Science.gov

Sample records for low-cost passive formation-flying

  1. Development of metamaterial based low cost passive wireless temperature sensor

    NASA Astrophysics Data System (ADS)

    Karim, Hasanul; Shuvo, Mohammad Arif Ishtiaq; Delfin, Diego; Lin, Yirong; Choudhuri, Ahsan; Rumpf, R. C.

    2014-03-01

    Wireless passive temperature sensors are gaining increasing attention due to the ever-growing need of precise monitoring of temperature in high temperature energy conversion systems such as gas turbines and coal-based power plants. Unfortunately, the harsh environment such as high temperature and corrosive atmosphere present in these systems limits current solutions. In order to alleviate these issues, this paper presents the design, simulation, and manufacturing process of a low cost, passive, and wireless temperature sensor that can withstand high temperature and harsh environment. The temperature sensor was designed following the principle of metamaterials by utilizing Closed Ring Resonators (CRR) embedded in a dielectric matrix. The proposed wireless, passive temperature sensor behaves like an LC circuit that has a resonance frequency that depends on temperature. A full wave electromagnetic solver Ansys Ansoft HFSS was used to perform simulations to determine the optimum dimensions and geometry of the sensor unit. The sensor unit was prepared by conventional powder-binder compression method. Commercially available metal washers were used as CRR structures and Barium Titanate (BTO) was used as the dielectric materials. Response of the fabricated sensor at room temperature was analyzed using a pair of horn antenna connected with a network analyzer.

  2. Passive mine drainage treatment: an effective low-cost alternative

    SciTech Connect

    Holm, J.D.

    1985-12-01

    Two prototype Passive Mine Drainage Treatment Systems have been designed and constructed in Colorado. These projects have addressed acid mine drainage from inactive coal mines. Metal removal for both systems is accomplished using simulated peat bogs composed of sphagnum moss and hypnum moss retained by loose rock check dams. Acid neutralization is accomplished using crushed limestone filled channels. Neutralization and aeration are enhanced with drop structures and waterfalls placed in the drainage channel. Preliminary water quality results show dramatic treatment effects with the PMDT system. This investigation presents cost data for design and construction of the two PMDT systems. Cost projections for periodic maintenance requirements are provided along with a suggested method for financing maintenance costs. Performance data for the first system installed are presented. 14 references, 1 figure, 2 tables.

  3. Graphene radio frequency and microwave passive components for low cost wearable electronics

    NASA Astrophysics Data System (ADS)

    Huang, Xianjun; Leng, Ting; Hsin Chang, Kuo; Cing Chen, Jia; Novoselov, Kostya S.; Hu, Zhirun

    2016-06-01

    Graphene RF and microwave passive components such as coplanar waveguide transmission lines, open/short-circuited resonators and wideband antenna on paper substrate were designed, screen printed and characterized in this work. The experimental results demonstrate that the screen printed graphene passive components can be used for RF signal transmitting, processing and radiating/receiving; revealing that graphene ink can be a low cost alternative to much more expensive metal nanoparticle inks, such as silver nanoparticle ink. The screen printed graphene is processed at low temperature so that it is compatible with heat-sensitive flexible materials like papers, PTFE (Polytetrafluoroethylene) and textiles. The screen printed graphene passive components reported here are of high conductivity, high flexibility, light weight and low cost, making them ideal candidate for low cost wearable electronics. This work makes it prospective to manufacture RF and microwave passive components in mass production by screen printing in much lower cost to any other known techniques.

  4. J3Gen: A PRNG for Low-Cost Passive RFID

    PubMed Central

    Melià-Seguí, Joan; Garcia-Alfaro, Joaquin; Herrera-Joancomartí, Jordi

    2013-01-01

    Pseudorandom number generation (PRNG) is the main security tool in low-cost passive radio-frequency identification (RFID) technologies, such as EPC Gen2. We present a lightweight PRNG design for low-cost passive RFID tags, named J3Gen. J3Gen is based on a linear feedback shift register (LFSR) configured with multiple feedback polynomials. The polynomials are alternated during the generation of sequences via a physical source of randomness. J3Gen successfully handles the inherent linearity of LFSR based PRNGs and satisfies the statistical requirements imposed by the EPC Gen2 standard. A hardware implementation of J3Gen is presented and evaluated with regard to different design parameters, defining the key-equivalence security and nonlinearity of the design. The results of a SPICE simulation confirm the power-consumption suitability of the proposal. PMID:23519344

  5. A Low-Cost Energy-Efficient Cableless Geophone Unit for Passive Surface Wave Surveys

    PubMed Central

    Dai, Kaoshan; Li, Xiaofeng; Lu, Chuan; You, Qingyu; Huang, Zhenhua; Wu, H. Felix

    2015-01-01

    The passive surface wave survey is a practical, non-invasive seismic exploration method that has increasingly been used in geotechnical engineering. However, in situ deployment of traditional wired geophones is labor intensive for a dense sensor array. Alternatively, stand-alone seismometers can be used, but they are bulky, heavy, and expensive because they are usually designed for long-term monitoring. To better facilitate field applications of the passive surface wave survey, a low-cost energy-efficient geophone system was developed in this study. The hardware design is presented in this paper. To validate the system’s functionality, both laboratory and field experiments were conducted. The unique feature of this newly-developed cableless geophone system allows for rapid field applications of the passive surface wave survey with dense array measurements. PMID:26404270

  6. A Low-Cost Energy-Efficient Cableless Geophone Unit for Passive Surface Wave Surveys.

    PubMed

    Dai, Kaoshan; Li, Xiaofeng; Lu, Chuan; You, Qingyu; Huang, Zhenhua; Wu, H Felix

    2015-01-01

    The passive surface wave survey is a practical, non-invasive seismic exploration method that has increasingly been used in geotechnical engineering. However, in situ deployment of traditional wired geophones is labor intensive for a dense sensor array. Alternatively, stand-alone seismometers can be used, but they are bulky, heavy, and expensive because they are usually designed for long-term monitoring. To better facilitate field applications of the passive surface wave survey, a low-cost energy-efficient geophone system was developed in this study. The hardware design is presented in this paper. To validate the system's functionality, both laboratory and field experiments were conducted. The unique feature of this newly-developed cableless geophone system allows for rapid field applications of the passive surface wave survey with dense array measurements. PMID:26404270

  7. A low cost integrated transceiver for mobile UHF passive RFID reader applications

    NASA Astrophysics Data System (ADS)

    Jingchao, Wang; Chun, Zhang; Baoyong, Chi; Ziqiang, Wang; Fule, Li; Zhihua, Wang

    2009-09-01

    A low cost integrated transceiver for mobile UHF passive RFID reader applications is implemented in a 0.18-μm CMOS process. The transceiver contains an OOK modulator and a power amplifier in the transmitter chain, an IQ direct-down converter, variable-gain amplifiers, channel-select filters and a 10-bit ADC in the receiver chain. The measured output P1DB power of the transmitter is 17.6 dBm and the measured receiver sensitivity is -70 dBm. The on-chip integer N synthesizer achieves a frequency resolution of 200 kHz with a phase noise of -104 dBc/Hz at 100 kHz frequency offset and -120.83 dBc/Hz at 1 MHz frequency offset. The transmitter, the receiver and the frequency synthesizer consume 201.34, 25.3 and 54 mW, respectively. The chip has a die area of 4 × 2.5 mm2 including pads.

  8. Low Cost, Low Power, Passive Muon Telescope For Interrogating Martian Sub-Surface

    NASA Astrophysics Data System (ADS)

    Naudet, C. J.; Tanaka, H.; Kedar, S.; Plaut, J. J.; Webb, F.

    2012-12-01

    Muon radiography is a technique that uses naturally occurring showers of muons (penetrating particles generated by cosmic rays) to image the interior of geological structures in much the same way as standard X-ray radiography. Unlike gamma rays and neutrons that penetrate only a few meters of rock, muons can traverse through up to several kilometers of a geological target. Recent development and application of the technique to terrestrial volcanoes, caves, and mines have demonstrated that a low-power, passive muon detector can image deep into kilometer-scale geological structures and provide unprecedentedly crisp density profile images of their interior. Preliminary estimates of muon production on Mars indicate that the near-horizontal Martian mu-on flux, which is used for muon radiography of surface features, is at least as strong as that on Earth, making the technique suitable for geological exploration of Mars. The muon telescope represents an entirely new class of instruments for planetary exploration, providing a wholly new type of measurement for delineation of potentially habitable subsurface environments through detection of caves, sub-surface ice, and water, and for the interpretation of composition and evolutionary state of the Martian surface. Muon radiography is a proven, sim-ple, low cost, and efficient technology that could detect subsurface radiation-shielded habitable environments that would not be detectable by any other technique available today. Thanks to its low power and low data rate demands, it could be integrated as a secondary instrument on future missions with minimal impact on primary mission operations. A mission that includes a muon detector could set the stage for a future mission to directly explore subsurface habitable envi-ronments on Mars. Developing the technology now would position it favorably for a surface mission in the 2018-2024 time period to explore Martian regions with previously-identified po-tential trace gas sources

  9. Bristle-sensors—low-cost flexible passive dry EEG electrodes for neurofeedback and BCI applications

    NASA Astrophysics Data System (ADS)

    Grozea, Cristian; Voinescu, Catalin D.; Fazli, Siamac

    2011-04-01

    In this paper, we present a new, low-cost dry electrode for EEG that is made of flexible metal-coated polymer bristles. We examine various standard EEG paradigms, such as capturing occipital alpha rhythms, testing for event-related potentials in an auditory oddball paradigm and performing a sensory motor rhythm-based event-related (de-) synchronization paradigm to validate the performance of the novel electrodes in terms of signal quality. Our findings suggest that the dry electrodes that we developed result in high-quality EEG recordings and are thus suitable for a wide range of EEG studies and BCI applications. Furthermore, due to the flexibility of the novel electrodes, greater comfort is achieved in some subjects, this being essential for long-term use.

  10. Bristle-sensors--low-cost flexible passive dry EEG electrodes for neurofeedback and BCI applications.

    PubMed

    Grozea, Cristian; Voinescu, Catalin D; Fazli, Siamac

    2011-04-01

    In this paper, we present a new, low-cost dry electrode for EEG that is made of flexible metal-coated polymer bristles. We examine various standard EEG paradigms, such as capturing occipital alpha rhythms, testing for event-related potentials in an auditory oddball paradigm and performing a sensory motor rhythm-based event-related (de-) synchronization paradigm to validate the performance of the novel electrodes in terms of signal quality. Our findings suggest that the dry electrodes that we developed result in high-quality EEG recordings and are thus suitable for a wide range of EEG studies and BCI applications. Furthermore, due to the flexibility of the novel electrodes, greater comfort is achieved in some subjects, this being essential for long-term use. PMID:21436526

  11. Low-cost passive solar-retrofit options for mobile homes

    SciTech Connect

    Brant, S.; Holtz, M.; Tasker, M.

    1981-03-01

    Passive solar heating and cooling retrofit options can significantly reduce the energy consumption of new and existing mobile homes. The initial efforts of the Solar Energy Research Institute to explore the solar potential for the existing stock of mobile homes and those in the production stage are described.

  12. Low Cost, Low Power, Passive Muon Telescope for Interrogating Martian Sub-Surface

    NASA Technical Reports Server (NTRS)

    Kedar, Sharon; Tanaka, Hirukui; Naudet, Charles; Plaut, Jeffrey J.; Jones, Cathleen E.; Webb, Frank H.

    2012-01-01

    It has been demonstrated on Earth that a low power, passive muon detector can penetrate deep into geological structures up to several kilometers in size providing high density images of their interiors. Muon tomography is an entirely new class of planetary instrumentation that is ideally suited to address key areas in Mars Science, such as: the search for life and habitable environments, the distribution and state of water and ice and the level of geologic activity on Mars today.

  13. Low-cost foil metallization using arc discharge for passivated emitter and rear solar cells

    NASA Astrophysics Data System (ADS)

    Kurimoto, Yuji; Yamasaki, Ichiro

    2016-04-01

    For the cost reduction of passivated emitter and rear cells (PERC), we propose a new rear contact formation method, in which an aluminum foil and an arc discharge system are used. The arc discharge system consists of inexpensive parts and does not contain any sophisticated part such as a laser ablation apparatus. Therefore, this system can save the cost of the rear contact forming process. We applied this technique to a test production of PERC. It is found that the arc discharge system can provide a similar performance to that attained by a conventional PERC production method.

  14. Low-cost passive sensors for monitoring corrosion in concrete structures

    NASA Astrophysics Data System (ADS)

    Abu Yosef, Ali E.; Pasupathy, Praveenkumar; Wood, Sharon L.; Neikirk, Dean P.

    2011-04-01

    A passive sensor platform has been developed at the University of Texas at Austin to monitor corrosion of embedded reinforcement in concrete structures. The sensors are powered and interrogated in a wireless manner. Initial sensor designs used a sacrificial corroding steel wire to indicate the risk of corrosion within concrete. The wire was physically connected to the sensor circuitry and passed through the circuit protection layer. Consequently, it allowed contaminants to reach the circuit electric components causing corrosion and limiting the service life of the sensor. A novel sensor configuration that relies on wireless inductive coupling between a resonant circuit and the transducer element is presented. The non-contact design eliminates the breach concern and enhances the durability of the senor. Preliminary test results of the new design will be discussed in this paper.

  15. Testing Of An Ultraviolet (UV)-Transparent Polymer-Based Passive Sampler for Rapid, Ultra-Low-Cost EDC Screening Applications

    EPA Science Inventory

    A new passive sampling method with rapid low-cost spectral detection has recently been developed. The method makes use of an ultraviolet (UV)-transparent polymer which serves as both a concentrator for dissolved compounds, and an optical cell for UV spectral detection. Because ...

  16. Formation Flying and Deformable Instruments

    SciTech Connect

    Rio, Yvon

    2009-05-11

    Astronomers have always attempted to build very stable instruments. They fight all that can cause mechanical deformation or image motion. This has led to well established technologies (autoguide, active optics, thermal control, tip/tilt correction), as well as observing methods based on the use of controlled motion (scanning, micro scanning, shift and add, chopping and nodding). Formation flying disturbs this practice. It is neither possible to reduce the relative motion to very small amplitudes, nor to control it at will. Some impacts on Simbol-X instrument design, and operation are presented.

  17. Inkjet catalyst printing and electroless copper deposition for low-cost patterned microwave passive devices on paper

    NASA Astrophysics Data System (ADS)

    Cook, Benjamin S.; Fang, Yunnan; Kim, Sangkil; Le, Taoran; Goodwin, W. Brandon; Sandhage, Kenneth H.; Tentzeris, Manos M.

    2013-09-01

    A scalable, low-cost process for fabricating copper-based microwave components on flexible, paper-based substrates is demonstrated. An inkjet printer is used to deposit a catalyst-bearing solution (tailored for such printing) in a desired pattern on commercially-available, recyclable, non-toxic (Teslin®) paper. The catalystbearing paper is then immersed in an aqueous copper-bearing solution to allow for electroless deposition of a compact and conformal layer of copper in the inkjet-derived pattern. Meander monopole antennas comprised of such electroless-deposited copper patterns on paper exhibited comparable performance as for antennas synthesized via inkjet printing of a commercially-available silver nanoparticle ink. However, the solution-based patterning and electroless copper deposition process avoids nozzle-clogging problems and costs associated with noble metal particle-based inks. This process yields compact conductive copper layers without appreciable oxidation and without the need for an elevated temperature, post-deposition thermal treatment commonly required for noble metal particle-based ink processes. This low-cost copper patterning process is readily scalable on virtually any substrate and may be used to generate a variety of copper-based microwave devices on flexible, paper-based substrates.

  18. Benchmark Problems for Space Mission Formation Flying

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Leitner, Jesse A.; Folta, David C.; Burns, Richard

    2003-01-01

    To provide a high-level focus to distributed space system flight dynamics and control research, several benchmark problems are suggested for space mission formation flying. The problems cover formation flying in low altitude, near-circular Earth orbit, high altitude, highly elliptical Earth orbits, and large amplitude lissajous trajectories about co-linear libration points of the Sun-Earth/Moon system. These problems are not specific to any current or proposed mission, but instead are intended to capture high-level features that would be generic to many similar missions that are of interest to various agencies.

  19. Ka-Band Autonomous Formation Flying Sensor

    NASA Technical Reports Server (NTRS)

    Tien, Jeffrey; Purcell, George, Jr.; Srinivasan, Jeffrey; Ciminera, Michael; Srinivasan, Meera; Meehan, Thomas; Young, Lawrence; Aung, MiMi; Amaro, Luis; Chong, Yong; Quirk, Kevin

    2004-01-01

    Ka-band integrated range and bearing-angle formation sensor called the Autonomous Formation Flying (AFF) Sensor has been developed to enable deep-space formation flying of multiple spacecraft. The AFF Sensor concept is similar to that of the Global Positioning System (GPS), but the AFF Sensor would not use the GPS. The AFF Sensor would reside in radio transceivers and signal-processing subsystems aboard the formation-flying spacecraft. A version of the AFF Sensor has been developed for initial application to the two-spacecraft StarLight optical-interferometry mission, and several design investigations have been performed. From the prototype development, it has been concluded that the AFF Sensor can be expected to measure distances and directions with standard deviations of 2 cm and 1 arc minute, respectively, for spacecraft separations ranging up to about 1 km. It has also been concluded that it is necessary to optimize performance of the overall mission through design trade-offs among the performance of the AFF Sensor, the field of view of the AFF Sensor, the designs of the spacecraft and the scientific instruments that they will carry, the spacecraft maneuvers required for formation flying, and the design of a formation-control system.

  20. Model stream channel testing of a UV-transparent polymer-based passive sampler for ultra-low-cost water screening applications

    EPA Science Inventory

    Passive samplers are increasingly being considered for analyses of waters for screening applications, to monitor for the presence of unwanted chemical compounds. Passive samplers typically work by accumulating and concentrating chemicals from the surrounding water over time, all...

  1. Enhanced Formation Flying for the Earth Observing-1 (EO-1) New Millennium Mission

    NASA Technical Reports Server (NTRS)

    Folta, David; Quinn, David

    1997-01-01

    With scientific objectives for Earth observation programs becoming more ambitious and spacecraft becoming more autonomous, the need for new technical approaches on the feasibility of achieving and maintaining formations of spacecraft has come to the forefront. The trend to develop small low cost spacecraft has led many scientists to recognize the advantage of flying several spacecraft in formation, an example of which is shown in the figure below, to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, formation flying imposes additional complications on orbit maintenance, especially when each spacecraft has its own orbit requirements. However, advances in automation proposed by GSFC Codes 550 and 712 allow more of the burden in maneuver planning and execution to be placed onboard the spacecraft, mitigating some of the associated operational concerns. The purpose of this analysis is to develop the fundamentals of formation flying mechanics, concepts for understanding the relative motion of free flying spacecraft, and an operational control theory for formation maintenance of the Earth Observing-1 (EO-l) spacecraft that is part of the New Millennium. Results of this development can be used to determine the appropriateness of formation flying for a particular case as well as the operational impacts. Applications to the Mission to Planet Earth (MTPE) Earth Observing System (EOS) and New Millennium (NM) were highly considered in analysis and applications. This paper presents the proposed methods for the guidance and control of the EO-1 spacecraft to formation fly with the Landsat-7 spacecraft using an autonomous closed loop three axis navigation control, GPS, and Cross link navigation support. Simulation results using various fidelity levels of modeling, algorithms developed and implemented in MATLAB, and autonomous 'fuzzy logic' control using AutoCon will be presented. The results of these

  2. Relative Navigation for Spacecraft Formation Flying

    NASA Technical Reports Server (NTRS)

    Hartman, Kate R.; Gramling, Cheryl J.; Lee, Taesul; Kelbel, David A.; Long, Anne C.

    1998-01-01

    The Goddard Space Flight Center Guidance, Navigation, and Control Center (GNCC) is currently developing and implementing advanced satellite systems to provide autonomous control of formation flyers. The initial formation maintenance capability will be flight-demonstrated on the Earth-Orbiter-1 (EO-l) satellite, which is planned under the National Aeronautics and Space Administration New Millennium Program to be a coflight with the Landsat-7 (L-7) satellite. Formation flying imposes relative navigation accuracy requirements in addition to the orbit accuracy requirements for the individual satellites. In the case of EO-1 and L-7, the two satellites are in nearly coplanar orbits, with a small difference in the longitude of the ascending node to compensate for the Earth's rotation. The GNCC has performed trajectory error analysis for the relative navigation of the EO-1/L-7 formation, as well as for a more advanced tracking configuration using cross- link satellite communications. This paper discusses the orbit determination and prediction accuracy achievable for EO-1 and L-7 under various tracking and orbit determination scenarios and discusses the expected relative separation errors in their formation flying configuration.

  3. Relative navigation for spacecraft formation flying

    NASA Technical Reports Server (NTRS)

    Hartman, Kate R.; Gramling, Cheryl J.; Lee, Taesul; Kelbel, David A.; Long, Anne C.

    1998-01-01

    The Goddard Space Flight Center Guidance, Navigation, and Control Center (GNCC) is currently developing and implementing advanced satellite systems to provide autonomous control of formation flyers. The initial formation maintenance capability will be flight-demonstrated on the Earth-Orbiter-1 (EO-1) satellite, which is planned under the National Aeronautics and Space Administration New Millennium Program to be a coflight with the Landsat-7 (L-7) satellite. Formation flying imposes relative navigation accuracy requirements in addition to the orbit accuracy requirements for the individual satellites. In the case of EO-1 and L-7, the two satellites are in nearly coplanar orbits, with a small difference in the longitude of the ascending node to compensate for the Earth's rotation. The GNCC has performed trajectory error analysis for the relative navigation of the EO-1/L-7 formation, as well as for a more advanced tracking configuration using cross-link satellite communications. This paper discusses the orbit determination and prediction accuracy achievable for EO-1 and L-7 under various tracking and orbit determination scenarios and discusses the expected relative separation errors in their formation flying configuration.

  4. Network Configuration Analysis for Formation Flying Satellites

    NASA Technical Reports Server (NTRS)

    Knoblock, Eric J.; Wallett, Thomas M.; Konangi, Vijay K.; Bhasin, Kul B.

    2001-01-01

    The performance of two networks to support autonomous multi-spacecraft formation flying systems is presented. Both systems are comprised of a ten-satellite formation, with one of the satellites designated as the central or 'mother ship.' All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/EP over ATM protocol architecture within the formation, and the second system uses the IEEE 802.11 protocol architecture within the formation. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IP queuing delay, IP queue size and IP processing delay at the mother ship as well as end-to-end delay for both systems. In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  5. Satellite formation flying control by mass exchange

    NASA Astrophysics Data System (ADS)

    Ivanov, Danil; Ovchinnikov, Michael; Shestakov, Sergey

    2014-09-01

    Novel approach for formation flying relative motion control is proposed and studied. It is based on a mass exchange between satellites. A certain mass is separated from one satellite in a given direction with a given velocity. It impacts absolutely inelastically another satellite to impart a pulse. The mass exchange causes desired change in a relative motion trajectory of both satellites. The feasibility of such a control approach is shown in the paper. The Hill-Clohessy-Wiltshire equations are used for relative motion representation. The resulting trajectory equations after mass exchange are analytically derived. The control approach is applied to formation reconfiguration, drift-stop and also to relative motion trajectory maintenance under perturbation effect J2. The mass exchange approach is verified by numerical simulations.

  6. An algorithm for enhanced formation flying of satellites in low earth orbit

    NASA Astrophysics Data System (ADS)

    Folta, David C.; Quinn, David A.

    1998-01-01

    With scientific objectives for Earth observation programs becoming more ambitious and spacecraft becoming more autonomous, the need for innovative technical approaches on the feasibility of achieving and maintaining formations of spacecraft has come to the forefront. The trend to develop small low-cost spacecraft has led many scientists to recognize the advantage of flying several spacecraft in formation to achieve the correlated instrument measurements formerly possible only by flying many instruments on a single large platform. Yet, formation flying imposes additional complications on orbit maintenance, especially when each spacecraft has its own orbit requirements. However, advances in automation and technology proposed by the Goddard Space Flight Center (GSFC) allow more of the burden in maneuver planning and execution to be placed onboard the spacecraft, mitigating some of the associated operational concerns. The purpose of this paper is to present GSFC's Guidance, Navigation, and Control Center's (GNCC) algorithm for Formation Flying of the low earth orbiting spacecraft that is part of the New Millennium Program (NMP). This system will be implemented as a close-loop flight code onboard the NMP Earth Orbiter-1 (EO-1) spacecraft. Results of this development can be used to determine the appropriateness of formation flying for a particular case as well as operational impacts. Simulation results using this algorithm integrated in an autonomous `fuzzy logic' control system called AutoCon™ are presented.

  7. Optimum Guidance Law and Information Management for a Large Number of Formation Flying Spacecrafts

    NASA Astrophysics Data System (ADS)

    Tsuda, Yuichi; Nakasuka, Shinichi

    In recent years, formation flying technique is recognized as one of the most important technologies for deep space and orbital missions that involve multiple spacecraft operations. Formation flying mission improves simultaneous observability over a wide area, redundancy and reconfigurability of the system with relatively small and low cost spacecrafts compared with the conventional single spacecraft mission. From the viewpoint of guidance and control, realizing formation flying mission usually requires tight maintenance and control of the relative distances, speeds and orientations between the member satellites. This paper studies a practical architecture for formation flight missions focusing mainly on guidance and control, and describes a new guidance algorithm for changing and keeping the relative positions and speeds of the satellites in formation. The resulting algorithm is suitable for onboard processing and gives the optimum impulsive trajectory for satellites flying closely around a certain reference orbit, that can be elliptic, parabolic or hyperbolic. Based on this guidance algorithm, this study introduces an information management methodology between the member spacecrafts which is suitable for a large formation flight architecture. Routing and multicast communication based on the wireless local area network technology are introduced. Some mathematical analyses and computer simulations will be shown in the presentation to reveal the feasibility of the proposed formation flight architecture, especially when a very large number of satellites join the formation.

  8. Autonomous Formation Flying from Ground to Flight

    NASA Technical Reports Server (NTRS)

    Chapman, Keith B.; Dell, Gregory T.; Rosenberg, Duane L.; Bristow, John

    1999-01-01

    The cost of on-orbit operations remains a significant and increasingly visible concern in the support of satellite missions. Headway has been made in automating some ground operations; however, increased mission complexity and more precise orbital constraints have compelled continuing human involvement in mission design and maneuver planning operations. AI Solutions, Inc. in cooperation with the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center (GSFC) has tackled these more complex problems through the development of AutoCon as a tool for an automated solution. NASA is using AutoCon to automate the maneuver planning for the Earth Orbiter-1 (EO-1) mission. AutoCon was developed originally as a ground system tool. The EO-1 mission will be using a scaled version of AutoCon on-board the EO-1 satellite to command orbit adjustment maneuvers. The flight version of AutoCon plans maneuvers based on formation flying algorithms developed by GSFC, JPL, and other industry partners. In its fully autonomous mode, an AutoCon planned maneuver will be executed on-board the satellite without intervention from the ground. This paper describes how AutoCon automates maneuver planning for the formation flying constraints of the EO-1 mission. AutoCon was modified in a number of ways to automate the maneuver planning on-board the satellite. This paper describes how the interface and functionality of AutoCon were modified to support the on-board system. A significant component of this modification was the implementation of a data smoother, based on a Kalman filter, that ensures that the spacecraft states estimated by an on-board GPS receiver are as accurate as possible for maneuver planning. This paper also presents the methodology use to scale the AutoCon functionality to fit and execute on the flight hardware. This paper also presents the modes built that allow the incremental phasing in of autonomy. New technologies for autonomous operations are usually

  9. Reconfigurable Software for Controlling Formation Flying

    NASA Technical Reports Server (NTRS)

    Mueller, Joseph B.

    2006-01-01

    Software for a system to control the trajectories of multiple spacecraft flying in formation is being developed to reflect underlying concepts of (1) a decentralized approach to guidance and control and (2) reconfigurability of the control system, including reconfigurability of the software and of control laws. The software is organized as a modular network of software tasks. The computational load for both determining relative trajectories and planning maneuvers is shared equally among all spacecraft in a cluster. The flexibility and robustness of the software are apparent in the fact that tasks can be added, removed, or replaced during flight. In a computational simulation of a representative formation-flying scenario, it was demonstrated that the following are among the services performed by the software: Uploading of commands from a ground station and distribution of the commands among the spacecraft, Autonomous initiation and reconfiguration of formations, Autonomous formation of teams through negotiations among the spacecraft, Working out details of high-level commands (e.g., shapes and sizes of geometrically complex formations), Implementation of a distributed guidance law providing autonomous optimization and assignment of target states, and Implementation of a decentralized, fuel-optimal, impulsive control law for planning maneuvers.

  10. Networks for Autonomous Formation Flying Satellite Systems

    NASA Technical Reports Server (NTRS)

    Knoblock, Eric J.; Konangi, Vijay K.; Wallett, Thomas M.; Bhasin, Kul B.

    2001-01-01

    The performance of three communications networks to support autonomous multi-spacecraft formation flying systems is presented. All systems are comprised of a ten-satellite formation arranged in a star topology, with one of the satellites designated as the central or "mother ship." All data is routed through the mother ship to the terrestrial network. The first system uses a TCP/lP over ATM protocol architecture within the formation the second system uses the IEEE 802.11 protocol architecture within the formation and the last system uses both of the previous architectures with a constellation of geosynchronous satellites serving as an intermediate point-of-contact between the formation and the terrestrial network. The simulations consist of file transfers using either the File Transfer Protocol (FTP) or the Simple Automatic File Exchange (SAFE) Protocol. The results compare the IF queuing delay, and IP processing delay at the mother ship as well as application-level round-trip time for both systems, In all cases, using IEEE 802.11 within the formation yields less delay. Also, the throughput exhibited by SAFE is better than FTP.

  11. Formation Flying Spacecraft Concept for Heliophysics Applications

    NASA Astrophysics Data System (ADS)

    Novo-Gradac, Anne-Marie; Davila, Joseph; Yang, Guangning; Lu, Wei; Shah, Neerav; Li, Steven X.

    2016-05-01

    A number of space-based heliophysics instruments would benefit from formation flying spacecraft. An occulter or a focusing optic such as a photon sieve could be mounted on a separate spacecraft rather than at the end of a boom. This would enable science measurements to be made on smaller, less expensive spacecraft. To accomplish this goal, the relative position of the spacecraft must be monitored and controlled to high precision. We describe two separate optical sensing systems that monitor relative position of the spacecraft to the level required for a photon sieve mission concept wherein the photon sieve is mounted on one spacecraft while the imaging detector is mounted on another. The first system employs a novel time of flight measurement of a laser beam that includes imbedded optical data packets. The contents of the returning data packet can be compared to the departing data packet to provide an extremely high resolution distance measurement. Employing three such systems allows measurement of pitch and yaw in addition to longitudinal separation. The second optical system monitors lateral motion. A mildy divergent laser beam is transmitted from one spacecraft to a sensor array on the second spacecraft. Monitoring the position of the brightest portion of the beam on the sensor array provides a direct measurement of lateral relative motion. Employing at least two such systems enables monitoring roll of the spacecraft as well as centration. We will also discuss low force thruster systems required for high precision station keeping.

  12. High-performance low-cost back-channel-etch amorphous gallium-indium-zinc oxide thin-film transistors by curing and passivation of the damaged back channel.

    PubMed

    Park, Jae Chul; Ahn, Seung-Eon; Lee, Ho-Nyeon

    2013-12-11

    High-performance, low-cost amorphous gallium-indium-zinc oxide (a-GIZO) thin-film-transistor (TFT) technology is required for the next generation of active-matrix organic light-emitting diodes. A back-channel-etch structure is the most appropriate device structure for high-performance, low-cost a-GIZO TFT technology. However, channel damage due to source/drain etching and passivation-layer deposition has been a critical issue. To solve this problem, the present work focuses on overall back-channel processes, such as back-channel N2O plasma treatment, SiOx passivation deposition, and final thermal annealing. This work has revealed the dependence of a-GIZO TFT characteristics on the N2O plasma radio-frequency (RF) power and frequency, the SiH4 flow rate in the SiOx deposition process, and the final annealing temperature. On the basis of these results, a high-performance a-GIZO TFT with a field-effect mobility of 35.7 cm(2) V(-1) s(-1), a subthreshold swing of 185 mV dec(-1), a switching ratio exceeding 10(7), and a satisfactory reliability was successfully fabricated. The technology developed in this work can be realized using the existing facilities of active-matrix liquid-crystal display industries. PMID:24221957

  13. Protocol for Communication Networking for Formation Flying

    NASA Technical Reports Server (NTRS)

    Jennings, Esther; Okino, Clayton; Gao, Jay; Clare, Loren

    2009-01-01

    An application-layer protocol and a network architecture have been proposed for data communications among multiple autonomous spacecraft that are required to fly in a precise formation in order to perform scientific observations. The protocol could also be applied to other autonomous vehicles operating in formation, including robotic aircraft, robotic land vehicles, and robotic underwater vehicles. A group of spacecraft or other vehicles to which the protocol applies could be characterized as a precision-formation- flying (PFF) network, and each vehicle could be characterized as a node in the PFF network. In order to support precise formation flying, it would be necessary to establish a corresponding communication network, through which the vehicles could exchange position and orientation data and formation-control commands. The communication network must enable communication during early phases of a mission, when little positional knowledge is available. Particularly during early mission phases, the distances among vehicles may be so large that communication could be achieved only by relaying across multiple links. The large distances and need for omnidirectional coverage would limit communication links to operation at low bandwidth during these mission phases. Once the vehicles were in formation and distances were shorter, the communication network would be required to provide high-bandwidth, low-jitter service to support tight formation-control loops. The proposed protocol and architecture, intended to satisfy the aforementioned and other requirements, are based on a standard layered-reference-model concept. The proposed application protocol would be used in conjunction with conventional network, data-link, and physical-layer protocols. The proposed protocol includes the ubiquitous Institute of Electrical and Electronics Engineers (IEEE) 802.11 medium access control (MAC) protocol to be used in the datalink layer. In addition to its widespread and proven use in

  14. Formation Flying in Earth, Libration, and Distant Retrograde Orbits

    NASA Technical Reports Server (NTRS)

    Folta, David C.

    2004-01-01

    This slide presentation examines the current and future state of formation flying, LEO formations, control strategies for flight in the vicinity of the libration points, and distant retrograde orbit formations. This discussion of LEO formations includes background on perturbation theory/accelerations and LEO formation flying. The discussion of strategies for formation flight in the vicinity of the libration points includes libration missions and natural and controlled libration orbit formations. A reference list is included.

  15. Low Cost, Durable Seal

    SciTech Connect

    Roberts, George; Parsons, Jason; Friedman, Jake

    2010-12-17

    Seal durability is critical to achieving the 2010 DOE operational life goals for both stationary and transportation PEM fuel cell stacks. The seal material must be chemically and mechanically stable in an environment consisting of aggressive operating temperatures, humidified gases, and acidic membranes. The seal must also be producible at low cost. Currentlyused seal materials do not meet all these requirements. This project developed and demonstrated a high consistency hydrocarbon rubber seal material that was able to meet the DOE technical and cost targets. Significant emphasis was placed on characterization of the material and full scale molding demonstrations.

  16. Control system design for spacecraft formation flying: Theory and experiment

    NASA Astrophysics Data System (ADS)

    Robertson, Andrew Dunbar

    Spacecraft formation flying is an enabling technology for many future space science missions, such as separated spacecraft interferometers (SSI). However the sensing, control and coordination of such instruments pose many new design challenges. SSI missions will require precise relative sensing and control, fuel-efficient, fuel-balanced operation to maximize mission life and group-level autonomy to reduce operations costs. Enabling these new formation flying capabilities requires precise relative sensing and estimation, enhanced control capabilities such as cooperative control (multiple independent spacecraft acting together), group-level formation management and informed design of a system architecture to manage distributed sensing and control-system resources. This research defines an end-to-end control system, including the key elements unique to the formation flying problem: cooperative control, relative sensing, coordination, and the control-system architecture. A new control-system design optimizes performance under typical spacecraft constraints (e.g., on-off actuators, finite fuel, limited computation power, limited contact with ground control, etc.). Standard control techniques have been extended, and new ones synthesized to meet these goals. In designing this control system, several contributions have been made to the field of spacecraft formation flying control including: an analytic two-vehicle fuel-time-optimal cooperative control algorithm, a fast numeric multi-vehicle, optimal cooperative control algorithm that can be used as a feedforward or a feedback controller, a fleet-level coordinator for autonomous fuel balancing, validation of GPS-based relative sensing for formation flying, and trade studies of the relative control and relative-estimation-architecture design problems. These research contributions are mapped to possible applications for three spacecraft formation flying missions currently in development. The lessons learned from this research

  17. GVE-Based Dynamics and Control for Formation Flying Spacecraft

    NASA Technical Reports Server (NTRS)

    Breger, Louis; How, Jonathan P.

    2004-01-01

    Formation flying is an enabling technology for many future space missions. This paper presents extensions to the equations of relative motion expressed in Keplerian orbital elements, including new initialization techniques for general formation configurations. A new linear time-varying form of the equations of relative motion is developed from Gauss Variational Equations and used in a model predictive controller. The linearizing assumptions for these equations are shown to be consistent with typical formation flying scenarios. Several linear, convex initialization techniques are presented, as well as a general, decentralized method for coordinating a tetrahedral formation using differential orbital elements. Control methods are validated using a commercial numerical propagator.

  18. HYDRA: High Speed Simulation Architecture for Precision Spacecraft Formation Flying

    NASA Technical Reports Server (NTRS)

    Martin, Bryan J.; Sohl, Garett A.

    2003-01-01

    This viewgraph presentation describes HYDRA, which is architecture to facilitate high-fidelity and real-time simulation of formation flying missions. The contents include: 1) Motivation; 2) Objective; 3) HYDRA-Description and Overview; 4) HYDRA-Hierarchy; 5) Communication in HYDRA; 6) Simulation Specific Concerns in HYDRA; 7) Example application (Formation Acquisition); and 8) Sample Problem Results.

  19. Formation Flying of Tethered and Nontethered Spacecraft

    NASA Technical Reports Server (NTRS)

    Quadrelli, Marco B.

    2005-01-01

    A paper discusses the effect of the dynamic interaction taking place within a formation composed of a rigid and a deformable vehicle, and presents the concept of two or more tethered spacecraft flying in formation with one or more separated free-flying spacecraft. Although progress toward formation flight of nontethered spacecraft has already been achieved, the document cites potential advantages of tethering, including less consumption of fuel to maintain formation, very high dynamic stability of a rotating tethered formation, and intrinsically passive gravity-gradient stabilization. The document presents a theoretical analysis of the dynamics of a system comprising one free-flying spacecraft and two tethered spacecraft in orbit, as a prototype of more complex systems. The spacecraft are modeled as rigid bodies and the tether as a mass-less spring with structural viscous damping. Included in the analysis is a study of the feasibility of a centralized control system for maintaining a required formation in low Earth orbit. A numerical simulation of a retargeting maneuver is reported to show that even if the additional internal dynamics of the system caused by flexibility is considered, high pointing precision can be achieved if a fictitious rigid frame is used to track the tethered system, and it should be possible to position the spacecraft with centimeter accuracy and to orient the formation within arc seconds of the desired direction also in the presence of low Earth orbit environmental perturbations. The results of the study demonstrate that the concept is feasible in Earth orbit and point the way to further study of these hybrid tethered and free-flying systems for related applications in orbit around other Solar System bodies.

  20. PRISMA—A formation flying project in implementation phase

    NASA Astrophysics Data System (ADS)

    Persson, Staffan; Veldman, Sytze; Bodin, Per

    2009-11-01

    The PRISMA project for autonomous formation flying and rendezvous has passed its critical design review in February-March 2007. The project comprises two satellites which are an in-orbit testbed for Guidance, Navigation and Control (GNC) algorithms and sensors for advanced formation flying and rendezvous. Several experiments involving GNC algorithms, sensors and thrusters will be performed during a 10 month mission with launch planned for the second half of 2009. The project is run by the Swedish Space Corporation (SSC) in close cooperation with the German Aerospace Center (DLR), the French Space Agency (CNES) and the Technical University of Denmark (DTU). Additionally, the project also will demonstrate flight worthiness of two novel motor technologies: one that uses environmentally clean and non-hazardous propellant, and one that consists of a microthruster system based on MEMS technology. The project will demonstrate autonomous formation flying and rendezvous based on several sensors—GPS, RF-based and vision based—with different objectives and in different combinations. The GPS-based onboard navigation system, contributed by DLR, offers relative orbit information in real-time in decimetre range. The RF-based navigation instrument intended for DARWIN, under CNES development, will be tested for the first time on PRISMA, both for instrument performance, but also in closed loop as main sensor for formation flying. Several rendezvous and proximity manoeuvre experiments will be demonstrated using only vision based sensor information coming from the modified star camera provided by DTU. Semi-autonomous operations ranging from 200 km to 1 m separation between the satellites will be demonstrated. With the project now in the verification phase particular attention is given to the specific formation flying and rendezvous functionality on instrument, GNC-software and system level.

  1. Autonomous guidance & control of Earth-orbiting formation flying spacecraft

    NASA Astrophysics Data System (ADS)

    Hamel, Jean-Francois

    Formation flying of spacecraft has gained a lot of interest within the engineering and scientific community in recent years. However, formation flying leads to an increased complexity of the guidance and control system, whose complexity grows rapidly with the number of spacecraft in the formation. Moreover, there is an increasing need for autonomy to decrease the cost of ground support since ground support operations are often a non-negligible part of the cost of a mission. Therefore, a formation flying guidance and control system needs to perform autonomous decisions and trade-offs in real-time to decrease the number of tasks that need to be performed by the ground segment and make formation flying affordable. This work presents the development of analytical formation flying guidance and control laws for autonomous on-board applications. Firstly, an analytical model of relative motion for elliptical and perturbed reference orbits is developed. This model is solely based on the initial orbit elements of the reference trajectory and can predict the relative motion of any spacecraft orbiting close to the reference trajectory, taking into account the secular drift caused by the J2 perturbation. Secondly, a new tool, the Fuel-Equivalent Space, is presented. The Fuel-Equivalent Space theory maps the relative orbit elements into a mathematical space where similar displacements on any axis is similar in terms of maneuvering fuel cost, therefore translating the minimum fuel problem into a simple distance minimization problem. Then, a neighbouring optimum feedback control law is developed. This feedback control law makes use of the optimal control theory to yield a semi-analytical controller that guarantees near-optimal maneuvering for any of the spacecraft orbiting close to the reference trajectory. Finally, it is shown that all these three new developments can be tied in together with simple analytical guidance laws to yield a fully autonomous guidance and control

  2. PROBA-3: a Formation Flying Solar Coronagraph Mission

    NASA Astrophysics Data System (ADS)

    Zhukov, Andrei

    2016-07-01

    PROBA-3 is the next project in the PROBA line of technology demonstration missions of ESA. PROBA-3, to be launched in 2019, is a mission dedicated to the in-flight demonstration of precise formation flying techniques and technologies. The PROBA-3 mission will place two spacecraft in a highly elliptical orbit around the Earth. The two spacecraft will fly in a precise formation, producing a very long baseline solar coronagraph called ASPIICS (Association of Spacecraft for Polarimetric and Imaging Investigation of the Corona of the Sun). One spacecraft will carry the optical telescope, and the second spacecraft will carry the external occulter of the coronagraph. The inter-satellite distance of around 150 m will allow observing the corona close to the solar limb with very low straylight. The PROBA-3/ASPIICS design will be described, and technical challenges of a formation flying mission will be discussed.

  3. Proceedings from the 2nd International Symposium on Formation Flying Missions and Technologies

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Topics discussed include: The Stellar Imager (SI) "Vision Mission"; First Formation Flying Demonstration Mission Including on Flight Nulling; Formation Flying X-ray Telescope in L2 Orbit; SPECS: The Kilometer-baseline Far-IR Interferometer in NASA's Space Science Roadmap Presentation; A Tight Formation for Along-track SAR Interferometry; Realization of the Solar Power Satellite using the Formation Flying Solar Reflector; SIMBOL-X : Formation Flying for High-Energy Astrophysics; High Precision Optical Metrology for DARWIN; Close Formation Flight of Micro-Satellites for SAR Interferometry; Station-Keeping Requirements for Astronomical Imaging with Constellations of Free-Flying Collectors; Closed-Loop Control of Formation Flying Satellites; Formation Control for the MAXIM Mission; Precision Formation Keeping at L2 Using the Autonomous Formation Flying Sensor; Robust Control of Multiple Spacecraft Formation Flying; Virtual Rigid Body (VRB) Satellite Formation Control: Stable Mode-Switching and Cross-Coupling; Electromagnetic Formation Flight (EMFF) System Design, Mission Capabilities, and Testbed Development; Navigation Algorithms for Formation Flying Missions; Use of Formation Flying Small Satellites Incorporating OISL's in a Tandem Cluster Mission; Semimajor Axis Estimation Strategies; Relative Attitude Determination of Earth Orbiting Formations Using GPS Receivers; Analysis of Formation Flying in Eccentric Orbits Using Linearized Equations of Relative Motion; Conservative Analytical Collision Probabilities for Orbital Formation Flying; Equations of Motion and Stability of Two Spacecraft in Formation at the Earth/Moon Triangular Libration Points; Formations Near the Libration Points: Design Strategies Using Natural and Non-Natural Ares; An Overview of the Formation and Attitude Control System for the Terrestrial Planet Finder Formation Flying Interferometer; GVE-Based Dynamics and Control for Formation Flying Spacecraft; GNC System Design for a New Concept of X

  4. Formation Flying With Decentralized Control in Libration Point Orbits

    NASA Technical Reports Server (NTRS)

    Folta, David; Carpenter, J. Russell; Wagner, Christoph

    2000-01-01

    A decentralized control framework is investigated for applicability of formation flying control in libration orbits. The decentralized approach, being non-hierarchical, processes only direct measurement data, in parallel with the other spacecraft. Control is accomplished via linearization about a reference libration orbit with standard control using a Linear Quadratic Regulator (LQR) or the GSFC control algorithm. Both are linearized about the current state estimate as with the extended Kalman filter. Based on this preliminary work, the decentralized approach appears to be feasible for upcoming libration missions using distributed spacecraft.

