorithm were implemented in the Version 4 product. Moreover, the latent heat product based on the Spectral Latent Heating (SLH) algorithm is available since Version 4 product. Current orbital operation status of the GPM/DPR and highlights of the Version 4 product are reported.
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- 2016
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18. Design and qualification of the interferometer for the GOSAT-2 spectrometer
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Henry Buijs, Michel Roux, Louis Moreau, Marc-André Soucy, and Yan Montembault
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Earth observation ,Interferometry ,Geography ,Spacecraft ,Spectrometer ,business.industry ,Greenhouse gas ,Astronomical interferometer ,Satellite ,business ,Aerospace ,Remote sensing - Abstract
GOSAT-2 is the successor of the Greenhouse gases Observing SATellite (GOSAT, "IBUKI") launched in 2009 by Japan Aerospace Exploration Agency (JAXA). GOSAT-2 will continue and enhance space borne measurements of greenhouse gases started by GOSAT and monitor the impacts of climate change and human activities on the carbon cycle. It will also contribute to climate science and climate change related policies. The GOSAT-2 spacecraft will carry two earth observation instruments: FTS-2, the second generation of the TANSO-FTS and CAI-2, a Cloud and Aerosol Imager. Mitsubishi Electric Corporation is the prime contractor of GOSAT-2. Harris is the subcontractor of the spectrometer. ABB, who successfully designed, manufactured, and delivered the interferometer for the TANSO-FTS instrument for GOSAT, is currently delivering the modulator for the FTS-2 instrument to Mitsubishi Electric Corporation. Built on the TANSO-FTS heritage, FTS-2 is a thermal and near infrared sensor for carbon observation based on a Fourier transform spectrometer featuring larger optical throughput than TANSO-FTS. This paper presents an overview of the design of the FTS-2 interferometer as well as key qualification and performance verification activities conducted on the interferometer flight model.
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- 2016
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19. Assembly aligning and measuring of a reflective telescope primary mirror
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Chia-Yen Chan, Ming-Ying Hsu, Chun-Chieh Lie, Ting-Ming Huang, Yu-Chuan Lin, and Kun-Huan Wu
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Materials science ,business.industry ,Reflecting telescope ,Mechanical engineering ,Shim (magnetism) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,010309 optics ,Primary mirror ,Optics ,Material selection ,Bonding strength ,0103 physical sciences ,0210 nano-technology ,business ,Neutral plane ,Aerospace ,GLUE - Abstract
Gluing technology has been widely used in aerospace, optical, electrical and mechanical and other related industries, and already has excellent bonding strength, mechanical properties and airtightness, gluing material selection and process which is a key issue. In this paper, we choice EC2216 glue to assemble a reflective telescope primary mirror. In this study, a lightweight aluminum mirror with a diameter of 566 mm with three stainless parts have been taken as the gluing and assembly benchmark. We control the thickness of the glue between 0.35 ± 0.15 mm by a 0.3 mm shim, and control stainless parts on the Neutral plane effectively at the same time, after the installation of bipod in the future, this assembly can ensure effective verification to avoid stress is transmitted to the mirror distortion caused by the optical system. This paper aims to provide assembly and aligning by coordinate measurement machine (CMM). In order to obtain more accurate optimization results, we trace parts and the measurement results of CMM.
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- 2016
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20. Landsat 9: status and plans
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Jeffrey A. Pedelty, Jeffrey G. Masek, Julia A. Barsi, Matthew Montanaro, Brian L. Markham, Philip W. Dabney, and Del T. Jenstrom
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010504 meteorology & atmospheric sciences ,Computer science ,business.industry ,Stray light ,0211 other engineering and technologies ,02 engineering and technology ,Orbital mechanics ,Aerospace ,business ,01 natural sciences ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Remote sensing - Abstract
The Landsat 9 mission, currently under development and proceeding towards a targeted launch in late 2020, will be very similar to the Landsat 8 mission, launched in 2013. Like Landsat 8, Landsat 9 is a joint effort between NASA and USGS with two sensors, the Operational Land Imager 2 (OLI-2), essentially a copy of the OLI on Landsat 8 and the Thermal Infrared Sensor 2 (TIRS-2), very similar to the TIRS on Landsat 8. The OLI-2, like OLI, provides 14-bit image data, though for Landsat 9, all 14 bits will be retained and transmitted to the ground. The focal plane modules to be used for OLI-2 were flight spares for OLI and are currently being retested by Ball Aerospace. Results indicate radiometric performance comparable to OLI. The TIRS was a class C instrument, with a 3-year design lifetime, and therefore had limited redundancy. TIRS-2 will be a class B instrument, with a 5-year design lifetime, like OLI (and OLI-2), necessitating design changes to increase redundancy. The stray light and Scene Select Mechanism (SSM) encoder problems observed on orbit with TIRS have also instigated a few design changes to TIRS-2. Stray light analysis and testing have indicated that additional baffles in the TIRS-2 optical system will suppress the out-of-field response. The SSM encoder problems have not been definitively traced to a route cause, though conductive anodic filament growth in the circuit boards is suspected. Improved designs for the encoder are being considered for TIRS-2. The spare Focal Plane Array (FPA) from TIRS is planned for use in TIRS-2; FPA spectral and radiometric performance testing is scheduled for September of this year at NASA's Goddard Space Flight Center.