  5. Microsatellites enabling multicaptor formation flying ; the Essaim demonstrator

    NASA Astrophysics Data System (ADS)

    Alary, D.; Carrin, G.

    2004-11-01

    In the last decade, the microsatellites capabilities have been strongly enhanced. On the same time, costs have been reduced to enable the conception of formation flying systems, sent to orbit with a single lauch. This kind of system is made of several identical satellites, each making an individual measurement ; all the individual measurements can be processed on ground to provide an enriched synthetic measurement, which would have required a big satellite for a less or equal level of performance. The techniques are well known since years, but micro or minisatellites can now turn them into real spaceborne applications. A few years ago, under a French MoD contract, EADS Astrium and THALES Airborne Systems started the development of the Essaim demonstrator. Essaim is designed to demonstrate the electro-magnetic signal interception feasibility from space, and the possibilities of a formation flying (swarm) system to prepare for coming fully operational systems. It is based onseveral microsatellites of 120kg each, flying in a "swarm" configuration, roughly controlled. All the microsatellites are launched simultaneously as piggyback payloads on ARIANE 5, by the end of this year. The microsatellites are built around the Myriade bus developed by CNES in cooperation with EADS Astrium. A three years experimentation phase is scheduled under the contract. This experiment opens the route to other experiments based on the same principle. Several months prior the launch, we already know that it shall be a very promising way.

  6. Relative dynamics and motion control of nanosatellite formation flying

    NASA Astrophysics Data System (ADS)

    Pimnoo, Ammarin; Hiraki, Koju

    2016-04-01

    Orbit selection is a necessary factor in nanosatellite formation mission design/meanwhile, to keep the formation, it is necessary to consume fuel. Therefore, the best orbit design for nanosatellite formation flying should be one that requires the minimum fuel consumption. The purpose of this paper is to analyse orbit selection with respect to the minimum fuel consumption, to provide a convenient way to estimate the fuel consumption for keeping nanosatellite formation flying and to present a simplified method of formation control. The formation structure is disturbed by J2 gravitational perturbation and other perturbing accelerations such as atmospheric drag. First, Gauss' Variation Equations (GVE) are used to estimate the essential ΔV due to the J2 perturbation and atmospheric drag. The essential ΔV presents information on which orbit is good with respect to the minimum fuel consumption. Then, the linear equations which account for J2 gravitational perturbation of Schweighart-Sedwick are presented and used to estimate the fuel consumption to maintain the formation structure. Finally, the relative dynamics motion is presented as well as a simplified motion control of formation structure by using GVE.

  7. Initialization of Formation Flying Using Primer Vector Theory

    NASA Technical Reports Server (NTRS)

    Mailhe, Laurie; Schiff, Conrad; Folta, David

    2002-01-01

    In this paper, we extend primer vector analysis to formation flying. Optimization of the classical rendezvous or free-time transfer problem between two orbits using primer vector theory has been extensively studied for one spacecraft. However, an increasing number of missions are now considering flying a set of spacecraft in close formation. Missions such as the Magnetospheric MultiScale (MMS) and Leonardo-BRDF (Bidirectional Reflectance Distribution Function) need to determine strategies to transfer each spacecraft from the common launch orbit to their respective operational orbit. In addition, all the spacecraft must synchronize their states so that they achieve the same desired formation geometry over each orbit. This periodicity requirement imposes constraints on the boundary conditions that can be used for the primer vector algorithm. In this work we explore the impact of the periodicity requirement in optimizing each spacecraft transfer trajectory using primer vector theory. We first present our adaptation of primer vector theory to formation flying. Using this method, we then compute the AV budget for each spacecraft subject to different formation endpoint constraints.

  8. Formation flying in elliptic orbits with the J2 perturbation

    NASA Astrophysics Data System (ADS)

    Hou, Xi-Yun; Zhao, Yu-Hui; Liu, Lin

    2012-11-01

    Relative dynamics between the chief satellite and the deputy ones in formation flying is crucial to maintaining the formation. A good choice of the formation usually requires a lower control frequency or less control energy. For formation flying missions in highly elliptic orbits, the well-known C-W equation is not accurate enough. Instead, Lawden's equation is often used. First, the solution to Lawden's equation with a very simple form is deduced. Then the J2 perturbation is added. It is found that Lawden's solution is not necessarily valid when the J2 perturbation is considered. Completely discarding Lawden's solution and borrowing the idea of mean orbit elements, two rules to initialize the formation are proposed. The deviation speed is greatly reduced. Different from previous studies on the J2 perturbation, except for the relatively simple expression for the semi-major axis, the tedious formulae of the long period terms and the short period terms of other orbital elements are not used. In addition, the deviation speed is further reduced by compensation of the nonlinear effects. Finally, a loose control strategy of the formation is proposed. To test the robustness of this strategy, a third body perturbation is added in numerical simulations.

  9. Low-cost inkjet antennas for RFID applications

    NASA Astrophysics Data System (ADS)

    Çiftçi, T.; Karaosmanoğlu, B.; Ergül, Ö.

    2016-03-01

    We present paper-based inkjet antennas that are fabricated by using silver-based cartridges in standard printers. In addition to their low costs, the produced antennas are flexible, environmentally friendly, and suitable for radio-frequency identification (RFID) applications. Among alternative choices, hybrid structures involving loop and parasitic meander parts are preferred and successfully combined with passive RFID chips. We also discuss main challenges in the design and fabrication of low-cost inkjet antennas and the related RFID tags.

  10. Innovative optical power detection array system for relative positioning of inner-formation flying system

    NASA Astrophysics Data System (ADS)

    Hou, Zhendong; Wang, Zhaokui; Zhang, Yulin

    2016-09-01

    The Inner-formation flying system (IFFS) is conceived to feature a spherical proof mass falling freely within a large cavity for space gravity detection, of which first application focuses on the Earth's gravity field recovery. For the IFFS, it is the relative position of the proof mass to its surrounding cavity that is feedback into thrusters for tracking control, even as part of data to detect gravity. Since the demonstration and verification of demanding technologies using small satellite platforms is a very sensible choice prior to detection mission, an optical power detection array system (OPDAS) is proposed to measure the relative position with advantages of low cost and high adaptability. Besides that, its large dynamic range can reduce the requirement for satellite platform and releasing mechanism, which is also an attracting trait for small satellite application. The concept of the OPDAS is firstly presented, followed by the algorithm to position the proof mass. Then the radiation pressure caused by the measuring beam is modeled, and its disturbance on the proof mass is simulated. The experimental system to test the performance of a prototype of the OPDAS is established, and the preliminary results show that a precision of less than 0.4 mm across a dynamic range of several centimeters can be reached by the prototype of the OPDAS.

  11. Low-cost ladar imagers

    NASA Astrophysics Data System (ADS)

    Vasile, S.; Lipson, J.

    2008-04-01

    We have developed low-cost LADAR imagers using photon-counting Geiger avalanche photodiode (GPD) arrays, signal amplification and conditioning interface with integrated active quenching circuits (AQCs) and readout integrated circuit (ROIC) arrays for time to digital conversion (TDC) implemented in FPGA. Our goal is to develop a compact, low-cost LADAR receiver that could be operated with room temperature Si-GPD arrays and cooled InGaAs GPD arrays. We report on architecture selection criteria, integration issues of the GPD, AQC and TDC, gating and programmable features for flexible and low-cost re-configuration, as well as on timing resolution, precision and accuracy of our latest LADAR designs.

  12. Bounded relative orbits about asteroids for formation flying and applications

    NASA Astrophysics Data System (ADS)

    Baresi, Nicola; Scheeres, Daniel J.; Schaub, Hanspeter

    2016-06-01

    The relative motion about 4179 Toutatis is studied in order to investigate the feasibility of formation flying as an alternative concept for future asteroid exploration missions. In particular, the existence of quasi-frozen orbits about slowly rotating bodies allows us to compute families of periodic orbits in the body-fixed frame of the asteroid. Since these periodic orbits are of the center×center type, quasi-periodic invariant tori are calculated via fully numerical procedures and used to initialize spacecraft formations about the central body. Numerical simulations show that the resulting in-plane and out-of-plane relative trajectories remain bounded over long time spans; i.e., more than 30 days.

  13. The Precision Formation Flying Integrated Analysis Tool (PFFIAT)

    NASA Technical Reports Server (NTRS)

    Stoneking, Eric; Lyon, Richard G.; Sears, Edie; Lu, Victor

    2004-01-01

    Several space missions presently in the concept phase (e.g. Stellar Imager, Submillimeter Probe of Evolutionary Cosmic Structure, Terrestrial Planet Finder) plan to use multiple spacecraft flying in precise formation to synthesize unprecedently large aperture optical systems. These architectures present challenges to the attitude and position determination and control system; optical performance is directly coupled to spacecraft pointing with typical control requirements being on the scale of milliarcseconds and nanometers. To investigate control strategies, rejection of environmental disturbances, and sensor and actuator requirements, a capability is needed to model both the dynamical and optical behavior of such a distributed telescope system. This paper describes work ongoing at NASA Goddard Space Flight Center toward the integration of a set of optical analysis tools (Optical System Characterization and Analysis Research software, or OSCAR) with the Formation Flying Test Bed (FFTB). The resulting system is called the Precision Formation Flying Integrated Analysis Tool (PFFIAT), and it provides the capability to simulate closed-loop control of optical systems composed of elements mounted on multiple spacecraft. The attitude and translation spacecraft dynamics are simulated in the FFTB, including effects of the space environment (e.g. solar radiation pressure, differential orbital motion). The resulting optical configuration is then processed by OSCAR to determine an optical image. From this image, wavefront sensing (e.g. phase retrieval) techniques are being developed to derive attitude and position errors. These error signals will be fed back to the spacecraft control systems, completing the control loop. A simple case study is presented to demonstrate the present capabilities of the tool.

  14. Solar Power Satellite System Configured by Formation Flying

    NASA Astrophysics Data System (ADS)

    Takeichi, N.; Ueno, H.; Oda, M.

    2004-12-01

    A new concept of a solar power satellite system configured by formation flying (Formation-Flying Solar Power Satellite: FF-SPS) is presented. The solar power satellite system consists of two sunlight reflectors and an Earth-pointing segment. The Earth-pointing segment is on a common GEO, and the reflectors are placed on the north and south using solar pressure to raise their orbit planes. In this way, three separate structures comprise one solar power satellite system without any large rotation mechanisms. Two candidate configurations of FF-SPS are presented, and their feasibility are discussed focusing on the orbital and attitude mechanics of the reflector. One and the other are to place the reflector perpendicularly above and below the sub-reflector and the center of mass of the Earth-pointing segment, respectively. A larger amount of the control propellant is required for orbital control in the former configuration, and for the attitude control in the latter configuration. Through some analyses, it is shown that the required propellant for the control of the latter concept is about half of the former concept, which is about only 20% larger than that for previous concepts. It is considered that the latter concept minimized the demand for the orbital control by taking advantage of the characteristics of FF-SPS; it is possible to achieve an arbitrary attitude control. The structural feasibility is also discussed through FEM analyses. It is revealed that it is possible to assemble the lightweight reflector structure with sufficient stiffness using deployable structures based on current technologies. Although FF-SPS requires more control propellant than previous concepts, its feasibility is technologically equivalent to previous ones. Moreover, FF-SPS is the first concept that has both Earth-pointing and Sun-pointing segments without any single point of failure.

  15. Low-cost commercial transport

    NASA Technical Reports Server (NTRS)

    Mcpherson, J.

    1991-01-01

    The topics presented are covered in viewgraph form. The objectives are to develop and validate technology, design tools and methodologies to enable the low cost commercial development and operational uses of hydrogen and hydrocarbon fueled liquid engines, low pressure booster engines and hybrid engines.

  16. Low Cost Graphics. Second Edition.

    ERIC Educational Resources Information Center

    Tinker, Robert F.

    This manual describes the CALM TV graphics interface, a low-cost means of producing quality graphics on an ordinary TV. The system permits the output of data in graphic as well as alphanumeric form and the input of data from the face of the TV using a light pen. The integrated circuits required in the interface can be obtained from standard…

  17. Low Cost Sensor Calibration Options

    EPA Science Inventory

    Low-cost sensors ($1 D0-500) represent a unique class of air monitoring devices that may provide for more ubiquitous pollutant monitoring. They vary widely in design and measure pollutants, ranging from ozone, particulate matter, to volatile organic compounds. Many of these senso...

  18. Results of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Hawkins, Albin; Bauer, Frank (Technical Monitor)

    2002-01-01

    NASA's first autonomous formation flying mission completed its primary goal of demonstrating an advanced technology called enhanced formation flying. To enable this technology, the Flight Dynamics Analysis Branch at the Goddard Space Flight Center implemented a universal 3-axis formation flying algorithm in an autonomous executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm, the onboard flight design and the validation results of this unique system. Results from fully autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon, its ground-based predecessor used in operations, and the original standalone algorithm. Maneuvers discussed encompass reactionary, routine formation maintenance, and inclination control. Orbital data is also examined to verify that all formation flying requirements were met.

  19. Results Of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Hawkins, Albin

    2002-01-01

    NASA's first autonomous formation flying mission completed its primary goal of demonstrating an advanced technology called Enhanced Formation Flying. To enable this technology, a team at the Goddard Space Flight Center implemented a universal 3-axis formation flying algorithm in an autonomous executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm, the onboard flight design and the validation results of this unique system. Results from fully autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon(trademark), its ground-based predecessor used in operations, and the original standalone algorithm. Maneuvers discussed encompass reactionary, routine formation maintenance, and inclination control. Orbital data is also examined to verify that all formation flying requirements were met.

  20. Low-cost microsensors program

    NASA Astrophysics Data System (ADS)

    Anderson, John S.; Bradley, Daryl; Chen, Chungte W.; Chin, Richard; Jurgelewicz, K.; Radford, William A.; Kennedy, Adam; Murphy, Daniel F.; Ray, Michael; Wyles, Richard; Brown, James C.; Newsome, Gwendolyn W.

    2001-10-01

    The objectives of the Low Cost Microsensors (LCMS) Program are twofold. The first is to develop and deliver a long-range infrared (IR) sensor built upon an uncooled vanadium oxide (VOx) 640 X 512 format focal plane array (FPA) engine. The second is to develop an expendable microsensor built upon a VOx 160 X 128 format FPA engine. The 640 X 480 sensor is applicable to long-range surveillance and targeting missions and is a reusable asset. The 160 X 120 sensor is designed for applications where miniaturization is required as well as low cost and low power. The 160 X 120 is also intended for expendable military applications. The intent of this DUS&T effort is to further reduce the cost, weight, and power of uncooled IR sensors, and to increase the capability of these sensors, thereby expanding their applicability to military and commercial markets never before addressed by thermal imaging.

  1. SPHERES: Design of a Formation Flying Testbed for ISS

    NASA Astrophysics Data System (ADS)

    Sell, S. W.; Chen, S. E.

    2002-01-01

    The SPHERES (Synchronized Position Hold Engage and Reorient Experimental Satellites) payload is an innovative formation-flying spacecraft testbed currently being developed for use internally aboard the International Space Station (ISS). The purpose of the testbed is to provide a cost-effective, long duration, replenishable, and easily reconfigurable platform with representative dynamics for the development and validation of metrology, formation flying, and autonomy algorithms. The testbed components consist of three 8-inch diameter free-flying "satellites," five ultrasound beacons, and an ISS laptop workstation. Each satellite is self-contained with on-board battery power, cold-gas propulsion (CO2), and processing systems. Satellites use two packs of eight standard AA batteries for approximately 90 minutes of lifetime while beacons last the duration of the mission powered by a single AA battery. The propulsion system uses pressurized carbon dioxide gas, stored in replaceable tanks, distributed through an adjustable regulator and associated tubing to twelve thrusters located on the faces of the satellites. A Texas Instruments C6701 DSP handles control algorithm data while an FPGA manages all sensor data, timing, and communication processes on the satellite. All three satellites communicate with each other and with the controlling laptop via a wireless RF link. Five ultrasound beacons, located around a predetermined work area, transmit ultrasound signals that are received by each satellite. The system effectively acts as a pseudo-GPS system, allowing the satellites to determine position and attitude and to navigate within the test arena. The payload hardware are predominantly Commercial Off The Shelf (COTS) products with the exception of custom electronics boards, selected propulsion system adaptors, and beacon and satellite structural elements. Operationally, SPHERES will run in short duration test sessions with approximately two weeks between each session. During

  2. Autonomous Formation Flying from the Ground to Flight

    NASA Technical Reports Server (NTRS)

    Chapman, Keith B.; Dell, Gregory T.; Rosenberg, Duane L.; Bristow, John

    1999-01-01

    The cost of on-orbit operations remains a significant and increasingly visible concern in the support of satellite missions. Headway has been made in automating some ground operations; however, increased mission complexity and more precise orbital constraints have compelled continuing human involvement in mission design and maneuver planning operations. AI Solutions, Inc. in cooperation with the National Aeronautics and Space Administration's (NASA) Goddard Space Flight Center (GSFC) has tackled these more complex problems through the development of AutoCon(TM) as a tool for an automated solution. NASA is using AutoCon(TM) to automate the maneuver planning for the Earth Orbiter-1 (EO-1) mission. AutoCon(TM) was developed originally as a ground system tool. The EO-1 mission will be using a scaled version of AutoCon(TM) on-board the EO-1 satellite to command orbit adjustment maneuvers. The flight version of AutoCon(TM) plans maneuvers based on formation flying algorithms developed by GSFC, JPL, and other industry partners. In its fully autonomous mode, an AutoCon(TM) planned maneuver will be executed on-board the satellite without intervention from the ground. This paper describes how AutoCon(TM) automates maneuver planning for the formation flying constraints of the EO-1 mission. AutoCon(TM) was modified in a number of ways to automate the maneuver planning on-board the satellite. This paper describes how the interface and functionality of AutoCon(TM) were modified to support the on-board system. A significant component of this modification was the implementation of a data smoother, based on a Kalman filter, that ensures that the spacecraft states estimated by an on-board GPS receiver are as accurate as possible for maneuver planning. This paper also presents the methodology used to scale the AutoCon(TM) functionality to fit and execute on the flight hardware. This paper also presents the modes built into the system that allow the incremental phasing in of autonomy

  3. A Tethered Formation Flying Concept for the SPECS Mission

    NASA Technical Reports Server (NTRS)

    Quinn, David A.; Folta, David C.

    2000-01-01

    The Sub-millimeter Probe of the Evolution of Cosmic Structure (SPECS) is a bold new mission concept designed to address fundamental questions about the Universe, including how the first stars formed from primordial material, and the first galaxies from pre-galactic structures, how the galaxies evolve over time, and what the cosmic history of energy release, heavy element synthesis, and dust formation is. Half of the luminosity and 98% of the post Big-Bang photons exit in the sub-millimeter range. The spectrum of our own Milky Way Galaxy shows this, and many galaxies have even more pronounced long-wavelength emissions. There can be no doubt that revolutionary science will be enabled when we have tools to study the sub-millimeter sky with Hubble- Space-Telescope-class resolution and sensitivity. Ideally, a very large telescope with an effective aperture approaching one kilometer in diameter would be needed to obtain such high quality angular resolution at these long wavelengths. However, a single aperture one kilometer in diameter would not only be very difficult to build and maintain at the cryogenic temperatures required for good seeing, but could actually turn out to be serious overkill. Because cosmic sub-millimeter photons are plentiful and the new detectors will be sensitive, the observations needed to address the questions posed above can be made with an interferometer using well established aperture synthesis techniques. Possibly as few as three 3-4 meter diameter mirrors flying in precision formation could be used to collect the light. To mitigate the need for a great deal of propellant, tethers may be needed as well. A spin-stabilized, tethered formation is a possible configuration requiring a more advanced form of formation flying controller, where dynamics are coupled due to the existence of the tethers between nodes in the formation network. The paper presents one such concept, a proposed configuration for a mission concept which combines the best

  4. Relative Sensor with 4(pi) Coverage for Formation Flying Missions

    NASA Technical Reports Server (NTRS)

    Tien, Jeffrey Y.; Purcell, George H., Jr.; Sirinivasan, Jeffrey M.; Young, Lawrence E.

    2004-01-01

    The Terrestrial Planet Finder (TPF) pre-project, an element of NASA's Origins program, is currently developing two architectures for a mission to search for earth-like planets around nearby stars. One of the architectures being developed is the Formation Flying Interferometer (FFI). The FFI is envisioned to consist of up to seven spacecraft (as many as six 'collectors' with IR telescopes, and a 'combiner') flying in precise formation within f 1 cm of pre-determined trajectories for synchronized observations. The spacecraft-to-spacecraft separations are variable between 20 m and 100 m or more during observations to support various configurations of the interferometer in the planet-finding mode. The challenges involved with TPF autonomous operations, ranging from formation acquisition and formation maneuvering to high precision formation control during science observations, are unprecedented. In this paper we discuss the development of the formation acquisition sensor, which uses novel modulation and duplexing schemes to enable fast signal acquisition, multiple-spacecraft operation, and mitigation of inherent jamming conditions, while providing precise formation sensing and integrated radar capability. This approach performs delay synthesis and carrier cycle ambiguity resolution to improve range measurement, and uses differential carrier cycle ambiguity resolution to make precise bearing angle measurements without calibration maneuvers.

  5. Relative Sensor with 4Pi Coverage for Formation Flying Missions

    NASA Technical Reports Server (NTRS)

    Tien, Jeffrey Y.; Purcell, George H., Jr.; Srinivasan, Jeffrey M.; Young, Lawrence E.

    2004-01-01

    The Terrestrial Planet Finder (TPF) pre-project, an element of NASA s Origins program, is currently developing two architectures for a mission to search for earth-like planets around nearby stars. One of the architectures being developed is the Formation Flying Interferometer (FFI). The FFI is envisioned to consist of up to seven spacecraft (as many as six "collectors" with IR telescopes, and a "combiner") flying in precise formation within +/-1 cm of pre-determined trajectories for synchronized observations. The spacecraft-to-spacecraft separations are variable between 20 m and 100 m or more during observations to support various configurations of the interferometer in the planet-finding mode. The challenges involved with TPF autonomous operations, ranging from formation acquisition and formation maneuvering to high precision formation control during science observations, are unprecedented. In this paper we discuss the development of the formation acquisition sensor, which uses novel modulation and duplexing schemes to enable fast signal acquisition, multiple-spacecraft operation, and mitigation of inherent jamming conditions, while providing precise formation sensing and integrated radar capability. This approach performs delay synthesis and carrier cycle ambiguity resolution to improve range measurement, and uses differential carrier cycle ambiguity resolution to make precise bearing angle measurements without calibration maneuvers.

  6. Considerations on formation flying separations for earth observing satellite missions

    NASA Technical Reports Server (NTRS)

    Folta, David; Bordi, Francesco; Scolese, Christopher

    1992-01-01

    We assume that scientific requirements (or other mission requirements) call for simultaneous observations from sensors located on different formation-flying spacecraft, and assess how well various kinds of formations of two and three spacecraft can meet these simultaneity requirements. We simulate two types of formation, one where the slave spacecraft moves with respect to the reference spacecraft, and the other where the two spacecraft are kept at a constant time separation. For each type of formation we consider two attitudes: a perfect local vertical local horizontal (LVLH) and an attitude which represents the maximum allowable mission tolerance offset from the mission requirements for attitude determination. We simulate formations of multiple spacecraft and determine how well they can perform simultaneous observations. For each spacecraft we compute the instantaneous ground projection of the center of the imager's fieId of view and plot the movement of the instantaneous ground projection of one spacecraft in the formation relative to the other. The size and shape of this effective ground target parametrize the size and shape of the actual ground target as well as the size and shape of the imager's field of view and the percentage of overlap required.

  7. Formation Flying of Components of a Large Space Telescope

    NASA Technical Reports Server (NTRS)

    Mettler, Edward; Quadrelli, Marco; Breckenridge, William

    2009-01-01

    A conceptual space telescope having an aperture tens of meters wide and a focal length of hundreds of meters would be implemented as a group of six separate optical modules flying in formation: a primary-membrane-mirror module, a relay-mirror module, a focal-plane-assembly module containing a fast steering mirror and secondary and tertiary optics, a primary-mirror-figure-sensing module, a scanning-electron-beam module for controlling the shape of the primary mirror, and a sunshade module. Formation flying would make it unnecessary to maintain the required precise alignments among the modules by means of an impractically massive rigid structure. Instead, a control system operating in conjunction with a metrology system comprising optical and radio subsystems would control the firing of small thrusters on the separate modules to maintain the formation, thereby acting as a virtual rigid structure. The control system would utilize a combination of centralized- and decentralized-control methods according to a leader-follower approach. The feasibility of the concept was demonstrated in computational simulations that showed that relative positions could be maintained to within a fraction of a millimeter and orientations to within several microradians.

  8. Formation Flying: The Future of Remote Sensing from Space

    NASA Technical Reports Server (NTRS)

    Leitner, Jesse

    2004-01-01

    Over the next two decades a revolution is likely to occur in how remote sensing of Earth, other planets or bodies, and a range of phenomena in the universe is performed from space. In particular, current launch vehicle fairing volume and mass constraints will continue to restrict the size of monolithic telescope apertures which can be launched to little or no greater size than that of the Hubble Space Telescope, the largest aperture currently flying in space. Systems under formulation today, such as the James Webb Space Telescope will be able to increase aperture size and, hence, imaging resolution, by deploying segmented optics. However, this approach is limited as well, by our ability to control such segments to optical tolerances over long distances with highly uncertain structural dynamics connecting them. Consequently, for orders of magnitude improved resolution as required for imaging black holes, imaging planets, or performing asteroseismology, the only viable approach will be to fly a collection of spacecraft in formation to synthesize a virtual segmented telescope or interferometer with very large baselines. This paper provides some basic definitions in the area of formation flying, describes some of the strategic science missions planned in the National Aeronautics and Space Administration, and identifies some of the critical technologies needed to enable some of the most challenging space missions ever conceived which have realistic hopes of flying.

  9. Autonomous Real-time Relative Navigation for Formation Flying Satellites

    NASA Astrophysics Data System (ADS)

    Shim, Shnhwa; Park, Sang-Young; Choi, Kyu-Hong

    2009-03-01

    Relative navigation system is presented using GPS measurements from a single-channel global positioning system (GPS) simulator. The objective of this study is to provide the real-time inter-satellite relative positions as well as absolute positions for two formation flying satellites in low earth orbit. To improve the navigation performance, the absolute states are estimated using ion-free GRAPHIC (group and phase ionospheric correction) pseudo-ranges and the relative states are determined using double-differential carrier-phase data and singled-differential C/A code data based on the extended Kalman filter and the unscented Kalman filter. Furthermore, pseudo-relative dynamic model and modified relative measurement model are developed. This modified EKF method prevents non-linearity of the measurement model from degrading precision by applying linearization about absolute navigation solutions not about the priori estimates. The LAMBDA method also has been used to improve the relative navigation performance by fixing ambiguities to integers for precise relative navigation. The software-based simulation has been performed and the steady state accuracies of 1 m and 6 mm (1σ of 3-dimensional difference errors) are achieved for the absolute and relative navigation using EKF for a short baseline leader/follower formation. In addition, the navigation performances are compared for the EKF and the UKF for 10 hours simulation, and relative position errors are mm-level for the two filters showing the similar trends.

  10. Optimal Lorentz-augmented spacecraft formation flying in elliptic orbits

    NASA Astrophysics Data System (ADS)

    Huang, Xu; Yan, Ye; Zhou, Yang

    2015-06-01

    An electrostatically charged spacecraft accelerates as it moves through the Earth's magnetic field due to the induced Lorentz force, providing a new means of propellantless electromagnetic propulsion for orbital maneuvers. The feasibility of Lorentz-augmented spacecraft formation flying in elliptic orbits is investigated in this paper. Assuming the Earth's magnetic field as a tilted dipole corotating with Earth, a nonlinear dynamical model that characterizes the orbital motion of Lorentz spacecraft in the vicinity of arbitrary elliptic orbits is developed. To establish a predetermined formation configuration at given terminal time, pseudospectral method is used to solve the optimal open-loop trajectories of hybrid control inputs consisted of Lorentz acceleration and thruster-generated control acceleration. A nontilted dipole model is also introduced to analyze the effect of dipole tilt angle via comparisons with the tilted one. Meanwhile, to guarantee finite-time convergence and system robustness against external perturbations, a continuous fast nonsingular terminal sliding mode controller is designed and the closed-loop system stability is proved by Lyapunov theory. Numerical simulations substantiate the validity of proposed open-loop and closed-loop control schemes, and the results indicate that an almost propellantless formation establishment can be achieved by choosing appropriate objective function in the pseudospectral method. Furthermore, compared to the nonsingular terminal sliding mode controller, the closed-loop controller presents superior convergence rate with only a bit more control effort. And the proposed controller can be applied in other Lorentz-augmented relative orbital control problems.

  11. Low-cost microsensors program

    NASA Astrophysics Data System (ADS)

    Anderson, John S.; Bradley, Daryl; Chen, Chungte W.; Chin, Richard; Hegg, Ronald G.; Kennedy, Adam; Murphy, Daniel F.; Ray, Michael; Wyles, Richard; Brown, James C.; Newsome, Gwendolyn W.

    2002-07-01

    The Low Cost Microsensors (LCMS) Program recently demonstrated state-of-the-art imagery in a long-range infrared (IR) sensor built upon an uncooled vanadium oxide (VOx) 640 X 480 format focal plane array (FPA) engine. The 640 X 480 sensor is applicable to long-range surveillance and targeting missions. The intent of this DUS&T effort is to further reduce the cost, weight, and power of uncooled IR sensors, and to increase the capability of these sensors, thereby expanding their applicability to military and commercial markets never before addressed by thermal imaging.

  12. Nonlinear relative position control of precise formation flying using polynomial eigenstructure assignment

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Chen, XueQin; Tsourdos, Antonios; White, Brian A.; Wu, YunHua

    2011-06-01

    A nonlinear relative position control algorithm is designed for spacecraft precise formation flying. Taking into account the effect of J2 gravitational perturbations and atmospheric drag, the relative motion dynamic equation of the formation flying is developed in a quasi-linear parameter-varying (QLPV) form without approximation. Base on this QLPV model, polynomial eigenstructure assignment (PEA) is applied to design the controller. The resulting PEA controller is a function of system state and parameters, and produces a closed-loop system with invariant performance over a wide range of conditions. Numerical simulation results show that the performance can fulfill precise formation flying requirements.

  13. The Precision Formation Flying Integrated Analysis Tool (PFFIAT)

    NASA Technical Reports Server (NTRS)

    Stoneking, Eric; Lyon, Richard G.; Sears, Edie; Lu, Victor

    2004-01-01

    Several space missions presently in the concept phase (e.g. Stellar Imager, Sub- millimeter Probe of Evolutionary Cosmic Structure, Terrestrial Planet Finder) plan to use multiple spacecraft flying in precise formation to synthesize unprecedently large aperture optical systems. These architectures present challenges to the attitude and position determination and control system; optical performance is directly coupled to spacecraft pointing with typical control requirements being on the scale of milliarcseconds and nanometers. To investigate control strategies, rejection of environmental disturbances, and sensor and actuator requirements, a capability is needed to model both the dynamical and optical behavior of such a distributed telescope system. This paper describes work ongoing at NASA Goddard Space Flight Center toward the integration of a set of optical analysis tools (Optical System Characterization and Analysis Research software, or OSCAR) with the Formation J?lying Test Bed (FFTB). The resulting system is called the Precision Formation Flying Integrated Analysis Tool (PFFIAT), and it provides the capability to simulate closed-loop control of optical systems composed of elements mounted on multiple spacecraft. The attitude and translation spacecraft dynamics are simulated in the FFTB, including effects of the space environment (e.g. solar radiation pressure, differential orbital motion). The resulting optical configuration is then processed by OSCAR to determine an optical image. From this image, wavefront sensing (e.g. phase retrieval) techniques are being developed to derive attitude and position errors. These error signals will be fed back to the spacecraft control systems, completing the control loop. A simple case study is presented to demonstrate the present capabilities of the tool.

  14. Low Cost Digital Vibration Meter

    PubMed Central

    Payne, W. Vance; Geist, Jon

    2007-01-01

    This report describes the development of a low cost, digital Micro Electro Mechanical System (MEMS) vibration meter that reports an approximation to the RMS acceleration of the vibration to which the vibration meter is subjected. The major mechanical element of this vibration meter is a cantilever beam, which is on the order of 500 µm in length, with a piezoresistor deposited at its base. Vibration of the device in the plane perpendicular to the cantilever beam causes it to bend, which produces a measurable change in the resistance of a piezoresistor. These changes in resistance along with a unique signal-processing scheme are used to determine an approximation to the RMS acceleration sensed by the device. PMID:27110459

  15. Results of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David C.; Hawkins, Albin; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    NASA's first autonomous formation flying mission completed its primary goal of demonstrating an advanced technology called enhanced formation flying. To enable this technology, the Guidance, Navigation, and Control center at the Goddard Space Flight Center (GSFC) implemented a universal 3-axis formation flying algorithm in an autonomous executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm and the onboard flight design and presents the validation results of this unique system. Results from functionality assessment through fully autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon(tm), its ground-based predecessor, and a standalone algorithm.

  16. Preliminary Results of NASA's First Autonomous Formation Flying Experiment: Earth Observing-1 (EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Hawkins, Albin

    2001-01-01

    NASA's first autonomous formation flying mission is completing a primary goal of demonstrating an advanced technology called enhanced formation flying. To enable this technology, the Guidance, Navigation, and Control center at the Goddard Space Flight Center has implemented an autonomous universal three-axis formation flying algorithm in executive flight code onboard the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft. This paper describes the mathematical background of the autonomous formation flying algorithm and the onboard design and presents the preliminary validation results of this unique system. Results from functionality assessment and autonomous maneuver control are presented as comparisons between the onboard EO-1 operational autonomous control system called AutoCon(tm), its ground-based predecessor, and a stand-alone algorithm.

  17. Finding Low-Cost Medical Care

    MedlinePlus

    ... costs and insurance requirements before you get care. Free and Low-Cost Clinics and Health Centers If ... in school), you may be able to find free or low-cost health clinics in your neighborhood. ...

  18. Low-Cost Large Aperture Telescopes for Optical Communications

    NASA Technical Reports Server (NTRS)

    Hemmati, Hamid

    2006-01-01

    Low-cost, 0.5-1 meter ground apertures are required for near-Earth laser communications. Low-cost ground apertures with equivalent diameters greater than 10 meters are desired for deep-space communications. This presentation focuses on identifying schemes to lower the cost of constructing networks of large apertures while continuing to meet the requirements for laser communications. The primary emphasis here is on the primary mirror. A slumped glass spherical mirror, along with passive secondary mirror corrector and active adaptive optic corrector show promise as a low-cost alternative to large diameter monolithic apertures. To verify the technical performance and cost estimate, development of a 1.5-meter telescope equipped with gimbal and dome is underway.

  19. Decentralized formation flying control in a multiple-team hierarchy.

    PubMed

    Mueller, Joseph B; Thomas, Stephanie J

    2005-12-01

    In recent years, formation flying has been recognized as an enabling technology for a variety of mission concepts in both the scientific and defense arenas. Examples of developing missions at NASA include magnetospheric multiscale (MMS), solar imaging radio array (SIRA), and terrestrial planet finder (TPF). For each of these missions, a multiple satellite approach is required in order to accomplish the large-scale geometries imposed by the science objectives. In addition, the paradigm shift of using a multiple satellite cluster rather than a large, monolithic spacecraft has also been motivated by the expected benefits of increased robustness, greater flexibility, and reduced cost. However, the operational costs of monitoring and commanding a fleet of close-orbiting satellites is likely to be unreasonable unless the onboard software is sufficiently autonomous, robust, and scalable to large clusters. This paper presents the prototype of a system that addresses these objectives-a decentralized guidance and control system that is distributed across spacecraft using a multiple team framework. The objective is to divide large clusters into teams of "manageable" size, so that the communication and computation demands driven by N decentralized units are related to the number of satellites in a team rather than the entire cluster. The system is designed to provide a high level of autonomy, to support clusters with large numbers of satellites, to enable the number of spacecraft in the cluster to change post-launch, and to provide for on-orbit software modification. The distributed guidance and control system will be implemented in an object-oriented style using a messaging architecture for networking and threaded applications (MANTA). In this architecture, tasks may be remotely added, removed, or replaced post launch to increase mission flexibility and robustness. This built-in adaptability will allow software modifications to be made on-orbit in a robust manner. The

  20. Low cost Earth Attitude Sensor

    NASA Astrophysics Data System (ADS)

    Liberati, Fabrizio; Perrotta, Giorgio; Verzegnassi, Fulvia

    2004-06-01

    A patent-pending, low-cost, moderate performance, Earth Attitude Sensor for LEO satellites is described in this paper. The paper deals with the system concepts, the technology adopted and the simulation results. The sensor comprises three or four narrow field of view mini telescopes pointed towards the Earth edge to detect and measure the variation of the off-nadir angle of the Earth-to-black sky transition using thermopile detectors suitably placed in the foci of the optical min telescopes. The system's innovation consists in the opto-mechanical configuration adopted that is sturdy and has no moving parts being, thus, inherently reliable. In addition, with a view to reducing production costs, the sensor does without hi-rel and is instead mainly based on COTS parts suitably chosen. Besides it is flexible and can be adapted to perform attitude measurement onboard spacecraft flying in orbits other than LEO with a minimum of modifications to the basic design. At present the sensor is under development by IMT and OptoService.

  1. A Novel Approach for a Low-Cost Deployable Antenna

    NASA Technical Reports Server (NTRS)

    Amend, Chris; Nurnberger, Michael; Oppenheimer, Paul; Koss, Steve; Purdy, Bill

    2010-01-01

    The Naval Research Laboratory (NRL) has designed, built, and fully qualified a low cost, low Passive Intermodulation (PIM) 12-foot (3.66-m) diameter deployable ultra high frequency (UHF) antenna for the Tacsat-4 program. The design utilized novel approaches in reflector material and capacitive coupling techniques. This paper discusses major design trades, unique design characteristics, and lessons learned from the development of the Tacsat 4 deployable antenna. This antenna development was sponsored by the Office of Naval Research.

  2. Low-cost periodontal therapy.

    PubMed

    Slots, Jørgen

    2012-10-01

    Periodontitis is a complex infectious disease that affects low-income individuals disproportionately. Periodontitis is associated with specific bacterial species and herpesviruses, and successful prevention and treatment of the disease is contingent upon effective control of these pathogens. This article presents an efficacious, highly safe, minimally invasive, practical and low-cost periodontal therapy that involves professional and patient-administered mechanical therapy and antimicrobial agents. The major components are scaling for calculus removal, periodontal pocket irrigation with potent antiseptics, and treatment with systemic antibiotics for advanced disease. Povidone-iodine and sodium hypochlorite have all the characteristics for becoming the first-choice antiseptics in the management of periodontal diseases. Both agents show excellent antibacterial and antiviral properties, are readily available throughout the world, have been safely used in periodontal therapy for decades, offer significant benefits for individuals with very limited financial resources, and are well accepted by most dental professionals and patients. Four per cent chlorhexidine applied with a toothbrush to the most posterior part to the tongue dorsum can markedly reduce or eliminate halitosis in most individuals. Systemic antibiotics are used to treat periodontopathic bacteria that are not readily reached by topical therapy, such as pathogens within gingival tissue, within furcation defects, at the base of periodontal pockets, and on the tongue, tonsils and buccal mucosae. Valuable antibiotic therapies are amoxicillin-metronidazole (250 mg of amoxicillin and 250 mg of metronidazole, three times daily for 8 days) for young and middle-aged patients, and ciprofloxacin-metronidazole (500 mg of each, twice daily for 8 days) for elderly patients and for patients in developing countries who frequently harbor enteric rods subgingivally. Scaling to remove dental calculus and the prudent

  3. Low Cost Mission to Deimos

    NASA Astrophysics Data System (ADS)

    Quantius, Dominik; Püsler, H.; Braukhane, A.; Gülzow, P.; Bauer, W.; Vollhardt, A.; Romberg, O.; Scheibe, K.; Hoffmann, H.; Bürner, A.

    The German non-profit amateur satellite organisation AMSAT-Deutschland successfully de-signed, built and launched four HEO satellites in the last three decades. Now they are going to build a satellite to leave the Earth orbit based on their flight-proven P3-D satellite design. Due to energetic constraints the most suitable launch date for the planned P5-A satellite to Mars will be in 2018. To efficiently use the relatively long time gap until launch a possible prior Moon mission came into mind. In co-operation with the DLR-Institute of Space Systems in Bremen, Germany, two studies on systems level for a first P5 satellite towards Moon and a following one towards Mars have been performed. By using the DLR's Concurrent Engineering Facility (CEF) two consistent satellite concepts were designed including mission analysis, configuration, propulsion, subsystem dimensioning, payload selection, budgeting and cost. The present paper gives an insight in the accomplished design process and the results of the performed study towards Mars. The developed Mars orbiter is designed to carry the following four main instruments besides flexible communication abilities: • multispectral line scanner for Martian cloud investigations and Deimos (and Phobos) stereo pictures during close flybys • Deimos framing camera for high resolution pictures of Deimos (and Phobos) including video mode • sensor imaging infrared spectrometer for mineralogy of Martian (also Deimos and Phobos) silicates and surface temperature measurements • radio science for research of Deimos ( Phobos) gravity, profiling of Mars ionosphere, occurrence of third meteoritic ionosphere layer; sounding of neutral atmosphere; solar corona activity This study presents a non-industrial satellite concept that could be launched as piggyback load on Ariane 5 into GTO. It promises a low cost mission into a Mars orbit that allows close approaches to Deimos and Phobos.

  4. Low Cost Large Space Antennas

    NASA Technical Reports Server (NTRS)

    Chmielewski, Artur B.; Freeland, Robert

    1997-01-01

    The mobile communication community could significantly benefit from the availability of low-cost, large space-deployable antennas. A new class of space structures, called inflatable deployable structures, will become an option for this industry in the near future. This new technology recently made significant progress with respect to reducing the risk of flying large inflatable structures in space. This progress can be attributed to the successful space flight of the Inflatable Antenna Experiment in May of 1996, which prompted the initiation of the NASA portion of the joint NASA/DOD coordinated Space Inflatables Program, which will develop the technology to be used in future mobile communications antennas along with other users. The NASA/DOD coordinated Space Inflatables Program was initiated in 1997 as a direct result of the Inflatable Antenna Experiment. The program adds a new NASA initiative to a substantial DOD program that involves developing a series of ground test hardware, starting with 3 meter diameter units and advancing the manufacturing techniques to fabricate a 25 meter ground demonstrator unit with surface accuracy exceeding the requirements for mobile communication applications. Simultaneously, the program will be advancing the state of the art in several important inflatable technology areas, such as developing rigidizable materials for struts and tori and investigating thin film technology issues, such as application of coatings, property measurement and materials processing and assembly techniques. A very important technology area being addressed by the program is deployment control techniques. The program will sponsor activities that will lead to understanding the effects of material strain energy release, residual air in the stowed structure, and the design of the launch restraint and release system needed to control deployment dynamics. Other technology areas directly applicable to developing inflatable mobile communication antennas in the near

  5. Enabling Spacecraft Formation Flying in Any Earth Orbit Through Spaceborne GPS and Enhanced Autonomy Technologies

    NASA Technical Reports Server (NTRS)

    Bauer, F. H.; Bristow, J. O.; Carpenter, J. R.; Garrison, J. L.; Hartman, K. R.; Lee, T.; Long, A. C.; Kelbel, D.; Lu, V.; How, J. P.; Busse, F.

    2000-01-01

    Formation flying is quickly revolutionizing the way the space community conducts autonomous science missions around the Earth and in space. This technological revolution will provide new, innovative ways for this community to gather scientific information, share this information between space vehicles and the ground, and expedite the human exploration of space. Once fully matured, this technology will result in swarms of space vehicles flying as a virtual platform and gathering significantly more and better science data than is possible today. Formation flying will be enabled through the development and deployment of spaceborne differential Global Positioning System (GPS) technology and through innovative spacecraft autonomy techniques, This paper provides an overview of the current status of NASA/DoD/Industry/University partnership to bring formation flying technology to the forefront as quickly as possible, the hurdles that need to be overcome to achieve the formation flying vision, and the team's approach to transfer this technology to space. It will also describe some of the formation flying testbeds, such as Orion, that are being developed to demonstrate and validate these innovative GPS sensing and formation control technologies.

  6. Low cost attitude control system scanwheel development

    NASA Technical Reports Server (NTRS)

    Bialke, William; Selby, Vaughn

    1991-01-01

    In order to satisfy a growing demand for low cost attitude control systems for small spacecraft, development of low cost scanning horizon sensor coupled to a low cost/low power consumption Reaction Wheel Assembly was initiated. This report addresses the details of the versatile design resulting from this effort. Tradeoff analyses for each of the major components are included, as well as test data from an engineering prototype of the hardware.

  7. Low Cost Hydrogen Production Platform

    SciTech Connect

    Timothy M. Aaron, Jerome T. Jankowiak

    2009-10-16

    conducted to identify any potential design deficiency related to the concept. The analysis showed that no fundamental design flaw existed with the concept, but additional simulations and prototypes would be required to verify the design prior to fabricating a production unit. These identified risks were addressed in detail during Phase II of the development program. Along with the models of the high temperature components, a detailed process and 3D design model of the remainder of system, including PSA, compression, controls, water treatment and instrumentation was developed and evaluated. Also, in Phase II of the program, laboratory/fullscale testing of the high temperature components was completed and stable operation/control of the system was verified. The overall design specifications and test results were then used to develop accurate hydrogen costs for the optimized system. Praxair continued development and testing of the system beyond the Phase II funding provided by the DOE through the end of 2008. This additional testing is not documented in this report, but did provide significant additional data for development of a prototype system as detailed in the Phase III proposal. The estimated hydrogen product costs were developed (2007 basis) for the 4.8 kg/h system at production rates of 1, 5, 10, 100 and 1,000 units built per year. With the low cost SMR approach, the product hydrogen costs for the 4.8 kg/h units at 50 units produced per year were approximately $3.02 per kg. With increasing the volume production to 1,000 units per year, the hydrogen costs are reduced by about 12% to $2.67 per kg. The cost reduction of only 12% is a result of significant design and fabrication efficiencies being realized in all levels of production runs through utilizing the DFMA principles. A simplified and easily manufactured design does not require large production volumes to show significant cost benefits. These costs represent a significant improvement and a new benchmark in the

  8. A Robust Control Approach for the Formation Flying of Multiple Spacecraft

    NASA Technical Reports Server (NTRS)

    Mesbahi, M.; Hadaegh, F. Y.

    1998-01-01

    We present a disturbance rejection mechanism for the formation flying of multiple spacecraft based on a robust control approach in terms of an H(sub infinity) control problem. The corresponding H(sub infinity) control problem is then solved numerically using linear matrix inequalities.

  9. A Concept for In-space, System-level Validation of Spacecraft Precision Formation Flying

    NASA Technical Reports Server (NTRS)

    Leitner, Jesse; Carpenter, J. Russell; Naasz, Bo J.; Scharf, Daniel P.; Hadaegh, Fred Y.; Ahmed, Asif

    2007-01-01

    A number of international space agencies and organizations, to include the National Aeronautics and Space Administration (NASA), the European Space Agency (ESA), and the Centre National d'Etudes Spatiales (CNES), to name a few, have embraced the concept of spacecraft formation flying to revolutionize the capabilities of astronomy and Earth remote sensing from space. The concept has been around well over a decade and a wide array of technologies and capabilities have been developed to enable multiple spacecraft to collaborate in a highly-coupled manner as would be required for a formation flying mission. Furthermore, many relevant capabilities for formation flying have been demonstrated in the area of rendezvous and docking, loosely-controlled formations, and in missions with collaborating spacecraft with very precise metrology. .However, in considering the case of precision formation flying (PFF), i.e, when the relative geometry of multiple vehicles must be controlled on-board in a continuous and precise manner, there have been several missions proposed, but the realization in space has not yet occurred due to a range of issues. This paper will briefly examine those issues and present a concept for demonstrating a core capability for performing PFF, necessary for virtually any PFF mission concept, that will help to overcome the problems encountered in prior attempts and help to allay the risks to enable future PFF science missions.

  10. Hardware-In-The-Loop Testing of Continuous Control Algorithms for a Precision Formation Flying Demonstration Mission

    NASA Technical Reports Server (NTRS)

    Naasz, Bo J.; Burns, Richard D.; Gaylor, David; Higinbotham, John

    2004-01-01

    A sample mission sequence is defined for a low earth orbit demonstration of Precision Formation Flying (PFF). Various guidance navigation and control strategies are discussed for use in the PFF experiment phases. A sample PFF experiment is implemented and tested in a realistic Hardware-in-the-Loop (HWIL) simulation using the Formation Flying Test Bed (FFTB) at NASA's Goddard Space Flight Center.

  11. Enabling Spacecraft Formation Flying through Position Determination, Control and Enhanced Automation Technologies

    NASA Technical Reports Server (NTRS)

    Bristow, John; Bauer, Frank; Hartman, Kate; How, Jonathan

    2000-01-01

    Formation Flying is revolutionizing the way the space community conducts science missions around the Earth and in deep space. This technological revolution will provide new, innovative ways for the community to gather scientific information, share that information between space vehicles and the ground, and expedite the human exploration of space. Once fully matured, formation flying will result in numerous sciencecraft acting as virtual platforms and sensor webs, gathering significantly more and better science data than call be collected today. To achieve this goal, key technologies must be developed including those that address the following basic questions posed by the spacecraft: Where am I? Where is the rest of the fleet? Where do I need to be? What do I have to do (and what am I able to do) to get there? The answers to these questions and the means to implement those answers will depend oil the specific mission needs and formation configuration. However, certain critical technologies are common to most formations. These technologies include high-precision position and relative-position knowledge including Global Positioning System (GPS) mid celestial navigation; high degrees of spacecraft autonomy inter-spacecraft communication capabilities; targeting and control including distributed control algorithms, and high precision control thrusters and actuators. This paper provides an overview of a selection of the current activities NASA/DoD/Industry/Academia are working to develop Formation Flying technologies as quickly as possible, the hurdles that need to be overcome to achieve our formation flying vision, and the team's approach to transfer this technology to space. It will also describe several of the formation flying testbeds, such as Orion and University Nanosatellites, that are being developed to demonstrate and validate many of these innovative sensing and formation control technologies.

  12. Use of RF Metrology Subsystem for Formation Flying Command & Control Purposes

    NASA Astrophysics Data System (ADS)

    Sougmagne, R.; Andreis, O.; Dellandrea, B.; Mehlen, C.; Alison, B.

    2007-08-01

    The development of the "RF metrology and data-link instrument" for formation flying missions was initiated in 2001 by ESA/CNES for the DARWIN mission in order to define a subsystem able to provide both relative positioning service and inter-vehicle communication data link for formation flying missions. Today, the number of target missions is wide: SIMBOL-X, PEGASE, PROBA-3, XEUS, DARWIN, … THALES ALENIA SPACE is currently developing and manufacturing the first European multi-mission RF metrology and data link instrument (called FFRFS for Formation Flying Radio-Frequency Sensor) in the frame of the FFIORD (Formation Flying In Orbit RF Demonstration) contribution of CNES to the Swedish PRISMA mission: flight models will be delivered in early 2008. The first goal of the FFRFS is to provide relative positioning (accuracy better than 1cm for distance and 1 degree for the line of sight) for formation of 2 to 4 vehicles over a large operational range (3m to 30km). One of its key features is its omni-directional coverage, providing safe conditions during deployment phase or failure recovery situations. Moreover, it offers an omni- directional communication link for the formations allowing inter-vehicle data rate of 12kbps for transmission of telemetry, telecommands or GNC data. These characteristics make the FFRFS the key element of the command & control of a formation flying. The paper presents the outcomes of a study performed under CNES contract on the use of the FFRFS for: Data exchange between vehicles when the formation is established Synchronisation of the on-board time of all the formation's spacecrafts Failure Detection, Isolation and Recovery (FDIR) mainly for the anti-collision aspects. The proposed concepts are illustrated by their application to SIMBOL-X mission, an hard X-ray telescope constituted of 2 satellites flying at 20m distance, currently on study at THALES ALENIA SPACE under CNES phase A contract.

  13. ISIS : a formation flying ionospheric seismic imaging experiment

    NASA Astrophysics Data System (ADS)

    Mimoun, D.; Lognonné, Ph; Garcia, R.; Occhipinti, G.; Abbondanza, S.

    Today, available techniques for the lithosphere tomography are limited by the number of seismic stations that we can deploy : it is sometimes difficult to access to some remote regions, but foremost the number of stations that are deployable over the oceans is strongly reduced. If we can dispose of some sites on islands (which are all characterized by a strong background noise), and on the measurements on coastal areas borders, it is therefore difficult to inverse the fine structure of the oceanic lithosphere. A promising idea is to use a long known idea, that earthquakes have a measurable impact on the ionosphere. As a matter of fact, the decrease of the atmosphere density with respect to altitude implies an amplification of the Rayleigh waves in the atmosphere, up to a maximum at about 250 km. This effect has been quantified for the Denali earthquake (Ducic et al, 2003) though its impact on the TEC content on the ionosphere. We therefore propose to detect this effect from space, thanks to a spaceborne multistatic SAR. Our concept includes 3 satellites in formation (along the same orbit) in a MEO orbit (about 19000 km). The master satellite payload is a slightly modified SAR, which operates around two main frequencies, in order to allow the computation of the delay induced by ionospheric fluctuations. The two other satellites have a passive payload which is time-synchronized with the master SAR: the use of their crossing rays will allow a 3D reconstruction of the ionosphere. A preliminary design of the space segment proposes an implementation on a MEO-orbit compatible bus, with high peak power capabilities. In order to allow the compatibility of the payload concept with the on-board available power, we have assumed that the satellite will enter in its alert mode on ground request. When an earthquake occurs, we dispose of a ten minutes delay to "wake-up" the satellite. When not in alert mode, its nominal imaging frequency will be reduced to allow the detection of

  14. Thermoplastic rubberlike material produced at low cost

    NASA Technical Reports Server (NTRS)

    Hendel, F. J.

    1966-01-01

    Thermoplastic rubberlike material is prepared by blending a copolymer of ethylene and vinyl acetate with asphalt and a petroleum distillate. This low cost material is easily molded or extruded and is compatible with a variety of fillers.

  15. A Low Cost TDRSS Compatible Transmitter Option

    NASA Technical Reports Server (NTRS)

    Whiteman, Don

    2005-01-01

    The NASA Space-based Telemetry and Range Safety (STARS) program has developed and tested a low cost Ku-Band transmitter alternative for TDRSS applications based on an existing IRIG shaped offset quaternary phase shift keying (SOQPSK) transmitter. This paper presents information related to the implementation of this low cost system, as well as performance measurements of the alternative TDRSS transmitter system compared with an existing QPSK TDRSS transmitter.

  16. Change Detection Experiments Using Low Cost UAVs

    NASA Technical Reports Server (NTRS)

    Logan, Michael J.; Vranas, Thomas L.; Motter, Mark; Hines, Glenn D.; Rahman, Zia-ur

    2005-01-01

    This paper presents the progress in the development of a low-cost change-detection system. This system is being developed to provide users with the ability to use a low-cost unmanned aerial vehicle (UAV) and image processing system that can detect changes in specific fixed ground locations using video provided by an autonomous UAV. The results of field experiments conducted with the US Army at Ft. A.P.Hill are presented.

  17. Precision Formation Keeping at L2 Using the Autonomous Formation Flying Sensor

    NASA Technical Reports Server (NTRS)

    McLoughlin, Terence H.; Campbell, Mark

    2004-01-01

    Recent advances in formation keeping for large numbers of spacecraft using the Autonomous Formation Flying are presented. This sensor, currently under development at JPL, has been identified as a key component in future formation flying spacecraft missions. The sensor provides accurate range and bearing measurements between pairs of spacecraft using GPS technology. Previous theoretical work by the authors has focused on developing a decentralized scheduling algorithm to control the tasking of such a sensor between the relative range and bearing measurements to each node in the formation. The resulting algorithm has been modified to include switching constraints in the sensor. This paper also presents a testbed for real time validation of a sixteen-node formation based on the Stellar Imager mission. Key aspects of the simulation include minimum fuel maneuvers based on free-body dynamics and a three body propagator for simulating the formation at L2.

  18. A network architecture for precision formation flying using the IEEE 802.11 MAC Protocol

    NASA Technical Reports Server (NTRS)

    Clare, Loren P.; Gao, Jay L.; Jennings, Esther H.; Okino, Clayton

    2005-01-01

    Precision Formation Flying missions involve the tracking and maintenance of spacecraft in a desired geometric formation. The strong coupling of spacecraft in formation flying control requires inter-spacecraft communication to exchange information. In this paper, we present a network architecture that supports PFF control, from the initial random deployment phase to the final formation. We show that a suitable MAC layer for the application protocol is IEEE's 802.11 MAC protocol. IEEE 802.11 MAC has two modes of operations: DCF and PCF. We show that DCF is suitable for the initial deployment phase while switching to PCF when the spacecraft are in formation improves jitter and throughput. We also consider the effect of routing on protocol performance and suggest when it is profitable to turn off route discovery to achieve better network performance.

  19. Control of tetrahedron satellite formation flying in the geosynchronous orbit using solar radiation pressure

    NASA Astrophysics Data System (ADS)

    Hou, Yong-Gang; Zhang, Ming-Jiang; Zhao, Chang-Yin; Sun, Rong-Yu

    2016-04-01

    In this paper, the control of tetrahedron satellite formation flying in the geosynchronous orbit (GEO) using solar radiation pressure is investigated. The long term disturbing effect of the main zonal and tesseral harmonics J2 and J_{22} of the geopotential are eliminated by adjusting the initial orbital elements, and a tetrahedron satellite formation flying in the GEO is designed. Then a control system using solar radiation pressure is further proposed to maintain the tetrahedron satellite formation, in which a sliding mode control (SMC) is developed to determine the control force. The control force is acquired from the solar sails equipped on the satellites, and the final control law and strategy using solar radiation pressure are presented. Moreover, three kinds of numerical simulations are especially given to verify the validity of the control system using solar radiation. It shows that Laplace precession of the GEO satellite can be avoided effectively, and the in-plane and out-of-plane errors of the formation can be eliminated easily. And hence the control of tetrahedron satellite formation flying in the GEO using solar radiation pressure is proved to be feasible.

  20. NASA's Autonomous Formation Flying Technology Demonstration, Earth Observing-1(EO-1)

    NASA Technical Reports Server (NTRS)

    Folta, David; Bristow, John; Hawkins, Albin; Dell, Greg

    2002-01-01

    NASA's first autonomous formation flying mission, the New Millennium Program's (NMP) Earth Observing-1 (EO-1) spacecraft, recently completed its principal goal of demonstrating advanced formation control technology. This paper provides an overview of the evolution of an onboard system that was developed originally as a ground mission planning and operations tool. We discuss the Goddard Space Flight Center s formation flying algorithm, the onboard flight design and its implementation, the interface and functionality of the onboard system, and the implementation of a Kalman filter based GPS data smoother. A number of safeguards that allow the incremental phasing in of autonomy and alleviate the potential for mission-impacting anomalies from the on- board autonomous system are discussed. A comparison of the maneuvers planned onboard using the EO-1 autonomous control system to those from the operational ground-based maneuver planning system is presented to quantify our success. The maneuvers discussed encompass reactionary and routine formation maintenance. Definitive orbital data is presented that verifies all formation flying requirements.

  1. Integration of Libration Point Orbit Dynamics into a Universal 3-D Autonomous Formation Flying Algorithm

    NASA Technical Reports Server (NTRS)

    Folta, David; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The autonomous formation flying control algorithm developed by the Goddard Space Flight Center (GSFC) for the New Millennium Program (NMP) Earth Observing-1 (EO-1) mission is investigated for applicability to libration point orbit formations. In the EO-1 formation-flying algorithm, control is accomplished via linearization about a reference transfer orbit with a state transition matrix (STM) computed from state inputs. The effect of libration point orbit dynamics on this algorithm architecture is explored via computation of STMs using the flight proven code, a monodromy matrix developed from a N-body model of a libration orbit, and a standard STM developed from the gravitational and coriolis effects as measured at the libration point. A comparison of formation flying Delta-Vs calculated from these methods is made to a standard linear quadratic regulator (LQR) method. The universal 3-D approach is optimal in the sense that it can be accommodated as an open-loop or closed-loop control using only state information.

  2. Low-cost Solar Array (LSA) project

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Progress made by the Low-Cost Silicon Solar Array Project during the period January through March 1978 is reported. It includes task reports on silicon material processing, large-area silicon sheet development, encapsulation materials testing and development, project engineering and operations, and manufacturing techniques, plus the steps taken to integrate these efforts.

  3. Low cost techniques for fabricating lobed bearings

    NASA Technical Reports Server (NTRS)

    Schuller, F. T.

    1968-01-01

    New low cost technique utilizes shims to create the lobes in bearing. Conventional methods of manufacture require accurate off-center grinding of the inside diameter of a bearing in a housing at various arc lengths depending on the number of lobes required.

  4. Low cost silicon solar cell array

    NASA Technical Reports Server (NTRS)

    Bartels, F. T. C.

    1974-01-01

    The technological options available for producing low cost silicon solar cell arrays were examined. A project value of approximately $250/sq m and $2/watt is projected, based on mass production capacity demand. Recommendations are included for the most promising cost reduction options.

  5. Low-Cost Aqueous Coal Desulfurization

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Vasilakos, N.; Corcoran, W. H.; Grohmann, K.; Rohatgi, N. K.

    1982-01-01

    Water-based process for desulfurizing coal not only eliminates need for costly organic solvent but removes sulfur more effectively than an earlier solvent-based process. New process could provide low-cost commercial method for converting high-sulfur coal into environmentally acceptable fuel.

  6. Construction of a low-cost luximeter

    NASA Astrophysics Data System (ADS)

    Pedroso, L. S.; de Macedo, J. A.; de Araújo, M. S. T.; Voelzke, M. R.

    2016-04-01

    This paper proposes the construction of an electronic instrument called digital luximeter, combining simplicity and low cost, making it simpler and cheaper than those on the market. Its construction tends to facilitate dissemination and access to this type of measuring instrument between high school teachers and educational institutions, making it ideal to be a science lab.

  7. Low-cost inertial measurement unit.

    SciTech Connect

    Deyle, Travis Jay

    2005-03-01

    Sandia National Laboratories performs many expensive tests using inertial measurement units (IMUs)--systems that use accelerometers, gyroscopes, and other sensors to measure flight dynamics in three dimensions. For the purpose of this report, the metrics used to evaluate an IMU are cost, size, performance, resolution, upgradeability and testing. The cost of a precision IMU is very high and can cost hundreds of thousands of dollars. Thus the goals and results of this project are as follows: (1) Examine the data flow in an IMU and determine a generic IMU design. (2) Discuss a high cost IMU implementation and its theoretically achievable results. (3) Discuss design modifications that would save money for suited applications. (4) Design and implement a low cost IMU and discuss its theoretically achievable results. (5) Test the low cost IMU and compare theoretical results with empirical results. (6) Construct a more streamlined printed circuit board design reducing noise, increasing capabilities, and constructing a self-contained unit. Using these results, we can compare a high cost IMU versus a low cost IMU using the metrics from above. Further, we can examine and suggest situations where a low cost IMU could be used instead of a high cost IMU for saving cost, size, or both.

  8. Sport for All. Low Cost Sports Halls.

    ERIC Educational Resources Information Center

    Council of Europe, Strasbourg (France).

    This report of the conference on low-cost sports halls, sponsored by the Council of Europe, is divided into two sections: technical studies and conclusions. The introduction to the report provides an overview of the long-term program of the Council of Europe with regard to sport for all and a discussion of multipurpose sports halls. Sociocultural,…

  9. Low-cost image analysis system

    SciTech Connect

    Lassahn, G.D.

    1995-01-01

    The author has developed an Automatic Target Recognition system based on parallel processing using transputers. This approach gives a powerful, fast image processing system at relatively low cost. This system scans multi-sensor (e.g., several infrared bands) image data to find any identifiable target, such as physical object or a type of vegetation.

  10. Testing low cost anaerobic digestion (AD) systems

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To evaluate the potential for low technology and low cost digesters for small dairies, BARC and researchers from the University of Maryland installed six modified Taiwanese-model field-scale (FS) digesters near the original dairy manure digester. The FS units receive the same post-separated liquid ...

  11. Strategies to fight low-cost rivals.

    PubMed

    Kumar, Nirmalya

    2006-12-01

    Companies find it challenging and yet strangely reassuring to take on opponents whose strategies, strengths, and weaknesses resemble their own. Their obsession with familiar rivals, however, has blinded them to threats from disruptive, low-cost competitors. Successful price warriors, such as the German retailer Aldi, are changing the nature of competition by employing several tactics: focusing on just one or a few consumer segments, delivering the basic product or providing one benefit better than rivals do, and backing low prices with superefficient operations. Ignoring cutprice rivals is a mistake because they eventually force companies to vacate entire market segments. Price wars are not the answer, either: Slashing prices usually lowers profits for incumbents without driving the low-cost entrants out of business. Companies take various approaches to competing against cut-price players. Some differentiate their products--a strategy that works only in certain circumstances. Others launch low-cost businesses of their own, as many airlines did in the 1990s--a so-called dual strategy that succeeds only if companies can generate synergies between the existing businesses and the new ventures, as the financial service providers HSBC and ING did. Without synergies, corporations are better off trying to transform themselves into low-cost players, a difficult feat that Ryanair accomplished in the 1990s, or into solution providers. There will always be room for both low-cost and value-added players. How much room each will have depends not only on the industry and customers' preferences, but also on the strategies traditional businesses deploy. PMID:17183797

  12. Looking Back and Looking Forward: Reprising the Promise and Predicting the Future of Formation Flying and Spaceborne GPS Navigation Systems

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H.; Dennehy, Neil

    2015-01-01

    A retrospective consideration of two 15-year old Guidance, Navigation and Control (GN&C) technology 'vision' predictions will be the focus of this paper. A look back analysis and critique of these late 1990s technology roadmaps out-lining the future vision, for two then nascent, but rapidly emerging, GN&C technologies will be performed. Specifically, these two GN&C technologies were: 1) multi-spacecraft formation flying and 2) the spaceborne use and exploitation of global positioning system (GPS) signals to enable formation flying. This paper reprises the promise of formation flying and spaceborne GPS as depicted in the cited 1999 and 1998 papers. It will discuss what happened to cause that promise to be mostly unfulfilled and the reasons why the envisioned formation flying dream has yet to become a reality. The recent technology trends over the past few years will then be identified and a renewed government interest in spacecraft formation flying/cluster flight will be highlighted. The authors will conclude with a reality-tempered perspective, 15 years after the initial technology roadmaps were published, predicting a promising future of spacecraft formation flying technology development over the next decade.

  13. Low cost paths to binary optics

    NASA Technical Reports Server (NTRS)

    Nelson, Arthur; Domash, Lawrence

    1993-01-01

    Application of binary optics has been limited to a few major laboratories because of the limited availability of fabrication facilities such as e-beam machines and the lack of standardized design software. Foster-Miller has attempted to identify low cost approaches to medium-resolution binary optics using readily available computer and fabrication tools, primarily for the use of students and experimenters in optical computing. An early version of our system, MacBEEP, made use of an optimized laser film recorder from the commercial typesetting industry with 10 micron resolution. This report is an update on our current efforts to design and build a second generation MacBEEP, which aims at 1 micron resolution and multiple phase levels. Trails included a low cost scanning electron microscope in microlithography mode, and alternative laser inscribers or photomask generators. Our current software approach is based on Mathematica and PostScript compatibility.

  14. Low-cost laser diode array

    DOEpatents

    Freitas, Barry L.; Skidmore, Jay A.

    1999-01-01

    A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost.

  15. Low-cost laser diode array

    DOEpatents

    Freitas, B.L.; Skidmore, J.A.

    1999-06-01

    A substrate is used to fabricate a low-cost laser diode array. A substrate is machined from an electrically insulative material that is thermally conductive, or two substrates can be bonded together in which the top substrate is electrically as well as thermally conductive. The substrate thickness is slightly longer than the cavity length, and the width of the groove is wide enough to contain a bar and spring (which secures the laser bar firmly along one face of the groove). The spring also provides electrical continuity from the backside of the bar to the adjacent metalization layer on the laser bar substrate. Arrays containing one or more bars can be formed by creating many grooves at various spacings. Along the groove, many bars can be adjoined at the edges to provide parallel electrical conduction. This architecture allows precise and predictable registration of an array of laser bars to a self-aligned microlens array at low cost. 19 figs.

  16. Low cost sonoluminescence experiment in pressurized water

    NASA Astrophysics Data System (ADS)

    Bernal, L.; Insabella, M.; Bilbao, L.

    2012-06-01

    We present a low cost design for demostration and mesurements of light emmision from a sonoluminescence experiment. Using presurized water introduced in an acrylic cylinder and one piezoelectric from an ultrasonic cleaner, we are able to generate cavitacion zones with emission of light. The use of argon to pressurize the water improves the emission an the light can be seen at naked eye in a softlit ambient.

  17. Experience with low cost jet engines

    NASA Technical Reports Server (NTRS)

    Cummings, R. L.

    1972-01-01

    A summary is given of the results of a NASA program for reducing the cost of turbojet and turbofan engines. The design, construction, and testing of a simple turbojet, designed for use in missiles, is described. Low cost axial stage fabrication, the design of a fan jet engine suitable for propulsion of light aircraft, and application of such engines to provide higher flight speeds, are discussed.

  18. Low Cost Processing of Commingled Thermoplastic Composites

    NASA Astrophysics Data System (ADS)

    Chiasson, Matthew Lee

    A low cost vacuum consolidation process has been investigated for use with commingled thermoplastic matrix composites. In particular, the vacuum consolidation behaviour of commingled polypropylene/glass fibre and commingled nylon/carbon fibre precursors were studied. Laminates were consolidated in a convection oven under vacuum pressure. During processing, the consolidation of the laminate packs was measured by use of non-contact eddy current sensors. The consolidation curves are then used to tune an empirical consolidation model. The overall quality of the resulting laminates is also discussed. Dynamic mechanical analysis, differential scanning calorimetry and mechanical tensile testing were also performed in order to determine the effects of varying processing parameters on the physical and mechanical properties of the laminates. Through this analysis, it was determined that the nylon/carbon fibre blend was not suitable for vacuum consolidation, while the polypropylene/glass fibre blend is a viable option for vacuum consolidation. The ultimate goal of this work is to provide a foundation from which low cost unmanned aerial vehicle (UAV) components can be designed and manufactured from thermoplastic matrix composites using a low cost processing technique as an alternative to traditional thermoset composite materials.

  19. Small, Low Cost, Launch Capability Development

    NASA Technical Reports Server (NTRS)

    Brown, Thomas

    2014-01-01

    A recent explosion in nano-sat, small-sat, and university class payloads has been driven by low cost electronics and sensors, wide component availability, as well as low cost, miniature computational capability and open source code. Increasing numbers of these very small spacecraft are being launched as secondary payloads, dramatically decreasing costs, and allowing greater access to operations and experimentation using actual space flight systems. While manifesting as a secondary payload provides inexpensive rides to orbit, these arrangements also have certain limitations. Small, secondary payloads are typically included with very limited payload accommodations, supported on a non interference basis (to the prime payload), and are delivered to orbital conditions driven by the primary launch customer. Integration of propulsion systems or other hazardous capabilities will further complicate secondary launch arrangements, and accommodation requirements. The National Aeronautics and Space Administration's Marshall Space Flight Center has begun work on the development of small, low cost launch system concepts that could provide dedicated, affordable launch alternatives to small, high risk university type payloads and spacecraft. These efforts include development of small propulsion systems and highly optimized structural efficiency, utilizing modern advanced manufacturing techniques. This paper outlines the plans and accomplishments of these efforts and investigates opportunities for truly revolutionary reductions in launch and operations costs. Both evolution of existing sounding rocket systems to orbital delivery, and the development of clean sheet, optimized small launch systems are addressed.

  20. Low cost miniature data collection platform

    NASA Technical Reports Server (NTRS)

    1977-01-01

    The development of the RF elements of a telecommunications package involved detailed study and analysis of concepts and techniques followed by laboratory testing and evaluation of designs. The design goals for a complete telecommunications package excluding antenna were a total weight of 300 grams, in a total volume of 400 cu cm with a capability of unattended operation for a period of six months. Of utmost importance is extremely low cost when produced in lots of 10,000. Early in the program it became apparent that a single Miniature Data Collection Platform would not satisfy all users. A single high efficiency system would not satisfy a user who had available a large battery capacity but required a low cost system. Conversely, the low cost system would not satisfy the end user who had a very limited battery capacity. A system design to satisfy these varied requirements was implemented by designing several versions of the system building blocks and then constructing three systems from these building blocks.

  1. Low-Cost Spectral Sensor Development Description.

    SciTech Connect

    Armijo, Kenneth Miguel; Yellowhair, Julius

    2014-11-01

    Solar spectral data for all parts of the US is limited due in part to the high cost of commercial spectrometers. Solar spectral information is necessary for accurate photovoltaic (PV) performance forecasting, especially for large utility-scale PV installations. A low-cost solar spectral sensor would address the obstacles and needs. In this report, a novel low-cost, discrete- band sensor device, comprised of five narrow-band sensors, is described. The hardware is comprised of commercial-off-the-shelf components to keep the cost low. Data processing algorithms were developed and are being refined for robustness. PV module short-circuit current ( I sc ) prediction methods were developed based on interaction-terms regression methodology and spectrum reconstruction methodology for computing I sc . The results suggest the computed spectrum using the reconstruction method agreed well with the measured spectrum from the wide-band spectrometer (RMS error of 38.2 W/m 2 -nm). Further analysis of computed I sc found a close correspondence of 0.05 A RMS error. The goal is for ubiquitous adoption of the low-cost spectral sensor in solar PV and other applications such as weather forecasting.

  2. Low-cost Flexible Memristor Fabrication

    NASA Astrophysics Data System (ADS)

    Kirilyuk, Inna; Gergel-Hackett, Nadine

    2014-03-01

    Memristors are two-terminal electronic devices that exhibit unique electrical characteristics, including nonvolatile electrical switching between resistive states. These unique electrical characteristics may enable the use of memristors as logic and/or memory components in novel computer architectures. Flexible memristors have been shown to not only exhibit the electrical characteristics unique to the devices, but are also operable after 4,000 flexes, require voltages less than 10 V, show on:off ratios >10,000:1, are nonvolatile for up to 14 days, and are fabricated at room-temperature with sol-gel solution processing. To increase accessibility to the technology and decrease production costs, we are developing methods of flexible memristor fabrication that are low-cost compared to current conventional fabrication. This low-cost fabrication includes exploring alternative materials and processes for device contacts, synthesizing and storing titanium dioxide sol-gel using standard wet chemistry tools without the use of a glove box, and using a low-cost spinner to spin sol-gel onto devices. The fabrication is performed entirely in an undergraduate lab setting by undergraduate students. Research funded in part by the Mary Baldwin College Summer Research Fellows Program and the Virginia Foundation for Independent Colleges.

  3. Investigation of Low Cost Sensor-Based Leak Detection System for Fence Line Applications

    EPA Science Inventory

    With recent technological advances, low-cost time-resolved sensors may become effective tools to support time-integrated passive sampling strategies by helping to decipher origin of emissions in real-time. As part of the Petroleum Refinery Risk and Technology Review, New Source ...

  4. Investigation of a Low Cost Sensor-Based Leak Detection System for Fence Line Applications

    EPA Science Inventory

    With recent technological advances, low-cost time-resolved sensors may become effective tools to support time-integrated passive sampling strategies by helping to decipher origin of emissions in real-time. As part of the Petroleum Refinery Risk and Technology Review, New Source P...

  5. Simulation of Guidance, Navigation, and Control Systems for Formation Flying Missions

    NASA Technical Reports Server (NTRS)

    Burns, Rich; Bauer, Frank H. (Technical Monitor)

    2002-01-01

    Concepts for missions of distributed spacecraft flying in formation abound. From high resolution interferometry to spatially distributed in-situ measurements, these mission concepts levy a myriad of guidance, navigation, and control (GNC) requirements on the spacecraft/formation as a single system. A critical step toward assessing and meeting these challenges lies in realistically simulating distributed spacecraft systems. The Formation Flying TestBed (FFTB) at NASA Goddard Space Flight Center's (GSFC) Guidance, Navigation, and Control Center is a hardware-in-the-loop simulation and development facility focused on GNC issues relevant to formation flying systems. The FFTB provides a realistic simulation of the vehicle dynamics and control for formation flying missions in order to: (1) conduct feasibility analyses of mission requirements, (2) conduct and answer mission and spacecraft design trades, and (3) serve as a host for GNC software and hardware development and testing. The initial capabilities of the FFTB are based upon an integration of high fidelity hardware and software simulation, emulation, and test platforms developed or employed at GSFC in recent years, including a high-fidelity Global Positioning System (GPS) simulator which has been a fundamental component of the GNC Center's GPS Test Facility. The FFTB will be continuously evolving over the next several years from a tool with capabilities in GPS navigation hardware/software-in-the-loop analysis and closed loop GPS-based orbit control algorithm assessment. Eventually, it will include full capability to support all aspects of multi-sensor, absolute and relative state determination and control, in all (attitude and orbit) degrees of freedom, as well as information management for satellite clusters and constellations. A detailed description of the FFTB architecture is presented in the paper.

  6. A Hardware-in-the-Loop Testbed for Spacecraft Formation Flying Applications

    NASA Technical Reports Server (NTRS)

    Leitner, Jesse; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    The Formation Flying Test Bed (FFTB) at NASA Goddard Space Flight Center (GSFC) is being developed as a modular, hybrid dynamic simulation facility employed for end-to-end guidance, navigation, and control (GN&C) analysis and design for formation flying clusters and constellations of satellites. The FFTB will support critical hardware and software technology development to enable current and future missions for NASA, other government agencies, and external customers for a wide range of missions, particularly those involving distributed spacecraft operations. The initial capabilities of the FFTB are based upon an integration of high fidelity hardware and software simulation, emulation, and test platforms developed at GSFC in recent years; including a high-fidelity GPS simulator which has been a fundamental component of the Guidance, Navigation, and Control Center's GPS Test Facility. The FFTB will be continuously evolving over the next several years from a too[ with initial capabilities in GPS navigation hardware/software- in-the- loop analysis and closed loop GPS-based orbit control algorithm assessment to one with cross-link communications and relative navigation analysis and simulation capability. Eventually the FFT13 will provide full capability to support all aspects of multi-sensor, absolute and relative position determination and control, in all (attitude and orbit) degrees of freedom, as well as information management for satellite clusters and constellations. In this paper we focus on the architecture for the FFT13 as a general GN&C analysis environment for the spacecraft formation flying community inside and outside of NASA GSFC and we briefly reference some current and future activities which will drive the requirements and development.

  7. Designing a Low-Cost Multifunctional Infant Incubator.

    PubMed

    Tran, Kevin; Gibson, Aaron; Wong, Don; Tilahun, Dagmawi; Selock, Nicholas; Good, Theresa; Ram, Geetha; Tolosa, Leah; Tolosa, Michael; Kostov, Yordan; Woo, Hyung Chul; Frizzell, Michael; Fulda, Victor; Gopinath, Ramya; Prasad, J Shashidhara; Sudarshan, Hanumappa; Venkatesan, Arunkumar; Kumar, V Sashi; Shylaja, N; Rao, Govind

    2014-04-01

    Every year, an unacceptably large number of infant deaths occur in developing nations, with premature birth and asphyxia being two of the leading causes. A well-regulated thermal environment is critical for neonatal survival. Advanced incubators currently exist, but they are far too expensive to meet the needs of developing nations. We are developing a thermodynamically advanced low-cost incubator suitable for operation in a low-resource environment. Our design features three innovations: (1) a disposable baby chamber to reduce infant mortality due to nosocomial infections, (2) a passive cooling mechanism using low-cost heat pipes and evaporative cooling from locally found clay pots, and (3) insulated panels and a thermal bank consisting of water that effectively preserve and store heat. We developed a prototype incubator and visited and presented our design to our partnership hospital site in Mysore, India. After obtaining feedback, we have determined realistic, nontrivial design requirements and constraints in order to develop a new prototype incubator for clinical trials in hospitals in India. PMID:24713428

  8. Low-cost large-angle steering mirror development

    NASA Astrophysics Data System (ADS)

    Wassom, Steven R.

    2009-08-01

    The Space Dynamics Laboratory has combined internal funds with its background in space-rated mechanisms to develop a prototype low-cost large-angle 2-axis fine steering mirror (FSM). The FSM has a 75-mm clear aperture, 30-degree mechanical elevation angle, 120-degree mechanical azimuth angle, and a 70-Hertz small-amplitude bandwidth. Key components include a rotary voice coil, unique patent-pending feedback sensor, brushless DC motor and optical encoder. Average error is <1 arcsec and total mechanical mass is <1 kg. Additional accomplishments include a passive launch lock, launch vibration testing, portable demonstration electronics development, and thermal-vacuum testing to pressures down to 1e-7 torr and temperatures down to 164 K.

  9. Finite-time output feedback attitude coordination control for formation flying spacecraft without unwinding

    NASA Astrophysics Data System (ADS)

    Guo, Yong; Song, Shen-Min; Li, Xue-Hui

    2016-05-01

    In this paper, two finite-time attitude coordinated controllers for formation flying spacecraft are investigated based on rotation matrix. Because rotation matrix can represent the set of attitudes both globally and uniquely, the two controllers can deal with unwinding that can result in extra fuel consumption. To address the lack of angular velocity measurement, the second attitude coordinated controller is given by using a novel filter. Through homogeneous method and Lyapunov theories, it is shown that the proposed controllers can achieve the finite-time stability. Numerical simulations also demonstrate that the proposed control schemes are effective.

  10. Time-Varying Expression of the Formation Flying along Circular Trajectories

    NASA Technical Reports Server (NTRS)

    Kawaguchi, Jun'ichiro

    2007-01-01

    Usually, the formation flying associated with circular orbits is discussed through the well-known Hill s or C-W equations of motion. This paper dares to present and discuss the coordinates that may contain time-varying coefficients. The discussion presents how the controller s performance is affected by the selection of coordinates, and also looks at the special coordinate suitable for designating a target bin to which each spacecraft in the formation has only to be guided. It is revealed that the latter strategy may incorporate the J2 disturbance automatically.

  11. Measuring rainfall with low-cost cameras

    NASA Astrophysics Data System (ADS)

    Allamano, Paola; Cavagnero, Paolo; Croci, Alberto; Laio, Francesco

    2016-04-01

    In Allamano et al. (2015), we propose to retrieve quantitative measures of rainfall intensity by relying on the acquisition and analysis of images captured from professional cameras (SmartRAIN technique in the following). SmartRAIN is based on the fundamentals of camera optics and exploits the intensity changes due to drop passages in a picture. The main steps of the method include: i) drop detection, ii) blur effect removal, iii) estimation of drop velocities, iv) drop positioning in the control volume, and v) rain rate estimation. The method has been applied to real rain events with errors of the order of ±20%. This work aims to bridge the gap between the need of acquiring images via professional cameras and the possibility of exporting the technique to low-cost webcams. We apply the image processing algorithm to frames registered with low-cost cameras both in the lab (i.e., controlled rain intensity) and field conditions. The resulting images are characterized by lower resolutions and significant distortions with respect to professional camera pictures, and are acquired with fixed aperture and a rolling shutter. All these hardware limitations indeed exert relevant effects on the readability of the resulting images, and may affect the quality of the rainfall estimate. We demonstrate that a proper knowledge of the image acquisition hardware allows one to fully explain the artefacts and distortions due to the hardware. We demonstrate that, by correcting these effects before applying the image processing algorithm, quantitative rain intensity measures are obtainable with a good accuracy also with low-cost modules.

  12. Low-cost microprocessor controlled shadowband radiometer

    NASA Astrophysics Data System (ADS)

    Michalsky, J. J.; Lebaron, B. A.; Harrison, L. C.

    1985-06-01

    This paper describes the second phase in the development of a low-cost microprocessor-controlled rotating shadowband radiometer at PNL. The initial work, to develop a solar photometer, resulted in a mechanical design that is adopted for the solar radiometer with only minor changes. The goals of this effort are: (1) to improve the data acquisition system; and (2) to derive corrections for the silicon cell-based pyranometer that would allow measurements of total horizontal, diffuse horizontal, and direct normal solar radiation approaching first-class instrumentation accuracy at a fraction of the cost. Significant progress on temperature, cosine and spectral corrections is achieved.

  13. Low cost subpixel method for vibration measurement

    SciTech Connect

    Ferrer, Belen; Espinosa, Julian; Perez, Jorge; Acevedo, Pablo; Mas, David; Roig, Ana B.

    2014-05-27

    Traditional vibration measurement methods are based on devices that acquire local data by direct contact (accelerometers, GPS) or by laser beams (Doppler vibrometers). Our proposal uses video processing to obtain the vibration frequency directly from the scene, without the need of auxiliary targets or devices. Our video-vibrometer can obtain the vibration frequency at any point in the scene and can be implemented with low-cost devices, such as commercial cameras. Here we present the underlying theory and some experiments that support our technique.

  14. A Low Cost Electrostatically Focused TWT

    NASA Technical Reports Server (NTRS)

    Vancil, Bernard K.; Wintucky, Edwin G.; Williams, W. D. (Technical Monitor)

    2002-01-01

    Ring-loop circuits are well known for their simplicity, low cost, compactness, low mass, high gain and efficiency and absence of backward wave oscillations. Peak powers over 20 kw have been achieved. They also have low harmonic output and excellent phase performance. We have developed a double ring-loop circuit that permits electrostatic focusing of an electron beam to at least 0.4 micro pervs. This eliminates the magnet stack and further lowers cost and weight. It permits glass rod fastening of circuit elements as well as gun and collector assemblies, as is done in cathode ray tubes. Using CRT construction techniques, the TWT can be built on automated equipment.

  15. Low cost damage tolerant composite fabrication

    NASA Technical Reports Server (NTRS)

    Palmer, R. J.; Freeman, W. T.

    1988-01-01

    The resin transfer molding (RTM) process applied to composite aircraft parts offers the potential for using low cost resin systems with dry graphite fabrics that can be significantly less expensive than prepreg tape fabricated components. Stitched graphite fabric composites have demonstrated compression after impact failure performance that equals or exceeds that of thermoplastic or tough thermoset matrix composites. This paper reviews methods developed to fabricate complex shape composite parts using stitched graphite fabrics to increase damage tolerance with RTM processes to reduce fabrication cost.

  16. Low cost satellite transportable Ground Station

    NASA Astrophysics Data System (ADS)

    Laufman, G. E.; Slivkoff, W. J.

    A low cost Transportable Ground Station (TGS) for satellite tracking, telemetry and control (TTC) applications is described. The initial focus of the TGS is to provide S-band space-ground-link-subsystem TTC services for these satellites with compatible transponders. The TGS also has the capability to be expanded to perform mission control station tasks including telemetry data analysis, command formulation, mission analysis and satellite ephemeris generation. The TGS consists of a shelter and a folded 5-m antenna both of which are mounted on a commercial air ride trailer. The TGS size meets requirements for United States highway transportation. The TGS can also be transported via C-130 aircraft.

  17. A low cost LST pointing control system

    NASA Technical Reports Server (NTRS)

    Glaese, J. R.; Kennel, H. F.; Nurre, G. S.; Seltzer, S. M.; Shelton, H. L.

    1975-01-01

    Vigorous efforts to reduce costs, coupled with changes in LST guidelines, took place in the Fall of 1974. These events made a new design of the LST and its Pointing and Attitude Control System possible. The major design changes are summarized as: an annular Support Systems Module; removal of image motion compensation; reaction wheels instead of CMG's; a magnetic torquer system to also perform the emergency and backup functions, eliminating the previously required mass expulsion system. Preliminary analysis indicates the Low Cost LST concept can meet the newly defined requirements and results in a significantly reduced development cost.

  18. LSA Low-cost Solar Array project

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The activities of the Low-Cost Silicon Solar Array Project during the period October through December, 1977 are reported. The LSSA Project is assigned responsibility for advancing silicon solar array technology while encouraging industry to reduce the price of arrays to a level at which photovoltaic electric power systems will be competitive with more conventional power sources early in the next decade. Set forth are the goals and plans with which the Project intends to accomplish this and the progress that was made during the quarter.

  19. Properties Of Low Cost, High Volume Glasses

    NASA Astrophysics Data System (ADS)

    Lind, M. A.; Hartman, J. S.; Buckwalter, C. Q.

    1980-02-01

    The properties of new and weathered samples of low cost, high volume glasses have been studied to determine their usefulness for solar energy applications. Glasses of varying compositions produced by float, drawn, rolled, fusion, and twin ground techniques were examined. Spectral transmittance and reflectance were measured and solar weighted values calculated. Laser raytrace techniques were used to evaluate surface parallelism and bulk homogeneity. Compositional changes were examined with scanning electron microscopy, X-ray fluorescence, and Auger electron spectroscopy. These techniques were used in conjunction with ellipsometry to study the surface effects associated with weathering.

  20. Polymeric MST - high precision at low cost

    NASA Astrophysics Data System (ADS)

    Elderstig, Håkan; Larsson, Olle

    1997-09-01

    A low-cost production process for fabrication of polymeric microstructures from micromachined silicon is demonstrated in a splice for the splicing of optical fibers and an optical motherboard. Measurements on splices showed less than 0.5 dB insertion losses. The prototype polymeric motherboard concisted of an optical receiver module. The detector that was mounted on the polymeric optical motherboard detected about 70% of the transferred light. Measurements with modulated light indicates an optical bandwidth of 5 GHz at 2 V reverse current on the pin-diode.

  1. Low-cost Solar Array (LSA) project

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The activities of the Low-Cost Solar Array Project are described for the period April through June 1978. The Project is assigned responsibility for advancing solar array technology while encouraging industry to reduce the price of arrays to a level at which photovoltaic electric power systems will be competitive with more conventional power sources early in the next decade. Set forth are the goals and plans with which the Project intends to accomplish this and the progress that was made during the quarter.