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- 2016
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21. An overview of interferometric metrology and NDT techniques and applications for the aerospace industry
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Cédric Thizy, Fabian Languy, Marc Georges, and Jean-François Vandenrijt
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business.industry ,Infrared ,Computer science ,Holography ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Holographic interferometry ,01 natural sciences ,law.invention ,Metrology ,010309 optics ,Interferometry ,Shearography ,law ,Nondestructive testing ,0103 physical sciences ,Thermography ,Speckle imaging ,Aerospace engineering ,0210 nano-technology ,business ,Aerospace ,Digital holography ,Remote sensing - Abstract
We review some full-field interferometric techniques which have been successfully applied in different applications related to the aerospace industry. The first part of the paper concerns the long-wave infrared (LWIR) digital holographic interferometry which allows the measurement large displacements that occur when space structures undergo large temperature excursions. A second part of the paper concerns different developments in interferometric nondestructive testing (NDT) techniques intended to improve their usability in aerospace industrial environments. Among others, we discuss LWIR speckle interferometry for simultaneous deformation and temperature variation measurements and new post-processing techniques applied to shearography for an easier detection of flaws in composite structures.
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- 2016
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22. SALT tracker upgrade utilizing aerospace processes and procedures
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Grant Nelson, Anthony Koeslag, Chris Coetzee, Paul Rabe, Janus D. Brink, Ockert J. Strydom, Eben P. Wiid, Keith Browne, Vic Moore, Martin Wilkinson, Wouter Lochner, Jonathan Love, Raoul van den Berg, and Adelaide Malan
- Subjects
Telescope ,Upgrade ,Computer science ,business.industry ,law ,Payload ,Systems engineering ,Instrumentation (computer programming) ,Aerospace ,business ,Simulation ,law.invention - Abstract
The SALT Tracker was originally designed to carry a payload of approximately 1000 kg. The current loading exceeds 1300 kg and more instrumentation, for example, the Near-Infrared (NIR) arm of the Robert Stobie Spectrograph (RSS), is being designed for the telescope. In general, provision also had to be made to expand the envelope of the tracker payload carrying capacity for future growth as some of the systems on SALT are currently running with small safety margins. It was therefore decided to upgrade the SALT Tracker to be able to carry a payload of 1875 kg. Before the project "Kick-Off" it became evident that neither SALT nor SAAO had the required standard of formal processes and procedures to execute a project of this nature. The Project Management, Mechanical Design and Review processes and procedures were adopted from the Aerospace Industry and tailored for our application. After training the project team in the application of these processes/procedures and gaining their commitment, the Tracker Upgrade Project was "Kicked-Off" in early May 2013. The application of these aerospace-derived processes and procedures, as used during the Tracker Upgrade Project, were very successful as is shown in this paper where the authors also highlight some of the details of the implemented processes and procedures as well as specific challenges that needed to be met while executing a project of this nature and technical complexity.
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- 2016
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23. Status and path forward for the large ultraviolet/optical/infrared surveyor (LUVOIR) mission concept study
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Aki Roberge, Shawn Domagal-Goldman, Matthew R. Bolcar, A. Mandell, Erin C. Smith, Mario R. Perez, Norman Rioux, and Julie A. Crooke
- Subjects
Physics ,Operations research ,business.industry ,Process (engineering) ,Technical evaluation ,computer.file_format ,Surveyor ,01 natural sciences ,010309 optics ,0103 physical sciences ,Systems engineering ,Executable ,business ,Aerospace ,010303 astronomy & astrophysics ,computer ,PATH (variable) - Abstract
In preparation of the 2020 Astrophysics Decadal Survey, National Aeronautics and Space Administration (NASA) has commenced a process for the astronomical community to study several large mission concepts leveraging the lessons learned from past Decadal Surveys. This will enable the Decadal Survey committee to make more informed recommendations to NASA on its astrophysics science and mission priorities with respect to cost and risk. Four astrophysics large mission concepts were identified. Each of them had a Science and Technology Definition Teem (STDT) chartered to produce scientifically compelling, feasible, and executable design reference mission (DRM) concepts to present to the 2020 Decadal Survey. In addition, The Aerospace Corporation will perform an independent cost and technical evaluation (CATE) of each of these mission concept studies in advance of the 2020 Decadal Survey, by interacting with the STDTs to provide detailed technical details on certain areas for which “deep dives” are appropriate. This paper presents the status and path forward for one of the four large mission concepts, namely, the Large UltraViolet, Optical, InfraRed surveyor (LUVOIR).
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- 2016
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24. Front Matter: Volume 9804
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Tzu-Yang Yu, Andrew L. Gyekenyesi, H. Felix Wu, and Peter J. Shull
- Subjects
Engineering ,business.industry ,Advanced materials ,Aerospace ,business ,Civil infrastructure ,Construction engineering ,Characterization (materials science) - Published
- 2016
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25. Optimum selection of high performance mirror substrates for diamond finishing
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Lovell E. Comstock, Leonard Gerard Wamboldt, James Scott Sutherland, and Kenneth Smith Woodard
- Subjects
business.industry ,Computer science ,Mechanical engineering ,Diamond ,chemistry.chemical_element ,02 engineering and technology ,Substrate (printing) ,engineering.material ,01 natural sciences ,Blank ,010309 optics ,020210 optoelectronics & photonics ,chemistry ,0103 physical sciences ,0202 electrical engineering, electronic engineering, information engineering ,engineering ,Benchmark (computing) ,Beryllium ,Aerospace ,business ,Selection (genetic algorithm) ,Near net shape - Abstract
Due to advances in manufacturing processes, the substrate options for high performance diamond machined mirrors are expanding. Fewer compromises have to be made to achieve the needed weight, stiffness and finish while maintaining reasonable costs. In addition to the traditional mirror materials like aluminum and beryllium, there are some less common materials that can now be included in the trade space that fill the cost and performance continuum between wrought aluminum and beryllium mirrors. Aluminum and beryllium, respectively, had been the low cost/fair performance and very high cost/very high performance bounds for substrate selection. These additional substrates provide multiple near net shape blank options and processes, mostly within these bounds, that can be considered in a mirror cost versus performance trade analysis. This paper will include a summary of some advances in manufacturing processes that provide more substrate options for diamond machined mirrors with some sample performance analysis and data. This is merged with the traditional substrate options to illustrate the now larger mirror substrate trade space. Some benchmark structural analysis is provided to back up a generic mirror design trade study.