  2. Low Cost Mission Operations Workshop. [Space Missions

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The presentations given at the Low Cost (Space) Mission Operations (LCMO) Workshop are outlined. The LCMO concepts are covered in four introductory sections: Definition of Mission Operations (OPS); Mission Operations (MOS) Elements; The Operations Concept; and Mission Operations for Two Classes of Missions (operationally simple and complex). Individual presentations cover the following topics: Science Data Processing and Analysis; Mis sion Design, Planning, and Sequencing; Data Transport and Delivery, and Mission Coordination and Engineering Analysis. A list of panelists who participated in the conference is included along with a listing of the contact persons for obtaining more information concerning LCMO at JPL. The presentation of this document is in outline and graphic form.

  3. Stray light analysis and optimization of the ASPIICS/PROBA-3 formation flying solar coronagraph

    NASA Astrophysics Data System (ADS)

    Mazzoli, A.; Landini, F.; Vives, S.; Lamy, P.; Halain, J. P.; Rochus, P.

    2010-07-01

    PROBA-3 is a technology mission devoted to the in-orbit demonstration of formation flying techniques and technologies. PROBA-3 will implement a giant coronagraph (called ASPIICS) that will both demonstrate and exploit the capabilities and performances of formation flying. ASPIICS is distributed on two spacecrafts separated by 150m, one hosting the external occulting disk and the other the optical part of the coronagraph. This part implements a three-mirror-anastigmat (TMA) telescope. Its pupil is placed about 800mm in front of the primary mirror, a solution allowing an efficient baffling and a high reduction of the stray light inside the instrument. A complete stray light analysis of the TMA has been carried out to design the baffles and to establish the required roughness of the mirrors. The analysis has been performed in two steps: first, by calculating the diffraction pattern behind the occulter due to an extended monochromatic source having the diameter of the Sun; second, by propagating this diffraction pattern, through all the telescope optical components, to the prime focal plane. The results obtained are described in this article.

  4. Low cost approach to Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Spear, Anthony J.

    1995-10-01

    Mars Pathfinder, launching in December '96 and landing in July '97, will demo a low cost delivery system to the surface of Mars. Historically, spacecraft that orbit or land on a distant body carry a large amount of fuel for braking. Mars Pathfinder, thrusting only for navigation, enters directly into the Martian atmosphere, aerobrakes with its aeroshell, deploys a parachute at 10 km above the surface and, within 100 m off the surface, ignites solid rockets for final braking prior to deployment of air bags which cushion touchdown. After landing, petals open to upright the lander, exposing solar panels to the sun. Even though the lander and rover are expected to last longer, the major objectives of Mars Pathfinder, demonstrating EDL (Entry, Descent, Landing) and lander-rover surface operations, will occur within the first few days, at which time panoramic images of the surface will be transmitted and the rover will be deployed to conduct both mobility tests and rock composition measurements. While Mars Pathfinder is primarily an engineering demo, it accomplishes a focused, exciting set of science investigations with a stereo, multi-color lander imager; atmospheric instrumentation, used as a weather station after landing; and the rover with cameras and the APXS (Alpha Proton X-ray Spectrometer). This paper features Mars Pathfinder's approach to innovative and cost effective mission accomplishment, under a development cost cap. Mars Pathfinder is pathfinding a new way of doing business at NASA and JPL for small, low cost, Discovery class missions.

  5. SIMBOL-X: A Formation Flying Mission on HEO for Exploring the Universe

    NASA Technical Reports Server (NTRS)

    Gamet, Philippe; Epenoy, R.; Salcedo, C.

    2007-01-01

    SIMBOL-X is a high energy new generation telescope covering by a single instrument a continuous energy range starting at classical X-rays and extending to hard X-rays, i.e. from 0.5 to 80 keV. It is using in this field a focalizing payload which until now was used for energy below 10 keV only, via the construction of a telescope distributed on two satellites flying in formation. SIMBOL-X permits a gain of two orders of magnitude in sensibility and spatial resolution in comparison to state of the art hard X-rays instruments. The mirror satellite will be in free flight on a high elliptical orbit and will target the object to observe very precisely, thus focusing the hard X-ray emission thanks to this mirror module. At the focal point area which is situated 20 meters behind the mirror satellite, the detector satellite maintains its position on a forced orbit thanks to a radio link with the mirror satellite and a lateral displacement sensor using a beam emitted onboard the mirror satellite. This configuration is said "formation flying". The location of the detector satellite shall be very finely tuned as it carries the focal plane of this distributed telescope. To provide science measurements, the Simbol-X orbit has been chosen High elliptic (HEO), which means elliptical orbit with a high perigee altitude. Preliminary studies where made with an orbit with an altitude of the perigee of 44000km and altitude of the apogee of 253000km. The orbit was seven days ground track repeated in order to maintain a perigee pass over the Malindi ground station to download scientific telemetry. But as studies went on, difficulties in mass budget, link budget, perigee maintenance and formation flying maintenance were raised. This was mainly due to the vicinity of the Moon and its disturbing effect on the satellites orbits. Alternative orbits have been proposed in order to demonstrate the feasibility of the mission. The problematic of bringing the two satellites from their injection

  6. High efficiency low cost solar cell power

    NASA Technical Reports Server (NTRS)

    Bekey, I.; Blocker, W.

    1978-01-01

    A concept for generating high-efficiency, low-cost, solar-cell power is outlined with reference to solar cell parameters, optical concentrators, and thermal control procedures. A design for a 12.5-kw power module for space operation is discussed noting the optical system, spectrum splitter, light conversion system, cell cooling, power conditioner, and tracking mechanism. It is found that for an unconcentrated array, efficiency approaches 60% when ten or more bandgaps are used. For a 12-band system, a computer program distributed bandgaps for maximum efficiency and equal cell currents. Rigid materials and thin films have been proposed for optical components and prisms, gratings, and dichroic mirrors have been recommended for spectrum splitting. Various radiator concepts are noted including that of Weatherston and Smith (1960) and Hedgepeth and Knapp (1978). The concept may be suitable for the Solar Power Satellite.

  7. Low-cost access to space

    NASA Astrophysics Data System (ADS)

    Slayton, Donald K.; Daniels, Mark; Grimes, David

    1992-03-01

    The paper discusses the wide range of orbital launch capabilities of the Conestoga series and the suborbital sounding rocket services of the Starfire family. Both launchers are designed with flight-proven components and offer low cost and a high degree of reliability. Current information on the market for small-sized space payloads and the ability of the above launchers to support these requirements are addressed. The Conestoga orbital launch design embodies the concept of achieving payload growth flexibility without the need to change either the basic vehicle design or the operational approach. Low technical, schedule, and cost risk is achieved with the Conestoga design due to the high degree of previously flight-proven hardware utilized. The Conestoga launch vehicle series performance curves are illustrated. The various Starfire configurations and their microgravity performance are shown.

  8. Low Cost Methods to Accomplish Aeronomy Science

    NASA Astrophysics Data System (ADS)

    Swenson, G. R.

    2013-12-01

    Accomplishment of aeronomy science using low cost methods involves a number of innovative considerations. These methods will be discussed. They include making broad use of internet to control and operate distributed sensors. Sensor controls should be simple and most important reliable. Imagers are a common sensor for optical systems and include common computer interfaces and menu driven operations which often don't require special software or engineering development. Small, inexpensive but reliable satellite systems are evolving in the Cubesat community. Effective use of students is invaluable, giving them responsibility to operate instrumentation and to routinely archive the data. Management of students is especially important in the early phase of their training to insure quality performance. These ideas will be elaborated on, and most importantly, the science motive is the most important driver for what is done.

  9. Low-cost flight test telemetry systems

    NASA Astrophysics Data System (ADS)

    Fogliani, Mario Noriega

    A traditional Flight Test Telemetry system is based on a peer-to-peer architecture where a system of antennae enables a signal to be transmitted between an aircraft and a receiving ground station. Said system generally requires costly infrastructures on the ground and complex antennae components to be installed on the aircraft. Newer approaches may use satellite communications, but the available spectrum is being encroached by commercial wireless networks such as mobile broadband. Given the very fast growth that the mobile broadband technology is experiencing, it might be feasible to utilize this ever-expanding new infrastructure as a low-cost alternative to conventional flight test telemetry systems. This Thesis Work will research on the feasibility and performance of the commercial mobile data networks when employed on-board a small aircraft such as a Cessna 172 for telemetry purposes.

  10. Low-cost photomask inspection system

    NASA Astrophysics Data System (ADS)

    Gharpure, Damayanti C.; David, Sunil K.

    1995-12-01

    The competitive demand for increased production rates and tighter quality control in manufacturing integrated circuits requires inspection at higher speeds, finer resolution and at various stages during fabrication, all at an affordable cost. Manual inspection is tedious and entails a degree of concentration that is difficult to maintain over long periods of time. This paper presents a simple, low cost photo mask inspection system based on an IBM compatible PC. Both the reference comparison as well as feature extraction approaches have been implemented for guaranteed defect detection. The defects are further analyzed to obtain details regarding the location, dimension, and type of defect. The system also generates a diagnostic report providing detailed information regarding each defect, that has been detected, for use in on line mask repair. The paper describes configuration of the system along with the image processing algorithms used. The paper also discusses the results obtained, the specifications and over all performance of the system.

  11. A complete low cost radon detection system.

    PubMed

    Bayrak, A; Barlas, E; Emirhan, E; Kutlu, Ç; Ozben, C S

    2013-08-01

    Monitoring the (222)Rn activity through the 1200 km long Northern Anatolian fault line, for the purpose of earthquake precursory, requires large number of cost effective radon detectors. We have designed, produced and successfully tested a low cost radon detection system (a radon monitor). In the detector circuit of this monitor, First Sensor PS100-7-CER-2 windowless PIN photodiode and a custom made transempedence/shaping amplifier were used. In order to collect the naturally ionized radon progeny to the surface of the PIN photodiode, a potential of 3500 V was applied between the conductive hemi-spherical shell and the PIN photodiode. In addition to the count rate of the radon progeny, absolute pressure, humidity and temperature were logged during the measurements. A GSM modem was integrated to the system for transferring the measurements from the remote locations to the data process center. PMID:23583920

  12. Low-cost solar array structure development

    NASA Technical Reports Server (NTRS)

    Wilson, A. H.

    1981-01-01

    Early studies of flat-plate arrays have projected costs on the order of $50/square meter for installed array support structures. This report describes an optimized low-cost frame-truss structure that is estimated to cost below $25/square meter, including all markups, shipping an installation. The structure utilizes a planar frame made of members formed from light-gauge galvanized steel sheet and is supposed in the field by treated-wood trusses that are partially buried in trenches. The buried trusses use the overburden soil to carry uplift wind loads and thus to obviate reinforced-concrete foundations. Details of the concept, including design rationale, fabrication and assembly experience, structural testing and fabrication drawings are included.

  13. Technology for low cost solid rocket boosters.

    NASA Technical Reports Server (NTRS)

    Ciepluch, C.

    1971-01-01

    A review of low cost large solid rocket motors developed at the Lewis Research Center is given. An estimate is made of the total cost reduction obtainable by incorporating this new technology package into the rocket motor design. The propellant, case material, insulation, nozzle ablatives, and thrust vector control are discussed. The effect of the new technology on motor cost is calculated for a typical expandable 260-in. booster application. Included in the cost analysis is the influence of motor performance variations due to specific impulse and weight changes. It is found for this application that motor costs may be reduced by up to 30% and that the economic attractiveness of future large solid rocket motors will be improved when the new technology is implemented.

  14. Low cost attitude sensors for spacecraft

    NASA Technical Reports Server (NTRS)

    Auer, S.; Von Bun, F. O.

    1990-01-01

    A review is presented of two-low cost attitude sensors developed with existing technology, but with emphasis directed to reducing the unit costs without compromising reliability or quality. The solar aspect sensor was developed to determine the angle of the sun with respect to the optical axis of the Shuttle Solar Backscatter Ultraviolet (SSBUV) Experiment Package. Using sensor readings updated every five milliseconds, signal processing electronics determine the location of the center of the sun's image on the array. An earth horizon sensor was developed to measure the nadir angle with respect to the optical axis of the SSBUV Experiment Package to an accuracy of + or - 0.5 deg. Operation of each of the sensors is described along with flight results obtained when flown onboard Atlantis as part of the SSBUV Experiment Package.

  15. Low Cost Large Core Vehicle Structures Assessment

    NASA Technical Reports Server (NTRS)

    Hahn, Steven E.

    1998-01-01

    Boeing Information, Space, and Defense Systems executed a Low Cost Large Core Vehicle Structures Assessment (LCLCVSA) under contract to NASA Marshall Space Flight Center (MSFC) between November 1997 and March 1998. NASA is interested in a low-cost launch vehicle, code named Magnum, to place heavy payloads into low earth orbit for missions such as a manned mission to Mars, a Next Generation Space Telescope, a lunar-based telescope, the Air Force's proposed space based laser, and large commercial satellites. In this study, structural concepts with the potential to reduce fabrication costs were evaluated in application to the Magnum Launch Vehicle (MLV) and the Liquid Fly Back Booster (LFBB) shuttle upgrade program. Seventeen concepts were qualitatively evaluated to select four concepts for more in-depth study. The four structural concepts selected were: an aluminum-lithium monocoque structure, an aluminum-lithium machined isogrid structure, a unitized composite sandwich structure, and a unitized composite grid structure. These were compared against a baseline concept based on the Space Shuttle External Tank (ET) construction. It was found that unitized composite structures offer significant cost and weight benefits to MLV structures. The limited study of application to LFBB structures indicated lower, but still significant benefits. Technology and facilities development roadmaps to prepare the approaches studied for application to MLV and LFBB were constructed. It was found that the cost and schedule to develop these approaches were in line with both MLV and LFBB development schedules. Current Government and Boeing programs which address elements of the development of the technologies identified are underway. It is recommended that NASA devote resources in a timely fashion to address the specific elements related to MLV and LFBB structures.

  16. Low-cost remote chemical sensing

    NASA Astrophysics Data System (ADS)

    Holland, Stephen Keith

    The intentional or accidental release of a hazardous chemical, such as a chemical warfare agent (CWA) or a toxic industrial chemical (TIC), could endanger many lives. In domestic chemical release situations, a rapid response, which is critical for casualty minimization, requires that primary and first responders have the ability to rapidly probe the threatened area from a safe distance. First responders require sensors that are portable, remote (stand-off), sensitive, robust, and cost effective. While a number of remote chemical sensors are being developed, none meet the requirements of the first responder community due to their cost, complexity, and size. This work proposes a unique approach to hazardous chemical detection based on low-cost, low-energy, uncooled pyroelectric infrared detectors fitted with narrow bandpass filters. Prototype remote differential absorption radiometers (DARs) based on low-cost pyroelectric detectors fitted with relatively broad (30 cm-1) bandpass filters for sensitivity to hazardous chemical simulants, including methanol, dimethyl methylphosphonate (DMMP), and diisopropyl methylphosphonate (DIMP), were developed and tested. A methanol detection limit of 0.014 atm cm was demonstrated with the prototype sensor. This is well below military prescribed detection limits and demonstrates that sensors based on uncooled pyroelectric detectors can achieve sensitivities exceeding military requirements. Once chemical sensitivity was demonstrated, a prototype multi-spectral sensor comprised of 8 pyroelectric detectors. The measured methanol detection limit for this sensor was 0.033 atm cm. This prototype exhibited a unique response to three hazardous chemical simulants which could be used to detect and to identify the chemical reliably. To improve chemical sensitivity in realistic sensing environments, correction for background effects, such as temperature variations and spectral emissivity characteristics, is required. A simple background

  17. Summary of the effects of engine throttle response on airplane formation-flying qualities

    NASA Technical Reports Server (NTRS)

    Walsh, Kevin R.

    1992-01-01

    A flight evaluation as conducted to determine the effect of engine throttle response characteristics on precision formation-flying qualities. A variable electronic throttle control system was developed and flight-tested on a TF-104G airplane with a J79-11B engine at the NASA Dryden Flight Research Facility. Ten research flights were flown to evaluate the effects of throttle gain, time delay, and fuel control rate limiting on engine handling qualities during a demanding precision wing formation task. Handling quality effects of lag filters and lead compensation time delays were also evaluated. Data from pilot ratings and comments indicate that throttle control system time delays and rate limits cause significant degradations in handling qualities. Threshold values for satisfactory (level 1) and adequate (level 2) handling qualities of these key variables are presented.

  18. Analysis of Formation Flying in Eccentric Orbits Using Linearized Equations of Relative Motion

    NASA Technical Reports Server (NTRS)

    Lane, Christopher; Axelrad, Penina

    2004-01-01

    Geometrical methods for formation flying design based on the analytical solution to Hill's equations have been previously developed and used to specify desired relative motions in near circular orbits. By generating relationships between the vehicles that are intuitive, these approaches offer valuable insight into the relative motion and allow for the rapid design of satellite configurations to achieve mission specific requirements, such as vehicle separation at perigee or apogee, minimum separation, or a specific geometrical shape. Furthermore, the results obtained using geometrical approaches can be used to better constrain numerical optimization methods; allowing those methods to converge to optimal satellite configurations faster. This paper presents a set of geometrical relationships for formations in eccentric orbits, where Hill.s equations are not valid, and shows how these relationships can be used to investigate formation designs and how they evolve with time.

  19. Application of Analytic Solution in Relative Motion to Spacecraft Formation Flying in Elliptic Orbit

    NASA Astrophysics Data System (ADS)

    Cho, Hancheol; Park, Sang-Young; Choi, Kyu-Hong

    2008-09-01

    The current paper presents application of a new analytic solution in general relative motion to spacecraft formation flying in an elliptic orbit. The calculus of variations is used to analytically find optimal trajectories and controls for the given problem. The inverse of the fundamental matrix associated with the dynamic equations is not required for the solution in the current study. It is verified that the optimal thrust vector is a function of the fundamental matrix of the given state equations. The cost function and the state vector during the reconfiguration can be analytically obtained as well. The results predict the form of optimal solutions in advance without having to solve the problem. Numerical simulation shows the brevity and the accuracy of the general analytic solutions developed in the current paper.

  20. Control of Formation-Flying Multi-Element Space Interferometers with Direct Interferometer-Output Feedback

    NASA Technical Reports Server (NTRS)

    Lu, Hui-Ling; Cheng, H. L.; Lyon, Richard G.; Carpenter, Kenneth G.

    2007-01-01

    The long-baseline space interferometer concept involving formation flying of multiple spacecraft holds great promise as future space missions for high-resolution imagery. A major challenge of obtaining high-quality interferometric synthesized images from long-baseline space interferometers is to accurately control these spacecraft and their optics payloads in the specified configuration. Our research focuses on the determination of the optical errors to achieve fine control of long-baseline space interferometers without resorting to additional sensing equipment. We present a suite of estimation tools that can effectively extract from the raw interferometric image relative x/y, piston translational and tip/tilt deviations at the exit pupil aperture. The use of these error estimates in achieving control of the interferometer elements is demonstrated using simulated as well as laboratory-collected interferometric stellar images.

  1. Control of Formation-Flying Multi-Element Space Interferometers with Direct Interferometer-Output Feedback

    NASA Technical Reports Server (NTRS)

    Lu, Hui-Ling; Cheng, Victor H. L.; Lyon, Richard G.; Carpenter, Kenneth G.

    2007-01-01

    The long-baseline space interferometer concept involving formation flying of multiple spacecrafts holds great promise as future space missions for high-resolution imagery. A major challenge of obtaining high-quality interferometric synthesized images from long-baseline space interferometers is to accurately control these spacecraft and their optics payloads in the specified configuration. Our research focuses on the determination of the optical errors to achieve fine control of long-baseline space interferometers without resorting to additional sensing equipment. We present a suite of estimation tools that can effectively extract from the raw interferometric image relative x/y, piston translational and tip/tilt deviations at the exit pupil aperture. The use of these error estimates in achieving control of the interferometer elements is demonstrated using simulated as well as laboratory-collected interferometric stellar images.

  2. Neural network-based distributed attitude coordination control for spacecraft formation flying with input saturation.

    PubMed

    Zou, An-Min; Kumar, Krishna Dev

    2012-07-01

    This brief considers the attitude coordination control problem for spacecraft formation flying when only a subset of the group members has access to the common reference attitude. A quaternion-based distributed attitude coordination control scheme is proposed with consideration of the input saturation and with the aid of the sliding-mode observer, separation principle theorem, Chebyshev neural networks, smooth projection algorithm, and robust control technique. Using graph theory and a Lyapunov-based approach, it is shown that the distributed controller can guarantee the attitude of all spacecraft to converge to a common time-varying reference attitude when the reference attitude is available only to a portion of the group of spacecraft. Numerical simulations are presented to demonstrate the performance of the proposed distributed controller. PMID:24807141

  3. Design of a LQR Controller of Reduced Inputs for Multiple Spacecraft Formation Flying

    NASA Technical Reports Server (NTRS)

    Starin, Scott R.; Yedavalli, R. K.; Sparks, Andrew G.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    Regarding multiple spacecraft formation flying, the observation is made that control thrust need only be applied coplanar to the local horizon to achieve complete controllability of a two-satellite formation. Without the need for zenith-nadir (radial) thrust, simplifications and reduction of the weight of the propulsion system may be accomplished. This work focuses on the validation of this radial-excluding control system on its own merits, and in comparison to a related system which does provide thrust parallel to the orbital radius. Simulations are performed using commercial ODE solvers to propagate the Keplerian dynamics of a controlled satellite relative to an uncontrolled, leader satellite. The conclusion is drawn that, despite the exclusion of the radial thrust axis, the remaining control thrust available still provides enough control to design a gain matrix of adequate performance using linear-quadratic regulator (LQR) techniques.

  4. Close proximity formation flying via linear quadratic tracking controller and artificial potential function

    NASA Astrophysics Data System (ADS)

    Palacios, Leonel; Ceriotti, Matteo; Radice, Gianmarco

    2015-11-01

    A Riccati-based tracking controller with collision avoidance capabilities is presented for proximity operations of spacecraft formation flying near elliptic reference orbits. The proposed dynamical model incorporates nonlinear accelerations from an artificial potential field, in order to perform evasive maneuvers during proximity operations. In order to validate the design of the controller, test cases based on the physical and orbital features of the Prototype Research Instruments and Space Mission Technology Advancement (PRISMA) will be implemented, extending it to scenarios with multiple spacecraft performing reconfigurations and on-orbit position switching. The results show that the tracking controller is effective, even when nonlinear repelling accelerations are present in the dynamics to avoid collisions, and that the potential-based collision avoidance scheme is convenient for reducing collision threat.

  5. Ionosphere influence on success rate of GPS ambiguity resolution in a satellite formation flying

    NASA Astrophysics Data System (ADS)

    Baroni, Leandro

    2015-10-01

    Satellite formation flying is one of the most promising technologies for future space missions. The distribution of sensors and payloads among different satellites provides more redundancy, flexibility, improved communication coverage, among other advantages. One of the fundamental issues in spacecraft formation flying is precise position and velocity determination between satellites. For missions in low Earth orbits, GPS system can meet the precision requirement in relative positioning, since the satellite dynamics is modeled properly. The key for high accuracy GPS relative positioning is to resolve the ambiguities to their integer values. Ambiguities resolved successfully can improve the positioning accuracy to decimetre or even millimetre-level. So, integer carrier phase ambiguity resolution is often a prerequisite for high precision GPS positioning. The determination of relative position was made using an extended Kalman filter. The filter must take into account imperfections in dynamic modeling of perturbations affecting the orbital flight, and changes in solar activity that affects the GPS signal propagation, for mitigating these effects on relative positioning accuracy. Thus, this work aims to evaluate the impact of ionosphere variation, caused by changes in solar activity, in success rate of ambiguity resolution. Using the Ambiguity Dilution of Precision (ADOP) concept, the ambiguity success rate is analyzed and the expected precision of the ambiguity-fixed solution is calculated. Evaluations were performed using actual data from GRACE mission and analyzed for their performance in real scenarios. Analyses were conducted in different configurations of relative position and during different levels of solar activity. Results bring the impact of various disturbances and modeling of solar activity level on the success rate of ambiguity resolution.

  6. Low-cost color LCD helmet display

    NASA Astrophysics Data System (ADS)

    Leinenwever, Roger; Best, Leonard G.; Ericksen, Bryce J.

    1992-10-01

    The goal of this helmet-mounted display (HMD) project was development and demonstration of a low-cost color display incorporating see-through optics. A full field-of-regard visual presentation was to be provided through the use of a head-tracker system and the HMD was to be suitable for use with low-cost cockpit trainers. The color imaging devices selected for the project are commercially available liquid crystal display (LCD) panels. The LCDs are 3.0 inch (diagonal) thin film transistor (TFT) types using a delta format for the red, green, blue (RGB) matrix. Fiber optic light panels mounted behind the LCDs provide a cool light source of greater than 3400 foot-lamberts (ft-L). Approximately 3 percent of the applied light source is emitted by the LCD image source. The video displayed is in a 3:4 format representing a 30 degree(s) vertical by 40 degree(s) horizontal biocular instantaneous field-of-view (IFOV) visual image from a graphic image generation system and is controlled in a full field of regard based on positional information from a head-tracker system. The optical elements of the HMD are designed as an exit pupil forming, see-through system and require the eye to be in a 15 mm volume for viewing the scene. The beam splitting function of the optics allows the user to see through the optics for reading cockpit instrumentation, while viewing outside the cockpit reveals the out-the-window (OTW) scene. The optic design allows for the IFOV to be displayed through a set of field lens, relay lens, folding mirror, beam splitter and spherical mirror system. The beam splitters and spherical mirrors for both optical paths are coated for approximately 50 percent transmission and reflectance. This approach, combined with the losses through the rest of the optical path, provides a theoretical maximum of 10.9 percent of the LCD image source intensity arriving at the eye. Initial tests of image intensity at the eye for a full white scene have measured at approximately 11 ft-L.

  7. Low cost PC based scanning Kelvin probe

    NASA Astrophysics Data System (ADS)

    Baikie, I. D.; Estrup, P. J.

    1998-11-01

    We have developed a novel, low cost, scanning Kelvin probe (SKP) system that can measure work function (wf) and surface potential (sp) topographies to within 1 meV energy resolution. The control and measurement subcomponents are PC based and incorporate a flexible user interface, permitting software control of major parameters and allowing easy user implementation via automatic setup and scanning procedures. We review the mode of operation and design features of the SKP including the digital oscillator, the compact ambient voice-coil head-stage, and signal processing techniques. This system offers unique tip-to-sample spacing control (to within 40 nm) which provides a method of simultaneously imaging sample height topographies and is essential to avoid spurious or "apparent" wf changes due to scanning-induced spacing changes. We illustrate SKP operation in generating high resolution wf/sp profiles of metal interfaces (as a tip characterization procedure) and operational electronic devices. The SKP potentially has a very wide range of applications ranging from semiconductor quality control thin film and surface analyses to corrosion and biopotential imaging.

  8. Low Cost RF Amplifier for Community TV

    NASA Astrophysics Data System (ADS)

    Ch, Syafaruddin; Sasongko, Sudi Mariyanto Al; Made Budi Suksmadana, I.; Mustiko Okta Muvianto, Cahyo; Ariessaputra, Suthami

    2016-01-01

    he capability of television to deliver audio video makes this media become the most effective method to spread information. This paper presents an experiment of RF amplifier design having low-cost design and providing sufficient RF power particularly for community television. The RF amplifier consists of two stages of amplifier. The first stage amplifier was used to leverage output of TV modulator from 11dBm to enable to drive next stage amplifier. CAD simulation and fabrication were run to reach optimum RF amplifier design circuit. The associated circuit was made by determining stability circle, stability gain, and matching impedance. Hence, the average power of first stage RF amplifier was 24.68dBm achieved. The second stage used RF modules which was ready match to 50 ohm for both input and output port. The experiment results show that the RF amplifier may operate at frequency ranging from 174 to 230MHz. The average output power of the 2nd stage amplifier was 33.38 Watt with the overall gain of 20.54dB. The proposed RF amplifier is a cheap way to have a stable RF amplifier for community TV. The total budget for the designed RF amplifier is only a 1/5 compared to local design of final TV amplifier.

  9. Performance of several low-cost accelerometers

    USGS Publications Warehouse

    Evans, J.R.; Allen, R.M.; Chung, A. I.; Cochran, E.S.; Guy, R.; Hellweg, M.; Lawrence, J. F.

    2014-01-01

    Several groups are implementing low‐cost host‐operated systems of strong‐motion accelerographs to support the somewhat divergent needs of seismologists and earthquake engineers. The Advanced National Seismic System Technical Implementation Committee (ANSS TIC, 2002), managed by the U.S. Geological Survey (USGS) in cooperation with other network operators, is exploring the efficacy of such systems if used in ANSS networks. To this end, ANSS convened a working group to explore available Class C strong‐motion accelerometers (defined later), and to consider operational and quality control issues, and the means of annotating, storing, and using such data in ANSS networks. The working group members are largely coincident with our author list, and this report informs instrument‐performance matters in the working group’s report to ANSS. Present examples of operational networks of such devices are the Community Seismic Network (CSN; csn.caltech.edu), operated by the California Institute of Technology, and Quake‐Catcher Network (QCN; Cochran et al., 2009; qcn.stanford.edu; November 2013), jointly operated by Stanford University and the USGS. Several similar efforts are in development at other institutions. The overarching goals of such efforts are to add spatial density to existing Class‐A and Class‐B (see next paragraph) networks at low cost, and to include many additional people so they become invested in the issues of earthquakes, their measurement, and the damage they cause.

  10. A low cost MRI permanent magnet prototype

    NASA Astrophysics Data System (ADS)

    Esparza-Coss, Emilio; Cole, David M.

    1998-08-01

    Here we present the proceedings in designing and constructing a low cost, friendly use, Magnetic Resonance Imaging (MRI) prototype magnet; 55 cm×45 cm×30 cm in size scaleable to full body; with a C-shaped assembly to provide open access to the 10 cm C-gap; operational at 0.22 Tesla where the low field increments the tissue contrast; structured with methodically selected and strategically positioned permanent magnets to reach the required field homogeneity as well as to be practically free of maintenance; and having iron flux return to leave an extremely low fringe field. The magnetic flux is funneled through the iron and focused by carefully designed and finely machined iron pole faces of 8.9 cm radius to create a homogeneity of less than 20 parts per million (PPM), without shimming, in a roughly 1.3 cm by 2 cm main axes oval region. An image of an okra plant was taken to test its performance.

  11. A low cost MRI permanent magnet prototype

    SciTech Connect

    Esparza-Coss, Emilio; Cole, David M.

    1998-08-28

    Here we present the proceedings in designing and constructing a low cost, friendly use, Magnetic Resonance Imaging (MRI) prototype magnet; 55 cmx45 cmx30 cm in size scaleable to full body; with a C-shaped assembly to provide open access to the 10 cm C-gap; operational at 0.22 Tesla where the low field increments the tissue contrast; structured with methodically selected and strategically positioned permanent magnets to reach the required field homogeneity as well as to be practically free of maintenance; and having iron flux return to leave an extremely low fringe field. The magnetic flux is funneled through the iron and focused by carefully designed and finely machined iron pole faces of 8.9 cm radius to create a homogeneity of less than 20 parts per million (PPM), without shimming, in a roughly 1.3 cm by 2 cm main axes oval region. An image of an okra plant was taken to test its performance.

  12. LOTUS: a low-cost, ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; Smith, R. J.; Snodgrass, C.; de Val-Borro, M.

    2016-08-01

    We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5x95 arcsec) and wide (5x25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky testing shows a wavelength range of 3200-6300 Angstroms with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependant spectral resolution of R=225-430. By repeated observations of the symbiotic emission line star AG Peg we demonstrate the wavelength stability of the system is less than 2 Angstroms rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

  13. Prototype of a low cost multiparameter probe

    NASA Astrophysics Data System (ADS)

    Koski, K.; Schwingle, R.; Pullin, M.

    2010-12-01

    Commercial multi-parameter probes provide accurate, high-resolution temporal data collection of a variety of water quality parameters, but their cost (>5,000) prohibits more than a few sampling locations. We present a design and prototype for a low cost (<250) probe. The cost of the probe is ~5% of commercially available probes, allowing for data collection from ~20 times more sampling points in a field location. The probe is constructed from a single-board microcontroller, a commercially available temperature sensor, a conductivity sensor, and a fabricated optical rhodamine sensor. Using a secure digital (SD) memory card, the probe can record over a month of data at a user specified interval. Construction, calibration, field deployment and data retrieval can be accomplished by a skilled undergraduate. Initial deployment will take place as part of a tracer test in the Valles Caldera National Preserve in northern New Mexico. Future work includes: addition of commercial ion selective electrodes (pH, bromide, nitrate, and others); construction of optically based sensors (chlorophyll, dissolved oxygen, and others); wireless networking between the sensors; and reduction of biofouling.

  14. LOTUS: A low cost, ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; Smith, R. J.; Snodgrass, C.; de Val-Borro, M.

    2016-05-01

    We describe the design, construction and commissioning of LOTUS; a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5 × 95 arcsec) and wide (5 × 25 arcsec) options that are optimized for spectral resolution and flux calibration respectively. On sky testing shows a wavelength range of 3200-6300 Å with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependant spectral resolution of R = 225 - 430. By repeated observations of the symbiotic emission line star AG Peg we demonstrate the wavelength stability of the system is <2 Å rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

  15. LOTUS: a low-cost, ultraviolet spectrograph

    NASA Astrophysics Data System (ADS)

    Steele, I. A.; Marchant, J. M.; Jermak, H. E.; Barnsley, R. M.; Bates, S. D.; Clay, N. R.; Fitzsimmons, A.; Jehin, E.; Jones, G.; Mottram, C. J.; Smith, R. J.; Snodgrass, C.; de Val-Borro, M.

    2016-08-01

    We describe the design, construction and commissioning of a simple, low-cost long-slit spectrograph for the Liverpool Telescope. The design is optimized for near-UV and visible wavelengths and uses all transmitting optics. It exploits the instrument focal plane field curvature to partially correct axial chromatic aberration. A stepped slit provides narrow (2.5 × 95 arcsec) and wide (5 × 25 arcsec) options that are optimized for spectral resolution and flux calibration, respectively. On sky testing shows a wavelength range of 3200-6300 Å with a peak system throughput (including detector quantum efficiency) of 15 per cent and wavelength dependent spectral resolution of R = 225-430. By repeated observations of the symbiotic emission line star AG Peg, we demonstrate the wavelength stability of the system is <2 Å rms and is limited by the positioning of the object in the slit. The spectrograph is now in routine operation monitoring the activity of comet 67P/Churyumov-Gerasimenko during its current post-perihelion apparition.

  16. Low cost way to recover logging residues

    SciTech Connect

    Hassler, C.C.; Sinclair, S.A.; Blinn, C.R.

    1983-01-01

    Integration of a residue harvesting component into a traditional harvest system can offer a reasonable alternative to whole-tree chipping of existing natural stands in supplying wood to energy conversion facilitites. Initial attempts at integration should focus on a low cost, incremental expansion that minimizes the impact on productivity for the traditional harvest component, is easily adapted into a traditional harvest system, and has application to a wide range of harvesting firms in practice. Two traditional systems are analyzed - three-person and four-person systems - where chainsaws are used to fell, limb, top, and buck and rubber-tired cable skidders move the wood. Residue recovery is introduced through the addition of a 120-horsepower mobile chipper with self-mounted knuckleboom loader and two used chip vans. The productivity and cost of the residue recovery component is analyzed over a range of stand types and factors affecting productivity and costs. In general, residue recovery for a three-person system is economical only in stands of large sized timber while the four-person system becomes economical in medium sized lumber. (Refs. 12).

  17. Fast Paced, Low Cost Projects at MSFC

    NASA Technical Reports Server (NTRS)

    Watson-Morgan, Lisa; Clinton, Raymond

    2012-01-01

    What does an orbiting microsatellite, a robotic lander and a ruggedized camera and telescope have in common? They are all fast paced, low cost projects managed by Marshall Space Flight Center (MSFC) teamed with successful industry partners. MSFC has long been synonymous with human space flight large propulsion programs, engineering acumen and risk intolerance. However, there is a growing portfolio/product line within MSFC that focuses on these smaller, fast paced projects. While launching anything into space is expensive, using a managed risk posture, holding to schedule and keeping costs low by stopping at egood enough f were key elements to their success. Risk is defined as the possibility of loss or failure per Merriam Webster. The National Aeronautics and Space Administration (NASA) defines risk using procedural requirement 8705.4 and establishes eclasses f to discern the acceptable risk per a project. It states a Class D risk has a medium to significant risk of not achieving mission success. MSFC, along with industry partners, has created a niche in Class D efforts. How did the big, cautious MSFC succeed on these projects that embodied the antithesis of its heritage in human space flight? A key factor toward these successful projects was innovative industry partners such as Dynetics Corporation, University of Alabama in Huntsville (UAHuntsville), Johns Hopkins Applied Physics Laboratory (JHU APL), Teledyne Brown Engineering (TBE), Von Braun Center for Science and Innovation (VCSI), SAIC, and Jacobs. Fast Affordable Satellite Technology (FastSat HSV01) is a low earth orbit microsatellite that houses six instruments with the primary scientific objective of earth observation and technology demonstration. The team was comprised of Dynetics, UAHuntsvile, SAIC, Goddard Space Flight Center (GSFC) and VCSI with the United States Air Force Space Test Program as the customer. The team completed design, development, manufacturing, environmental test and integration in

  18. MPEG-1 low-cost encoder solution

    NASA Astrophysics Data System (ADS)

    Grueger, Klaus; Schirrmeister, Frank; Filor, Lutz; von Reventlow, Christian; Schneider, Ulrich; Mueller, Gerriet; Sefzik, Nicolai; Fiedrich, Sven

    1995-02-01

    A solution for real-time compression of digital YCRCB video data to an MPEG-1 video data stream has been developed. As an additional option, motion JPEG and video telephone streams (H.261) can be generated. For MPEG-1, up to two bidirectional predicted images are supported. The required computational power for motion estimation and DCT/IDCT, memory size and memory bandwidth have been the main challenges. The design uses fast-page-mode memory accesses and requires only one single 80 ns EDO-DRAM with 256 X 16 organization for video encoding. This can be achieved only by using adequate access and coding strategies. The architecture consists of an input processing and filter unit, a memory interface, a motion estimation unit, a motion compensation unit, a DCT unit, a quantization control, a VLC unit and a bus interface. For using the available memory bandwidth by the processing tasks, a fixed schedule for memory accesses has been applied, that can be interrupted for asynchronous events. The motion estimation unit implements a highly sophisticated hierarchical search strategy based on block matching. The DCT unit uses a separated fast-DCT flowgraph realized by a switchable hardware unit for both DCT and IDCT operation. By appropriate multiplexing, only one multiplier is required for: DCT, quantization, inverse quantization, and IDCT. The VLC unit generates the video-stream up to the video sequence layer and is directly coupled with an intelligent bus-interface. Thus, the assembly of video, audio and system data can easily be performed by the host computer. Having a relatively low complexity and only small requirements for DRAM circuits, the developed solution can be applied to low-cost encoding products for consumer electronics.

  19. Low-cost sustainable wall construction system

    SciTech Connect

    Vohra, A.; Rosenfeld, A.H.

    1998-07-01

    Houses with no wall cavities, such as those made of adobe, stone, brick, or block, have poor thermal properties but are rarely insulated because of the cost and difficulty of providing wall insulation. A simple, low-cost technique using loose-fill indigenous materials has been demonstrated for the construction of highly insulated walls or the retrofit of existing walls in such buildings. Locally available pumice, in sandbags stacked along the exterior wall of an adobe house in New Mexico, added a thermal resistance (R) of 16 F{sm{underscore}bullet}ft{sup 2}{sm{underscore}bullet}h/Btu (2.8 m{sup 2}{sm{underscore}bullet}K/W). The total cost of the sandbag insulation wall retrofit was $3.76 per square foot ($40.50/m{sup 2}). Computer simulations of the adobe house using DOE 2.1E show savings of $275 per year, corresponding to 50% reduction in heating energy consumption. The savings-to-investment ratio ranges from 1.1 to 3.2, so the cost of conserved energy is lower than the price of propane, natural gas and electric heat, making the system cost-effective. Prototype stand-alone walls were also constructed using fly ash and sawdust blown into continuous polypropylene tubing, which was folded between corner posts as it was filled to form the shape of the wall. Other materials could also be used. The inexpensive technique solves the problem of insulating solid-wall hours and constructing new houses without specialized equipment and skills, thereby saving energy, reducing greenhouse gas emissions, and improving comfort for people in many countries. The US Department of Energy (DOE) has filed patent applications on this technology, which is part of a DOE initiative on sustainable building envelope materials and systems.

  20. Low Cost Precision Lander for Lunar Exploration

    NASA Astrophysics Data System (ADS)

    Hoppa, G. V.; Head, J. N.; Gardner, T. G.; Seybold, K. G.

    2004-12-01

    For 60 years the US Defense Department has invested heavily in producing small, low mass, precision-guided vehicles. The technologies matured under these programs include terrain-aided navigation, closed loop terminal guidance algorithms, robust autopilots, high thrust-to-weight propulsion, autonomous mission management software, sensors, and data fusion. These technologies will aid NASA in addressing New Millennium Science and Technology goals as well as the requirements flowing from the Moon to Mars vision articulated in January 2004. Establishing and resupplying a long-term lunar presence will require automated landing precision not yet demonstrated. Precision landing will increase safety and assure mission success. In our lander design, science instruments amount to 10 kg, 16% of the lander vehicle mass. This compares favorably with 7% for Mars Pathfinder and less than 15% for Surveyor. The mission design relies on a cruise stage for navigation and TCMs for the lander's flight to the moon. The landing sequence begins with a solid motor burn to reduce the vehicle speed to 300-450 m/s. At this point the lander is about 2 minutes from touchdown and has 600 to 700 m/s delta-v capability. This allows for about 10 km of vehicle divert during terminal descent. This concept of operations closely mimics missile operational protocol used for decades: the vehicle remains inert, then must execute its mission flawlessly on a moment's notice. The vehicle design uses a propulsion system derived from heritage MDA programs. A redesigned truss provides hard points for landing gear, electronics, power supply, and science instruments. A radar altimeter and a Digital Scene Matching Area Correlator (DSMAC) provide data for the terminal guidance algorithms. This approach leverages the billions of dollars DoD has invested in these technologies, to land useful science payloads precisely on the lunar surface at relatively low cost.

  1. Low-cost respiratory motion tracking system

    NASA Astrophysics Data System (ADS)

    Goryawala, Mohammed; Del Valle, Misael; Wang, Jiali; Byrne, James; Franquiz, Juan; McGoron, Anthony

    2008-03-01

    Lung cancer is the cause of more than 150,000 deaths annually in the United States. Early and accurate detection of lung tumors with Positron Emission Tomography has enhanced lung tumor diagnosis. However, respiratory motion during the imaging period of PET results in the reduction of accuracy of detection due to blurring of the images. Chest motion can serve as a surrogate for tracking the motion of the tumor. For tracking chest motion, an optical laser system was designed which tracks the motion of a patterned card placed on the chest by illuminating the pattern with two structured light sources, generating 8 positional markers. The position of markers is used to determine the vertical, translational, and rotational motion of the card. Information from the markers is used to decide whether the patient's breath is abnormal compared to their normal breathing pattern. The system is developed with an inexpensive web-camera and two low-cost laser pointers. The experiments were carried out using a dynamic phantom developed in-house, to simulate chest movement with different amplitudes and breathing periods. Motion of the phantom was tracked by the system developed and also by a pressure transducer for comparison. The studies showed a correlation of 96.6% between the respiratory tracking waveforms by the two systems, demonstrating the capability of the system. Unlike the pressure transducer method, the new system tracks motion in 3 dimensions. The developed system also demonstrates the ability to track a sliding motion of the patient in the direction parallel to the bed and provides the potential to stop the PET scan in case of such motion.

  2. Manufacturing Large Membrane Mirrors at Low Cost

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Relatively inexpensive processes have been developed for manufacturing lightweight, wide-aperture mirrors that consist mainly of reflectively coated, edge-supported polyimide membranes. The polyimide and other materials in these mirrors can withstand the environment of outer space, and the mirrors have other characteristics that make them attractive for use on Earth as well as in outer space: With respect to the smoothness of their surfaces and the accuracy with which they retain their shapes, these mirrors approach the optical quality of heavier, more expensive conventional mirrors. Unlike conventional mirrors, these mirrors can be stowed compactly and later deployed to their full sizes. In typical cases, deployment would be effected by inflation. Potential terrestrial and outer-space applications for these mirrors include large astronomical telescopes, solar concentrators for generating electric power and thermal power, and microwave reflectors for communication, radar, and short-distance transmission of electric power. The relatively low cost of manufacturing these mirrors stems, in part, from the use of inexpensive tooling. Unlike in the manufacture of conventional mirrors, there is no need for mandrels or molds that have highly precise surface figures and highly polished surfaces. The surface smoothness is an inherent property of a polyimide film. The shaped area of the film is never placed in contact with a mold or mandrel surface: Instead the shape of a mirror is determined by a combination of (1) the shape of a fixture that holds the film around its edge and (2) control of manufacturing- process parameters. In a demonstration of this manufacturing concept, spherical mirrors having aperture diameters of 0.5 and 1.0 m were fabricated from polyimide films having thicknesses ranging from <20 m to 150 m. These mirrors have been found to maintain their preformed shapes following deployment.

  3. Low-cost, multiplexed biosensor for disease diagnosis

    NASA Astrophysics Data System (ADS)

    Myatt, Christopher J.; Delaney, Marie; Todorof, Kathryn; Heil, James; Givens, Monique; Schooley, Robert T.; Lochhead, Michael J.

    2009-02-01

    Cost-effective disease diagnosis in resource-limited settings remains a critical global health challenge. Qualitative rapid tests based on lateral flow technology provide valuable screening information, but require relatively expensive confirmatory tests and generally lack quantitation. We report on a fluorescence technology that combines low cost instrumented readout with passive pumping in a disposable cartridge. The detection system utilizes a novel waveguide illumination approach in conjunction with commercial CMOS imagers. Total instrument cost in production are projected to be around $100 This cost structure and instrument ease of use will enable use in point-of-care settings, outside of centralized laboratories. The system has been used for detection and analysis of proteins, antibodies, nucleic acids, and cells. Here we will report first on our development of a multiplexed, array-based serology assay for HIV and common AIDS co-infections. Data will be presented for HIV/HCV antibody testing in human serum samples. In addition, we will present data on the use of the system for sensitive detection of bacterial RNA. Current detection limit for the model multiplexed RNA sandwich assay is 1 femtomolar target RNA. Finally, a high magnification version of the system is used to image immunostained human T cells.

  4. Low-Cost WDM-PON With Colorless Bidirectional Transceivers

    NASA Astrophysics Data System (ADS)

    Shin, Dong Jae; Keh, Y. C.; Kwon, J. W.; Lee, E. H.; Lee, J. K.; Park, M. K.; Park, J. W.; Oh, Y. K.; Kim, S. W.; Yun, I. K.; Shin, H. C.; Heo, D.; Lee, J. S.; Shin, H. S.; Kim, H. S.; Park, S. B.; Jung, D. K.; Hwang, Seongtaek; Oh, Y. J.; Jang, D. H.; Shim, C. S.

    2006-01-01

    This paper presents a low-cost bidirectional (BiDi) wavelength-division-multiplexed passive optical network (WDM-PON) employing colorless uncooled BiDi transceivers (TRxs) and superluminescent diode (SLD)-based broadband light sources (BLSs). The C band is allocated for upstream and the E+ band for downstream in consideration of BiDi packaging, SLD development, and wavelength alignment of dual-window arrayed waveguide gratings (AWGs). The BiDi TRx integrates an uncooled Fabry-Pérot laser diode (FP-LD), a p-i-n photodiode (PD), and a 45°-angled thin-film filter in a small-form-factor (SFF) package. The SLD-based BLSs provide 13-dBm amplified spontaneous emissions (ASEs) with spectral ripples of < 3 dB and polarization dependencies of < 1 dB. Colorless operations over 32 100-GHz-spaced channels are demonstrated from -20 to 80°C in 155-Mb/s BiDi transmissions over 25 km.

  5. Measurement of luminescence decays: High performance at low cost

    NASA Astrophysics Data System (ADS)

    Sulkes, Mark; Sulkes, Zoe

    2011-11-01

    The availability of inexpensive ultra bright LEDs spanning the visible and near-ultraviolet combined with the availability of inexpensive electronics equipment makes it possible to construct a high performance luminescence lifetime apparatus (˜5 ns instrumental response or better) at low cost. A central need for time domain measurement systems is the ability to obtain short (˜1 ns or less) excitation light pulses from the LEDs. It is possible to build the necessary LED driver using a simple avalanche transistor circuit. We describe first a circuit to test for small signal NPN transistors that can avalanche. We then describe a final optimized avalanche mode circuit that we developed on a prototyping board by measuring driven light pulse duration as a function of the circuit on the board and passive component values. We demonstrate that the combination of the LED pulser and a 1P28 photomultiplier tube used in decay waveform acquisition has a time response that allows for detection and lifetime determination of luminescence decays down to ˜5 ns. The time response and data quality afforded with the same components in time-correlated single photon counting are even better. For time-correlated single photon counting an even simpler NAND-gate based LED driver circuit is also applicable. We also demonstrate the possible utility of a simple frequency domain method for luminescence lifetime determinations.

  6. Definition of Relative Orbit Elements of Spacecraft Formation Flying for Purpose of Orbit Design

    NASA Astrophysics Data System (ADS)

    Xiao, Yelun

    Much efforts have been made to the research concerning the dynamical characteristics of spacecraft formation flying, several articles have been published including the authors' IAC papers IAF-98-A.2.06, IAA-99-IAA.11.1.09, IAA-01-IAA.11.4.08. The problem can be deduced to the issue of relative orbit motion of one satellite called accompany satellite around another called reference or central satellite, the latter being supposed to move in circular or near-circular orbit and to have equal semimajor axis as the former. It has been shown that the trajectory of relative motion is an ellipse constantly fixed to the orbital frame of the central satellite. It is known that the relative motion is completely determined by initial state of relative motion x0, y0, z0, vx0, vy0, vz0 (called parameter set 1). On the other hand the relative motion is caused by difference in eccentricity vectors and by non-coplanarity vector and influenced by the angle btw. the two vectors (called parameter set 2). Now the authors try to define relative orbit elements determining all geometrical and kinematical properties of the relative motion and having clear physical meaning similar to traditional orbit elements. Based on deep study of the dynamical characteristics we decide to define the elements as follows: (1) semimajor axis of the ellipse of relative trajectory; (2 and 3) elevation and azimuth angles of the normal determining the orientation of the relative motion plane wrt the reference orbit frame; (4) argument of latitude at epoch (initial instant) of reference satellite and (5) phase angle of the accompany satellite at epoch. These are minimum-required and independent elements. All others are secondary (or derived) parameters. For example, aspect ratio, i.e., ratio of major axis to minor axis, describing the shape of relative trajectory, is determined by elements 2 and 3, because of the inherent property that the projection of relative trajectory on reference orbit plane must be a 2

  7. Very-Low-Cost, Rugged Vacuum System

    NASA Technical Reports Server (NTRS)

    Kline-Schoder, Robert; Sorensen, Paul; Passow, Christian; Bilski, Steve

    2013-01-01

    NASA, DoD, DHS, and commercial industry have a need for miniaturized, rugged, low-cost vacuum systems. Recent advances in sensor technology have led to the development of very small mass spectrometer detectors as well as other miniature analytical instruments. However, the vacuum systems to support these sensors remain large, heavy, and power-hungry. To meet this need, a miniaturized vacuum system was created based on a very small, rugged, and inexpensive- to-manufacture molecular drag pump (MDP). The MDP is enabled by the development of a miniature, veryhigh- speed, rugged, low-power, brushless DC motor optimized for wide temperature operation and long life. Such a pump represents an order-of-magnitude reduction in mass, volume, and cost over current, commercially available, state-ofthe- art vacuum pumps. The vacuum system consists of the MDP coupled to a ruggedized rough pump (for terrestrial applications or for planets with substantial atmospheres). The rotor in the MDP consists of a simple smooth cylinder of aluminum spinning at approximately 200,000 RPM inside an outer stator housing. The pump stator comprises a cylindrical aluminum housing with one or more specially designed grooves that serve as flow channels. To minimize the length of the pump, the gas is forced down the flow channels of the outer stator to the base of the pump. The gas is then turned and pulled toward the top through a second set of channels cut into an inner stator housing that surrounds the motor. The compressed gas then flows down channels in the motor housing to the exhaust port of the pump. The exhaust port of the pump is connected to a diaphragm or scroll pump. This pump delivers very high performance in a very small envelope. The design was simplified so that a smaller compression ratio, easier manufacturing process, and enhanced ruggedness can be achieved at the lowest possible cost. The machining of the rotor and stators is very simple compared to that necessary to fabricate TMP

  8. Low-Cost Illumination-Grade LEDs

    SciTech Connect

    Epler, John

    2013-08-31

    technology was commercialized in our LUXEON Q product in Sept., 2013. Also, the retention of the sapphire increased the robustness of the device, enabling sales of low-cost submount-free chips to lighting manufacturers. Thus, blue LED die sales were initiated in the form of a PSS-FC in February, 2013.

  9. Formation Flying Satellite Control Around the L2 Sun-Earth Libration Point

    NASA Technical Reports Server (NTRS)

    Hamilton, Nicholas H.; Folta, David; Carpenter, Russell; Bauer, Frank (Technical Monitor)

    2002-01-01

    A growing interest in formation flying satellites demands development and analysis of control and estimation algorithms for station-keeping and formation maneuvering. This paper discusses the development of a discrete linear-quadratic-regulator control algorithm for formations in the vicinity of the L2 sun-earth libration point. The development of an appropriate Kalman filter is included as well. Simulations are created for the analysis of the station-keeping and various formation maneuvers of the Stellar Imager mission. The simulations provide tracking error, estimation error, and control effort results. From the control effort, useful design parameters such as delta V and propellant mass are determined. For formation maneuvering, the formation spacecraft track to within 4 meters of their desired position and within 1.5 millimeters per second of their desired zero velocity. The filter, with few exceptions, keeps the estimation errors within their three-sigma values. Without noise, the controller performs extremely well, with the formation spacecraft tracking to within several micrometers. Each spacecraft uses around 1 to 2 grams of propellant per maneuver, depending on the circumstances.

  10. Coupled Attitude and Orbit Dynamics and Control in Formation Flying Systems

    NASA Technical Reports Server (NTRS)

    Xu, Yun-Jun; Fitz-Coy, Norman; Mason, Paul

    2003-01-01

    Formation flying systems can range from global constellations offering extended service coverage to clusters of highly coordinated vehicles that perform distributed sensing. Recently, the use of groups of micro-satellites in the areas of near Earth explorations, deep space explorations, and military applications has received considerable attention by researchers and practitioners. To date, most proposed control strategies are based on linear models (e.g., Hill-Clohessy-Wiltshire equations) or nonlinear models that are restricted to circular reference orbits. Also, all models in the literature are uncoupled between relative position and relative attitude. In this paper, a generalized dynamic model is proposed. The reference orbit is not restricted to the circular case. In this formulation, the leader or follower satellite can be in either a circular or an elliptic orbit. In addition to maintaining a specified relative position, the satellites are also required to maintain specified relative attitudes. Thus the model presented couples vehicle attitude and orbit requirements. Orbit perturbations are also included. In particular, the J(sub 2) effects are accounted in the model. Finally, a sliding mode controller is developed and used to control the relative attitude of the formation and the simulation results are presented.

  11. Topics in constrained optimal control: Spacecraft formation flying, constrained attitude control, and rank minimization problems

    NASA Astrophysics Data System (ADS)

    Kim, Yoonsoo

    This dissertation focuses on cooperative control between multiple agents (e.g., spacecraft, UAVs). In particular, motivated by future NASA's multiple spacecraft missions, we have been guided to consider fundamental aspects of spacecraft formation flying, including collision avoidance issues; constraints on the relative position and attitude. In this venue, we have realized that one of the main challenges is dealing with nonconvex state constraints. In this dissertation, we will address such complications using classical control theory, heuristic techniques, and more recent semidefinite programming-based approaches. We then proceed to consider communication and interspacecraft sensing issues in multiple agent dynamic system setting. In this direction, we will study (1) how conventional control techniques should be augmented to meet our design objectives when the information flow between multiple agents is taken into account; (2) which information structures (e.g., information graphs) yield best performance guarantees in terms of stability, robustness, or fast agreement. In this work, we provide theoretical answers to these problems. Moreover, as many design problems involving information networks and graphs lead to combinatorial problems, which can be formulated as rank optimization problems over matrices, we consider these class of problems in this dissertation. Rank optimization problems also arise in system theory and are considered to be of paramount importance in modern control synthesis problems.

  12. Application of SDRE technique to orbital and attitude control of spacecraft formation flying

    NASA Astrophysics Data System (ADS)

    Massari, Mauro; Zamaro, Mattia

    2014-01-01

    This paper proposes the application of a nonlinear control technique for coupled orbital and attitude relative motion of formation flying. Recently, mission concepts based on the formations of spacecraft that require an increased performance level for in-space maneuvers and operations, have been proposed. In order to guarantee the required performance level, those missions will be characterized by very low inter-satellite distance and demanding relative pointing requirements. Therefore, an autonomous control with high accuracy will be required, both for the control of relative distance and relative attitude. The control system proposed in this work is based on the solution of the State-Dependent Riccati Equation (SDRE), which is one of the more promising nonlinear techniques for regulating nonlinear systems in all the major branches of engineering. The coupling of the relative orbital and attitude motion is obtained considering the same set of thrusters for the control of both orbital and attitude relative dynamics. In addition, the SDRE algorithm is implemented with a timing update strategy both for the controller and the proposed nonlinear filter. The proposed control system approach has been applied to the design of a nonlinear controller for an up-to-date formation mission, which is ESA Proba-3. Numerical simulations considering a tracking signal for both orbital and attitude relative maneuver during an operative orbit of the mission are presented.

  13. Relative navigation for autonomous formation flying satellites using the state-dependent Riccati equation filter

    NASA Astrophysics Data System (ADS)

    Park, Han-Earl; Kim, Young-Rok

    2016-01-01

    A relative navigation method for autonomous formation flying using the state-dependent Riccati equation filter (SDREF) is presented. In the SDREF, nonlinear relative dynamics, including J2 perturbation, are parameterized into a state-dependent coefficient (SDC) form without any loss of nonlinearity. The relative navigation algorithm is established based on the carrier-phase differential GPS (CDGPS) and single-frequency GPS data, in which the SDREF is used as a nonlinear estimator. To evaluate the SDREF performance, two different extended Kalman filters (EKFR1 and EKFR2) are introduced. The dynamic models of all the filters are based on relative motion including J2 perturbation. However, the SDREF and the EKFR1 use linear state propagation, whereas EKFR2 employs nonlinear state propagation. The navigation simulation is performed for each filter using live GPS signals simulated by a GPS signal generator, and the result is analyzed in terms of estimation accuracy and computational load. As a result, the SDREF provides a relative navigation solution with 3-D RMS accuracies of 6.0 mm and 0.153 mm/s for position and velocity, respectively, for a separation of 50 km with a computation time of approximately 34 s. The simulation results demonstrate that the SDREF estimates the relative states as rapidly as the EKFR1 and as accurately as the EKFR2, which means that the developed SDREF combines the strong points of EKFR1 and EKFR2 and overcomes their disadvantages.

  14. Spacecraft Formation Flying Maneuvers Using Linear Quadratic Regulation With No Radial Axis Inputs

    NASA Technical Reports Server (NTRS)

    Starin, Scott R.; Yedavalli, R. K.; Sparks, Andrew G.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    Regarding multiple spacecraft formation flying, the observation has been made that control thrust need only be applied coplanar to the local horizon to achieve complete controllability of a two-satellite (leader-follower) formation. A formulation of orbital dynamics using the state of one satellite relative to another is used. Without the need for thrust along the radial (zenith-nadir) axis of the relative reference frame, propulsion system simplifications and weight reduction may be accomplished. This work focuses on the validation of this control system on its own merits, and in comparison to a related system which does provide thrust along the radial axis of the relative frame. Maneuver simulations are performed using commercial ODE solvers to propagate the Keplerian dynamics of a controlled satellite relative to an uncontrolled leader. These short maneuver simulations demonstrate the capacity of the controller to perform changes from one formation geometry to another. Control algorithm performance is evaluated based on measures such as the fuel required to complete a maneuver and the maximum acceleration required by the controller. Based on this evaluation, the exclusion of the radial axis of control still allows enough control authority to use Linear Quadratic Regulator (LQR) techniques to design a gain matrix of adequate performance over finite maneuvers. Additional simulations are conducted including perturbations and using no radial control inputs. A major conclusion presented is that control inputs along the three axes have significantly different relationships to the governing orbital dynamics that may be exploited using LQR.

  15. Relative orbit determination for satellite formation flying based on quantum ranging

    NASA Astrophysics Data System (ADS)

    Shen, Yanghe; Xu, Luping; Zhang, Hua; Chen, Shanshan; Song, Shibin

    2015-08-01

    Relative orbit determination is widely used in the field of autonomously controlled satellite formation flying (SFF). Currently, some traditional techniques cannot meet the strict requirement of the accuracy of relative orbit determination for certain space missions. Thus, the primary purpose of this study is to design some special type of sensor to increase the accuracy of the distance measurement, which can eventually lead to an improvement in the accuracy of relative orbit determination for SFF. Two types of quantum sensors are proposed, based on the double-points quantum ranging (DPQR) and the triangle quantum ranging (TQR) schemes that utilize the second-order correlation between the entangled photons. Simulation result shows that the ranging accuracy of the TQR-type sensor is more precise than that of the DPQR-type one. Additionally, the unscented Kalman filter (UKF) is used to estimate the relative state of the SFF, which uses the TQR-type sensor as the measurement model compared with a traditional sensor. The simulation results show that the quantum sensor is superior to the traditional one and their estimation errors of the position and velocity remain within 1 cm and 1 mm/s, respectively, at a relative distance of 1 km between the chief and deputy satellites.

  16. Distance-based relative orbital elements determination for formation flying system

    NASA Astrophysics Data System (ADS)

    He, Yanchao; Xu, Ming; Chen, Xi

    2016-01-01

    The present paper deals with determination of relative orbital elements based only on distance between satellites in the formation flying system, which has potential application in engineering, especially suited for rapid orbit determination required missions. A geometric simplification is performed to reduce the formation configuration in three-dimensional space to a plane. Then the equivalent actual configuration deviating from its nominal design is introduced to derive a group of autonomous linear equations on the mapping between the relative orbital elements differences and distance errors. The primary linear equations-based algorithm is initially proposed to conduct the rapid and precise determination of the relative orbital elements without the complex computation, which is further improved by least-squares method with more distance measurements taken into consideration. Numerical simulations and comparisons with traditional approaches are presented to validate the effectiveness of the proposed methods. To assess the performance of the two proposed algorithms, accuracy validation and Monte Carlo simulations are implemented in the presence of noises of distance measurements and the leader's absolute orbital elements. It is demonstrated that the relative orbital elements determination accuracy of two approaches reaches more than 90% and even close to the actual values for the least-squares improved one. The proposed approaches can be alternates for relative orbit determination without assistance of additional facilities in engineering for their fairly high efficiency with accuracy and autonomy.

  17. Scaled-model guidelines for formation-flying solar coronagraph missions.

    PubMed

    Landini, Federico; Romoli, Marco; Baccani, Cristian; Focardi, Mauro; Pancrazzi, Maurizio; Galano, Damien; Kirschner, Volker

    2016-02-15

    Stray light suppression is the main concern in designing a solar coronagraph. The main contribution to the stray light for an externally occulted space-borne solar coronagraph is the light diffracted by the occulter and scattered by the optics. It is mandatory to carefully evaluate the diffraction generated by an external occulter and the impact that it has on the stray light signal on the focal plane. The scientific need for observations to cover a large portion of the heliosphere with an inner field of view as close as possible to the photospheric limb supports the ambition of launching formation-flying giant solar coronagraphs. Their dimension prevents the possibility of replicating the flight geometry in a clean laboratory environment, and the strong need for a scaled model is thus envisaged. The problem of scaling a coronagraph has already been faced for exoplanets, for a single point source on axis at infinity. We face the problem here by adopting an original approach and by introducing the scaling of the solar disk as an extended source. PMID:26872181

  18. Parallel Estimation and Control Architectures for Deep-Space Formation Flying Spacecraft

    NASA Technical Reports Server (NTRS)

    Hadaegh, Fred Y.; Smith, Roy S.

    2006-01-01

    The formation flying of precisely controlled spacecraft in deep space can be used to implement optical instruments capable of imaging planets in other solar systems. The distance of the formation from Earth necessitates a significant level of autonomy and each spacecraft must base its actions on its estimates of the location and velocity of the other spacecraft. Precise coordination and control is the key requirement in such missions and the flow of information between spacecraft must be carefully designed. Doing this in an efficient and optimal manner requires novel techniques for the design of the on-board estimators. The use of standard Kalman filter-based designs can lead to unanticipated dynamics--which we refer to as disagreement dynamics--in the estimators' errors. We show how communication amongst the spacecraft can be designed in order to control all of the dynamics within the formation. We present several results relating the topology of the communication network to the resulting closed-loop control dynamics of the formation. The consequences for the design of the control, communication and coordination are discussed.

  19. A Preliminary Formation Flying Orbit Dynamics Analysis for Leonardo-BRDF

    NASA Technical Reports Server (NTRS)

    Hughes, Steven P.; Mailhe, Laurie M.

    2001-01-01

    Leonardo-BRDF is a NASA mission concept proposed to allow the investigation of radiative transfer and its effect on the Earth's climate and atmospheric phenomenon. Enabled by the recent developments in small-satellite and formation flying technology, the mission is envisioned to be composed of an array of spacecraft in carefully designed orbits. The different perspectives provided by a distributed array of spacecraft offer a unique advantage to study the Earth's albedo. This paper presents the orbit dynamics analysis performed in the context of the Leonardo-BRDF science requirements. First, the albedo integral is investigated and the effect of viewing geometry on science return is studied. The method used in this paper, based on Gauss quadrature, provides the optimal formation geometry to ensure that the value of the integral is accurately approximated. An orbit design approach is presented to achieve specific relative orbit geometries while simultaneously satisfying orbit dynamics constraints to reduce formation-keeping fuel expenditure. The relative geometry afforded by the design is discussed in terms of mission requirements. An optimal two-burn initialization scheme is presented with the required delta-V to distribute all spacecraft from a common parking orbit into their appropriate orbits in the formation. Finally, formation-keeping strategies are developed and the associated delta-V's are calculated to maintain the formation in the presence of perturbations.

  20. Spacecraft Formation Flying Maneuvers Using Linear-Quadratic Regulation with No Radial Axis Inputs

    NASA Technical Reports Server (NTRS)

    Starin, Scott R.; Yedavalli, R. K.; Sparks, Andrew G.; Bauer, Frank H. (Technical Monitor)

    2001-01-01

    Regarding multiple spacecraft formation flying, the observation has been made that control thrust need only be applied coplanar to the local horizon to achieve complete controllability of a two-satellite (leader-follower) formation. A formulation of orbital dynamics using the state of one satellite relative to another is used. Without the need for thrust along the radial (zenith-nadir) axis of the relative reference frame ' propulsion system simplifications and weight reduction may be accomplished. Several linear-quadratic regulators (LQR) are explored and compared based on performance measures likely to be important to many missions, but not directly optimized in the LQR designs. Maneuver simulations are performed using commercial ODE solvers to propagate the Keplerian dynamics of a controlled satellite relative to an uncontrolled leader. These short maneuver simulations demonstrate the capacity of the controller to perform changes from one formation geometry to another. This work focusses on formations in which the controlled satellite has a relative trajectory which projects onto the local horizon of the uncontrolled satellite as a circle. This formation has potential uses for distributed remote sensing systems.

  1. A distributed model predictive control (MPC) fault reconfiguration strategy for formation flying satellites

    NASA Astrophysics Data System (ADS)

    Esfahani, N. R.; Khorasani, K.

    2016-05-01

    In this paper, an active distributed (also referred to as semi-decentralised) fault recovery control scheme is proposed that employs inaccurate and unreliable fault information into a model-predictive-control-based design. The objective is to compensate for the identified actuator faults that are subject to uncertainties and detection time delays, in the attitude control subsystems of formation flying satellites. The proposed distributed fault recovery scheme is developed through a two-level hierarchical framework. In the first level, or the agent level, the fault is recovered locally to maintain as much as possible the design specifications, feasibility, and tracking performance of all the agents. In the second level, or the formation level, the recovery is carried out by enhancing the entire team performance. The fault recovery performance of our proposed distributed (semi-decentralised) scheme is compared with two other alternative schemes, namely the centralised and the decentralised fault recovery schemes. It is shown that the distributed (semi-decentralised) fault recovery scheme satisfies the recovery design specifications and also imposes lower fault compensation control effort cost and communication bandwidth requirements as compared to the centralised scheme. Our proposed distributed (semi-decentralised) scheme also outperforms the achievable performance capabilities of the decentralised scheme. Simulation results corresponding to a network of four precision formation flight satellites are also provided to demonstrate and illustrate the advantages of our proposed distributed (semi-decentralised) fault recovery strategy.

  2. Formation Flying Satellite Control Around the L2 Sun-Earth Libration Point

    NASA Astrophysics Data System (ADS)

    Hamilton, Nicholas H.

    2001-12-01

    A growing interest in formation flying satellites demands development and analysis of control and estimation algorithms for station-keeping and formation maneuvering. This thesis discusses the development of a discrete linear-quadratic- regulator control algorithm for formations in the vicinity of the L2 sun-earth libration point. The development of an appropriate Kalman filter is included as well. Simulations are created for the analysis of the station-keeping and various formation maneuvers of the Stellar Imager mission. The simulations provide tracking error, estimation error, and control effort results. From the control effort, useful design parameters such as AV and propellant mass are determined. For formation maneuvering, the drone spacecraft track to within 4 meters of their desired position and within 1.3 millimeters per second of their desired zero velocity. The filter, with few exceptions, keeps the estimation errors within their three-sigma values. Without noise, the controller performs extremely well, with the drones tracking to within several micrometers. Bach drone uses around 1 to 2 grams of propellant per maneuver, depending on the circumstances.

  3. Summary of the effects of engine throttle response on airplane formation-flying qualities

    NASA Technical Reports Server (NTRS)

    Walsh, Kevin R.

    1993-01-01

    A flight evaluation was conducted to determine the effect of engine throttle response characteristics on precision formation-flying qualities. A variable electronic throttle control system was developed and flight-tested on a TF-104G airplane with a J79-11B engine at the NASA Dryden Flight Research Facility. This airplane was chosen because of its known, very favorable thrust response characteristics. Ten research flights were flown to evaluate the effects of throttle gain, time delay, and fuel control rate limiting on engine handling qualities during a demanding precision wing formation task. Handling quality effects of lag filters and lead compensation time delays were also evaluated. The Cooper and Harper Pilot Rating Scale was used to assign levels of handling quality. Data from pilot ratings and comments indicate that throttle control system time delays and rate limits cause significant degradations in handling qualities. Threshold values for satisfactory (level 1) and adequate (level 2) handling qualities of these key variables are presented. These results may provide engine manufacturers with guidelines to assure satisfactory handling qualities in future engine designs.

  4. Agent Based Software for the Autonomous Control of Formation Flying Spacecraft

    NASA Technical Reports Server (NTRS)

    How, Jonathan P.; Campbell, Mark; Dennehy, Neil (Technical Monitor)

    2003-01-01

    Distributed satellite systems is an enabling technology for many future NASA/DoD earth and space science missions, such as MMS, MAXIM, Leonardo, and LISA [1, 2, 3]. While formation flying offers significant science benefits, to reduce the operating costs for these missions it will be essential that these multiple vehicles effectively act as a single spacecraft by performing coordinated observations. Autonomous guidance, navigation, and control as part of a coordinated fleet-autonomy is a key technology that will help accomplish this complex goal. This is no small task, as most current space missions require significant input from the ground for even relatively simple decisions such as thruster burns. Work for the NMP DS1 mission focused on the development of the New Millennium Remote Agent (NMRA) architecture for autonomous spacecraft control systems. NMRA integrates traditional real-time monitoring and control with components for constraint-based planning, robust multi-threaded execution, and model-based diagnosis and reconfiguration. The complexity of using an autonomous approach for space flight software was evident when most of its capabilities were stripped off prior to launch (although more capability was uplinked subsequently, and the resulting demonstration was very successful).

  5. Low Cost Cryocoolers for High Temperature Superconductor Communication Filters

    NASA Technical Reports Server (NTRS)

    Brown, Davina

    1998-01-01

    This final report describes the work performed by a consortium of Industry and Government to develop low cost cryocoolers. The specific application was for low cost commercial based high temperature superconductor communication filters. This program was initiated in January 1995 and resulted in the successful demonstration of an HTS filter dewar cooled by a low cost pulse tube cryocooler. Further development of this cryocooler technology is proceeding through various contracts underway and proposed at this time.

  6. Low Cost Precision Lander for Lunar Exploration

    NASA Astrophysics Data System (ADS)

    Head, J. N.; Gardner, T. G.; Hoppa, G. V.; Seybold, K. G.

    2004-12-01

    ) provide data for the terminal guidance algorithms. DSMAC acquires high-resolution images for real-time correlation with a reference map. This system provides ownship position with a resolution comparable to the map. Since the DSMAC can sample at 1.5 mrad, any imaging acquired below 70 km altitude will surpass the resolution available from previous missions. DSMAC has a mode where image data are compressed and downlinked. This capability could be used to downlink live images during terminal guidance. Approximately 500 kbitps telemetry would be required to provide the first live descent imaging sequence since Ranger. This would provide unique geologic context imaging for the landing site. The development path to produce such a vehicle is that used to develop missiles. First, a pathfinder vehicle is designed and built as a test bed for hardware integration including science instruments. Second, a hover test vehicle would be built. Equipped with mass mockups for the science payload, the vehicle would otherwise be an exact copy of the flight vehicle. The hover vehicle would be flown on earth to demonstrate the proper function and integration of the propulsion system, autopilots, navigation algorithms, and guidance sensors. There is sufficient delta-v in the proposed design to take off from the ground, fly a ballistic arc to over 100 m altitude, then guide to a precision soft landing. Once the vehicle has flown safely on earth, then the validated design would be used to produce the flight vehicle. Since this leverages the billions of dollars DOD has invested in these technologies, it should be possible to land useful science payloads precisely on the lunar surface at relatively low cost.

  7. Dynamic Neural Network-Based Pulsed Plasma Thruster (PPT) Fault Detection and Isolation for Formation Flying of Satellites

    NASA Astrophysics Data System (ADS)

    Valdes, A.; Khorasani, K.

    The main objective of this paper is to develop a dynamic neural network-based fault detection and isolation (FDI) scheme for the Pulsed Plasma Thrusters (PPTs) that are used in the Attitude Control Subsystem (ACS) of satellites that are tasked to perform a formation flying mission. By using data collected from the relative attitudes of the formation flying satellites our proposed "High Level" FDI scheme can detect the pair of thrusters which is faulty, however fault isolation cannot be accomplished. Based on the "High Level" FDI scheme and the DNN-based "Low Level" FDI scheme developed earlier by the authors, an "Integrated" DNN-based FDI scheme is then proposed. To demonstrate the FDI capabilities of the proposed schemes various fault scenarios are simulated.

  8. Low Cost Upper Atmosphere Sounder (LOCUS)

    NASA Astrophysics Data System (ADS)

    Gerber, Daniel; Swinyard, Bruce M.; Ellison, Brian N.; Aylward, Alan D.; Aruliah, Anasuya; Plane, John M. C.; Feng, Wuhu; Saunders, Christopher; Friend, Jonathan; Bird, Rachel; Linfield, Edmund H.; Davies, A. Giles; Parkes, Steve

    2014-05-01

    The Mesosphere - Lower Thermosphere region (MLT) is often quoted as being the least well known region of the atmosphere, meaning that measurements of this altitude range are sparser than for the neighbouring layers. The reason for this apparent lack of observations can be traced back to a combination of two facts - A) the MLT is ill suited for in-situ sampling on a global scale because the residual air drag is prohibitive for suborbital vehicles (rockets are traditionally used to sample the MLT region, but they only provide snapshot measurements both geographically, as well as temporally), and B) Some of the most important trace gases in the MLT have spectral emission lines in the THz range, a frequency band which has only just become accessible to conventional remote sensing technologies (i.e. passive heterodyne detection) thanks to ongoing technology development, but which still poses massive - often prohibitive - demands on the complexity, weight and power consumption of satellite borne remote sensing detectors. To mitigate the substantial power requirements of a Local Oscillator (LO) able to pump a heterodyne receiver at THZ frequencies, we are suggesting the use of Quantum Cascade Laser diodes (QCL). Combining a QCL LO with a sub-harmonic Schottky mixer in an integrated receiver system would allow us to build a THz passive heterodyne detector for atmospheric remote sensing that is both very compact and power efficient, and could therefore be built and launched much more cheaply than competitive systems. Many of the technologies required for such an instrument already exist at technology readiness levels (TRL) of 3-5. A consortium of RAL Space, University College London (UCL), University of Leeds, Surrey Satellite Technology Ltd (SSTL) and STAR-Dundee have been awarded a grant through the ESA In Orbit Demonstration Programme (IOD) to start developing an integrated, sub-harmonic heterodyne receiver with a QCL LO up to a TRL that would allow IOD hopefully in the

  9. First Results from a Hardware-in-the-Loop Demonstration of Closed-Loop Autonomous Formation Flying

    NASA Technical Reports Server (NTRS)

    Gill, E.; Naasz, Bo; Ebinuma, T.

    2003-01-01

    A closed-loop system for the demonstration of autonomous satellite formation flying technologies using hardware-in-the-loop has been developed. Making use of a GPS signal simulator with a dual radio frequency outlet, the system includes two GPS space receivers as well as a powerful onboard navigation processor dedicated to the GPS-based guidance, navigation, and control of a satellite formation in real-time. The closed-loop system allows realistic simulations of autonomous formation flying scenarios, enabling research in the fields of tracking and orbit control strategies for a wide range of applications. The autonomous closed-loop formation acquisition and keeping strategy is based on Lyapunov's direct control method as applied to the standard set of Keplerian elements. This approach not only assures global and asymptotic stability of the control but also maintains valuable physical insight into the applied control vectors. Furthermore, the approach can account for system uncertainties and effectively avoids a computationally expensive solution of the two point boundary problem, which renders the concept particularly attractive for implementation in onboard processors. A guidance law has been developed which strictly separates the relative from the absolute motion, thus avoiding the numerical integration of a target trajectory in the onboard processor. Moreover, upon using precise kinematic relative GPS solutions, a dynamical modeling or filtering is avoided which provides for an efficient implementation of the process on an onboard processor. A sample formation flying scenario has been created aiming at the autonomous transition of a Low Earth Orbit satellite formation from an initial along-track separation of 800 m to a target distance of 100 m. Assuming a low-thrust actuator which may be accommodated on a small satellite, a typical control accuracy of less than 5 m has been achieved which proves the applicability of autonomous formation flying techniques to

  10. Anti-Collision Function Design and Performances of the CNES Formation Flying Experiment on the PRISMA Mission

    NASA Technical Reports Server (NTRS)

    Cayeux, P.; Raballand, F.; Borde, J.; Berges, J.-C.; Meyssignac, B.

    2007-01-01

    Within the framework of a partnership agreement, EADS ASTRIUM has worked since June 2006 for the CNES formation flying experiment on the PRISMA mission. EADS ASTRIUM is responsible for the anti-collision function. This responsibility covers the design and the development of the function as a Matlab/Simulink library, as well as its functional validation and performance assessment. PRISMA is a technology in-orbit testbed mission from the Swedish National Space Board, mainly devoted to formation flying demonstration. PRISMA is made of two micro-satellites that will be launched in 2009 on a quasi-circular SSO at about 700 km of altitude. The CNES FFIORD experiment embedded on PRISMA aims at flight validating an FFRF sensor designed for formation control, and assessing its performances, in preparation to future formation flying missions such as Simbol X; FFIORD aims as well at validating various typical autonomous rendezvous and formation guidance and control algorithms. This paper presents the principles of the collision avoidance function developed by EADS ASTRIUM for FFIORD; three kinds of maneuvers were implemented and are presented in this paper with their performances.

  11. First Results from a Hardware-in-the-Loop Demonstration of Closed-Loop Autonomous Formation Flying

    NASA Technical Reports Server (NTRS)

    Gill, E.; Naasz, Bo; Ebinuma, T.

    2003-01-01

    A closed-loop system for the demonstration of formation flying technologies has been developed at NASA s Goddard Space Flight Center. Making use of a GPS signal simulator with a dual radio frequency outlet, the system includes two GPS space receivers as well as a powerful onboard navigation processor dedicated to the GPS-based guidance, navigation, and control of a satellite formation in real-time. The closed-loop system allows realistic simulations of autonomous formation flying scenarios, enabling research in the fields of tracking and orbit control strategies for a wide range of applications. A sample scenario has been set up where the autonomous transition of a satellite formation from an initial along-track separation of 800 m to a final distance of 100 m has been demonstrated. As a result, a typical control accuracy of about 5 m has been achieved which proves the applicability of autonomous formation flying techniques to formations of satellites as close as 50 m.

  12. System design and instrument development for future formation-flying magnetospheric satellite mission SCOPE

    NASA Astrophysics Data System (ADS)

    Saito, Y.; Fujimoto, M.; Maezawa, K.; Kojima, H.; Takashima, T.; Matsuoka, A.; Shinohara, I.; Tsuda, Y.; Higuchi, K.; Toda, T.

    Japan Aerospace Exploration Agency JAXA is currently planning a next generation magnetosphere observation mission called SCOPE cross-Scale COupling in the Plasma universE The main purpose of this mission is to investigate the dynamic behaviors of plasmas in the Terrestrial magnetosphere that range over various time and spatial scales The basic idea of the SCOPE mission is to distinguish temporal and spatial variations of physical processes by putting five formation flying spacecraft into the key region of the Terrestrial magnetosphere The orbit of SCOPE is a highly elliptical orbit with its apogee 30Re from the Earth center SCOPE consists of one 450kg mother satellite and four 90kg daughter satellites flying 5 to 5000km apart from each other The inter-satellite link is used for telemetry command operation as well as ranging to determine the relative orbit of 5 satellites in a small distance which cannot be resolved by the ground-based orbit determination The SCOPE mission is designed such that observational studies from the new perspective that is the cross-scale coupling viewpoint are enabled The orbit is so designed that the spacecraft will visit most of the key regions in the magnetosphere that is the bow shock the magnetospheric boundary the inner-magnetosphere and the near-Earth magnetotail In order to realize the science objectives high performance Plasma Particle sensors DC AC Magnetic and Electric field sensors and Wave Particle Correlator are planned to be onboard the SCOPE satellite All the SCOPE satellites have two 5m spin-axis antenna

  13. Low cost attitude control system reaction wheel development

    NASA Technical Reports Server (NTRS)

    Bialke, William

    1991-01-01

    In order to satisfy a growing demand for low cost attitude control systems for small spacecraft, development of a low power and low cost Reaction Wheel Assembly was initiated. The details of the versatile design resulting from this effort are addressed. Tradeoff analyses for each of the major components are included, as well as test data from an engineering prototype of the hardware.

  14. Low cost airborne microwave landing system receiver, task 3

    NASA Technical Reports Server (NTRS)

    Hager, J. B.; Vancleave, J. R.

    1979-01-01

    Work performed on the low cost airborne Microwave Landing System (MLS) receiver is summarized. A detailed description of the prototype low cost MLS receiver is presented. This detail includes block diagrams, schematics, board assembly drawings, photographs of subassemblies, mechanical construction, parts lists, and microprocessor software. Test procedures are described and results are presented.

  15. A low-cost compact metric adaptive optics system

    NASA Astrophysics Data System (ADS)

    Mansell, Justin D.; Henderson, Brian; Wiesner, Brennen; Praus, Robert; Coy, Steve

    2007-09-01

    The application of adaptive optics has been hindered by the cost, size, and complexity of the systems. We describe here progress we have made toward creating low-cost compact turn-key adaptive optics systems. We describe our new low-cost deformable mirror technology developed using polymer membranes, the associated USB interface drive electronics, and different ways that this technology can be configured into a low-cost compact adaptive optics system. We also present results of a parametric study of the stochastic parallel gradient descent (SPGD) control algorithm.

  16. Low cost voice compression for mobile digital radios

    NASA Technical Reports Server (NTRS)

    Omura, J. K.

    1985-01-01

    A new technique for low cost rubust voice compression at 4800 bits per second was studied. The approach was based on using a cascade of digital biquad adaptive filters with simplified multipulse excitation followed by simple bit sequence compression.

  17. Low-cost exterior insulation process and structure

    DOEpatents

    Vohra, A.

    1999-03-02

    A low-cost exterior insulation process of stacking bags of insulating material against a wall and covering them with wire mesh and stucco provides a durable structure with good insulating value. 2 figs.

  18. A Low-Cost, Precision Hydrometer for Classroom Use.

    ERIC Educational Resources Information Center

    Murphy, Michael D.

    1983-01-01

    Describes a low cost hydrometer which can be assembled by students using stock laboratory items with a total retail cost of 17 cents. Includes list of required materials (with supplies) and experimental results on the instrument's accuracy. (JM)

  19. Composite hubs for low cost gas turbine engines

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1977-01-01

    A detailed stress analysis was performed using NASTRAN to demonstrate theoretically the adequacy of composite hubs for low cost turbine engine applications. Composite hubs are adequate for this application from the steady state stress view point.

  20. Low-cost orbiting grinder for cutting ducts

    NASA Technical Reports Server (NTRS)

    Lang, E. J.

    1970-01-01

    Low-cost, portable machine cuts ducts made from heat-treated alloys. An abrasive wheel, powered by a high-speed air motor mounted on an expandible plug against the inner wall of the duct, gives precise cutting.

  1. Proceedings of the Low-Cost Solar Array Wafering Workshop

    NASA Technical Reports Server (NTRS)

    Morrison, A. D.

    1982-01-01

    The technology and economics of silicon ingot wafering for low cost solar arrays were discussed. Fixed and free abrasive sawing wire, ID, and multiblade sawing, materials, mechanisms, characterization, and innovative concepts were considered.

  2. A Low-Cost Electronic Solar Energy Control

    ERIC Educational Resources Information Center

    Blade, Richard A.; Small, Charles T.

    1978-01-01

    Describes the design of a low-cost electronic circuit to serve as a differential thermostat, to control the operation of a solar heating system. It uses inexpensive diodes for sensoring temperature, and a mechanical relay for a switch. (GA)

  3. A Low-Cost and High-Performance Conductivity Meter.

    ERIC Educational Resources Information Center

    da Rocha, Rogerio T.; And Others

    1997-01-01

    Describes an apparatus that is stable and accurate enough for quantitative conductivity experiments but maintains the simplicity of construction and use as well as low cost. Discusses principles and implementation and the performance of the assembled apparatus. (JRH)

  4. A low-cost high-definition wireless sensor system utilizing intersymbol interference.

    PubMed

    Pohl, A

    1998-01-01

    A new method for wireless interrogation of a passive SAW sensor with multiple reflectors, utilizing the signal interference during overlap of the sensor's response bursts, is introduced. Within this time interval, the amplitude or the phase, respectively, is measured. By varying the frequency of the relatively long interrogation bursts, the amount of interference and destructive interferences (notches) are searched, respectively. So the measurand influencing the sensor or its identification information can be gained. The principle yields high resolution with a low cost interrogating system. The basic principle, calculations of sensitivity, and experimental results for temperature measurements are presented. The hardware effort and the performance of the system are discussed. PMID:18244298

  5. First demonstration of OFDM ECDMA for low cost optical access networks.

    PubMed

    Guo, X; Wang, Q; Li, X; Zhou, L; Fang, L; Wonfor, A; Wei, J L; von Lindeiner, J; Penty, R V; White, I H

    2015-05-15

    We demonstrate for the first time to the best of our knowledge an analogue orthogonal frequency division multiplexing (OFDM) based electrical code division multiplexing access (ECDMA) passive optical network (PON) for next generation access applications. Advantages of the system include low cost, high capacity, and enhanced spectral efficiency. A proof-of-principle 16 QAM OFDM ECDMA PON downlink experiment is used to show the transmission of an aggregate data rate of 24.8  Gb/s within an eight-user system. Transmission is achieved over 25 km of single-mode telecommunications fiber (SMF) with negligible dispersion and crosstalk penalties. PMID:26393737

  6. Low-cost optical instrumentation for biomedical measurements

    NASA Astrophysics Data System (ADS)

    Kostov, Yordan; Rao, Govind

    2000-12-01

    Low-cost instruments for measurement in medicine, biotechnology, and environmental monitoring are presented. Recent developments in optoelectronic technology enable practical compact designs. This article presents the available types of light emitters, detectors, and wavelength selection components that are used in low-cost instruments. The main spectroscopic techniques (absorption, reflectance, luminescence intensity, lifetime, and polarization, evanescent wave and surface plasmon resonance) that are used with these instruments are described. Numerous examples of devices for a broad variety of biomedical measurements are presented.

  7. The REFSAT approach to low-cost GPS terminals

    NASA Technical Reports Server (NTRS)

    Sennott, J. W.; Choudhury, A. K.; Taylor, R. E.

    1979-01-01

    A concept utilizing a geostationary reference satellite (REFSAT) that broadcasts navigation aiding signals to low cost civil user terminals which employ the constellation of 24 NAVSTAR Global Positioning System (GPS) satellites for position determination is described. The signal acquisition, tracking and position fixing properties of such low cost, dual channel, L-band, civil user receiver designed to receive both GPS navigation and REFSAT navigation aiding signals is presented. REFSAT reduces the cost of user equipment.

  8. Cost Modeling for low-cost planetary missions

    NASA Technical Reports Server (NTRS)

    Kwan, Eric; Habib-Agahi, Hamid; Rosenberg, Leigh

    2005-01-01

    This presentation will provide an overview of the JPL parametric cost models used to estimate flight science spacecrafts and instruments. This material will emphasize the cost model approaches to estimate low-cost flight hardware, sensors, and instrumentation, and to perform cost-risk assessments. This presentation will also discuss JPL approaches to perform cost modeling and the methodologies and analyses used to capture low-cost vs. key cost drivers.