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- 2016
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26. Overview of Sumitomo coolers and Dewars for space use
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Shoji Tsunematsu, Takao Nakagawa, Kenichi Kikuchi, Kazuhisa Mitsuda, Kenichi Kanao, Toshiyuki Nishibori, Ryota Sato, Hiroshi Murakami, Yoichi Sato, Hiroyuki Sugita, Katsuhiro Narasaki, Kiyomi Ootsuka, Akinobu Okabayashi, and Masahide Murakami
- Subjects
010302 applied physics ,Engineering ,Stirling engine ,business.industry ,Single stage ,Space use ,Thermodynamics ,Cryocooler ,01 natural sciences ,law.invention ,law ,0103 physical sciences ,Aerospace engineering ,010306 general physics ,business ,Aerospace - Abstract
Sumitomo Heavy Industries, ltd. (SHI) has been developing cooler and Dewar technology for space application with Japan Aerospace Exploration Agency. SHI has four types of coolers to cover temperature range from 1.7K to 80K or more. Those are Single stage Stirling coolers for 80K, two-stage Stirling coolers for 20K, 4K-class cooler and 1K-class cooler. 4K and 1K class coolers consist of a Joule-Thomson cooler and a two-stage Stirling as a pre-cooler. SHI also provided Dewars. In this paper, SHI’s cooler and Dewar technology are described.
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- 2016
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27. Advances in in situ inspection of automated fiber placement systems
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Peter D. Juarez, Jeffrey P. Seebo, and K. Elliott Cramer
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Automated optical inspection ,Engineering drawing ,Materials science ,business.industry ,Fiber (computer science) ,Carbon fibers ,Process (computing) ,Mechanical engineering ,02 engineering and technology ,Substrate (printing) ,021001 nanoscience & nanotechnology ,020303 mechanical engineering & transports ,Through transmission ,0203 mechanical engineering ,visual_art ,Thermography ,visual_art.visual_art_medium ,0210 nano-technology ,Aerospace ,business - Abstract
Automated Fiber Placement (AFP) systems have been developed to help take advantage of the tailorability of composite structures in aerospace applications. AFP systems allow the repeatable placement of uncured, spool fed, preimpregnated carbon fiber tape (tows) onto substrates in desired thicknesses and orientations. This automated process can incur defects, such as overlapping tow lines, which can severely undermine the structural integrity of the part. Current defect detection and abatement methods are very labor intensive, and still mostly rely on human manual inspection. Proposed is a thermographic in situ inspection technique which monitors tow placement with an on board thermal camera using the preheated substrate as a through transmission heat source. An investigation of the concept is conducted, and preliminary laboratory results are presented. Also included will be a brief overview of other emerging technologies that tackle the same issue.
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- 2016
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28. Aerospace laser communications technology as enabler for worldwide quantum key distribution
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Tobias Vogl, Harald Weinfurter, Christopher Schmidt, Gwenaelle Mélen, Sebastian Nauerth, Florian Moll, Markus Michael Rau, and Christian Fuchs
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quantum key distribution ,Computer science ,business.industry ,CubeSat ,Satellitennetze ,Optical communication ,Electrical engineering ,02 engineering and technology ,Quantum channel ,Quantum key distribution ,021001 nanoscience & nanotechnology ,01 natural sciences ,010309 optics ,low earth orbit ,Satellite bus ,air-ground experiment ,0103 physical sciences ,Satellite ,0210 nano-technology ,business ,Aerospace ,Telecommunications ,Free-space optical communications ,Free-space optical communication - Abstract
A worldwide growing interest in fast and secure data communications pushes technology development along two lines. While fast communications can be realized using laser communications in fiber and free-space, inherently secure communications can be achieved using quantum key distribution (QKD). By combining both technologies in a single device, many synergies can be exploited, therefore reducing size, weight and power of future systems. In recent experiments we demonstrated quantum communications over large distances as well as between an aircraft and a ground station which proved the feasibility of QKD between moving partners. Satellites thus may be used as trusted nodes in combination with QKD receiver stations on ground, thereby enabling fast and secure communications on a global scale. We discuss the previous experiment with emphasis on necessary developments to be done and corresponding ongoing research work of German Aerospace Center (DLR) and Ludwig Maximilians University Munich (LMU). DLR is performing research on satellite and ground terminals for the high-rate laser communication component, which are enabling technologies for the QKD link. We describe the concept and hardware of three generations of OSIRIS (Optical High Speed Infrared Link System) laser communication terminals for low Earth orbiting satellites. The first type applies laser beam pointing solely based on classical satellite control, the second uses an optical feedback to the satellite bus and the third, currently being in design phase, comprises of a special coarse pointing assembly to control beam direction independent of satellite orientation. Ongoing work also targets optical terminals for CubeSats. A further increase of beam pointing accuracy can be achieved with a fine pointing assembly. Two ground stations will be available for future testing, an advanced stationary ground station and a transportable ground station. In parallel the LMU QKD source size will be reduced by more than an order of magnitude thereby simplifying its integration into future free-space optical communication links with CubeSats. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
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- 2016
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29. Comparison and analysis of two modern methods in the structural health monitoring techniques in aerospace
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Alireza Ahmadi and Mohammad Riahi
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Engineering ,business.industry ,Principal (computer security) ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Field (computer science) ,Manufacturing engineering ,010309 optics ,Range (aeronautics) ,Nondestructive testing ,0103 physical sciences ,Sustainability ,Structural health monitoring ,0210 nano-technology ,business ,Aerospace ,Reliability (statistics) - Abstract
Role of air transport in the development and expansion of world trade leading to economic growth of different countries is undeniable. Continuing the world’s trade sustainability without expansion of aerospace is next to impossible. Based on enormous expenses for design, manufacturing and maintenance of different aerospace structures, correct and timely diagnosis of defects in those structures to provide for maximum safety has the highest importance. Amid all this, manufacturers of commercial and even military aircrafts are after production of less expensive, lighter, higher fuel economy and nonetheless, higher safety. As such, two events has prevailed in the aerospace industries: (1) Utilization of composites for the fuselage as well as other airplane parts, (2) using modern manufacturing methods. Arrival of two these points have created the need for upgrading of the present systems as well as innovating newer methods in diagnosing and detection of defects in aerospace structures. Despite applicability of nondestructive testing (NDT) methods in aerospace for decades, due to some limitations in the defect detection’s certainty, particularly for composite material and complex geometries, shadow of doubt has fallen on maintaining complete confidence in using NDT. These days, two principal approach are ahead to tackle the above mentioned problems. First, approach for the short range is the creative and combinational mean to increase the reliability of NDT and for the long run, innovation of new methods on the basis of structural health monitoring (SHM) is in order. This has led to new philosophy in the maintenance area and in some instances; field of design has also been affected by it.
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- 2016
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30. A self-diagnostic adhesive for monitoring bonded joints in aerospace structures
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Yitao Zhuang, Yu-Hung Li, Fu-Kuo Chang, and Fotis Kopsaftopoulos
- Subjects
Fabrication ,Piezoelectric sensor ,business.industry ,Computer science ,Interface (computing) ,010401 analytical chemistry ,Mechanical engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Piezoelectricity ,0104 chemical sciences ,visual_art ,Nondestructive testing ,visual_art.visual_art_medium ,Adhesive ,Ceramic ,Structural health monitoring ,0210 nano-technology ,business ,Aerospace - Abstract
Bondline integrity is still one of the most critical concerns in the design of aircraft structures up to date. Due to the lack of confidence on the integrity of the bondline both during fabrication and service, the industry standards and regulations still require assembling the composite using conventional fasteners. Furthermore, current state-of-the-art non-destructive evaluation (NDE) and structural health monitoring (SHM) techniques are incapable of offering mature solutions on the issue of bondline integrity monitoring. Therefore, the objective of this work is the development of an intelligent adhesive film with integrated micro-sensors for monitoring the integrity of the bondline interface. The proposed method makes use of an electromechanical-impedance (EMI) based method, which is a rapidly evolving approach within the SHM family. Furthermore, an innovative screen-printing technique to fabricate piezoelectric ceramic sensors with minimal thickness has been developed at Stanford. The approach presented in this study is based on the use of (i) micro screen-printed piezoelectric sensors integrated into adhesive leaving a minimal footprint on the material, (ii) numerical and analytical modeling of the EMI spectrum of the adhesive bondline, (iii) novel diagnostic algorithms for monitoring the bondline integrity based on advanced signal processing techniques, and (iv) the experimental assessment via prototype adhesively bonded structures in static (varying loads) and dynamic (fatigue) environments. The proposed method will provide a huge confidence on the use of bonded joints for aerospace structures and lead to a paradigm change in their design by enabling enormous weight savings while maximizing the economic and performance efficiency.
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- 2016
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31. Thermal stress characterization using the impedance-based structural health monitoring system
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Francesco Lanza di Scalea, Xuan Zhu, and Mahmood Fateh
- Subjects
Measure (data warehouse) ,Admittance ,business.industry ,Computer science ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Piezoelectricity ,Reliability engineering ,Characterization (materials science) ,Stress (mechanics) ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Structural health monitoring ,0210 nano-technology ,Aerospace ,business ,Electrical impedance - Abstract
Structural health monitoring (SHM) has attracted researchers’ interests for the past two decades to reinforce the maintenance of the aging infrastructure systems all over the world. As one of the potential solutions, the electro-mechanical impedance (EMI) method was introduced in the early 1990s and has a great number of potential applications in the SHM of civil, mechanical and aerospace industries. This paper studied the impedance-based technique with the presence of environmental/operational variability, especially the influences of temperature and uniaxial stress on the admittance signature-based features. A comprehensive analytical model is established and provides satisfactory agreements with the experimental results. The stress and temperature sensitivities of all the proposed features are quantified using the experimental measurements, with discussions on their advantages and disadvantages. The final results illustrate that the EMI method can potentially provide effective measure for thermal stress.
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- 2016
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32. Effect of tubing material on conventional and thin FBG sensor for embedded environment impact monitoring of CFRP composites
- Author
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Yurim Park, Hyunseok Kwon, Hee-Jung Kwon, Pratik Shrestha, Jin-Hyuk Kim, and Chun-Gon Kim
- Subjects
Materials science ,business.industry ,Composite number ,02 engineering and technology ,Temperature cycling ,021001 nanoscience & nanotechnology ,01 natural sciences ,010309 optics ,Impact monitoring ,Fiber Bragg grating ,Low earth orbit ,0103 physical sciences ,Structural health monitoring ,Composite material ,Fbg sensor ,0210 nano-technology ,Aerospace ,business - Abstract
Applications of composite materials in aerospace structures is increasing due to the outstanding properties, however, monitoring such composite structures exposed to harsh environments is still a posing issue. Low Earth orbit space structures are exposed to property degradation and damage from high-degree vacuum, ultraviolet radiation, thermal cycling, and atomic oxygen attack which are detrimental to composite materials. In this study, FBG sensors for embedding in CFRP composite plates in different thickness locations to provide health and damage monitoring of the material exposed to such environments regarding the overall health of the material with a focus on the exposed surface are explored in comparison to conventional FBG sensors.