  9. “You can get there from here”: Advanced low cost propulsion concepts for small satellites beyond LEO

    NASA Astrophysics Data System (ADS)

    Baker, Adam M.; da Silva Curiel, Alex; Schaffner, Jake; Sweeting, Martin

    2005-07-01

    microsatellite from a typical 700 km sun-synchronous orbit to a lower or higher orbit using a low cost 40 N thrust concentrated hydrogen peroxide/kerosene bipropellant engine. A spin stabilized 'tug' concept capable of providing between 130 and 300 m/s of deltaV to the payload is described. Transfer of an enhanced microsatellite from LEO to lunar orbit using a novel, storable propellant solar thermal propulsion system under development at the Surrey Space Centre. The solar thermal propulsion unit is designed for low cost small satellite support and will be compared with a more traditional approach using and industry standard storable bipropellant chemical engine. Nanosatellite manoeuvring for formation flying using advanced low power electric propulsion. A colloid thruster system concept is planned for development jointly between SSTL, Queen Mary University London and Rutherford Appleton Laboratory, UK. The colloid thruster system is designed to complement an existing butane resistojet to give full 3-axis manoeuvrability to an upgraded SNAP nanosatellite platform which could be reflown in 2007 alongside ESA's Proba 2 technology demonstrator microsatellite. A comparison between low power resistojets, a colloid thruster system, and pulsed plasma thrusters for orbit manoeuvring of microsatellites will be made. This paper's final section will briefly describe some of the interplanetary missions which have been considered at the Surrey Space Centre, and will highlight the few as yet practical solutions for sending small spacecraft on high deltaV missions without the use of a costly upper stage.

  10. A low-cost FMCW radar for footprint detection from a mobile platform

    NASA Astrophysics Data System (ADS)

    Boutte, David; Taylor, Paul; Hunt, Allan

    2015-05-01

    Footprint and human trail detection in rugged all-weather environments is an important and challenging problem for perimeter security, passive surveillance and reconnaissance. To address this challenge a low-cost, wideband, frequency-modulated continuous wave (FMCW) radar operating at 33.4GHz - 35.5GHz is being developed through a Department of Homeland Security Science and Technology Directorate Phase I SBIR and has been experimentally demonstrated to be capable of detecting footprints and footprint trails on unimproved roads in an experimental setting. It uses a low-cost digital signal processor (DSP) that makes important operating parameters reconfigurable and allows for frequency sweep linearization, a key technique developed to increase footprint signal-to-noise ratio (SNR). This paper discusses the design, DSP implementation and experimental results of a low-cost FMCW radar for mobile footprint detection. A technique for wideband sweep linearization is detailed along with system performance metrics and experimental results showing receive-SNR from footprint trails in sand and on unimproved dirt roads. Results from a second stepped frequency CW (SFCW) Ka-band system are also shown, verifying the ability of both systems to detect footprints and footprint trails in an experimental setting. The results show that there is sufficient receive-SNR to detect even shallow footprints (~1cm) using a radar based detection system in Ka-band. Field experimental results focus on system proof of concept from a static position with mobile results also presented highlighting necessary improvements to both systems.

  11. Automated packaging platform for low-cost high-performance optical components manufacturing

    NASA Astrophysics Data System (ADS)

    Ku, Robert T.

    2004-05-01

    Delivering high performance integrated optical components at low cost is critical to the continuing recovery and growth of the optical communications industry. In today's market, network equipment vendors need to provide their customers with new solutions that reduce operating expenses and enable new revenue generating IP services. They must depend on the availability of highly integrated optical modules exhibiting high performance, small package size, low power consumption, and most importantly, low cost. The cost of typical optical system hardware is dominated by linecards that are in turn cost-dominated by transmitters and receivers or transceivers and transponders. Cost effective packaging of optical components in these small size modules is becoming the biggest challenge to be addressed. For many traditional component suppliers in our industry, the combination of small size, high performance, and low cost appears to be in conflict and not feasible with conventional product design concepts and labor intensive manual assembly and test. With the advent of photonic integration, there are a variety of materials, optics, substrates, active/passive devices, and mechanical/RF piece parts to manage in manufacturing to achieve high performance at low cost. The use of automation has been demonstrated to surpass manual operation in cost (even with very low labor cost) as well as product uniformity and quality. In this paper, we will discuss the value of using an automated packaging platform.for the assembly and test of high performance active components, such as 2.5Gb/s and 10 Gb/s sources and receivers. Low cost, high performance manufacturing can best be achieved by leveraging a flexible packaging platform to address a multitude of laser and detector devices, integration of electronics and handle various package bodies and fiber configurations. This paper describes the operation and results of working robotic assemblers in the manufacture of a Laser Optical Subassembly

  12. Low-cost resilience schemes for the Optical Ethernet

    NASA Astrophysics Data System (ADS)

    Cugini, Filippo; Valcarenghi, Luca; Castoldi, Piero; Guglielmucci, Michele

    2005-12-01

    Optical Ethernet (OE) architectures transport IP packets directly over the optical layer by providing a specific Layer 2 framing. Although the architectures represent a simple and low-cost solution, the limiting factor for their widespread deployment is represented by the lack of some efficient operation, administration, and maintenance (OA&M) features, such as resilience. Optical layer protection represents a low-cost resilience scheme for OE links. We present the experimental results of low-cost protection implementations that are based on different failure detection and failure protection activation schemes for IP-over-OE networks. Specifically, a dedicated span protection scheme and an evolution for shared protection based on generalized multiprotocol label switching (GMPLS) signaling in transparent domains is presented. Experimental results show that recovery times in the millisecond range are achieved.

  13. Development of low cost custom hybrid microcircuit technology

    NASA Technical Reports Server (NTRS)

    Perkins, K. L.; Licari, J. J.

    1981-01-01

    Selected potentially low cost, alternate packaging and interconnection techniques were developed and implemented in the manufacture of specific NASA/MSFC hardware, and the actual cost savings achieved by their use. The hardware chosen as the test bed for this evaluation ws the hybrids and modules manufactured by Rockwell International fo the MSFC Flight Accelerometer Safety Cut-Off System (FASCOS). Three potentially low cost packaging and interconnection alternates were selected for evaluation. This study was performed in three phases: hardware fabrication and testing, cost comparison, and reliability evaluation.

  14. Key issues for low-cost FGD installations

    SciTech Connect

    DePriest, W.; Mazurek, J.M.

    1995-12-01

    This paper will discuss various methods for installing low-cost FGD systems. The paper will include a discussion of various types of FGD systems available, both wet and dry, and will compare the relative cost of each type. Important design issues, such as use of spare equipment, materials of construction, etc. will be presented. An overview of various low-cost construction techniques (i.e., modularization) will be included. This paper will draw heavily from Sargent & Lundy`s database of past and current FGD projects together with information we gathered for several Electric Power Research Institute (EPRI) studies on the subject.

  15. Low cost composite materials for wind energy conversion systems

    NASA Technical Reports Server (NTRS)

    Weingart, O.

    1980-01-01

    A winding process utilizing a low-cost E-glass fabric called transverse-filament tape for low-cost production of wind turbine generators (WTG) is described. The process can be carried out continuously at high speed to produce large one-piece parts with tapered wall thicknesses on a tapered mandrel. It is being used to manufacture blades for the NASA/DOE 200-ft-diameter MOD-1 WTG and Rockwell/DOE 40-kW small wind energy conversion system (SWECS).

  16. Gelatin/graphene systems for low cost energy storage

    SciTech Connect

    Landi, Giovanni; Fedi, Filippo; Sorrentino, Andrea; Iannace, Salvatore; Neitzert, Heinz C.

    2014-05-15

    In this work, we introduce the possibility to use a low cost, biodegradable material for temporary energy storage devices. Here, we report the use of biologically derived organic electrodes composed of gelatin ad graphene. The graphene was obtained by mild sonication in a mixture of volatile solvents of natural graphite flakes and subsequent centrifugation. The presence of exfoliated graphene sheets was detected by atomic force microscopy (AFM) and Raman spectroscopy. The homogeneous dispersion in gelatin demonstrates a good compatibility between the gelatin molecules and the graphene particles. The electrical characterization of the resulting nanocomposites suggests the possible applications as materials for transient, low cost energy storage device.

  17. Hughes integrated synthetic aperture radar: High performance at low cost

    SciTech Connect

    Bayma, R.W.

    1996-11-01

    This paper describes the background and development of the low cost high-performance Hughes Integrated Synthetic Aperture Radar (HISAR{trademark}) which has a full range of capabilities for real-time reconnaissance, surveillance and earth resource mapping. HISAR uses advanced Synthetic Aperture Radar (SAR) technology to make operationally effective images of near photo quality, day or night and in all weather conditions. This is achieved at low cost by maximizing the use of commercially available radar and signal-processing equipment in the fabrication. Furthermore, HISAR is designed to fit into an executive-class aircraft making it available for a wide range of users. 4 refs., 8 figs.

  18. Low-cost encapsulation materials for terrestrial solar cell modules

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Baum, B.; Willis, P.

    1979-01-01

    The paper presents the findings of material surveys intended to identify low cost materials which could be functional as encapsulants (by 1986) for terrestrial solar cell modules. Economic analyses have indicated that in order to meet the low cost goal of $2.70 per sq m, some or all of the following material technologies must be developed or advanced: (1) UV screening outer covers; (2) elastomeric acrylics; (3) weatherproofing and waterproofing of structural wood and paper products; (4) transparent UV stabilizers for the UV-sensitive transparent pottants; and (5) cost-effective utilization of silicone and fluorocarbon materials.

  19. Geowall: Investigations into Low-Cost Stereo Display Technologies

    USGS Publications Warehouse

    Steinwand, Daniel R.; Davis, Brian; Weeks, Nathan

    2003-01-01

    Recently, the combination of new projection technology, fast, low-cost graphics cards, and Linux-powered personal computers has made it possible to provide a stereoprojection and stereoviewing system that is much more affordable than previous commercial solutions. These Geowall systems are low-cost visualization systems built with commodity off-the-shelf components, run on open-source (and other) operating systems, and using open-source applications software. In short, they are ?Beowulf-class? visualization systems that provide a cost-effective way for the U. S. Geological Survey to broaden participation in the visualization community and view stereoimagery and three-dimensional models2.

  20. Feasibility of Using Low-Cost Motion Capture for Automated Screening of Shoulder Motion Limitation after Breast Cancer Surgery

    PubMed Central

    Gritsenko, Valeriya; Dailey, Eric; Kyle, Nicholas; Taylor, Matt; Whittacre, Sean; Swisher, Anne K.

    2015-01-01

    Objective To determine if a low-cost, automated motion analysis system using Microsoft Kinect could accurately measure shoulder motion and detect motion impairments in women following breast cancer surgery. Design Descriptive study of motion measured via 2 methods. Setting Academic cancer center oncology clinic. Participants 20 women (mean age = 60 yrs) were assessed for active and passive shoulder motions during a routine post-operative clinic visit (mean = 18 days after surgery) following mastectomy (n = 4) or lumpectomy (n = 16) for breast cancer. Interventions Participants performed 3 repetitions of active and passive shoulder motions on the side of the breast surgery. Arm motion was recorded using motion capture by Kinect for Windows sensor and on video. Goniometric values were determined from video recordings, while motion capture data were transformed to joint angles using 2 methods (body angle and projection angle). Main Outcome Measure Correlation of motion capture with goniometry and detection of motion limitation. Results Active shoulder motion measured with low-cost motion capture agreed well with goniometry (r = 0.70–0.80), while passive shoulder motion measurements did not correlate well. Using motion capture, it was possible to reliably identify participants whose range of shoulder motion was reduced by 40% or more. Conclusions Low-cost, automated motion analysis may be acceptable to screen for moderate to severe motion impairments in active shoulder motion. Automatic detection of motion limitation may allow quick screening to be performed in an oncologist's office and trigger timely referrals for rehabilitation. PMID:26076031

  1. GPS-based relative navigation for the Proba-3 formation flying mission

    NASA Astrophysics Data System (ADS)

    Ardaens, Jean-Sébastien; D'Amico, Simone; Cropp, Alexander

    2013-10-01

    The primary objective of the Proba-3 mission is to build a solar coronagraph composed of two satellites flying in close formation on a high elliptical orbit and tightly controlled at apogee. Both spacecraft will embark a low-cost GPS receiver, originally designed for low-Earth orbits, to support the mission operations and planning during the perigee passage, when the GPS constellation is visible. The paper demonstrates the possibility of extending the utilization range of the GPS-based navigation system to serve as sensor for formation acquisition and coarse formation keeping. The results presented in the paper aim at achieving an unprecedented degree of realism using a high-fidelity simulation environment with hardware-in-the-loop capabilities. A modified version of the flight-proven PRISMA navigation system, composed of two single-frequency Phoenix GPS receivers and an advanced real-time onboard navigation filter, has been retained for this analysis. For several-day long simulations, the GPS receivers are replaced by software emulation to accelerate the simulation process. Special attention has been paid to the receiver link budget and to the selection of a proper attitude profile. Overall the paper demonstrates that, despite a limited GPS tracking time, the onboard navigation filter gets enough measurements to perform a relative orbit determination accurate at the centimeter level at perigee. Afterwards, the orbit prediction performance depends mainly on the quality of the onboard modeling of the differential solar radiation pressure acting on the satellites. When not taken into account, this perturbation is responsible for relative navigation errors at apogee up to 50 m. The errors can be reduced to only 10 m if the navigation filter is able to model this disturbance with 70% fidelity.

  2. Wind turbine generator rotor blade concepts with low cost potential

    NASA Technical Reports Server (NTRS)

    Sullivan, T. L.; Cahill, T. P.; Griffee, D. G., Jr.; Gewehr, H. W.

    1977-01-01

    Four processed for producing blades are examined. Two use filament winding techniques and two involve filling a mold or form to produce all or part of a blade. The processes are described and a comparison is made of cost, material properties, design and free vibration characteristics. Conclusions are made regarding the feasibility of each process to produce low cost, structurally adequate blades.

  3. Sport for All: Low-Cost Swimming Pools.

    ERIC Educational Resources Information Center

    Council for Cultural Cooperation, Strasbourg (France).

    This report is an outgrowth of discussions held by the Council for Cultural Cooperation (CCC) in Cologne, Germany from September 26-30, 1967 aimed at organizing a systematic exchange of information among European countries for the purpose of providing low-cost sport facilities. Part I deals with fundamental priorities, type, size, and site. The…

  4. Open source data logger for low-cost environmental monitoring.

    PubMed

    Baker, Ed

    2014-01-01

    The increasing transformation of biodiversity into a data-intensive science has seen numerous independent systems linked and aggregated into the current landscape of biodiversity informatics. This paper outlines how we can move forward with this programme, incorporating real time environmental monitoring into our methodology using low-power and low-cost computing platforms. PMID:24855446

  5. A low-cost propulsion option for small satellites

    NASA Astrophysics Data System (ADS)

    Sellers, Jerry Jon; Meerman, Maarten; Paul, Malcolm; Sweeting, Martin

    1995-03-01

    Low-cost satellites require low-cost propulsion systems. This paper starts with a brief history of the University of Surrey Satellite (UoSAT) missions and the on-going efforts to provide affordable access to space. Future mission options are discussed along with the need for low-cost propulsion to make them possible. Following this introduction, a review of the potential propulsion system options available to the satellite designer is presented along with a discussion of the choices that are currently available off-the-shelf and their potentially high cost. Research into low-cost propulsion options at the University of Surrey are then discussed. The ultimate objective of this research is to develop and operate a small satellite propulsion system for a fraction of the cost of traditional systems. Emphasis is given to a hydrogen peroxide/polyethylene hybrit rocket motor option. This system is currently being tested to characterize combustion parameters and assess its long-term potential as a satellite upper-stage. The current status of this research program is discussed fully including a description of the hardware, preliminary test results and future plans.

  6. Leveraging Knowledge: Impact on Low Cost Planetary Mission Design.

    ERIC Educational Resources Information Center

    Momjian, Jennifer

    This paper discusses innovations developed by the Jet Propulsion Laboratory (JPL) librarians to reduce the information query cycle time for teams planning low-cost, planetary missions. The first section provides background on JPL and its library. The second section addresses the virtual information environment, including issues of access, content,…

  7. Reducing High Absenteeism through Low-Cost Incentives.

    ERIC Educational Resources Information Center

    North Chaplik, Barbara D.; Engel, Ross A.

    1984-01-01

    Describes a study of the effects of a low-cost incentive program--including daily, weekly, and monthly reinforcements such as attention, approval, and inexpensive awards--on the absenteeism of high-absence employees in an urban school district's transportation department. A 20-percent reduction in absenteeism was achieved. (TE)

  8. Low-cost point-focus solar concentrator, phase 1

    NASA Technical Reports Server (NTRS)

    Nelson, E. V.; Derbidge, T. C.; Erskine, D.; Maraschin, R. A.; Niemeyer, W. A.; Matsushita, M. J.; Overly, P. T.

    1979-01-01

    The results of the preliminary design study for the low cost point focus solar concentrator (LCPFSC) development program are presented. A summary description of the preliminary design is given. The design philosophy used to achieve a cost effective design for mass production is described. The concentrator meets all design requirements specified and is based on practical design solutions in every possible way.

  9. ADVACATE -- LOW-COST PROCESS FOR SO2 CONTROL

    EPA Science Inventory

    The paper discusses sorbent chemistry and process chemistry of the ADVAnced siliCATE (ADVACATE) process, a simple, low-cost add-on technology for S02 control, easily retrofitted on existing utility boilers with minimal disruption. It is considered to be capable of removing 90% of...

  10. Open source data logger for low-cost environmental monitoring

    PubMed Central

    2014-01-01

    Abstract The increasing transformation of biodiversity into a data-intensive science has seen numerous independent systems linked and aggregated into the current landscape of biodiversity informatics. This paper outlines how we can move forward with this programme, incorporating real time environmental monitoring into our methodology using low-power and low-cost computing platforms. PMID:24855446

  11. This Confidential, Low-Cost Counseling Cuts Teacher Stress.

    ERIC Educational Resources Information Center

    Grier, Terry B.; Crawford, Sherron G.

    1986-01-01

    Confronted with increasing turnover due to burnout and job-related stress, McDowell County Schools (North Carolina) initiated a confidential, voluntary, and low-cost counseling program for teachers. The program, in its second year, is gaining acceptance and proving its worth. Absenteeism is down, working relationships are improving, and principals…

  12. Modular, Easy-to-Assemble, Low-Cost Zebrafish Facility

    PubMed Central

    Kim, Seongcheol; Carlson, Ryan; Zafreen, Lala; Rajpurohit, Surendra Kumar

    2009-01-01

    Abstract We have constructed a standalone, modular, low-cost water recirculation zebrafish facility in our laboratory. This is easy to maintain and will take only approximately $500 and a half a day to build an 80-tank module. The system described here will be useful to even investigators who are new to zebrafish aquaculture. PMID:19694524

  13. Low Cost Coherent Doppler Lidar Data Acquisition and Processing

    NASA Technical Reports Server (NTRS)

    Barnes, Bruce W.; Koch, Grady J.

    2003-01-01

    The work described in this paper details the development of a low-cost, short-development time data acquisition and processing system for a coherent Doppler lidar. This was done using common laboratory equipment and a small software investment. This system provides near real-time wind profile measurements. Coding flexibility created a very useful test bed for new techniques.

  14. A Low-Cost, Effective, Fumes Exhaust System.

    ERIC Educational Resources Information Center

    Jacobs, C. O.

    1979-01-01

    Discusses the importance of avoiding welding fumes. The sources of these fumes are presented in a table. Criticizes currently used ventilation systems and reviews the Occupational Safety and Health Act requirements. Describes a low-cost exhaust system developed for agricultural mechanics laboratories. (LRA)

  15. Low-Cost Elimination of Plasma Lines in Raman Spectra.

    ERIC Educational Resources Information Center

    Behlow, Herbert W., Jr.; Petersen, John D.

    1985-01-01

    Describes a low-cost ($120) device which eliminates plasma lines in Raman spectra. The device consists of two prisms and two mirrors which are held in a symmetrical relationship to one another so that a particular position will allow only one wavelength to pass through on a given axis. (JN)

  16. Low-cost coding techniques for digital fault diagnosis

    NASA Technical Reports Server (NTRS)

    Avizienis, A. A.

    1973-01-01

    Published report discusses fault location properties of arithmetic codes. Criterion for effectiveness of given code is detection probability of local fault by application of checking algorithm to results of entire set of algorithms of processor. Report also presents analysis of arithmetic codes with low-cost check algorithm which possesses partial fault-location properties.

  17. DEMONSTRATION OF LOW COST, LOW BURDEN EXPOSURE MONITORING STRATEGIES

    EPA Science Inventory

    This study is designed to develop and demonstrate relevant, low-cost, low-burden monitoring strategies that could be used in large longitudinal exposure/epidemiological studies, such as the National Children's Study. The focus of this study is on (1) recruiting and retaining p...

  18. Atmospheric corrosion model and monitor for low cost solar arrays

    NASA Technical Reports Server (NTRS)

    Kaelble, D. H.; Mansfeld, F. B.; Jeanjaquet, S. L.; Kendig, M.

    1981-01-01

    An atmospheric corrosion model and corrosion monitoring system has been developed for low cost solar arrays (LSA). The corrosion model predicts that corrosion rate is the product of the surface condensation probability of water vapor and the diffusion controlled corrosion current. This corrosion model is verified by simultaneous monitoring of weather conditions and corrosion rates at the solar array test site at Mead, Nebraska.

  19. An Overview of the Formation and Attitude Control System for the Terrestrial Planet Finder Formation Flying Interferometer

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel P.; Hadaegh, Fred Y.; Rahman, Zahidul H.; Shields, Joel F.; Singh, Gurkipal; Wette, Matthew R.

    2004-01-01

    The Terrestrial Planet Finder formation flying Interferometer (TPF-I) will be a five-spacecraft, precision formation operating near the second Sun-Earth Lagrange point. As part of technology development for TPF-I, a formation and attitude control system (FACS) is being developed that achieves the precision and functionality needed for the TPF-I formation and that will be demonstrated in a distributed, real-time simulation environment. In this paper we present an overview of FACS and discuss in detail its formation estimation, guidance and control architectures and algorithms. Since FACS is currently being integrated into a high-fidelity simulation environment, component simulations demonstrating algorithm performance are presented.

  20. An Overview of the Formation and Attitude Control System for the Terrestrial Planet Finder Formation Flying Interferometer

    NASA Technical Reports Server (NTRS)

    Scharf, Daniel P.; Hadaegh, Fred Y.; Rahman, Zahidul H.; Shields, Joel F.; Singh, Gurkipal

    2004-01-01

    The Terrestrial Planet Finder formation flying Interferometer (TPF-I) will be a five-spacecraft, precision formation operating near a Sun-Earth Lagrange point. As part of technology development for TPF-I, a formation and attitude control system (FACS) is being developed that achieves the precision and functionality associated with the TPF-I formation. This FACS will be demonstrated in a distributed, real-time simulation environment. In this paper we present an overview of the FACS and discuss in detail its constituent formation estimation, guidance and control architectures and algorithms. Since the FACS is currently being integrated into a high-fidelity simulation environment, component simulations demonstrating algorithm performance are presented.

  1. High resolution, low cost solar cell contact development

    NASA Technical Reports Server (NTRS)

    Mardesich, N.

    1979-01-01

    The experimental work demonstrating the feasibility of the MIDFILM process as a low cost means of applying solar cell collector metallization as reported. Cell efficiencies of above 14% (AMl, 28 C) were achieved with fritted silver metallization. Environmental tests suggest that the metallization is slightly humidity sensitive and degradation is observed on cells with high series resistance. The major yield loss in the fabrication of cells was due to discontinuous grid lines, resulting in high series resitance. Standard lead-tin solder plated interconnections do not appear compatible with the MIDFILM contact. Copper, nickel and molybdemun base powder were investigated as low cost metallization systems. The copper based powder degraded the cell response. The nickel and molybdenum base powders oxidized when sintered in the oxidizing atmosphere necessary to ash the photoresin.

  2. Novel concepts for low-cost IR security sensors

    NASA Astrophysics Data System (ADS)

    Liddiard, Kevin C.

    2005-05-01

    This paper reviews current IR security sensor technology and considers how new developments could impact on this increasingly important field, with relevance to military, industrial and domestic markets. We consider performance specifications for various applications, and investigate how trades can be made to meet market requirements. We address the definition of 'low cost', and suggest what might be acceptable for the various market segments. The paper discusses novel new patented technology, including the active microbolometer, where the IR detector functions as a transistor, and where arrays and readout are fabricated in the same technology on silicon wafer or other suitable substrates. Methods are discussed for achieving the desired performance for imaging and non-imaging 'smart' sensors in low cost packaging, including sealing at atmospheric pressure. We introduce the concept of mosaic pixel focal plane arrays (MP-FPA).

  3. Low-cost, focused-science Mars mission

    NASA Technical Reports Server (NTRS)

    Stuart, J. R.

    1983-01-01

    The Mars Orbiter Water Mission (MOWM) is discussed as an example of a low-cost, low-risk focused-science Mars mission which might be implemented in the near term within recently imposed fiscal constraints. MOWM is designed to act as a follow-on to the Viking results in the areas of comparative climatology and water, carbon dioxide and dust inventories. The STS-compatible space vehicle would be based on proven earth-orbiting satellite hardware, fulfilling requirements for both spinning and despun components, operation with nonoptimum solar cell orientation, PAM-A upper stage compatibility, and data storage for delayed transmission. Study results have shown the technical and economic feasibility of missions based on any of four submitted designs which meet these requirements, and of low-cost, well-focused science objective Mars missions in general.

  4. Low-cost flywheel demonstration program. Final report

    SciTech Connect

    1980-04-01

    The Applied Physics Laboratory/Department of Energy Low Cost Flywheel Demonstration Program was initiated on 1 October 1977 and was successfully concluded on 31 December 19'9. The total cost of this program was $355,190. All primary objectives were successfully achieved as follows: demonstration of a full-size, 1)kWh flywheel having an estimated cost in large-volume production of approximately $50/kWh; developmeNt of a ball-bearing system having losses comparable to the losses in a totally magnetic suspension system; successful and repeated demonstration of the low-cost flywheel in a complete flywheel energy-storage system based on the use of ordinary house voltage and frequency; and application of the experience gained in the hardware program to project the system design into a complete, full-scale, 30-kWh home-type flywheel energy-storage system.

  5. Use of talc as low-cost clarifier for wastewater.

    PubMed

    Grafia, Ana L; Castillo, Luciana A; Barbosa, Silvia E

    2014-01-01

    Talc is proposed as a low-cost mineral for wastewater clarification. In this sense, adsorption of methylene blue (MB) from aqueous solutions was studied comparatively by using sepiolite (qualified as very good adsorbent) and two talc samples with different particle size and purity degree. The MB adsorption was assessed by determining remnant dye in the supernatant using UV-vis spectroscopy and by detecting dye adsorbed on mineral samples through thermogravimetric analysis and infrared spectroscopy. Both isothermal curves and kinetic studies demonstrate that talc is a good dye adsorbent. Particularly, with dye concentrations similar to those of textile wastewater, talc was demonstrated to adsorb the same dye content of sepiolite at similar times. Natural talc could be employed as a low-cost alternative in wastewater treatment for the removal of cationic dyes. PMID:24552739

  6. Process and assembly plans for low cost commercial fuselage structure

    NASA Technical Reports Server (NTRS)

    Willden, Kurtis; Metschan, Stephen; Starkey, Val

    1991-01-01

    Cost and weight reduction for a composite structure is a result of selecting design concepts that can be built using efficient low cost manufacturing and assembly processes. Since design and manufacturing are inherently cost dependent, concurrent engineering in the form of a Design-Build Team (DBT) is essential for low cost designs. Detailed cost analysis from DBT designs and hardware verification must be performed to identify the cost drivers and relationships between design and manufacturing processes. Results from the global evaluation are used to quantitatively rank design, identify cost centers for higher ranking design concepts, define and prioritize a list of technical/economic issues and barriers, and identify parameters that control concept response. These results are then used for final design optimization.

  7. Zero-Net Power, Low-Cost Sensor Platform

    SciTech Connect

    Hardy, J.E.

    2005-04-15

    Numerous national studies and working groups have identified very low-power, low-cost sensors as a critical technology for increasing energy efficiency, reducing waste, and optimizing processes. This research addressed that need by developing an ultra low-power, low-cost sensor platform based on microsensor (MS) arrays that includes MS sensors, very low-power electronics, signal processing, and two-way data communications, all integrated into a single package. MSs were developed to measure carbon dioxide and room occupancy. Advances were made in developing a coating for detecting carbon dioxide and sensing thermal energy with MSs with a low power electrical readout. In addition, robust algorithms were developed for communications within buildings over power lines and an integrated platform was realized that included gas sensing, temperature, humidity, and room occupancy with on-board communications.

  8. Low cost fiber optic sensing of sugar solution

    NASA Astrophysics Data System (ADS)

    Muthuraju, M. E.; Patlolla, Anurag Reddy; Vadakkapattu Canthadai, Badrinath; Pachava, Vengalrao

    2015-03-01

    The demand for highly sensitive and reliable sensors to assess the refractive index of liquid get many applications in chemical and biomedical areas. Indeed, the physical parameters such as concentration, pressure and density, etc., can be found using the refractive index of liquid. In contrast to the conventional refractometer for measurement, optical fiber sensor has several advantages like remote sensing, small in size, low cost, immune to EMI etc., In this paper we have discussed determination of refractive index of sugar solution using optical fiber. An intensity modulated low cost plastic fiber optic refractive index sensor has been designed for the study. The sensor is based on principle of change in angle of reflected light caused by refractive index change of the medium surrounding the fiber. The experimental results obtained for the sugar solution of different refractive indices prove that the fiber optic sensor is cable of measuring the refractive indices as well as the concentrations.

  9. Low-Cost Phase Change Material for Building Envelopes

    SciTech Connect

    Abhari, Ramin

    2015-08-06

    A low-cost PCM process consisting of conversion of fats and oils to PCM-range paraffins, and subsequent “encapsulation” of the paraffin using conventional plastic compounding/pelletizing equipment was demonstrated. The PCM pellets produced were field-tested in a building envelope application. This involved combining the PCM pellets with cellulose insulation, whereby 33% reduction in peak heat flux and 12% reduction in heat gain was observed (average summertime performance). The selling price of the PCM pellets produced according to this low-cost process is expected to be in the $1.50-$3.00/lb range, compared to current encapsulated PCM price of about $7.00/lb. Whole-building simulations using corresponding PCM thermal analysis data suggest a payback time of 8 to 16 years (at current energy prices) for an attic insulation retrofit project in the Phoenix climate area.

  10. Glass as encapsulation for low-cost photovoltaic solar arrays

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.

    1981-01-01

    In photovoltaic systems, the encapsulant material that protects the solar cells should be highly transparent and very durable. Glass satisfies these two criteria and is considered a primary candidate for low-cost, photovoltaic encapsulation systems. In this paper, various aspects of glass encapsulation are treated that are important for the designer of photovoltaic systems. Candidate glasses and available information defining the state of the art of glass encapsulation materials and processes for automated, high volume production of terrestrial photovoltaic devices and related applications are presented. The desired characteristics of glass encapsulation are (1) low degradation rates, (2) high transmittance, (3) high reliability, (4) low-cost, and (5) high annual production capacity. The glass design areas treated herein include the types of glass, sources, prices, physical properties and glass modifications, such as antireflection coatings.

  11. Small and Low-Cost GNSS Radio Occultation Receivers

    NASA Astrophysics Data System (ADS)

    Cahoy, K.; Dyrud, L. P.; Fentzke, J. T.; Bishop, R. L.; Straus, P. R.; Lightsey, G.; Humphreys, T. E.; Meehan, T.; Mannucci, A. J.

    2011-12-01

    Several low-cost and small form factor GNSS radio occultation receivers are currently in various stages of development for both hosted payload opportunities like GEOScan onboard Iridium NEXT as well as stand-alone applications such as suborbital platforms and CubeSats. We describe the effects of different receiver designs on the scientific measurements: profiles of electron density in the ionosphere and temperature and pressure in the neutral atmosphere. Trades include different approaches to tracking and onboard processing. We also consider the impact of antenna type, antenna placement, local noise environment, and frequency diversity on the number and quality (signal to noise ratio, vertical extent) of measurements made. We conclude that low-cost and small form factor GNSS radio occultation receivers are well suited to take advantage of hosted payload opportunities and contribute valuable Earth-observing datasets.

  12. Fully automated low-cost setup for fringe projection profilometry.

    PubMed

    Rivera-Ortega, Uriel; Dirckx, Joris; Meneses-Fabian, Cruz

    2015-02-20

    In this paper an alternative low-cost, easy-to-use, and fully automated profilometry setup is proposed. The setup is based on a phase-shifting fringe projection technique with four projected fringe parameters. It uses the well-known triangulation arrangement and low-cost electronic and image acquisition components such as a data acquisition board, a motor controller board, a printer rail, a CMOS webcam, and an LCD projector. The position of the camera, the generation of the fringe pattern, the acquisition of the images, and the calculation of the wrapped and unwrapped phase are all performed in LabVIEW. The setup is portable and can be perfectly adapted to be used in other profilometry techniques such as electronic speckle pattern interferometry and laser scanning profilometry. PMID:25968198

  13. Low-cost hydrogen sensors: Technology maturation progress

    SciTech Connect

    Hoffheins, B.S.; Rogers, J.E.; Lauf, R.J.; Egert, C.M.; Haberman, D.P.

    1998-04-01

    The authors are developing a low-cost, solid-state hydrogen sensor to support the long-term goals of the Department of Energy (DOE) Hydrogen Program to encourage acceptance and commercialization of renewable energy-based technologies. Development of efficient production, storage, and utilization technologies brings with it the need to detect and pinpoint hydrogen leaks to protect people and equipment. The solid-state hydrogen sensor, developed at Oak Ridge National Laboratory (ORNL), is potentially well-suited to meet cost and performance objectives for many of these applications. Under a cooperative research and development Agreement and license agreement, they are teaming with a private company, DCH Technology, Inc., to develop the sensor for specific market applications related to the use of hydrogen as an energy vector. This report describes the current efforts to optimize materials and sensor performance to reach the goals of low-cost fabrication and suitability for relevant application areas.

  14. Lunar Prospector: developing a very low cost planetary mission.

    NASA Astrophysics Data System (ADS)

    Hubbard, G. S.

    Lunar Prospector, the first competitively selected planetary mission in NASA's Discovery Program, is described with emphasis on the lessons learned from managing a very low cost project. Insights into government-industry teaming, project management, contractual arrangements, schedule and budget reserve approach are discussed. The mission is conducting an orbital survey of the Moon's composition and structure. A mission overview and scientific data return is briefly described in the context of low cost mission development. The suite of five instruments is outlined: neutron spectrometer (NS), alpha particle spectrometer (APS), gamma ray spectrometer (GRS), magnetometer (MAG) and an electron reflectometer (ER). Scientific requirements and measurement approaches to detect water ice to a sensitivity of 50 ppm (hydrogen), measure key elemental constituents, detect gas release events and accurately map the Moon's gravitational and magnetic fields are described.

  15. MicroGPS for Low-Cost Orbit Determination

    NASA Astrophysics Data System (ADS)

    Wu, S. C.; Bertiger, W. I.; Kuang, D.; Lichten, S. M.; Nandi, S.; Romans, L. J.; Srinivasan, J. M.

    1997-07-01

    This article presents a new technology for satellite orbit determination using a simple Global Positioning System (GPS) receiver (microGPS) with ultra-low cost, power, and mass. The capability of low-cost orbit determination with microGPS for a low Earth-orbiting satellite, Student Nitric Oxide Explorer (SNOE), is demonstrated using actual GPS data from the GPS/Meteorology (MET) satellite. The measurements acquired by the microGPS receiver will be snapshots of carrier Doppler and ambiguous pseudorange. Among the challenges in orbit determination are the resolution of the pseudorange ambiguity; the estimation of the measurement time tag drift, which effects the in-track orbit position solution; and the convergence of the orbit solution from a cold start with essentially no knowledge of the orbit. The effects of data gaps and Doppler data quality are investigated. An efficient data acquisition scenario for SNOE is derived.

  16. Low Cost Vision Based Personal Mobile Mapping System

    NASA Astrophysics Data System (ADS)

    Amami, M. M.; Smith, M. J.; Kokkas, N.

    2014-03-01

    Mobile mapping systems (MMS) can be used for several purposes, such as transportation, highway infrastructure mapping and GIS data collecting. However, the acceptance of these systems is not wide spread and their use is still limited due the high cost and dependency on the Global Navigation Satellite System (GNSS). A low cost vision based personal MMS has been produced with an aim to overcome these limitations. The system has been designed to depend mainly on cameras and use of low cost GNSS and inertial sensors to provide a bundle adjustment solution with initial values. The system has the potential to be used indoor and outdoor. The system has been tested indoors and outdoors with different GPS coverage, surrounded features, and narrow and curvy paths. Tests show that the system is able to work in such environments providing 3D coordinates of better than 10 cm accuracy.

  17. WHITE BOX: LOW COST BOX FOR LAPAROSCOPIC TRAINING

    PubMed Central

    MARTINS, João Maximiliano Pedron; RIBEIRO, Roberto Vanin Pinto; CAVAZZOLA, Leandro Totti

    2015-01-01

    Background: Laparoscopic surgery is a reality in almost all surgical centers. Although with initial greater technical difficulty for surgeons, the rapid return to activities, less postoperative pain and higher quality aesthetic stimulates surgeons to evolve technically in this area. However, unlike open surgery where learning opportunities are more accessible, the laparoscopic training represents a challenge in surgeon formation. Aim: To present a low cost model for laparoscopic training box. Methods: This model is based in easily accessible materials; the equipment can be easily found based on chrome mini jet and passes rubber thread and a webcam attached to an aluminum handle. Results: It can be finalized in two days costing R$ 280,00 (US$ 90). Conclusion: It is possible to stimulate a larger number of surgeons to have self training in laparoscopy at low cost seeking to improve their surgical skills outside the operating room. PMID:26537148

  18. A low cost PSD-based monocular motion capture system

    NASA Astrophysics Data System (ADS)

    Ryu, Young Kee; Oh, Choonsuk

    2007-10-01

    This paper describes a monocular PSD-based motion capture sensor to employ with commercial video game systems such as Microsoft's XBOX and Sony's Playstation II. The system is compact, low-cost, and only requires a one-time calibration at the factory. The system includes a PSD(Position Sensitive Detector) and active infrared (IR) LED markers that are placed on the object to be tracked. The PSD sensor is placed in the focal plane of a wide-angle lens. The micro-controller calculates the 3D position of the markers using only the measured intensity and the 2D position on the PSD. A series of experiments were performed to evaluate the performance of our prototype system. From the experimental results we see that the proposed system has the advantages of the compact size, the low cost, the easy installation, and the high frame rates to be suitable for high speed motion tracking in games.

  19. Low-cost digital GPS receiver with software carrier detection

    NASA Astrophysics Data System (ADS)

    Wolf, M. H.

    1988-08-01

    The satellite navigation system global positioning system (GPS) will play a major role in the field of navigation. It will be able to compete with all previously existing radio navigation systems. Low-cost receivers will be built for a number of civilian users, such as general aviation, sea and land navigation. To permit production at low cost for the civil market, a new technique for a C/A (course and acquisition) code receiver has been developed. All the signal detecting and processing is carried out with the digital signal processing software in a Texas Instruments TMS 320C10. The advantage of this method is that complex functions can be effected in a computer program instead of in analog or digital circuits. This reduces the costs of the parts used in the receiver and also avoids calibration. Taken together, these two features greatly reduce the price of a navigation set. This paper discusses the underlying principles leading to this new receiver.

  20. Low cost integrating cavity for monitoring of environmental toxins

    NASA Astrophysics Data System (ADS)

    Bixler, Joel N.; Winkler, Chase A.; Mason, John D.; Yakovlev, Vladislav V.

    2015-03-01

    Contamination of the water source and air pollution are two major problems that must be faced in the coming years. The increasing worldwide contamination of freshwater systems with thousands of industrial and natural chemical compounds is one of the key environmental problems facing humanity today. It is estimated that pathogens in water cause more than 2 million deaths annually. Additionally, traditional water quality assessment methods, such as liquid chromatography and mass spectroscopy, are expensive and time consuming from sample collection to analysis. Low cost tools are needed which can provide high sensitivity in sensing, while remaining portable and providing near real time analysis. Here, we present a low cost integrating cavity that can be used for highly sensitive environmental sensing.

  1. Biodiesel production from low cost and renewable feedstock

    NASA Astrophysics Data System (ADS)

    Gude, Veera G.; Grant, Georgene E.; Patil, Prafulla D.; Deng, Shuguang

    2013-12-01

    Sustainable biodiesel production should: a) utilize low cost renewable feedstock; b) utilize energy-efficient, nonconventional heating and mixing techniques; c) increase net energy benefit of the process; and d) utilize renewable feedstock/energy sources where possible. In this paper, we discuss the merits of biodiesel production following these criteria supported by the experimental results obtained from the process optimization studies. Waste cooking oil, non-edible (low-cost) oils (Jatropha curcas and Camelina Sativa) and algae were used as feedstock for biodiesel process optimization. A comparison between conventional and non-conventional methods such as microwaves and ultrasound was reported. Finally, net energy scenarios for different biodiesel feedstock options and algae are presented.

  2. Situational Awareness from a Low-Cost Camera System

    NASA Technical Reports Server (NTRS)

    Freudinger, Lawrence C.; Ward, David; Lesage, John

    2010-01-01

    A method gathers scene information from a low-cost camera system. Existing surveillance systems using sufficient cameras for continuous coverage of a large field necessarily generate enormous amounts of raw data. Digitizing and channeling that data to a central computer and processing it in real time is difficult when using low-cost, commercially available components. A newly developed system is located on a combined power and data wire to form a string-of-lights camera system. Each camera is accessible through this network interface using standard TCP/IP networking protocols. The cameras more closely resemble cell-phone cameras than traditional security camera systems. Processing capabilities are built directly onto the camera backplane, which helps maintain a low cost. The low power requirements of each camera allow the creation of a single imaging system comprising over 100 cameras. Each camera has built-in processing capabilities to detect events and cooperatively share this information with neighboring cameras. The location of the event is reported to the host computer in Cartesian coordinates computed from data correlation across multiple cameras. In this way, events in the field of view can present low-bandwidth information to the host rather than high-bandwidth bitmap data constantly being generated by the cameras. This approach offers greater flexibility than conventional systems, without compromising performance through using many small, low-cost cameras with overlapping fields of view. This means significant increased viewing without ignoring surveillance areas, which can occur when pan, tilt, and zoom cameras look away. Additionally, due to the sharing of a single cable for power and data, the installation costs are lower. The technology is targeted toward 3D scene extraction and automatic target tracking for military and commercial applications. Security systems and environmental/ vehicular monitoring systems are also potential applications.

  3. Low Cost Mars Surface Exploration: The Mars Tumbleweed

    NASA Technical Reports Server (NTRS)

    Antol, Jeffrey; Calhoun, Philip; Flick, John; Hajos, Gregory; Kolacinski, Richard; Minton, David; Owens, Rachel; Parker, Jennifer

    2003-01-01

    The "Mars Tumbleweed," a rover concept that would utilize surface winds for mobility, is being examined as a low cost complement to the current Mars exploration efforts. Tumbleweeds carrying microinstruments would be driven across the Martian landscape by wind, searching for areas of scientific interest. These rovers, relatively simple, inexpensive, and deployed in large numbers to maximize coverage of the Martian surface, would provide a broad scouting capability to identify specific sites for exploration by more complex rover and lander missions.

  4. Low-cost trigger circuit for sampling oscilloscope

    NASA Astrophysics Data System (ADS)

    Burd, Aleksander; Opalska, Katarzyna

    2008-01-01

    The paper presents a low-cost trigger circuit for use in sampling oscilloscope with bandwidth in order of hundreds of MHz. The presented dual-step trigger circuit provides relatively high bandwidth because of significant reduction of possibility of incorrect turning on in trigger circuit flip-flop (caused by circuit instability called tremor or - describing the same phenomenon by other means - its metastability. The paper presents a circuit structure, principle of operation and its physical realization.

  5. Conestoga 2: A low cost commercial space transport system

    NASA Technical Reports Server (NTRS)

    Rasmussen, R. O.

    1984-01-01

    Conestoga 2 is currently under development. It is capable of inserting 500 Kg satellites into 800 Km circular polar orbits. Conestoga 2 makes maximum use of existing (developed) technology and hardware. Its commercial objective is to fill a need for low cost low Earth orbital transport not efficiently served by Shuttle or larger space transport systems. Low Earth orbit markets, foreign participation, and launch site considerations are discussed along with technical and economic trade-offs.

  6. Low cost, radial flow, solid oxide fuel cell

    SciTech Connect

    Petrik, M.A.

    1993-11-01

    The Interscience Radial Flow (IRF) SOFC is designed to minimize problems in high-temperature operation, and for low-cost fabrication. The cell has planar, non-sintered construction, uses particulate materials to form porous electrodes, and has internal radial flow. This phase was to demonstrate feasibility of multi-cell stack operation. Performance milestone was 15% DC HHV efficiency with hydrogen at > 50 mW/cm{sup 2} over 100 h.

  7. Low-cost gated system for monitoring phosphorescence lifetimes

    NASA Astrophysics Data System (ADS)

    Kostov, Yordan; Rao, Govind

    2003-09-01

    A low-cost, gated system for measurements of phosphorescence lifetimes is presented. An extensive description of the system operating principles and metrological characteristics is given. Remarkably, the system operates without optical filtering of the light emitting diode excitation source. A description of a practical system is also given and its performance is discussed. Because the device effectively suppresses high-level background fluorescence and scattered light, it is expected to find widespread application in bioprocess, environmental, and biomedical fields.

  8. Low cost electrochemical sensor module for measurement of gas concentration

    NASA Astrophysics Data System (ADS)

    Jasinski, Grzegorz; Strzelczyk, Anna; Koscinski, Piotr

    2016-01-01

    This paper describes a low cost electrochemical sensor module for gas concentration measurement. A module is universal and can be used for many types of electrochemical gas sensors. Device is based on AVR ATmega8 microcontroller. As signal processing circuit a specialized integrated circuit LMP91000 is used. The proposed equipment will be used as a component of electronic nose system employed for classifying and distinguishing different levels of air contamination.