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- 2016
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33. Rapid evaluation of mechanical boundary conditions using impedance based structural health monitoring
- Author
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Ryan A. Kettle and Steven R. Anton
- Subjects
business.industry ,Event (computing) ,Electromechanical impedance ,Computer science ,020208 electrical & electronic engineering ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Mechanical system ,Feature (computer vision) ,0202 electrical engineering, electronic engineering, information engineering ,Electronic engineering ,Range (statistics) ,Boundary value problem ,Structural health monitoring ,0210 nano-technology ,Aerospace ,business ,Electrical impedance - Abstract
Conventionally, structural health monitoring (SHM) has been primarily concerned with sensing, identifying, locating, and determining the severity of damage present in a structure that is in a static state. Instead, this study will investigate adapting the impedance SHM method to rapidly evaluate a mechanical system during a dynamic event. Also in contrast to conventional SHM, the objective is not to detect damage but instead to detect changes in the boundary conditions as they occur during a dynamic event. Rapid detection of changes in boundary conditions in highly dynamic environments has the potential to be used in a wide variety of applications, including the aerospace, civil, and mining industries. A key feature of this work will be the use of frequency ranges higher than what is typically used for SHM impedance measurements, in the range of several MHz. Using such high frequencies will allow for faster measurements of impedance, thus enabling the capture of variations in boundary conditions as they change during a dynamic event. An existing analytical model from the literature for electromechanical impedance based SHM will be utilized for this study.
- Published
- 2016
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34. Posture metrology for aerospace camera in the assembly of spacecraft
- Author
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Bile Wan, ZaiHua Yang, Tingyao Pan, Changyu Long, and Song Yang
- Subjects
Engineering ,Spacecraft ,business.industry ,Coordinate system ,Metrology ,Optical axis ,Intersection ,Physics::Space Physics ,Computer vision ,Satellite ,Artificial intelligence ,business ,Aerospace ,Theodolite - Abstract
During the spacecraft assembly process, the posture of the aerospace camera to the spacecraft coordinate system needs to be measured precisely, because the posture data are very important for the earth observing. In order to measure the angles between the camera optical axis and the spacecraft coordinate system’s three axes x, y, z, a measurement scheme was designed. The scheme was based on the principle of space intersection measurement with theodolites. Three thodolites were used to respectively collimate the camera axis and two faces of a base cube. Then, through aiming at each other, a measurement network was built. Finally, the posture of the camera was measured. The error analysis and measurement experiments showed that the precision can reach 6″. This method has been used in the assembly of satellite GF-2 with satisfactory results.
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- 2016
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35. A detection method for infrared multi-target in aerospace backgound
- Author
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Ningming Wang and Yazhou Zhang
- Subjects
Infrared image ,Multi target ,Infrared ,Computer science ,business.industry ,Data association ,Computer vision ,Artificial intelligence ,Morphological filter ,Aerospace ,business - Abstract
Main task of the infrared search and track system is analyzing and identifying targets of airspace. But first this is needed to detect all targets in infrared image. Therefore, the multi-target detection algorithms are studied and we propose an effective multi-target detection method. Firstly, an improved morphological operator is designed based on airspace background and target traits of infrared image. Background is weakened but targets are enhanced when infrared image is processed by the gray morphological filter. Then, potential targets are found by the maximum local sum algorithm. Finally, true targets are affirmed based on data association of sequence images. The infrared images got from long-wavelength infrared camera are processed with the method of the paper. Experiment results show that the method can detect targets in infrared image quickly and accurately.
- Published
- 2015
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36. Radiation environment study of near space in China area
- Author
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Dongdong Fan, Xingfeng Chen, Zhengqiang Li, and Xiaodong Mei
- Subjects
Ozone ,Meteorology ,business.industry ,Radiation ,Atmospheric sciences ,Near space ,Latitude ,chemistry.chemical_compound ,Geography ,chemistry ,Hotspot (geology) ,Astrophysics::Solar and Stellar Astrophysics ,Astrophysics::Earth and Planetary Astrophysics ,Aerospace ,business ,Ultraviolet radiation ,Stratosphere ,Physics::Atmospheric and Oceanic Physics - Abstract
Aerospace activity becomes research hotspot for worldwide aviation big countries. Solar radiation study is the prerequisite for aerospace activity to carry out, but lack of observation in near space layer becomes the barrier. Based on reanalysis data, input key parameters are determined and simulation experiments are tried separately to simulate downward solar radiation and ultraviolet radiation transfer process of near space in China area. Results show that atmospheric influence on the solar radiation and ultraviolet radiation transfer process has regional characteristic. As key factors such as ozone are affected by atmospheric action both on its density, horizontal and vertical distribution, meteorological data of stratosphere needs to been considered and near space in China area is divided by its activity feature. Simulated results show that solar and ultraviolet radiation is time, latitude and ozone density-variant and has complicated variation characteristics.
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- 2015
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37. Design of light-small high-speed image data processing system
- Author
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Xue Feng, Fei Li, and Jinbao Yang
- Subjects
Data processing ,Microcontroller ,Engineering ,business.industry ,Digital image processing ,Miniaturization ,business ,Field-programmable gate array ,Aerospace ,Computer hardware ,Digital signal processing ,Data processing system - Abstract
A light-small high speed image data processing system was designed in order to meet the request of image data processing in aerospace. System was constructed of FPGA, DSP and MCU (Micro-controller), implementing a video compress of 3 million pixels@15frames and real-time return of compressed image to the upper system. Programmable characteristic of FPGA, high performance image compress IC and configurable MCU were made best use to improve integration. Besides, hard-soft board design was introduced and PCB layout was optimized. At last, system achieved miniaturization, light-weight and fast heat dispersion. Experiments show that, system’s multifunction was designed correctly and worked stably. In conclusion, system can be widely used in the area of light-small imaging.
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- 2015
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38. Application of tunable diode laser absorption spectroscopy in the detection of oxygen
- Author
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Xin Zhou and Xing Jin
- Subjects
Physics ,Tunable diode laser absorption spectroscopy ,business.industry ,System of measurement ,Mechanical engineering ,Laser ,Combustion ,Automotive engineering ,law.invention ,Reliability (semiconductor) ,law ,Combustor ,Aerospace ,business ,Sensitivity (electronics) - Abstract
Most aircrafts is driven by chemic energy which is released in the combustion process. For improving the capability of engine and controlling the running on-time, the processes of fuel physics and chemistry need to be analysis by kinds of high quality sensor. In the research of designing and improving the processes of fuel physics and chemistry, the concentration, temperature and velocity of kinds of gas in the combustor need to be detected and measured. In addition, these engines and research equipments are always in the harsh environment of high temperature, high pressure and high speed. The harsh environment needs the sensor to be high reliability, well repetition, no cross- sensitivity between gases, and the traditional measurement system can’t satisfy the metrical requirement well. Tunable diode laser absorption spectroscopy (TDLAS) analytic measurement technology can well satisfy the measurement in the harsh environment, which can support the whole measurement plan and high quality measurement system. Because the TDLAS sensor has the excellence of small bulk, light weight, high reliability and well specifically measurement, the TDLAS measurement technology has wide prospects. Different from most measurements, only a beam of laser can be pass through the measured environment by TDLAS, and the measurement equipment needn’t be set in the harsh environment. So, the TDLAS equipment can’t be interrupted by the measured equipment. The ability of subsistence in the harsh environment is very valuable, especially in the measurement on the subject of aerospace with environment of high speed, combustion and plasma. This paper focuses on the collecting the articles on the subject of oxygen detection of TDLAS. By analyzing the research and results of the articles, we conclude the central issues, difficulties and results. And we can get some instructive conclusions.
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- 2015
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39. End-to-end performance analysis using engineering confidence models and a ground processor prototype
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Mark Chang, Bryan de Goeij, Michael Schmitt, Alain Lefebvre, Kotska Wallace, Thomas Jäger, Maximilian Sauer, Klaus-Werner Kruse, Markus Huchler, Adriaan Van't Hof, Tracy Phillips, Michael Eisinger, Matthew Maher, Alexandra Herzog, Arnaud Hélière, Steve Knight, and Frits van der Knaap
- Subjects
TS - Technical Sciences ,Engineering ,Industrial Innovation ,Atmosphere (unit) ,Aperture ,business.industry ,Image quality ,Multispectral image ,SSE - Space Systems Engineering ,Nano Technology ,Satellite ,Electronics ,Deconvolution ,business ,Aerospace ,Remote sensing - Abstract
The European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA) are co-operating to develop the EarthCARE satellite mission with the fundamental objective of improving the understanding of the processes involving clouds, aerosols and radiation in the Earth's atmosphere. The EarthCARE Multispectral Imager (MSI) is relatively compact for a space borne imager. As a consequence, the immediate point-spread function (PSF) of the instrument will be mainly determined by the diffraction caused by the relatively small optical aperture. In order to still achieve a high contrast image, de-convolution processing is applied to remove the impact of diffraction on the PSF. A Lucy-Richardson algorithm has been chosen for this purpose. This paper will describe the system setup and the necessary data pre-processing and post-processing steps applied in order to compare the end-to-end image quality with the L1b performance required by the science community.
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- 2015
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- View/download PDF
40. Feasibility analysis of digital single lens reflex applied in the field of aerospace measurement
- Author
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Xinghao Feng, Xuehai Tang, and Manliang Li
- Subjects
Engineering ,business.product_category ,Optics ,Spacecraft ,business.industry ,Optical detector ,Single lens ,Phase (waves) ,Takeoff ,Telephoto lens ,business ,Aerospace ,Field (computer science) - Abstract
The mainstrean digital single lens reflex (DSLR) image has the characteristics of true color and high quality, this paper proposes apply DSLR to probe spacecraft in order to obtain better quality Color images. Firstly, the performance parameters of mainstream DSLR and industrial-grade optical detector are analysed and compared detailedly; Secondly, the performance and positioning ways etc. of optical detector and DSLR system integrated special telephoto lens are analysed and compared. Furthermore, some experiments have been done in different conditions. The experiments indicate that the performances of DSLR and optical detector are similar. In addition, DSLR has the advantage of small size, low cost and Easy positioning, which can be used to obtain the scene of spacecraft in the takeoff phase and part of reentry phase.
- Published
- 2015
- Full Text
- View/download PDF
41. EarthCARE/CPR design results and PFM dvelopment status
- Author
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Hirotaka Nakatsuka, Yuichi Ohno, Nobuhiro Tomiyama, Yoshihiro Seki, Yasuyuki Ishii, Hiroaki Horie, Eiichi Tomita, Yoshihisa Aida, Kenji Sato, Kenta Maruyama, Nobuhiro Takahashi, and Kazuyuki Okada
- Subjects
Cloud radar ,Geography ,Meteorology ,business.industry ,law ,Information and Communications Technology ,Global warming ,Cloud computing ,Radar ,Aerospace ,business ,Earth observation satellite ,law.invention - Abstract
Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) is a Japanese-European collaborative earth observation satellite mission aimed to deepen understanding of the interaction process between clouds and aerosols and their effects on the Earth’s radiation. The outcome of this mission is expected to improve the accuracy of global climate change prediction. As one of instruments for EarthCARE, the Cloud Profiling Radar (CPR) is the world’s first space-borne Doppler cloud radar jointly developed by the Japan Aerospace Exploration Agency (JAXA) and the National Institute of Information and Communications Technology (NICT). In Japan, the critical design review of the CPR has been completed in 2013, and CPR proto-flight model was manufactured and integrated until summer in 2015. Finally, the proto-flight test have been just started. This paper describes the design results and current status of CPR proto-flight test.