  9. Investigation of low cost material processes for liquid rocket engines

    NASA Technical Reports Server (NTRS)

    Nguyentat, Thinh; Kawashige, Chester M.; Scala, James G.; Horn, Ronald M.

    1993-01-01

    The development of low cost material processes is essential to the achievement of economical liquid rocket propulsion systems in the next century. This paper will present the results of the evaluation of some promising material processes including powder metallurgy, vacuum plasma spray, metal spray forming, and bulge forming. The physical and mechanical test results from the samples and subscale hardware fabricated from high strength copper alloys and superalloys will be discussed.

  10. Human signatures in urban environments using low cost sensors

    NASA Astrophysics Data System (ADS)

    Winston, Mark; Zong, Lei; Calcutt, Wade; Jones, Barry; Houser, Jeff

    2006-05-01

    McQ has produced a family of small (98 cm 3), inexpensive ($100), unattended ground sensors well suited for urban environments. As a result, a broad range of data has been collected in urban settings. This paper discusses human signatures in urban environments using low cost seismic, infrared, acoustic, and magnetic transducers. Transducer performance and the effects of orientation, building construction, and environmental noise will be focused on. Detection methods used to exploit signatures and resulting performance statistics will also be discussed.

  11. A Flexible, Low Cost, Beam Loss Monitor Evaluation System

    SciTech Connect

    Hoyes, George Garnet; Pimol, Piti; Juthong, Nawin; Attaphibal, Malee

    2007-01-19

    A flexible, low cost, Beam Loss Monitor (BLM) Evaluation System based on Bergoz BLMs has been developed. Monitors can easily be moved to any location for beam loss investigations and/or monitor usefulness evaluations. Different PC pulse counting cards are compared and tested for this application using the display software developed based on LabVIEW. Beam problems uncovered with this system are presented.

  12. A low cost, portable instrument for measuring emittance

    NASA Technical Reports Server (NTRS)

    Mcdonald, G.

    1977-01-01

    A low cost, portable instrument has been developed with which emittance can be measured by comparison to a standard. A reflector collects infra-red radiation from a heated sample onto a low mass, black detector and the temperature rise of the black detector is measured with a thermocouple and meter. Graphical examples are presented for determination of emittance from measurements made on a sample at any known temperature.

  13. A low cost, portable instrument for measuring emittance

    NASA Technical Reports Server (NTRS)

    Mcdonald, G.

    1977-01-01

    A low cost, portable instrument was developed with which emittance can be measured by comparison to a standard. A reflector collects infrared radiation from a heated sample onto a low mass, black detector and the temperature rise of the black detector is measured with a thermocouple and meter. Graphical examples are presented for determination of emittance from measurements made on a sample at any known temperature.

  14. Low cost silicon-on-ceramic photovoltaic solar cells

    NASA Technical Reports Server (NTRS)

    Koepke, B. G.; Heaps, J. D.; Grung, B. L.; Zook, J. D.; Sibold, J. D.; Leipold, M. H.

    1980-01-01

    A technique has been developed for coating low-cost mullite-based refractory substrates with thin layers of solar cell quality silicon. The technique involves first carbonizing one surface of the ceramic and then contacting it with molten silicon. The silicon wets the carbonized surface and, under the proper thermal conditions, solidifies as a large-grained sheet. Solar cells produced from this composite silicon-on-ceramic material have exhibited total area conversion efficiencies of ten percent.

  15. LSSA (Low-cost Silicon Solar Array) project

    NASA Technical Reports Server (NTRS)

    1976-01-01

    Methods are explored for economically generating electrical power to meet future requirements. The Low-Cost Silicon Solar Array Project (LSSA) was established to reduce the price of solar arrays by improving manufacturing technology, adapting mass production techniques, and promoting user acceptance. The new manufacturing technology includes the consideration of new silicon refinement processes, silicon sheet growth techniques, encapsulants, and automated assembly production being developed under contract by industries and universities.

  16. Further development of a low cost solar panel

    NASA Astrophysics Data System (ADS)

    Muller, T.; Torok, R.; Erskine, D.; Short, R.

    1980-07-01

    A full-scale prototype panel section, with emphasis on the unglazed configuration was fabricated and tested. Design refinement, fabrication of full-scale prototypes by hand and semiautomated equipment, subscale and full-scale structural testing, outdoor performance tests, and an assessment of manufacturing requirements and production costs are included. The Low Cost Solar Panel, the project approach, and the more significant accomplishments of this contract are described in detail.

  17. Low-cost solar flat-plate-collector development

    NASA Astrophysics Data System (ADS)

    Wilhelm, W. G.

    Cost goals were developed for the collector which led to the rejection of conventional approaches and to the exploration of thin film technology. A thin film solar absorber suited for high speed continous-roll manufacture at low cost was designed. The absorber comprises two sheets of aluminum-foil/polmeric-material laminate bonded together at intervals to form channels with water as the heat transfer fluid. Several flat-plate panels were fabricated and tested.

  18. Low-cost projection-based virtual reality display

    NASA Astrophysics Data System (ADS)

    Pape, Dave; Anstey, Josephine; Dawe, Greg

    2002-05-01

    This paper describes the construction of a single screen, projection-based VR display using commodity, or otherwise low-cost components. The display is based on Linus PCs, and uses polarized stereo. Our aim is to create a system that is accessible to the many museums and schools that do not have large budgets for exploring new technology. In constructing this system we have been evaluating a number of options for the screens, projectors, and computer hardware.

  19. Investigation of low cost material processes for liquid rocket engines

    NASA Astrophysics Data System (ADS)

    Nguyentat, Thinh; Kawashige, Chester M.; Scala, James G.; Horn, Ronald M.

    1993-06-01

    The development of low cost material processes is essential to the achievement of economical liquid rocket propulsion systems in the next century. This paper will present the results of the evaluation of some promising material processes including powder metallurgy, vacuum plasma spray, metal spray forming, and bulge forming. The physical and mechanical test results from the samples and subscale hardware fabricated from high strength copper alloys and superalloys will be discussed.

  20. Securitizing receivables offers low-cost financing option.

    PubMed

    Sen, S; Lawler, J P

    1995-05-01

    Securitization began in the 1980s with mortgage payments, auto loans, and credit card debt being pooled and used as collateral for securities offerings. More recently, healthcare providers have securitized accounts receivables to obtain low-cost, off-balance-sheet financing. As the need to both raise capital and contain costs grows in health care, providers likely will make increased use of this financing method. PMID:10142191

  1. Low cost audiovisual playback and recording triggered by radio frequency identification using Raspberry Pi.

    PubMed

    Lendvai, Ádám Z; Akçay, Çağlar; Weiss, Talia; Haussmann, Mark F; Moore, Ignacio T; Bonier, Frances

    2015-01-01

    Playbacks of visual or audio stimuli to wild animals is a widely used experimental tool in behavioral ecology. In many cases, however, playback experiments are constrained by observer limitations such as the time observers can be present, or the accuracy of observation. These problems are particularly apparent when playbacks are triggered by specific events, such as performing a specific behavior, or are targeted to specific individuals. We developed a low-cost automated playback/recording system, using two field-deployable devices: radio-frequency identification (RFID) readers and Raspberry Pi micro-computers. This system detects a specific passive integrated transponder (PIT) tag attached to an individual, and subsequently plays back the stimuli, or records audio or visual information. To demonstrate the utility of this system and to test one of its possible applications, we tagged female and male tree swallows (Tachycineta bicolor) from two box-nesting populations with PIT tags and carried out playbacks of nestling begging calls every time focal females entered the nestbox over a six-hour period. We show that the RFID-Raspberry Pi system presents a versatile, low-cost, field-deployable system that can be adapted for many audio and visual playback purposes. In addition, the set-up does not require programming knowledge, and it easily customized to many other applications, depending on the research questions. Here, we discuss the possible applications and limitations of the system. The low cost and the small learning curve of the RFID-Raspberry Pi system provides a powerful new tool to field biologists. PMID:25870771

  2. Low cost audiovisual playback and recording triggered by radio frequency identification using Raspberry Pi

    PubMed Central

    Akçay, Çağlar; Weiss, Talia; Haussmann, Mark F.; Moore, Ignacio T.; Bonier, Frances

    2015-01-01

    Playbacks of visual or audio stimuli to wild animals is a widely used experimental tool in behavioral ecology. In many cases, however, playback experiments are constrained by observer limitations such as the time observers can be present, or the accuracy of observation. These problems are particularly apparent when playbacks are triggered by specific events, such as performing a specific behavior, or are targeted to specific individuals. We developed a low-cost automated playback/recording system, using two field-deployable devices: radio-frequency identification (RFID) readers and Raspberry Pi micro-computers. This system detects a specific passive integrated transponder (PIT) tag attached to an individual, and subsequently plays back the stimuli, or records audio or visual information. To demonstrate the utility of this system and to test one of its possible applications, we tagged female and male tree swallows (Tachycineta bicolor) from two box-nesting populations with PIT tags and carried out playbacks of nestling begging calls every time focal females entered the nestbox over a six-hour period. We show that the RFID-Raspberry Pi system presents a versatile, low-cost, field-deployable system that can be adapted for many audio and visual playback purposes. In addition, the set-up does not require programming knowledge, and it easily customized to many other applications, depending on the research questions. Here, we discuss the possible applications and limitations of the system. The low cost and the small learning curve of the RFID-Raspberry Pi system provides a powerful new tool to field biologists. PMID:25870771

  3. A low-cost rugged solution for solar lighting

    NASA Astrophysics Data System (ADS)

    Bharathwaj, A. N.; Srinivasan, Balaji

    2009-08-01

    We have explored the use of a low-cost, rugged optical system to collect and distribute natural sunlight for daytime lighting purposes. The sunlight collection and delivery is performed using a simple lens system in combination with a plastic optical fiber bundle. Based on such a system, we have demonstrated the ability to provide diffuse lighting over a 100 sq. ft. area. The work included the optimization of the lens and the fiber bundle according to data collected on the spatial distribution of focused sunlight. A key aspect of our work is the use of mirrors which could be easily maneuvered to maintain optimum coupling of light in the fiber throughout the day. An important issue that we addressed in our work is the devising of a low cost tracking mechanism to ensure nearuniform lighting throughout a day. The tracking system is an open loop system that is based on apriori data on the sun's movement and an initial alignment procedure. We have collected such data by tracking a beam of light reflected from a stationary mirror. Our data shows that the mirror needs to be rotated at the rate of 0.25 degrees/minute to maintain a fixed position at the collection plane. We expect to achieve a scalable, modular low cost lighting solution that works in conjunction with a LED array to illuminate common areas of commercial buildings during the daytime.

  4. Low cost composite materials for wind energy conversion systems

    SciTech Connect

    Weingart, O.

    1980-01-01

    Structural Composites Industries, Inc. (SCI) is developing new composite filament winding technology for low cost production of wind turbine generators (WTG). During 1977 the SCI TFT process was used to fabricate a 9072 kg (20,000 lb) filament-wound D-spar for a NASA/DOE 46 m (150 ft) composite wind turbine blade. In 1978 SCI designed a composite blade for the 91 m (300 ft) dia. NASA/DOE MOD-2 WTG. For the past year SCI has been under contract to NASA-Lewis Research Center to design and build two low cost 18 m (60 ft) blades for the 38 m (125 ft) dia. MOD-OA and to assess the applicability of the techniques developed for larger and smaller blades. SCI is also developing and constructing a 4-kW small wind energy conversion system (SWECS) for Rockwell International using low cost composites for the 9 m (31 ft) dia. rotor blades, 15 m (50 ft) tower and nacelle.

  5. Automated Low-Cost Photogrammetry for Flexible Structure Monitoring

    NASA Astrophysics Data System (ADS)

    Wang, C. H.; Mills, J. P.; Miller, P. E.

    2012-07-01

    Structural monitoring requires instruments which can provide high precision and accuracy, reliable measurements at good temporal resolution and rapid processing speeds. Long-term campaigns and flexible structures are regarded as two of the most challenging subjects in monitoring engineering structures. Long-term monitoring in civil engineering is generally considered to be labourintensive and financially expensive and it can take significant effort to arrange the necessary human resources, transportation and equipment maintenance. When dealing with flexible structure monitoring, it is of paramount importance that any monitoring equipment used is able to carry out rapid sampling. Low cost, automated, photogrammetric techniques therefore have the potential to become routinely viable for monitoring non-rigid structures. This research aims to provide a photogrammetric solution for long-term flexible structural monitoring purposes. The automated approach was achieved using low-cost imaging devices (mobile phones) to replace traditional image acquisition stations and substantially reduce the equipment costs. A self-programmed software package was developed to deal with the hardware-software integration and system operation. In order to evaluate the performance of this low-cost monitoring system, a shaking table experiment was undertaken. Different network configurations and target sizes were used to determine the best configuration. A large quantity of image data was captured by four DSLR cameras and four mobile phone cameras respectively. These image data were processed using photogrammetric techniques to calculate the final results for the system evaluation.

  6. Low-cost coherent UDWDM-PON by hybrid DBPSK/ASK-2 modulation

    NASA Astrophysics Data System (ADS)

    Li, Yuan; Deng, Zhuanhua; Hu, Rong; li, Cai; Li, Wei; Yuan, Zhilin; Yu, Shaohua

    2016-07-01

    The coherent ultra-dense wavelength division multiplexed passive optical network (UDWDM-PON) has been widely studied recently, in which the envelop detection based coherent reception of on-off keying (OOK) signal has been shown to possess both high receiver sensitivity and tolerance against laser linewidth/chirp. In order to increase the spectral efficiency (SE) to 2 bit/s/Hz, researchers formulated a hybrid DBPSK/ASK-2 modulation using the silicon Mach-Zehnder modulator (MZM), where both amplitude and phase modulation are employed. The experimental result shows that the proposed DBPSK/ASK-2 modulation is of better performance than PAM-4 at the same SE of 2 bit/s/Hz. When the low-cost silicon MZM and DFB laser of 4-MHz linewidth are employed, the receiver sensitivity of DBPSK/ASK-2 exceeds that of the PAM-4 by about 5.7 dB. This work can achieve about -46 dBm receiver sensitivity at 2.5 GBaud after transmission over 80-km standard single mode fiber (SSMF). The proposed DBPSK/ASK-2 modulation using low-cost silicon MZM and DFB laser is considered as a practical and reliable method for the future UDWDM-PON at the SE of 2 bit/s/Hz.

  7. Compact handheld low-cost biosensor platform for remote health monitoring

    NASA Astrophysics Data System (ADS)

    Hastanin, J.; Lenaerts, C.; Gailly, P.; Jans, H.; Huang, C.; Lagae, L.; Kokkinos, D.; Fleury-Frenette, K.

    2016-04-01

    In this paper, we present an original concept of plasmonic-related instrumentation platform dedicated to diagnostic biosensing tests out of the laboratory. The developed instrumental platform includes both disposable one-use microfluidic affinity biochip and compact optical readout device for biochip monitoring involving mobile Internet devices for data processing and communication. The biochip includes both microfluidic and optical coupling structures formed into a single plastic slab. The microfluidic path of the biochip operates in passive capillary pumping mode. In the proof-of-concept prototype, we address specifically the sensing format involving Surface Plasmon Resonance phenomenon. The biochip is plugged in the readout device without the use of an index matching fluid. An essential advantage of the developed biochip is that its implementation involves conventional hot embossing and thin film deposition process, perfectly suited for mass production of low-cost microfluidic biochip for biochemical applications.

  8. iScout low cost UGS system: overview of enhancements and performance characterization

    NASA Astrophysics Data System (ADS)

    Winston, Mark; Klug, Rob; Plummer, Thomas; Knobler, Ron

    2008-04-01

    McQ developed for the U.S. Army Research Laboratory (ARL) a very low-cost iScout® sensor system for detecting people in buildings and caves after military clearing operations to prevent their reuse by adversaries. The mission applications have expanded to include typical field operations such as Force Protection and facility security. To meet a broader mission capability, McQ significantly enhanced the performance of the iScout® Unattended Ground Sensor (UGS) system. The enhanced performance includes improvements to the seismic, acoustic, magnetic, and passive infrared sensor processing algorithms and multimodal fusion to improve target classification. Additional features are a new radio frequency (RF) network architecture, built-in global positioning system (GPS) for automatic sensor position reporting, a new rugged watertight case, and an extremely low power consumption electronics design. McQ will describe these enhancements and present data characterizing the performance of the enhanced iScout® sensors.

  9. Air Pollutant Emissions from Oil and Gas Production pads (Investigating Low Cost Passive Samplers)

    EPA Science Inventory

    To help achieve the goal of sustainable, environmentally responsible development of oil and gas resources, it isnecessary to understand the potential for air pollutant emissions from various extraction and production (E&P)processes at the upstream, wellpad level. Upstream oil and...

  10. Towards a Passive Low-Cost In-Home Gait Assessment System for Older Adults

    PubMed Central

    Wang, Fang; Stone, Erik; Skubic, Marjorie; Keller, James M.; Abbott, Carmen; Rantz, Marilyn

    2013-01-01

    In this paper, we propose a webcam-based system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed, step time and step length from a three-dimensional voxel reconstruction, which is built from two calibrated webcam views. The gait parameters are validated with a GAITRite mat and a Vicon motion capture system in the lab with 13 participants and 44 tests, and again with GAITRite for 8 older adults in senior housing. An excellent agreement with intra-class correlation coefficients of 0.99 and repeatability coefficients between 0.7% and 6.6% was found for walking speed, step time and step length given the limitation of frame rate and voxel resolution. The system was further tested with 10 seniors in a scripted scenario representing everyday activities in an unstructured environment. The system results demonstrate the capability of being used as a daily gait assessment tool for fall risk assessment and other medical applications. Furthermore, we found that residents displayed different gait patterns during their clinical GAITRite tests compared to the realistic scenario, namely a mean increase of 21% in walking speed, a mean decrease of 12% in step time, and a mean increase of 6% in step length. These findings provide support for continuous gait assessment in the home for capturing habitual gait. PMID:24235111

  11. Toward a passive low-cost in-home gait assessment system for older adults.

    PubMed

    Wang, Fang; Stone, Erik; Skubic, Marjorie; Keller, James M; Abbott, Carmen; Rantz, Marilyn

    2013-03-01

    In this paper, we propose a webcam-based system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed, step time, and step length from a 3-D voxel reconstruction, which is built from two calibrated webcam views. The gait parameters are validated with a GAITRite mat and a Vicon motion capture system in the laboratory with 13 participants and 44 tests, and again with GAITRite for 8 older adults in senior housing. Excellent agreement with intraclass correlation coefficients of 0.99 and repeatability coefficients between 0.7% and 6.6% was found for walking speed, step time, and step length given the limitation of frame rate and voxel resolution. The system was further tested with ten seniors in a scripted scenario representing everyday activities in an unstructured environment. The system results demonstrate the capability of being used as a daily gait assessment tool for fall risk assessment and other medical applications. Furthermore, we found that residents displayed different gait patterns during their clinical GAITRite tests compared to the realistic scenario, namely a mean increase of 21% in walking speed, a mean decrease of 12% in step time, and a mean increase of 6% in step length. These findings provide support for continuous gait assessment in the home for capturing habitual gait. PMID:24235111

  12. Low-Cost Propellant Launch From a Tethered Balloon

    NASA Technical Reports Server (NTRS)

    Wilcox, Brian

    2006-01-01

    A document presents a concept for relatively inexpensive delivery of propellant to a large fuel depot in low orbit around the Earth, for use in rockets destined for higher orbits, the Moon, and for remote planets. The propellant is expected to be at least 85 percent of the mass needed in low Earth orbit to support the NASA Exploration Vision. The concept calls for the use of many small ( 10 ton) spin-stabilized, multistage, solid-fuel rockets to each deliver 250 kg of propellant. Each rocket would be winched up to a balloon tethered above most of the atmospheric mass (optimal altitude 26 2 km). There, the rocket would be aimed slightly above the horizon, spun, dropped, and fired at a time chosen so that the rocket would arrive in orbit near the depot. Small thrusters on the payload (powered, for example, by boil-off gases from cryogenic propellants that make up the payload) would precess the spinning rocket, using data from a low-cost inertial sensor to correct for small aerodynamic and solid rocket nozzle misalignment torques on the spinning rocket; would manage the angle of attack and the final orbit insertion burn; and would be fired on command from the depot in response to observations of the trajectory of the payload so as to make small corrections to bring the payload into a rendezvous orbit and despin it for capture by the depot. The system is low-cost because the small rockets can be mass-produced using the same techniques as those to produce automobiles and low-cost munitions, and one or more can be launched from a U.S. territory on the equator (Baker or Jarvis Islands in the mid-Pacific) to the fuel depot on each orbit (every 90 minutes, e.g., any multiple of 6,000 per year).

  13. A low cost thermal infrared hyperspectral imager for small satellites

    NASA Astrophysics Data System (ADS)

    Crites, S. T.; Lucey, P. G.; Wright, R.; Garbeil, H.; Horton, K. A.

    2011-06-01

    The traditional model for space-based earth observations involves long mission times, high cost, and long development time. Because of the significant time and monetary investment required, riskier instrument development missions or those with very specific scientific goals are unlikely to successfully obtain funding. However, a niche for earth observations exploiting new technologies in focused, short lifetime missions is opening with the growth of the small satellite market and launch opportunities for these satellites. These low-cost, short-lived missions provide an experimental platform for testing new sensor technologies that may transition to larger, more long-lived platforms. The low costs and short lifetimes also increase acceptable risk to sensors, enabling large decreases in cost using commercial off the shelf (COTS) parts and allowing early-career scientists and engineers to gain experience with these projects. We are building a low-cost long-wave infrared spectral sensor, funded by the NASA Experimental Project to Stimulate Competitive Research program (EPSCOR), to demonstrate the ways in which a university's scientific and instrument development programs can fit into this niche. The sensor is a low-mass, power efficient thermal hyperspectral imager with electronics contained in a pressure vessel to enable the use of COTS electronics, and will be compatible with small satellite platforms. The sensor, called Thermal Hyperspectral Imager (THI), is based on a Sagnac interferometer and uses an uncooled 320x256 microbolometer array. The sensor will collect calibrated radiance data at long-wave infrared (LWIR, 8-14 microns) wavelengths in 230-meter pixels with 20 wavenumber spectral resolution from a 400-km orbit.

  14. Contrast in low-cost operational concepts for orbiting satellites

    NASA Astrophysics Data System (ADS)

    Walyus, Keith D.; Reis, James; Bradley, Arthur J.

    2002-12-01

    Older spacecraft missions, especially those in low Earth orbit with telemetry intensive requirements, required round-the-clock control center staffing. The state of technology relied on control center personnel to continually examine data, make decisions, resolve anomalies, and file reports. Hubble Space Telescope (HST) is a prime example of this description. Technological advancements in hardware and software over the last decade have yielded increases in productivity and operational efficiency, which result in lower cost. The re-engineering effort of HST, which has recently concluded, utilized emerging technology to reduce cost and increase productivity. New missions, of which NASA's Transition Region and Coronal Explorer Satellite (TRACE) is an example, have benefited from recent technological advancements and are more cost-effective than when HST was first launched. During its launch (1998) and early orbit phase, the TRACE Flight Operations Team (FOT) employed continually staffed operations. Yet once the mission entered its nominal phase, the FOT reduced their staffing to standard weekday business hours. Operations were still conducted at night and during the weekends, but these operations occurred autonomously without compromising their high standards for data collections. For the HST, which launched in 1990, reduced cost operations will employ a different operational concept, when the spacecraft enters its low-cost phase after its final servicing mission in 2004. Primarily due to the spacecraft"s design, the HST Project has determined that single-shift operations will introduce unacceptable risks for the amount of dollars saved. More importantly, significant cost-savings can still be achieved by changing the operational concept for the FOT, while still maintaining round-the-clock staffing. It"s important to note that the low-cost solutions obtained for one satellite may not be applicable for other satellites. This paper will contrast the differences between

  15. Low Cost Space Demonstration for a Single-Person Spacecraft

    NASA Technical Reports Server (NTRS)

    Griffin, Brand N.; Dischinger, Charles

    2011-01-01

    This paper introduces a concept for a single-person spacecraft and presents plans for flying a low-cost, robotic demonstration mission. Called FlexCraft, the vehicle integrates propulsion and robotics into a small spacecraft that enables rapid, shirt-sleeve access to space. It can be flown by astronauts or tele-operated and is equipped with interchangeable manipulators used for maintaining the International Space Station (ISS), exploring asteroids, and servicing telescopes or satellites. Most FlexCraft systems are verified using ground facilities; however, a test in the weightless environment is needed to assess propulsion and manipulator performance. For this, a simplified, unmanned, version of FlexCraft is flown on a low-cost launch vehicle to a 350 km circular orbit. After separation from the upper stage, the vehicle returns to a target box mounted on the stage testing the propulsion and control capability. The box is equipped with manipulator test items that are representative of tasks performed on ISS, asteroid missions, or for satellites servicing. Nominal and off-nominal operations are conducted over 3 days then the vehicle re-enters the atmosphere without becoming a debris hazard. From concept to management to operations, the FlexCraft demonstration is designed to be low cost project that is launched within three years. This is possible using a simplified test configuration that eliminates nine systems unique to the operational version and by designing-to-availability. For example, the propulsion system is the same as the Manned Maneuvering Unit because it capable, simple, human-rated and all components or equivalent parts are available. A description of the launch vehicle options, mission operations, configuration, and demonstrator subsystems is presented.

  16. A low cost alternative to high performance PCM bit synchronizers

    NASA Technical Reports Server (NTRS)

    Deshong, Bruce

    1993-01-01

    The Code Converter/Clock Regenerator (CCCR) provides a low-cost alternative to high-performance Pulse Code Modulation (PCM) bit synchronizers in environments with a large Signal-to-Noise Ratio (SNR). In many applications, the CCCR can be used in place of PCM bit synchronizers at about one fifth the cost. The CCCR operates at rates from 10 bps to 2.5 Mbps and performs PCM code conversion and clock regeneration. The CCCR has been integrated into a stand-alone system configurable from one to six channels and has also been designed for use in VMEbus compatible systems.

  17. Development of Low Cost Sensors for Hydrogen Safety Applications

    SciTech Connect

    Hoffheins, B.S.; Holmes, W., Jr.; Lauf, R.J.; Maxey, L.C.; Salter, C.; Walker, D.

    1999-04-07

    We are developing rugged and reliable hydrogen safety sensors that can be easily manufactured. Potential applications also require an inexpensive sensor that can be easily deployed. Automotive applications demand low cost, while personnel safety applications emphasize light-weight, battery-operated, and wearable sensors. Our current efforts involve developing and optimizing sensor materials for stability and compatibility with typical thick-film manufacturing processes. We are also tailoring the sensor design and size along with various packaging and communication schemes for optimal acceptance by end users.

  18. Low cost manned Mars mission based on indigenous propellant production

    NASA Technical Reports Server (NTRS)

    Bruckner, A. P.; Cinnamon, M.; Hamling, S.; Mahn, K.; Phillips, J.; Westmark, V.

    1993-01-01

    The paper describes a low-cost approach to the manned exploration of Mars (which involves an unmanned mission followed two years later by a manned mission) based on near-term technologies and in situ propellant production. Particular attention is given to the basic mission architecture and its major components, including the orbital analysis, the unmanned segment, the Earth Return Vehicle, the aerobrake design, life sciences, guidance, communications, power, propellant production, the surface rovers, and Mars science. Also discussed are the cost per mission over an assumed 8-yr initiative.

  19. Uncertainty in air quality observations using low-cost sensors

    NASA Astrophysics Data System (ADS)

    Castell, Nuria; Dauge, Franck R.; Dongol, Rozina; Vogt, Matthias; Schneider, Philipp

    2016-04-01

    Air pollution poses a threat to human health, and the WHO has classified air pollution as the world's largest single environmental health risk. In Europe, the majority of the population lives in areas where air quality levels frequently exceed WHO's ambient air quality guidelines. The emergence of low-cost, user-friendly and very compact air pollution platforms allowing observations at high spatial resolution in near real-time, provides us with new opportunities to simultaneously enhance existing monitoring systems as well as enable citizens to engage in more active environmental monitoring (citizen science). However the data sets generated by low-cost sensors show often questionable data quality. For many sensors, neither their error characteristics nor how their measurement capability holds up over time or through a range of environmental conditions, have been evaluated. We have conducted an exhaustive evaluation of the commercial low-cost platform AQMesh (measuring NO, NO2, CO, O3, PM10 and PM2.5) in laboratory and in real-world conditions in the city of Oslo (Norway). Co-locations in field of 24 platforms were conducted over a 6 month period (April to September 2015) allowing to characterize the temporal variability in the performance. Additionally, the field performance included the characterization on different monitoring urban monitoring sites characteristic of both traffic and background conditions. All the evaluations have been conducted against CEN reference method analyzers maintained according to the Norwegian National Reference Laboratory quality system. The results show clearly that a good performance in laboratory does not imply similar performance in real-world outdoor conditions. Moreover, laboratory calibration is not suitable for subsequent measurements in urban environments. In order to reduce the errors, sensors require on-site field calibration. Even after such field calibration, the platforms show a significant variability in the performance

  20. A simple low-cost single-crystal NMR setup

    NASA Astrophysics Data System (ADS)

    Vinding, Mads S.; Kessler, Tommy O.; Vosegaard, Thomas

    2016-08-01

    A low-cost single-crystal NMR kit is presented along with a web-based post-processing software. The kit consists of a piezo-crystal motor and a goniometer for the crystal, both embedded in a standard wide-bore NMR probe with a 3D printed scaffold. The NMR pulse program controls the angle setting automatically, and the post-processing software incorporates a range of orientation-angle discrepancies present in the kit and other single-crystal setups. Results with a NaNO3 single-crystal show a high degree of reproducibility and excellent agreement with previous findings for the anisotropic quadrupolar interaction.

  1. High efficiency, low cost thin GaAs solar cells

    NASA Technical Reports Server (NTRS)

    Fan, J. C. C.

    1982-01-01

    The feasibility of fabricating space-resistant, high efficiency, light-weight, low-cost GaAs shallow-homojunction solar cells for space application is demonstrated. This program addressed the optimal preparation of ultrathin GaAs single-crystal layers by AsCl3-GaAs-H2 and OMCVD process. Considerable progress has been made in both areas. Detailed studies on the AsCl3 process showed high-quality GaAs thin layers can be routinely grown. Later overgrowth of GaAs by OMCVD has been also observed and thin FaAs films were obtained from this process.

  2. Low cost coherent demodulation for mobile satellite terminals

    NASA Technical Reports Server (NTRS)

    Dutta, Santanu; Henely, Steven J.

    1993-01-01

    This paper describes some low cost approaches to coherent BPSK demodulation for mobile satellite receivers. The specific application is an Inmarsat-C Land Mobile Earth Station (LMES), but the techniques are applicable to any PSK demodulator. The techniques discussed include combined sampling and quadrature downconversion with a single A/D and novel DSP algorithms for carrier acquisition offering both superior performance and economy of DSP resources. The DSP algorithms run at 5.7 MIPS, and the entire DSP subsystem, built with commercially available parts, costs under $60 at quantity-10,000.

  3. Disposable sensor system: low cost UGS for urban operations

    NASA Astrophysics Data System (ADS)

    Calcutt, Wade; Houser, Jeff; Winston, Mark; Brady, Steve; Jones, Barry

    2006-05-01

    McQ has developed a family of low cost unattended ground sensors using conventional technology and manufacturing techniques. Intended for small unit operations in an urban environment, these are tactically useful sensors that can be manufactured in large quantities (1M-10M units/year) for a projected production cost of less than $100 each. Secondary characteristics are small size (98 cm 3), light weight (85 gm), moderate lifetime (40 hrs), and moderate communications ranges (100m). An overview of the DSS system: its features, performance, and scenarios for use in urban warfare, is presented.

  4. Low-cost solar room kit. Final grant report

    SciTech Connect

    1983-01-01

    A low cost solar room kit was developed which would make use of local framing materials, but provide inexperienced builders with a simple joining system and materials - such as glazings - not usually available in local stores. Since solar room applications are proven effective in providing supplementary home heat, a kit would make solar heat more accessible to home owners and tenants. Although a prototype and two working models of the kit were successfully built, commercial development cannot occur until problems in matching the glazing and framing system can be resolved, and more capital to lower production costs on the framing union pieces is available.

  5. Csi-star: a Low-cost CSI Orbital Testbed

    NASA Technical Reports Server (NTRS)

    Edberg, D.

    1992-01-01

    The topics are presented in viewgraph form and include the following: rationale for an on-orbit control-structurs interaction (CSI) test facility; CSI flight experiment objectives; feasibility study objectives; CSI free-flyer solution; feasibility study technical status summary; CSI-Star - a low-cost CSI free flyer; conceptual experiment design - option 2 configuration; Delta 2 - Quickstar Interface clambband capability; open and closed loop response of baselined truss with active struts; experiment weight baseline (option 1) configuration; experiment weight option 2 configuration; experiment power baseline (option 1) configuration; experiment power option 2 configuration; CSI Quickstar capabilities/requirements; and remaining work.

  6. High resolution image processing on low-cost microcomputers

    NASA Technical Reports Server (NTRS)

    Miller, R. L.

    1993-01-01

    Recent advances in microcomputer technology have resulted in systems that rival the speed, storage, and display capabilities of traditionally larger machines. Low-cost microcomputers can provide a powerful environment for image processing. A new software program which offers sophisticated image display and analysis on IBM-based systems is presented. Designed specifically for a microcomputer, this program provides a wide-range of functions normally found only on dedicated graphics systems, and therefore can provide most students, universities and research groups with an affordable computer platform for processing digital images. The processing of AVHRR images within this environment is presented as an example.

  7. Development of low cost contacts to silicon solar cells

    NASA Technical Reports Server (NTRS)

    Tanner, D. P.

    1980-01-01

    The results of the second phase of the program of developing low cost contacts to silicon solar cells using copper are presented. Phase 1 yielded the development of a plated Pd-Cr-Cu contact system. This process produced cells with shunting problems when they were heated to 400 C for 5 minutes. Means of stopping the identified copper diffusion which caused the shunting were investigated. A contact heat treatment study was conducted with Pd-Ag, Ci-Ag, Pd-Cu, Cu-Cr, and Ci-Ni-Cu. Nickel is shown to be an effective diffusion barrier to copper.

  8. Quantitative low-cost webcam-based microscopy

    NASA Astrophysics Data System (ADS)

    Parikesit, Gea Oswah Fatah; Darmawan, Marten; Faisal, Amir

    2010-11-01

    Digital web cameras (popularly known as webcams) have recently gained a significant increase of relevance in the field of optical microscopy, in particular to allow for quick and do-it-yourself methods in developing low-cost and portable microscopes suitable for life sciences and engineering applications in low-resource areas. Unfortunately, these methods were published without any systematic explanation and quantitative assessment of the imaging performances. We reproduce these do-it-yourself methods, discuss the optical considerations that are relevant for them, and quantitatively compare their imaging performances to a commercial digital microscope in order to clarify both the advantages and disadvantages of the webcam-based microscopes.

  9. Low-cost solar collector test and evaluation. Final report

    SciTech Connect

    Benjamin, C M

    1983-01-01

    Project was to test and evaluate a highly efficient low cost solar collector and to make this technology available to the average homeowner. The basic collector design was for use in mass production, so approximately forty collector panels were made for testing and to make it simple to be hand built. The collectors performed better than expected and written and visual material was prepared to make construction easier for a first time builder. Publicity was generated to make public aware of benefits with stories by Associated Press and in publications like Popular Science.

  10. High efficiency low cost monolithic module for SARSAT distress beacons

    NASA Technical Reports Server (NTRS)

    Petersen, Wendell C.; Siu, Daniel P.

    1992-01-01

    The program objectives were to develop a highly efficient, low cost RF module for SARSAT beacons; achieve significantly lower battery current drain, amount of heat generated, and size of battery required; utilize MMIC technology to improve efficiency, reliability, packaging, and cost; and provide a technology database for GaAs based UHF RF circuit architectures. Presented in viewgraph form are functional block diagrams of the SARSAT distress beacon and beacon RF module as well as performance goals, schematic diagrams, predicted performances, and measured performances for the phase modulator and power amplifier.

  11. Fault detection and isolation of the attitude control subsystem of spacecraft formation flying using extended Kalman filters

    NASA Astrophysics Data System (ADS)

    Ghasemi, S.; Khorasani, K.

    2015-10-01

    In this paper, the problem of fault detection and isolation (FDI) of the attitude control subsystem (ACS) of spacecraft formation flying systems is considered. For developing the FDI schemes, an extended Kalman filter (EKF) is utilised which belongs to a class of nonlinear state estimation methods. Three architectures, namely centralised, decentralised, and semi-decentralised, are considered and the corresponding FDI strategies are designed and constructed. Appropriate residual generation techniques and threshold selection criteria are proposed for these architectures. The capabilities of the proposed architectures for accomplishing the FDI tasks are studied through extensive numerical simulations for a team of four satellites in formation flight. Using a confusion matrix evaluation criterion, it is shown that the centralised architecture can achieve the most reliable results relative to the semi-decentralised and decentralised architectures at the expense of availability of a centralised processing module that requires the entire team information set. On the other hand, the semi-decentralised performance is close to the centralised scheme without relying on the availability of the entire team information set. Furthermore, the results confirm that the FDI results in formations with angular velocity measurement sensors achieve higher level of accuracy, true faulty, and precision, along with lower level of false healthy misclassification as compared to the formations that utilise attitude measurement sensors.

  12. Spacecraft Formation Flying near Sun-Earth L2 Lagrange Point: Trajectory Generation and Adaptive Full-State Feedback Control

    NASA Technical Reports Server (NTRS)

    Wong, Hong; Kapila, Vikram

    2004-01-01

    In this paper, we present a method for trajectory generation and adaptive full-state feedback control to facilitate spacecraft formation flying near the Sun-Earth L2 Lagrange point. Specifically, the dynamics of a spacecraft in the neighborhood of a Halo orbit reveals that there exist quasi-periodic orbits surrounding the Halo orbit. Thus, a spacecraft formation is created by placing a leader spacecraft on a desired Halo orbit and placing follower spacecraft on desired quasi-periodic orbits. To produce a formation maintenance controller, we first develop the nonlinear dynamics of a follower spacecraft relative to the leader spacecraft. We assume that the leader spacecraft is on a desired Halo orbit trajectory and the follower spacecraft is to track a desired quasi-periodic orbit surrounding the Halo orbit. Then, we design an adaptive, full-state feedback position tracking controller for the follower spacecraft providing an adaptive compensation for the unknown mass of the follower spacecraft. The proposed control law is simulated for the case of the leader and follower spacecraft pair and is shown to yield global, asymptotic convergence of the relative position tracking errors.

  13. Low-cost distributed solar-thermal-electric power generation

    NASA Astrophysics Data System (ADS)

    Der Minassians, Artin; Aschenbach, Konrad H.; Sanders, Seth R.

    2004-01-01

    Due to their high relative cost, solar electric energy systems have yet to be exploited on a widespread basis. It is believed in the energy community that a technology similar to photovoltaic (PV), but offered at about $1/W would lead to widespread deployment at residential and commercial sites. This paper addresses the investigation and feasibility study of a low-cost solar thermal electricity generation technology, suitable for distributed deployment. Specifically, we discuss a system based on nonimaging solar concentrators, integrated with free-piston Stirling engine devices incorporating integrated electric generation. We target concentrator-collector operation at moderate temperatures, in the range of 125°C to 150°C. This temperature is consistent with use of optical concentrators with concentration ratios on the order of 1-2. These low ratio concentrators admit wide angles of radiation acceptance and are thus compatible with no diurnal tracking, and no or only a few seasonal adjustments. Thus, costs and reliability hazards associated with tracking hardware systems are avoided. Further, we note that in the intended application, there is no shortage of incident solar energy, but rather it is the capital cost of the solar-electric system that is most precious. Thus, we outline a strategy for exploiting solar resources in a cost constrained manner. The paper outlines design issues, and a specific design for an appropriately dimensioned free-piston Stirling engine. Only standard low-cost materials and manufacturing methods are required to realize such a machine.

  14. A low-cost real color picker based on Arduino.

    PubMed

    Agudo, Juan Enrique; Pardo, Pedro J; Sánchez, Héctor; Pérez, Ángel Luis; Suero, María Isabel

    2014-01-01

    Color measurements have traditionally been linked to expensive and difficult to handle equipment. The set of mathematical transformations that are needed to transfer a color that we observe in any object that doesn't emit its own light (which is usually called a color-object) so that it can be displayed on a computer screen or printed on paper is not at all trivial. This usually requires a thorough knowledge of color spaces, colorimetric transformations and color management systems. The TCS3414CS color sensor (I2C Sensor Color Grove), a system for capturing, processing and color management that allows the colors of any non-self-luminous object using a low-cost hardware based on Arduino, is presented in this paper. Specific software has been developed in Matlab and a study of the linearity of chromatic channels and accuracy of color measurements for this device has been undertaken. All used scripts (Arduino and Matlab) are attached as supplementary material. The results show acceptable accuracy values that, although obviously do not reach the levels obtained with the other scientific instruments, for the price difference they present a good low cost option. PMID:25004152

  15. Low cost sensing technology for type 2 diabetes monitoring

    NASA Astrophysics Data System (ADS)

    Sarswat, Prashant; Free, Michael

    2015-03-01

    Alpha-hydroxybutyrate (2-hydroxybutyrate or α-HB) is becoming more widely recognized as an important metabolic biomarker that has been shown to be highly correlated with prediabetes and other metabolic diseases. In 2012 there were 86 million Americans with prediabetes, many of whom are not aware they have prediabetes, but could be diagnosed and treated to prevent type 2 diabetes if a simple, low-cost, convenient test were available. We have developed new, low-cost, accurate α-HB detection methods that can be used for the detection and monitoring of diseases such as prediabetes, type 2 diabetes, β-cell dysfunction, and early hyperglycemia. The new sensing method utilizes a diol recognition moiety, additives and a photoinitiator to detect α-HB at levels near 1 micro g/l in the presence of serum compounds such as lactic acid, sodium pyruvate, and glucose. The objective of this research is to improve the understanding of the interactions that enhance α-HB detection to enable additional improvements in α-HB detection as well as improvements in other biosensor applications.

  16. Low-cost fiber-optic chemochromic hydrogen detector

    SciTech Connect

    Benson, D.K.; Tracy, C.E.; Hishmeh, G.; Ciszek, P.; Lee, S.H.

    1998-08-01

    The ability to detect hydrogen gas leaks economically and with inherent safety is an important technology that could facilitate commercial acceptance of hydrogen fuel in various applications. In particular, hydrogen fueled passenger vehicles will require hydrogen leak detectors to signal the activation of safety devices such as shutoff valves, ventilating fans, alarms, etc. Such detectors may be required in several locations within a vehicle--wherever a leak could pose a safety hazard. It is therefore important that the detectors be very economical. This paper reports progress on the development of low-cost fiber-optic hydrogen detectors intended to meet the needs of a hydrogen-fueled passenger vehicle. In the design, the presence of hydrogen in air is sensed by a thin-film coating at the end of a polymer optical fiber. When the coating reacts reversibly with the hydrogen, its optical properties are changed. Light from a central electro-optic control unit is projected down the optical fiber where it is reflected from the sensor coating back to central optical detectors. A change in the reflected intensity indicates the presence of hydrogen. The fiber-optic detector offers inherent safety by removing all electrical power from the leak sites and offers reduced signal processing problems by minimizing electromagnetic interference. Critical detector performance requirements include high selectivity, response speed and durability as well as potential for low-cost production.

  17. Low-Cost Experimentation for the Study of Droplet Microfluidics

    PubMed Central

    Bardin, David; Lee, Abraham P.

    2014-01-01

    The continued growth of microfluidics into industry settings in areas such as point-of-care diagnostics and targeted therapeutics necessitates a workforce trained in microfluidic technologies and experimental methods. Laboratory courses for students at the university and high school levels will require cost-effective in-class demonstrations that instruct in chip design, fabrication, and experimentation at the microscale. We present a hand-operated pressure pumping system to form monodisperse picoliter to nanoliter droplet streams at low cost, and a series of exercises aimed at instructing in the specific art of droplet formation. Using this setup, the student is able to generate and observe the modes of droplet formation in flow-focusing devices, and the effect of device dimensions on the characteristics of formed droplets. Lastly, at ultra-low cost we demonstrate large plug formation in a T-junction using coffee stirrers as a master mold substitute. Our method reduces the cost of experimentation to enable intuitive instruction in droplet formation, with additional implications for creating droplets in the field or at point-of-care. PMID:25133595

  18. Remote Spectral Imaging Using a Low Cost Uav System

    NASA Astrophysics Data System (ADS)

    Tsouvaltsidis, C.; Salem, N. Zaid Al; Benari, G.; Vrekalic, D.; Quine, B.

    2015-08-01

    The purpose of this scientific survey is to support the research being conducted at York University in the field of spectroscopy and nanosatellites using Argus 1000 micro- spectrometer and low cost unmanned aerial vehicle (UAV) system. On the CanX-2 mission, the Argus spectrometer observes reflected infrared solar radiation emitted by Earth surface targets as small as 1.5 km within the 0.9-1.7 μm range. However, limitations in the volume of data due to onboard power constraints and a lack of an onboard camera system make it very difficult to verify these objectives using ground truth. In the last five years that Argus has been in operation, we have made over 200 observations over a series of land and ocean targets. We have recently examined algorithms to improve the geolocation accuracy of the spectrometer payload and began to conduct an analysis of soil health content using Argus spectral data. A field campaign is used to obtain data to assess geolocation accuracy using coastline crossing detection and to obtain airborne bare soil spectra in ground truth form. The payload system used for the field campaign consists of an Argus spectrometer, optical camera, GPS, and attitude sensors, integrated into a low-cost, unmanned aerial vehicle (UAV), which will be presented along with the experimental procedure and field campaign results.