- Published
- 2015
- Full Text
- View/download PDF
42. Distributed deformation measurement of large space deployable mechanism based on FBG sensors
- Author
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Mingyao Liu, Yi Liu, Zude Zhou, Ruiya Li, Tianliang Li, and Dong Yanfang
- Subjects
Engineering ,Artificial neural network ,business.industry ,Acoustics ,Physics::Optics ,Mechanism based ,Mechanical engineering ,Deformation (meteorology) ,Space (mathematics) ,Mechanism (engineering) ,Fiber Bragg grating ,Fbg sensor ,Aerospace ,business - Abstract
Space deployable mechanisms are widely used, important and multi-purpose components in aerospace fields. In order to ensure the mechanism in normal situation after unfolded, detecting the deformation caused by huge temperature difference in real-time is necessary. This paper designed a deployable mechanism setup, completed its distributed deformation measurement by means of fiber Bragg grating (FBG) sensors and BP neural network, proved the mechanism distributed strain takes place sequence and FBG sensor is capable for space deployable mechanisms deformation measuring.
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- 2015
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43. Design and implementation of spaceborne high resolution infrared touch screen
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Wen-xin Li, Jia-gao Xia, Ma Wen, Yi-peng Dong, and Li Taiguo
- Subjects
Engineering ,SIMPLE (military communications protocol) ,Infrared ,business.industry ,Reliability (computer networking) ,Frame (networking) ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,System testing ,Electronic engineering ,Field-programmable gate array ,business ,Aerospace ,Computer hardware ,Digital signal processing - Abstract
For the consideration of the special application environment of the electronic products used in aerospace and to further more improve the human-computer interaction of the manned aerospace area. The research is based on the design and implementation way of the high resolution spaceborne infrared touch screen on the basis of FPGA and DSP frame structure. Beside the introduction of the whole structure for the high resolution spaceborne infrared touch screen system, this essay also gives the detail information about design of hardware for the high resolution spaceborne infrared touch screen system, FPGA design, GUI design and DSP algorithm design based on Lagrange interpolation. What is more, the easy makes a comprehensive research of the reliability design for the high resolution spaceborne infrared touch screen for the special purpose of it. Besides, the system test is done after installation of spaceborne infrared touch screen. The test result shows that the system is simple and reliable enough, which has a stable running environment and high resolution, which certainly can meet the special requirement of the manned aerospace instrument products.
- Published
- 2015
- Full Text
- View/download PDF
44. The research on thermal adaptability reinforcement technology for photovoltaic modules
- Author
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Guozhong Zhou and Nana Su
- Subjects
Engineering ,Thermoelectric cooling ,business.industry ,media_common.quotation_subject ,Photovoltaic system ,Enclosure ,Mechanical engineering ,Failure rate ,Thermoelectric materials ,Adaptability ,Reliability (semiconductor) ,Aerospace ,business ,media_common - Abstract
Nowadays, Photovoltaic module contains more high-performance components in smaller space. It is also demanded to work in severe temperature condition for special use, such as aerospace. As temperature rises, the failure rate will increase exponentially which makes reliability significantly reduce. In order to improve thermal adaptability of photovoltaic module, this paper makes a research on reinforcement technologies. Thermoelectric cooler is widely used in aerospace which has harsh working environment. So, theoretical formulas for computing refrigerating efficiency, refrigerating capacity and temperature difference are described in detail. The optimum operating current of three classical working condition is obtained which can be used to guide the design of driven circuit. Taken some equipment enclosure for example, we use thermoelectric cooler to reinforce its thermal adaptability. By building physical model and thermal model with the aid of physical dimension and constraint condition, the model is simulated by Flotherm. The temperature field cloud is shown to verify the effectiveness of reinforcement.
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- 2015
- Full Text
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45. Fabrication of stable lightweight Be-38Al optics and optical support structures
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Kelsey Parker and Robert Hardesty
- Subjects
Engineering ,Fabrication ,Optics ,chemistry ,business.industry ,Optical engineering ,AlBeMet ,chemistry.chemical_element ,Satellite ,Beryllium ,business ,Aerospace - Abstract
This paper describes recent aerospace applications where Be-38Al (AlBeMet) has been successfully applied to produce optics and stable support structures. The information presented touches on historical uses of beryllium and beryllium-aluminum in satellite optical systems, and then presents recent uses and developments of Be-38Al and its application to optical substrates and stable support structures.
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- 2015
- Full Text
- View/download PDF
46. Application and testing of additive manufacturing for mirrors and precision structures
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Michael Norbert Sweeney, Martyn Acreman, Ray Myatt, Tom Vettese, and Mike Thompson
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Materials science ,business.industry ,Isotropy ,Optical instrumentation ,Mechanical engineering ,chemistry.chemical_element ,3D printing ,Surface finish ,Inconel 625 ,chemistry ,Beryllium ,Aerospace ,business ,AKA - Abstract
Additive Manufacturing (aka AM, and 3-D printing) is widely touted in the media as the foundation for the next industrial revolution. Beneath the hype, AM does indeed offer profound advantages in lead-time, dramatically reduced consumption of expensive raw materials, while enabling new and innovative design forms that cannot be produced by other means. General Dynamics and their industry partners have begun to embrace this technology for mirrors and precision structures used in the aerospace, defense, and precision optical instrumentation industries. Aggressively lightweighted, open and closed back test mirror designs, 75-150 mm in size, were first produced by AM from several different materials. Subsequent optical finishing and test experiments have exceeded expectations for density, surface finish, dimensional stability and isotropy of thermal expansion on the optical scale of measurement. Materials currently under examination include aluminum, titanium, beryllium, aluminum beryllium, Inconel 625, stainless steel/bronze, and PEKK polymer.
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- 2015
- Full Text
- View/download PDF
47. Optical Autocovariance Wind Lidar (OAWL): aircraft test-flight history and current plans
- Author
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Mike Adkins, Paul Kaptchen, Tom Delker, Jeff Applegate, Glenn E. Taudien, Bill Good, Carl Weimer, Michael Kaplan, Sara C. Tucker, and David Gleeson
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Backscatter ,business.industry ,Computer science ,Flight test ,law.invention ,Telescope ,Wavelength ,symbols.namesake ,Interferometry ,Autocovariance ,Lidar ,law ,symbols ,Aerospace ,business ,Doppler effect ,Remote sensing - Abstract
To address mission risk and cost limitations the US has faced in putting a much needed Doppler wind lidar into space, Ball Aerospace and Technologies Corp, with support from NASA’s Earth Science Technology Office (ESTO), has developed the Optical Autocovariance Wind Lidar (OAWL), designed to measure winds from aerosol backscatter at the 355 nm or 532 nm wavelengths. Preliminary proof of concept hardware efforts started at Ball back in 2004. From 2008 to 2012, under an ESTO-funded Instrument Incubator Program, Ball incorporated the Optical Autocovariance (OA) interferometer receiver into a prototype breadboard lidar system by adding a laser, telescope, and COTS-based data system for operation at the 355 nm wavelength. In 2011, the prototype system underwent ground-based validation testing, and three months later, after hardware and software modifications to ensure autonomous operation and aircraft safety, it was flown on the NASA WB-57 aircraft. The history of the 2011 test flights are reviewed, including efforts to get the system qualified for aircraft flights, modifications made during the flight test period, and the final flight data results. We also present lessons learned and plans for the new, robust, two-wavelength, aircraft system with flight demonstrations planned for Spring 2016.
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- 2015
- Full Text
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48. Research on optimal path planning algorithm of task-oriented optical remote sensing satellites
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Fengjing Liu, Shengli Xu, Jingpeng Yuan, and Yunhe Liu
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Earth observation ,Engineering ,business.industry ,Payload ,Coordinate system ,Visualization ,Transformation (function) ,Geographic coordinate conversion ,Physics::Space Physics ,Motion planning ,Aerospace ,business ,Algorithm ,Remote sensing - Abstract
GEO task-oriented optical remote sensing satellite, is very suitable for long-term continuous monitoring and quick access to imaging. With the development of high resolution optical payload technology and satellite attitude control technology, GEO optical remote sensing satellites will become an important developing trend for aerospace remote sensing satellite in the near future. In the paper, we focused on GEO optical remote sensing satellite plane array stare imaging characteristics and real-time leading mission of earth observation mode, targeted on satisfying needs of the user with the minimum cost of maneuver, and put forward the optimal path planning algorithm centered on transformation from geographic coordinate space to Field of plane, and finally reduced the burden of the control system. In this algorithm, bounded irregular closed area on the ground would be transformed based on coordinate transformation relations in to the reference plane for field of the satellite payload, and then using the branch and bound method to search for feasible solutions, cutting off the non-feasible solution in the solution space based on pruning strategy; and finally trimming some suboptimal feasible solutions based on the optimization index until a feasible solution for the global optimum. Simulation and visualization presentation software testing results verified the feasibility and effectiveness of the strategy.
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- 2015
- Full Text
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49. Rapid detection of delamination areas in laminated structural elements by means of optically monitored strain solitons
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Nikolay V. Petrov, Alexander M. Samsonov, Irina V. Semenova, G. V. Dreiden, and Andrey V. Belashov
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Materials science ,business.industry ,Nondestructive testing ,Delamination ,Oil transportation ,Composite material ,Aerospace ,business ,Holographic interferometry ,Rapid detection - Abstract
Modern structural elements are often made of laminated polymer materials or composites on the base of polymer matrices. The proper functioning of these elements may be of vital importance especially in automotive and aerospace industries, in gas and oil transportation. The major problem in their performance is a possibility of a sudden and irreversible delamination caused by various factors. We propose and study a NDT approach aimed to detect delamination areas in adhesively bonded layered structural elements made of different materials. The proposed approach is evaluated by use of holographic detection and monitoring of the evolution of bulk strain solitons generated in such structures.
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- 2015
- Full Text
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50. Cost-effective lightweight mirrors for aerospace and defense
- Author
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Kenneth Smith Woodard, Brian P. Roy, Leonard Gerard Wamboldt, and Lovell E. Comstock
- Subjects
Coating ,Machining ,business.industry ,Computer science ,Range (aeronautics) ,engineering ,Diamond ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,Diamond turning ,engineering.material ,Aerospace ,business ,Automotive engineering - Abstract
The demand for high performance, lightweight mirrors was historically driven by aerospace and defense (A&D) but now we are also seeing similar requirements for commercial applications. These applications range from aerospace-like platforms such as small unmanned aircraft for agricultural, mineral and pollutant aerial mapping to an eye tracking gimbaled mirror for optometry offices. While aerospace and defense businesses can often justify the high cost of exotic, low density materials, commercial products rarely can. Also, to obtain high performance with low overall optical system weight, aspheric surfaces are often prescribed. This may drive the manufacturing process to diamond machining thus requiring the reflective side of the mirror to be a diamond machinable material. This paper summarizes the diamond machined finishing and coating of some high performance, lightweight designs using non-exotic substrates to achieve cost effective mirrors. The results indicate that these processes can meet typical aerospace and defense requirements but may also be competitive in some commercial applications.
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- 2015
- Full Text
- View/download PDF
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