  19. Novel approach for low-cost muzzle flash detection system

    NASA Astrophysics Data System (ADS)

    Voskoboinik, Asher

    2008-04-01

    A low-cost muzzle flash detection based on CMOS sensor technology is proposed. This low-cost technology makes it possible to detect various transient events with characteristic times between dozens of microseconds up to dozens of milliseconds while sophisticated algorithms successfully separate them from false alarms by utilizing differences in geometrical characteristics and/or temporal signatures. The proposed system consists of off-the-shelf smart CMOS cameras with built-in signal and image processing capabilities for pre-processing together with allocated memory for storing a buffer of images for further post-processing. Such a sensor does not require sending giant amounts of raw data to a real-time processing unit but provides all calculations in-situ where processing results are the output of the sensor. This patented CMOS muzzle flash detection concept exhibits high-performance detection capability with very low false-alarm rates. It was found that most false-alarms due to sun glints are from sources at distances of 500-700 meters from the sensor and can be distinguished by time examination techniques from muzzle flash signals. This will enable to eliminate up to 80% of falsealarms due to sun specular reflections in the battle field. Additional effort to distinguish sun glints from suspected muzzle flash signal is made by optimization of the spectral band in Near-IR region. The proposed system can be used for muzzle detection of small arms, missiles and rockets and other military applications.

  20. Particle swarm optimization algorithm based low cost magnetometer calibration

    NASA Astrophysics Data System (ADS)

    Ali, A. S.; Siddharth, S., Syed, Z., El-Sheimy, N.

    2011-12-01

    Inertial Navigation Systems (INS) consist of accelerometers, gyroscopes and a microprocessor provide inertial digital data from which position and orientation is obtained by integrating the specific forces and rotation rates. In addition to the accelerometers and gyroscopes, magnetometers can be used to derive the absolute user heading based on Earth's magnetic field. Unfortunately, the measurements of the magnetic field obtained with low cost sensors are corrupted by several errors including manufacturing defects and external electro-magnetic fields. Consequently, proper calibration of the magnetometer is required to achieve high accuracy heading measurements. In this paper, a Particle Swarm Optimization (PSO) based calibration algorithm is presented to estimate the values of the bias and scale factor of low cost magnetometer. The main advantage of this technique is the use of the artificial intelligence which does not need any error modeling or awareness of the nonlinearity. The estimated bias and scale factor errors from the proposed algorithm improve the heading accuracy and the results are also statistically significant. Also, it can help in the development of the Pedestrian Navigation Devices (PNDs) when combined with the INS and GPS/Wi-Fi especially in the indoor environments

  1. A Low-Cost Real Color Picker Based on Arduino

    PubMed Central

    Agudo, Juan Enrique; Pardo, Pedro J.; Sánchez, Héctor; Pérez, Ángel Luis; Suero, María Isabel

    2014-01-01

    Color measurements have traditionally been linked to expensive and difficult to handle equipment. The set of mathematical transformations that are needed to transfer a color that we observe in any object that doesn't emit its own light (which is usually called a color-object) so that it can be displayed on a computer screen or printed on paper is not at all trivial. This usually requires a thorough knowledge of color spaces, colorimetric transformations and color management systems. The TCS3414CS color sensor (I2C Sensor Color Grove), a system for capturing, processing and color management that allows the colors of any non-self-luminous object using a low-cost hardware based on Arduino, is presented in this paper. Specific software has been developed in Matlab and a study of the linearity of chromatic channels and accuracy of color measurements for this device has been undertaken. All used scripts (Arduino and Matlab) are attached as supplementary material. The results show acceptable accuracy values that, although obviously do not reach the levels obtained with the other scientific instruments, for the price difference they present a good low cost option. PMID:25004152

  2. Low-cost space platforms for detection and tracking technologies

    NASA Astrophysics Data System (ADS)

    Cullen, Robert M.

    1991-08-01

    This paper describes the capabilities and applications of inexpensive satellite platforms capable of carrying dedicated sensor packages into low earth orbit on primary or shared launch services. These satellites permit achievement of rapid operational status by employing standard buses with fixed options for orbit and power. The satellites may be configured for experimental or operational missions with lifetimes up to several years. Low cost satellites can satisfy a range of mission requirements in the areas of surveillance, drug interdiction, environmental and geophysical observations, immigration control, fisheries law enforcement, remote sensing, real-time communications, store-and-forward communications, and technology testing. These satellites may be equipped for location determination missions with ID and homing transponders and tagged objects or persons. The satellites' size, power, and weight budgets are appropriately rated for the types of dedicated mission scenarios noted above. For applications requiring continuous visibility or high availability, constellations of satellites may be both appropriate and cost-effective. Orbital parameters are determined by the launch vehicle and the requirements of the primary payload. Geographical service areas are determined by the orbital footprint, the parameters of which are determined by the mission requirements and the selection of launch vehicle. The satellites' small size permits their launch on any of several launch vehicles in domestic or international inventory. Integral to each satellite is a communications and control package which, when coupled with companion low cost earth terminals, provides programmable mission scenarios under operator control. These satellites permit rapid implementation of operational systems within tight fiscal constraints.

  3. LCX: Proposal for a low-cost commercial transport

    NASA Technical Reports Server (NTRS)

    Hartman, Troy; Hayatdavoudi, Maziar; Hettinga, Joel; Hooper, Matt; Nguyen, Phong

    1994-01-01

    The LCX has been developed in response to a request for proposal for an aircraft with 153 passenger capacity and a range of 3000 nautical miles. The goals of the LCX are to provide an aircraft which will achieve the stated mission requirements at the lowest cost possible, both for the manufacturer and the operator. Low cost in this request is defined as short and long term profitability. To achieve this objective, modern technologies attributing to low-cost operation without greatly increasing the cost of manufacturing were employed. These technologies include hybrid laminar flow control and the use of developing new manufacturing processes and philosophies. The LCX will provide a competitive alternative to the use of the Airbus A319/320/321 and the Boeing 737 series of aircraft. The LCX has a maximum weight of 150,000 lb. carried by a wing of 1140 ft(exp 2) and an aspect ratio of 10. The selling price of the LCX is 31 million in 1994 US dollars.

  4. A Low Cost Single Chip VDL Compatible Transceiver ASIC

    NASA Technical Reports Server (NTRS)

    Becker, Robert

    2004-01-01

    Recent trends in commercial communications system components have focussed almost exclusively on cellular telephone technology. As many of the traditional sources of receiver components have discontinued non-cellular telephone products, the designers of avionics and other low volume radio applications find themselves increasingly unable to find highly integrated components. This is particularly true for low power, low cost applications which cannot afford the lavish current consumption of the software defined radio approach increasingly taken by certified device manufacturers. In this paper, we describe a low power transceiver chip targeting applications from low VHF to low UHF frequencies typical of avionics systems. The chip encompasses a selectable single or double conversion design for the receiver and a low power IF upconversion transmitter. All local oscillators are synthesized and integrated into the chip. An on-chip I-Q modulator and demodulator provide baseband modulation and demodulation capability allowing the use of low power, fixed point signal processing components for signal demodulation. The goal of this program is to demonstrate a low cost VDL mode-3 transceiver using this chip to receive text weather information sent using 4-slot TDMA with no support for voice. The data will be sent from an experimental ground station. This work is funded by NASA Glenn Research Center.

  5. Low-cost dipole hydrophone for use in towed arrays

    SciTech Connect

    Abraham, B.M.

    1996-04-01

    The design, fabrication, and testing of a low-cost acoustic particle velocity sensor are described. The primary design parameters for the dipole hydrophone are low-cost, low-mass, and small size. The sensor uses commercially available geophones to locally measure one or more components of the acoustic particle velocity field. The geophones are encapsulated in a syntactic foam to reduce their average density and hence increase their acoustic sensitivity. This method of fabrication greatly reduces costs compared to conventional methods which use machined cases. The on-axis voltage sensitivity was measured experimentally using two methods. The first used a uniaxial vibration shaker to estimate the intrinsic velocity sensitivity of the encapsulated geophone with the case fixed to the shaker head. The second measured the {ital in} {ital situ} acoustic sensitivity in water. Theoretical models of the voltage sensitivity for these two cases are developed and the results compare very well with the experimental data. Additionally, rotator tests were performed at frequencies of 100, 500, 600, and 1000 Hz to measure the quality of the dipole directivity pattern in water. Near-theoretical dipole patterns, with nulls better than 30 dB, were measured. {copyright} {ital 1996 American Institute of Physics.}

  6. NEW HIGHER PERFORMANCE LOW COST SELECTIVE SOLAR RADIATION CONTROL COATINGS

    SciTech Connect

    Timothy Ellison; Buddie Dotter; David Tsu

    2003-10-28

    Energy Conversion Devices, Inc., ECD, has developed a new high-speed low-cost process for depositing high quality dielectric optical coatings--Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD). This process can deposit SiO{sub x} about 10 times faster than the state-of-the-art conventional technology, magnetron sputtering, at about 1/10th the cost. This process is also being optimized for depositing higher refractive index materials such as Si{sub 3}N{sub 4} and TiO{sub 2}. In this program ECD, in collaboration with Southwall Technologies, Inc. (STI), demonstrated that this process can be used to fabricate high performance low cost Selective Solar Radiation Control (SSRC) films for use in the automotive industry. These coatings were produced on thin (2 mil thick) PET substrates in ECD's pilot roll-to-roll pilot MPECVD deposition machine. Such film can be laminated with PVB in a vehicle's windows. This process can also be used to deposit the films directly onto the glass. Such highly selective films, with a visible transmission (T{sub vis}) of > 70% and a shading coefficient of < 60% can significantly reduce the heat entering a car from solar radiation. Consequently, passenger comfort is increased and the energy needed to operate air conditioning (a/c) systems is reduced; consequently smaller a/c systems can be employed resulting in improved vehicle fuel efficiency.

  7. A Low Cost Rokkaku Kite Setup for Aerial Photogrammetric System

    NASA Astrophysics Data System (ADS)

    Khan, A. F.; Khurshid, K.; Saleh, N.; Yousuf, A. A.

    2015-03-01

    Orthogonally Projected Area (OPA) of a geographical feature has primarily been studied utilizing rather time consuming field based sampling techniques. Remote sensing on the contrary provides the ability to acquire large scale data at a snapshot of time and lets the OPA to be calculated conveniently and with reasonable accuracy. Unfortunately satellite based remote sensing provides data at high cost and limited spatial resolution for scientific studies focused at small areas such as micro lakes micro ecosystems, etc. More importantly, recent satellite data may not be readily available for a particular location. This paper describes a low cost photogrammetric system to measure the OPA of a small scale geographic feature such as a plot of land, micro lake or an archaeological site, etc. Fitted with a consumer grade digital imaging system, a Rokkaku kite aerial platform with stable flight characteristics is designed and fabricated for image acquisition. The data processing procedure involves automatic Ground Control Point (GCP) detection, intelligent target area shape determination with minimal human input. A Graphical User Interface (GUI) is built from scratch in MATLAB to allow the user to conveniently process the acquired data, archive and retrieve the results. Extensive on-field experimentation consists of multiple geographic features including flat land surfaces, buildings, undulating rural areas, and an irregular shaped micro lake, etc. Our results show that the proposed system is not only low cost, but provides a framework that is easy and fast to setup while maintaining the required constraints on the accuracy.

  8. Using a Low Cost Flight Simulation Environment for Interdisciplinary Education

    NASA Technical Reports Server (NTRS)

    Khan, M. Javed; Rossi, Marcia; ALi, Syed F.

    2004-01-01

    A multi-disciplinary and inter-disciplinary education is increasingly being emphasized for engineering undergraduates. However, often the focus is on interaction between engineering disciplines. This paper discusses the experience at Tuskegee University in providing interdisciplinary research experiences for undergraduate students in both Aerospace Engineering and Psychology through the utilization of a low cost flight simulation environment. The environment, which is pc-based, runs a low-cost of-the-shelf software and is configured for multiple out-of-the-window views and a synthetic heads down display with joystick, rudder and throttle controls. While the environment is being utilized to investigate and evaluate various strategies for training novice pilots, students were involved to provide them with experience in conducting such interdisciplinary research. On the global inter-disciplinary level these experiences included developing experimental designs and research protocols, consideration of human participant ethical issues, and planning and executing the research studies. During the planning phase students were apprised of the limitations of the software in its basic form and the enhancements desired to investigate human factors issues. A number of enhancements to the flight environment were then undertaken, from creating Excel macros for determining the performance of the 'pilots', to interacting with the software to provide various audio/video cues based on the experimental protocol. These enhancements involved understanding the flight model and performance, stability & control issues. Throughout this process, discussions of data analysis included a focus from a human factors perspective as well as an engineering point of view.

  9. LOW COST PRODUCTION OF CARBON FIBERS FROM LIGNIN MATERIALS

    SciTech Connect

    Gallego, Nidia C; Baker, Darren A; Baker, Frederick S

    2009-01-01

    The DOE Vehicle Technologies-funded work at ORNL is directed to the development of processes for the low cost production of carbon fibers. The objective of the project is to develop more energy-efficient, cost-effective processes for production of carbon fibers for use in composite materials for vehicles, which would substantially reduce vehicle weight, increase vehicle fuel economy, and result in lower CO2 emissions. Carbon fibers have the potential for substantial weight saving in vehicles because of their remarkable high strength, high modulus, and low density. However, carbon fibers are currently too expensive for large scale automotive use, which necessitates a large reduction in the cost of commercial grade fiber from about $20/lb to $5-7/lb. Lignin, a renewable resource material, has significant potential as a precursor material for low cost carbon fiber production. In this paper we report on progress to demonstrate the melt-spinning of precursor fibers from various lignin sources, the subsequent processing of the lignin precursor fibers into carbon fibers, and carbon fiber properties.

  10. IQ-Station: A Low Cost Portable Immersive Environment

    SciTech Connect

    Eric Whiting; Patrick O'Leary; William Sherman; Eric Wernert

    2010-11-01

    The emergence of inexpensive 3D TV’s, affordable input and rendering hardware and open-source software has created a yeasty atmosphere for the development of low-cost immersive environments (IE). A low cost IE system, or IQ-station, fashioned from commercial off the shelf technology (COTS), coupled with a targeted immersive application can be a viable laboratory instrument for enhancing scientific workflow for exploration and analysis. The use of an IQ-station in a laboratory setting also has the potential of quickening the adoption of a more sophisticated immersive environment as a critical enabler in modern scientific and engineering workflows. Prior work in immersive environments generally required either a head mounted display (HMD) system or a large projector-based implementation both of which have limitations in terms of cost, usability, or space requirements. The solution presented here provides an alternative platform providing a reasonable immersive experience that addresses those limitations. Our work brings together the needed hardware and software to create a fully integrated immersive display and interface system that can be readily deployed in laboratories and common workspaces. By doing so, it is now feasible for immersive technologies to be included in researchers’ day-to-day workflows. The IQ-Station sets the stage for much wider adoption of immersive environments outside the small communities of virtual reality centers.

  11. A low cost human computer interface based on eye tracking.

    PubMed

    Hiley, Jonathan B; Redekopp, Andrew H; Fazel-Rezai, Reza

    2006-01-01

    This paper describes the implementation of a human computer interface based on eye tracking. Current commercially available systems exist, but have limited use due mainly to their large cost. The system described in this paper was designed to be a low cost and unobtrusive. The technique was video-oculography assisted by corneal reflections. An off-the shelf CCD webcam was used to capture images. The images were analyzed in software to extract key features of the eye. The users gaze point was then calculated based on the relative position of these features. The system is capable of calculating eye-gaze in real-time to provide a responsive interaction. A throughput of eight gaze points per second was achieved. The accuracy of the fixations based on the calculated eye-gazes were within 1 cm of the on-screen gaze location. By developing a low-cost system, this technology is made accessible to a wider range of applications. PMID:17946167

  12. Formed platelets for low cost regeneratively cooled rocket combustion chambers

    NASA Astrophysics Data System (ADS)

    Burkhardt, Wendel M.

    1992-02-01

    The ongoing work performed to demonstrate the fabrication feasibility of a formed platelet regeneratively cooled combustion chamber liner is described. The combustion chambers are fabricated in three or four axial sections from formed platelet stacks joined together. The platelets are etched, stacked, and bonded into flat panels that contain the regen passages. The flat panels are formed into the final contour with a die. The formed platelet approach takes advantage of the inherent low cost, high accuracy, and thin wall capability of photoetched platelet technology to fabricate long life, low cost rocket combustion chambers. Combustion chamber liner sections were fabricated with extremely thin (tw = 0.20 mm (0.008-in.)) hot gas side walls and very high aspect ratio coolant channels (aspect ratio greater than 10:1). Combustion chamber liner sections were formed of both Zr-Cu and stainless steel. The results of both the forming of individual panels and the joining of panels together are discussed. Work performed demonstrating the feasibility of rocket combustion chamber liners from formed platelets is described. A discussion of the benefits of chamber liners so constructed and of a chamber producing 176,000 N (40 Klbf) of thrust currently fabricated is presented. The results of a study examining the forming of large scale platelet panels for an Space Shuttle Main Engine (SSME) Main Combustion Chamber (MCC) liner are included.

  13. Low Cost PEM Fuel Cell Metal Bipolar Plates

    SciTech Connect

    Wang, Conghua

    2013-05-30

    Bipolar plate is an important component in fuel cell stacks and accounts for more than 75% of stack weight and volume. The technology development of metal bipolar plates can effectively reduce the fuel cells stack weight and volume over 50%. The challenge is the metal plate corrosion protection at low cost for the broad commercial applications. This project is aimed to develop innovative technological solutions to overcome the corrosion barrier of low cost metal plates. The feasibility of has been demonstrated and patented (US Patent 7,309,540). The plan is to further reduce the cost, and scale up the technology. The project is built on three pillars: 1) robust experimental evidence demonstrating the feasibility of our technology, 2) a team that consists of industrial leaders in fuel cell stack application, design, and manufactures; 3) a low-risk, significant-milestone driven program that proves the feasibility of meeting program objectives The implementation of this project will reduce the fuel cell stack metal bipolar separator plate cost which accounts 15-21% of the overall stack cost. It will contribute to the market adoption of fuel cell technologies. In addition, this corrosion protection technology can be used similar energy devices, such as batteries and electrolyzers. Therefore, the success of the project will be benefit in broad markets.

  14. Engineering a responsive, low cost, tactical satellite, TACSAT-1

    NASA Astrophysics Data System (ADS)

    Hurley, M.; Duffey, T.; Huffine, Christopher; Weldy, Ken; Clevland, Jeff; Hauser, Joe

    2004-11-01

    The Secretary of Defense's Office of Force Transformation (OFT) is currently undertaking an initiative to develop a low-cost, responsive, operationally relevant space capability using small satellites. The Naval Research Laboratory (NRL) is tasked to be program manger for this initiative, which seeks to make space assets and capabilities available to operational users. TacSat-1 is the first in a series of small satellites that will result in rapid, tailored, and operationally relevant experimental space capabilities for tactical forces. Components of the resulting tactical architecture include a highly automated small satellite bus, modular payloads, common launch and payload interfaces, tasking and data dissemination using the SIPRNET (Secret Internet Protocol Routing Network), and low cost, rapid response launches. The overall goal of TacSat-1 is to demonstrate the utility of a broader complementary business model and provide a catalyst for energizing DoD and industry in the operational space area. This paper first provides a brief overview of the TacSat- 1 experiment and then discusses the engineering designs and practices used to achieve the aggressive cost and schedule goals. Non-standard approaches and engineering philosophies that allowed the TacSat-1 spacecraft to be finished in twelve months are detailed and compared with "normal" satellite programs where applicable. Specific subsystem design, integration and test techniques, which contributed to the successful completion of the TacSat-1 spacecraft, are reviewed. Finally, lessons learned are discussed.

  15. Silicon web process development. [for low cost solar cells

    NASA Technical Reports Server (NTRS)

    Duncan, C. S.; Hopkins, R. H.; Seidensticker, R. G.; Mchugh, J. P.; Hill, F. E.; Heimlich, M. E.; Driggers, J. M.

    1979-01-01

    Silicon dendritic web, a single crystal ribbon shaped during growth by crystallographic forces and surface tension (rather than dies), is a highly promising base material for efficient low cost solar cells. The form of the product smooth, flexible strips 100 to 200 microns thick, conserves expensive silicon and facilitates automation of crystal growth and the subsequent manufacturing of solar cells. These characteristics, coupled with the highest demonstrated ribbon solar cell efficiency-15.5%-make silicon web a leading candidate to achieve, or better, the 1986 Low Cost Solar Array (LSA) Project cost objective of 50 cents per peak watt of photovoltaic output power. The main objective of the Web Program, technology development to significantly increase web output rate, and to show the feasibility for simultaneous melt replenishment and growth, have largely been accomplished. Recently, web output rates of 23.6 sq cm/min, nearly three times the 8 sq cm/min maximum rate of a year ago, were achieved. Webs 4 cm wide or greater were grown on a number of occassions.

  16. Bamboo composite materials for low-cost housing

    NASA Astrophysics Data System (ADS)

    Dagilis, Trevor David

    Investigation into the use of bamboo in composite panels for low-cost housing is presented. Information on the housing situation, the state of the forest resources, and the needs for low-cost housing are given for Ecuador, which is seen as representative of countries with a history of bamboo use, and potential for further development. Specifically bamboo particleboard using Guadua angustifolia, Dendrocalamus strictus, Phyllostachys pubescens, and Bambusa vulgaris manufactured with steam injection pressing is presented. High strength panels including waferboard made from randomly placed and oriented Bambusa vulgaris wafers, bamboo particleboard overlaid with woven bamboo mats, and "picada panels" were developed. Emphasis was given to short press times, low resin contents, and low product densities in comparison with previous technology to ensure economic viability. This investigation is a unique contribution to the science of composite products and has developed a number of panel products that are both technically and economically feasible. A discussion of economic, social and environmental issues surrounding bamboo industrialisation is also presented.

  17. COMPASS Final Report: Low Cost Robotic Lunar Lander

    NASA Technical Reports Server (NTRS)

    McGuire, Melissa L.; Oleson, Steven R.

    2010-01-01

    The COllaborative Modeling for the Parametric Assessment of Space Systems (COMPASS) team designed a robotic lunar Lander to deliver an unspecified payload (greater than zero) to the lunar surface for the lowest cost in this 2006 design study. The purpose of the low cost lunar lander design was to investigate how much payload can an inexpensive chemical or Electric Propulsion (EP) system deliver to the Moon s surface. The spacecraft designed as the baseline out of this study was a solar powered robotic lander, launched on a Minotaur V launch vehicle on a direct injection trajectory to the lunar surface. A Star 27 solid rocket motor does lunar capture and performs 88 percent of the descent burn. The Robotic Lunar Lander soft-lands using a hydrazine propulsion system to perform the last 10% of the landing maneuver, leaving the descent at a near zero, but not exactly zero, terminal velocity. This low-cost robotic lander delivers 10 kg of science payload instruments to the lunar surface.

  18. Glass for low-cost photovoltaic solar arrays

    SciTech Connect

    Bouquet, F.L.

    1980-02-01

    In photovoltaic systems, the encapsulant material that protects the solar cells should be highly transparent and very durable. Glass satisfies these two criteria and is considered a primary candidate for low-cost, photovoltaic encapsulation systems. In this report, various aspects of glass encapsulation are treated that are important for the designer of photovoltaic systems. Candidate glasses and available information defining the state of the art of glass encapsulation materials and processes for automated, high volume production of terrestrial photovoltaic devices and related applications are presented. The criteria for consideration of the glass encapsulation systems were based on the LSA (Low-cost Solar Array) Project goals for arrays: (a) a low degradation rate, (b) high reliability, (c) an efficiency greater than 10 percent, (d) a total array price less than $500/kW, and (e) a production capacity of 5 x 10/sup 5/ kW/yr. The glass design areas treated herein include the types of glass, sources and costs, physical properties and glass modifications, such as antireflection coatings. 78 references.

  19. Recent developments in low cost stable structures for space

    SciTech Connect

    Thompson, T.C.; Grastataro, C.; Smith, B.G.

    1994-10-01

    The Los Alamos National Laboratory (LANL) in partnership with Composite Optics Incorporated (COI) is advancing the development of low cost, lightweight, composite technology for use in spacecraft and stable structures. The use of advanced composites is well developed, but the application of an all-composite tracker structure has never been achieved. This paper investigates the application of composite technology to the design and fabrication of an all-composite spacecraft bus for small satellites, using technology directly applicable to central tracking in a high luminosity environment. The satellite program Fast On-Orbit Recording of Transient Events (FORTE) is the second in a series of satellites to be launched into orbit for the US Department of Energy (DOE). This paper will discuss recent developments in the area of low cost composites, used for either spacecraft or ultra stable applications in high energy physics (HEP) detectors. The use of advanced composites is a relatively new development in the area of HEP. The Superconducting Super Collider (SSC) spawned a new generation of Trackers which made extensive use of graphite fiber reinforced plastic (GFRP) composite systems. LANL has designed a structure employing new fabrication technology. This concept will lower the cost of composite structures to a point that they may now compete with conventional materials. This paper will discuss the design, analysis and proposed fabrication of a small satellite structure. Central tracking structures using advanced materials capable of operating in an adverse environment typical of that found in a high luminosity collider could use identical concepts.

  20. a Low Cost Pressure Wave Generator Using Diaphragms

    NASA Astrophysics Data System (ADS)

    Caughley, A. J.; Haywood, D. J.; Wang, C.

    2008-03-01

    The high cost of Pressure Wave Generators (PWGs) is a major barrier to the more widespread use of high-efficiency pulse tube and Stirling cryocoolers. This paper describes the development and testing of a low-cost industrial-style PWG which employs metal diaphragms. The use of diaphragms removes the need for rubbing or clearance seals, and eliminates contamination problems by hermetically separating the gas circuit and the lubricated driving mechanism. A conventional low-cost electric motor is used for power input, via a novel high-efficiency kinematic linkage. A first prototype of the diaphragm PWG produced 3.2 kW of PV power with a measured electro-acoustic efficiency of 72%. Accelerated testing predicts a diaphragm life time in excess of 40,000 hours. An additional advantage of the use of diaphragms is the ability to directly cool the gas in the compression space. This eliminates or significantly reduces the requirement for an after cooler, and further decreases the cost of the whole cryocooler system. A pulse tube cryocooler has been successfully run at Industrial Research Ltd to 59K with the diaphragm PWG and no aftercooler. Another pulse tube cryocooler with the diaphragm PWG is undergoing development at Cryomech, the results of which will be given in another presentation.

  1. Algolcam: Low Cost Sky Scanning with Modern Technology

    NASA Astrophysics Data System (ADS)

    Connors, Martin; Bolton, Dempsey; Doktor, Ian

    2016-01-01

    Low cost DSLR cameras running under computer control offer good sensitivity, high resolution, small size, and the convenience of digital image handling. Recent developments in small single board computers have pushed the performance to cost and size ratio to unprecedented values, with the further advantage of very low power consumption. Yet a third technological development is motor control electronics which is easily integrated with the computer to make an automated mount, which in our case is custom built, but with similar mounts available commercially. Testing of such a system under a clear plastic dome at our auroral observatory was so successful that we have developed a weatherproof housing allowing use during the long, cold, and clear winter nights at northerly latitudes in Canada. The main advantage of this housing should be improved image quality as compared to operation through clear plastic. We have improved the driving software to include the ability to self-calibrate pointing through the web API of astrometry.net, and data can be reduced automatically through command line use of the Muniwin program. The mount offers slew in declination and RA, and tracking at sidereal or other rates in RA. Our previous tests with a Nikon D5100 with standard lenses in the focal length range 50-200 mm, operating at f/4 to f/5, allowed detection of 12th magnitude stars with 30 second exposure under very dark skies. At 85 mm focal length, a field of 15° by 10° is imaged with 4928 by 3264 color pixels, and we have adopted an 85 mm fixed focal length f/1.4 lens (as used by Project Panoptes), which we expect will give a limited magnitude approaching 15. With a large field of view, deep limiting magnitude, low cost, and ease of construction and use, we feel that the Algolcam offers great possibilities in monitoring and finding changes in the sky. We have already applied it to variable star light curves, and with a suitable pipeline for detection of moving or varying objects

  2. System identification of a small low-cost unmanned aerial vehicle using flight data from low-cost sensors

    NASA Astrophysics Data System (ADS)

    Hoffer, Nathan Von

    Remote sensing has traditionally been done with satellites and manned aircraft. While. these methods can yield useful scientificc data, satellites and manned aircraft have limitations in data frequency, process time, and real time re-tasking. Small low-cost unmanned aerial vehicles (UAVs) provide greater possibilities for personal scientic research than traditional remote sensing platforms. Precision aerial data requires an accurate vehicle dynamics model for controller development, robust flight characteristics, and fault tolerance. One method of developing a model is system identification (system ID). In this thesis system ID of a small low-cost fixed-wing T-tail UAV is conducted. The linerized longitudinal equations of motion are derived from first principles. Foundations of Recursive Least Squares (RLS) are presented along with RLS with an Error Filtering Online Learning scheme (EFOL). Sensors, data collection, data consistency checking, and data processing are described. Batch least squares (BLS) and BLS with EFOL are used to identify aerodynamic coecoefficients of the UAV. Results of these two methods with flight data are discussed.

  3. A Compact and Low Cost Electronic Nose for Aroma Detection

    PubMed Central

    Macías, Miguel Macías; Agudo, J. Enrique; Manso, Antonio García; Orellana, Carlos Javier García; Velasco, Horacio Manuel González; Caballero, Ramón Gallardo

    2013-01-01

    This article explains the development of a prototype of a portable and a very low-cost electronic nose based on an mbed microcontroller. Mbeds are a series of ARM microcontroller development boards designed for fast, flexible and rapid prototyping. The electronic nose is comprised of an mbed, an LCD display, two small pumps, two electro-valves and a sensor chamber with four TGS Figaro gas sensors. The performance of the electronic nose has been tested by measuring the ethanol content of wine synthetic matrices and special attention has been paid to the reproducibility and repeatability of the measurements taken on different days. Results show that the electronic nose with a neural network classifier is able to discriminate wine samples with 10, 12 and 14% V/V alcohol content with a classification error of less than 1%. PMID:23698265

  4. Low-cost laser rangefinder with crystal-controlled accuracy

    NASA Astrophysics Data System (ADS)

    Munro, James F.

    2005-02-01

    We present a novel laser ranging system that offers improved accuracy and low-cost implementations for short to medium range target distance and velocity measurement. This is accomplished through the emission of an eye-safe amplitude modulated laser beam, whose echo return is processed with a phase-computing discrete Fourier transform (DFT). The data for the DFT are collected directly from the received signal through equivalent time sampling, and the automatic gain control (AGC) function is moved to that part of the system where its varying signal propagation time will not impact measurement accuracy. All emission and data collection signals are derived directly from a single crystal oscillator, which establishes the system's accuracy. The system is also capable of resolving the distance/velocity ambiguity problem inherent in conventional hetero/homodyne laser ranging systems, and, lastly, digital data can be transmitted and received concurrently with the distance measurement process.

  5. Low-Cost Solar Water Heating Research and Development Roadmap

    SciTech Connect

    Hudon, K.; Merrigan, T.; Burch, J.; Maguire, J.

    2012-08-01

    The market environment for solar water heating technology has changed substantially with the successful introduction of heat pump water heaters (HPWHs). The addition of this energy-efficient technology to the market increases direct competition with solar water heaters (SWHs) for available energy savings. It is therefore essential to understand which segment of the market is best suited for HPWHs and focus the development of innovative, low-cost SWHs in the market segment where the largest opportunities exist. To evaluate cost and performance tradeoffs between high performance hot water heating systems, annual energy simulations were run using the program, TRNSYS, and analysis was performed to compare the energy savings associated with HPWH and SWH technologies to conventional methods of water heating.

  6. Electricity from sunlight. [low cost silicon for solar cells

    NASA Technical Reports Server (NTRS)

    Yaws, C. L.; Miller, J. W.; Lutwack, R.; Hsu, G.

    1978-01-01

    The paper discusses a number of new unconventional processes proposed for the low-cost production of silicon for solar cells. Consideration is given to: (1) the Battelle process (Zn/SiCl4), (2) the Battelle process (SiI4), (3) the Silane process, (4) the Motorola process (SiF4/SiF2), (5) the Westinghouse process (Na/SiCl4), (6) the Dow Corning process (C/SiO2), (7) the AeroChem process (SiCl4/H atom), and the Stanford process (Na/SiF4). Preliminary results indicate that the conventional process and the SiI4 processes cannot meet the project goal of $10/kg by 1986. Preliminary cost evaluation results for the Zn/SiCl4 process are favorable.

  7. Low-Cost, Portable Optical Imaging Systems for Cancer Diagnosis

    PubMed Central

    Pierce, Mark C.; Richards-Kortum, Rebecca

    2011-01-01

    Worldwide incidence and mortality rates due to cancer continue to rise, with the burden of disease increasingly shifting to developing countries. Several optical diagnostic methods such as diffuse optical tomography, wide-field autofluorescence imaging, confocal microscopy, and optical coherence tomography, are currently under development to enable earlier detection of cancer. However, these are primarily intended for use in healthcare facilities in industrialized countries. Using knowledge gained from early clinical studies with these large-scale systems, we have designed and tested low-cost, portable versions of these instruments. We propose that these systems may be used for early diagnosis and screening in developing countries, and that pilot clinical studies are warranted in these low-resource settings. PMID:21096559

  8. High resolution, low cost solar cell contact development

    NASA Technical Reports Server (NTRS)

    Mardesich, N.

    1981-01-01

    The MIDFILM cell fabrication and encapsulation processes were demonstrated as a means of applying low-cost solar cell collector metallization. The average cell efficiency of 12.0 percent (AM1, 28 C) was achieved with fritted silver metallization with a demonstration run of 500 starting wafers. A 98 percent mechanical yield and 80 percent electrical yield were achieved through the MIDFILM process. High series resistance was responsible for over 90 percent of the electrical failures and was the major factor causing the low average cell efficiency. Environmental evaluations suggest that the MIDFILM cells do not degrade. A slight degradation in power was experienced in the MIDFILM minimodules when the AMP Solarlok connector delaminated during the environmental testing.

  9. Design concepts for low-cost composite turbofan engine frame

    NASA Technical Reports Server (NTRS)

    Mitchell, S. C.; Stoffer, L. J.

    1980-01-01

    Design concepts for low cost, lightweight composite engine frames were applied to the design requirements for the frame of a commercial, high bypass engine. Four alternative composite frame design concepts identified which consisted of generic type components and subcomponents that could be adapted to use in different locations in the engine and the different engine sizes. A variety of materials and manufacturing methods were projected with a goal for the lowest number of parts at the lowest possible cost. After a preliminary evaluation of all four frame concepts, two designs were selected for an extended design and evaluation which narrowed the final selection down to one frame that was significantly lower in cost and slighty lighter than the other frame. An implementation plan for this lowest cost frame is projected for future development and includes prospects for reducing its weight with proposed unproven, innovative fabrication techniques.

  10. Design concepts for low cost composite engine frames

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1983-01-01

    Design concepts for low-cost, lightweight composite engine frames were applied to the design requirements for the frame of commercial, high-bypass turbine engines. The concepts consist of generic-type components and subcomponents that could be adapted for use in different locations in the engine and to different engine sizes. A variety of materials and manufacturing methods were assessed with a goal of having the lowest number of parts possible at the lowest possible cost. The evaluation of the design concepts resulted in the identification of a hybrid composite frame which would weigh about 70 percent of the state-of-the-art metal frame and cost would be about 60 percent.

  11. Composite propellant tank study for very low cost space transportation

    NASA Technical Reports Server (NTRS)

    Moser, D. J.; Keith, E. L.

    1992-01-01

    A study of life-cycle cost is conducted to determine acceptable options for composite propellant tanks at low cost and weight and for use at moderate pressures. The review examines all cost issues relevant to the production, mass, applications, and reliability of the tanks for pressure-fed rockets. Specific attention is given to the manufacturing and life-cycle issues relevant to the use of composite materials in this application since composites are effective materials for liquid propellant tanks. Specific costs and parametric considerations are given for several tank candidates with 62,303-lb capacities. The mass sensitivity of the fourth stage for the concept vehicle is shown to be high, and the use of a 325-psi fourth-stage tank is shown to yield the minimum cost/lb for the stage. Wound S-glass/epoxy composites can be employed as cost-effective replacements for steel in the design of liquid-propellant tanks.

  12. Design concepts for low-cost composite engine frames

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1983-01-01

    Design concepts for low-cost, lightweight composite engine frames were applied to the design requirements for the frame of commercial, high-bypass turbine engines. The concepts consist of generic-type components and subcomponents that could be adapted for use in different locations in the engine and to different engine sizes. A variety of materials and manufacturing methods were assessed with a goal of having the lowest number of parts possible at the lowest possible cost. The evaluation of the design concepts resulted in the identification of a hybrid composite frame which would weigh about 70 percent of the state-of-the-art metal frame and cost would be about 60 percent.

  13. Low-Cost Manufacturing of High- Temperature Polymer Composites

    NASA Technical Reports Server (NTRS)

    Sutter, James K.

    1998-01-01

    Major goals of NASA and the Integrated High Performance Turbine Engine Technology (IHPTET) initiative include improvements in the affordability of propulsion systems, significant increases in the thrust/weight ratio, and increases in the temperature capability of components of gas turbine engines. Members of NASA Lewis Research Center's HITEMP project worked cooperatively with Allison Advanced Development Corporation to develop a manufacturing method to produce low-cost components for gas turbine engines. Affordability for these polymer composites is defined by the savings in acquisition and life-cycle costs associated with engine weight reduction. To lower engine component costs, the Lewis/Allison team focused on chopped graphite fiber/polyimide resin composites. The high-temperature polyimide resin chosen, PMR-II-50, was developed at NASA Lewis.

  14. A Low Cost Grism Spectrometer for Small Telescopes

    NASA Astrophysics Data System (ADS)

    Ludovici, Dominic

    2016-06-01

    We have designed and built a low cost (appx. $500) low resolution (R ~ 300) grating-prism (grism) spectrometer for the University of Iowa's robotic observatory. Grism spectrometers differ from simple transmission grating systems by partially compensating for the curved focal plane using a wedge prism. The spectrometer has five optical elements, and was designed using a ray tracing program. The collimating and focusing optics are easily modified for other telescope optics. The optics are mounted in an enclosure made with a 3-d printer. The spectrometer was installed in a modified (extended) filter wheel and has been in routine operation since January 2016. I will show sample spectra using this system and discuss spectral calibration, and optical design considerations for other telescopes. I will also discuss how low-resolution spectrometers can be used in undergraduate teaching laboratories.

  15. Synthesis of CZTS Nanoparticles for Low-Cost Solar Cells.

    PubMed

    Kim, Donguk; Kim, Minha; Shim, Joongpyo; Kim, Doyoung; Choi, Wonseok; Park, Yong Seob; Choi, Youngkwan; Lee, Jaehyeong

    2016-05-01

    In this work, uniformly sized Cu2ZnSnS4 (CZTS) nanoparticles with easy control of chemical composition were synthesized and printable ink containing CZTS nanoparticles was prepared for low-cost-solar cell applications. In addition, we studied the effects of synthesis conditions, such as reaction temperature and time, on properties of the CZTS nanoparticles. For CZTS nanoparticles synthesis process, the reactants were mixed as the 2:1:1:4 molar ratios. The reaction temperature and time was varied from 220 degrees C to 320 degrees C and from 3 hours to 5 hours, respectively. The crystal structure and morphology of CZTS nanoparticles prepared under the various conditions were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), and energy dispersive X-ray spectroscopy (EDS) was used for compositional analysis of the CZTS nanoparticles. PMID:27483876

  16. Fabrication of low cost cutting wheel via thermal spray process

    NASA Astrophysics Data System (ADS)

    Anasyida, A. S.; Nurulakmal, M. S.

    2012-09-01

    The present study is mainly focused on development of metal cutting wheel. The process involved hard particles (abrasives) being bonded on the wheel to enhance the cutting capability by thermal spraying process and followed by polymer bonding. The purpose of this work is to produce low cost cutting wheel and study the performance of cutting behavior. Two different types of powders; silicon carbide (SiC) as bonding agent and chromium carbide (Cr3C2) as abrasives were used. Wear loss and depth of cut as function of load, cutting time and cutting speed were evaluated. The results showed that the speed and load were the main factors that affected the cutting efficiency and the optimum cutting process can be performed at low cutting speed and high load or at high cutting speed and low load.

  17. Low-cost cell-phone-based digital lux meter

    NASA Astrophysics Data System (ADS)

    Sumriddetchkajorn, Sarun; Somboonkaew, Armote

    2010-11-01

    The amount of light is an important issue in several scenarios ranging from scenic design, light pollution study, illumination engineering, and agriculture. It is typically determined by using a portable digital light or lux meter. By realizing that the proliferation of cell phones is currently tremendous, this paper proposes for the first time a low-cost cell phone based digital light meter. Our innovative idea comes from the fact that the digital camera built into the cell phone is functioned as a two-dimensional light sensitive device and the captured image can be made diffuse. In this way, the diffused image is correlated to the corresponding light level by the built-in microprocessor of the cell phone and our specific algorithm embedded. Our experiment using a typical cell phone embedded with a digital camera and our JAVA program will be discussed.

  18. A simple low-cost single-crystal NMR setup.

    PubMed

    Vinding, Mads S; Kessler, Tommy O; Vosegaard, Thomas

    2016-08-01

    A low-cost single-crystal NMR kit is presented along with a web-based post-processing software. The kit consists of a piezo-crystal motor and a goniometer for the crystal, both embedded in a standard wide-bore NMR probe with a 3D printed scaffold. The NMR pulse program controls the angle setting automatically, and the post-processing software incorporates a range of orientation-angle discrepancies present in the kit and other single-crystal setups. Results with a NaNO3 single-crystal show a high degree of reproducibility and excellent agreement with previous findings for the anisotropic quadrupolar interaction. PMID:27295612

  19. Development of a low-cost heat storage furnace

    SciTech Connect

    Lentz, E. )

    1987-01-01

    The author describes the development of a low cost central electric heat storage furnace for residential use in the USA. The heat storage furnace design uses crushed trap rock, a basaltic rock found throughout the USA. Residential furnaces were built and successfully tested both under laboratory conditions and in residences from Minnesota to New England. Although the furnace was developed for residential space heating, applications for commercial and industrial heating are under consideration. Heat storage using off-peak electricity is used as a load management tool in several ways. The specific application considered in this paper is space heating with warm air. In this application, the furnace converts off-peak electric power to heat and stores it for space heating during non-peak periods on a daily cycle basis.

  20. Comprehensive low-cost reliability centered maintenance. Final report

    SciTech Connect

    Rotton, S.J.; Dozier, I.J.; Thow, R.

    1995-09-01

    Reliability Centered Maintenance (RCM) is a maintenance optimization approach that all electric utilities can apply to power plant systems. The Electric Power Research Institute and PECO Energy Company jointly sponsored this Comprehensive Low-Cost Reliability Centered Maintenance project to demonstrate that the standard RCM methodology could be streamlined to reduce the cost of analysis while maintaining a high quality product. EPRI`s previous investigation of streamlined RCM methods being pioneered in the nuclear industry indicated that PECO Energy could expect to optimize its maintenance program at reduced cost by carefully controlling the scope without sacrificing documentation or technical quality. Using the insights obtained from these previous studies, three methods were defined in this project and were demonstrated in a large scale application to 60 systems at both the Limerick Generating Station and the Peach Bottom Atomic Power Station.

  1. Investigations on novel low-cost graphite composite bipolar plates

    NASA Astrophysics Data System (ADS)

    Scholta, J.; Rohland, B.; Trapp, V.; Focken, U.

    PEM fuel cells are viewed as one of the most environmentally friendly propulsion systems for automotive travel in the future. The PEM fuel cell is still too expensive for wide-spread commercialization. To achieve this cost target and at the same time meeting several technical requirements for mass production, a novel type of low-cost bipolar plates has been developed by SGL Technik GmbH. In this paper, test results of novel SGL bipolar plate materials concerning electrical conductivity (including material resistivity and contact resistances), corrosion, chemical compatibility, gas tightness and mechanical strength are presented. Based on the measurements of resistivity and cell performance, the investigated material appears to be a good choice for stable high performance PEMFC bipolar plates.

  2. Development of a low cost potentiostat using ATXMEGA32

    NASA Astrophysics Data System (ADS)

    Muid, Abdul; Djamal, Mitra; Wirawan, Rahadi

    2014-03-01

    Potentiostat is principal devices in modern electrochemical research especially in the investigation of mechanism reaction which associated with the redox chemistry reaction and other chemical phenomena. Several applications measurement is developed based on this tool such as measurement of sample concentrations, quality test of food and medicine, environmental monitoring and biosensors or development of a protein sensor. We have developed a low cost, simple and portable potentiostat with a relatively small dimension. TLC2264 op-amp and ATMEGA32 microcontroller is used to build controller circuit system. Range potential measurement of this tool is between -1600mV and +1600mV within frequency range 1Hz - 1 kHz. The developed instrument has been tested for measuring samples using different voltammetry techniques, like cyclic, square wave, and linear sweep with relative error under 2.5%.

  3. Low-cost directionally-solidified turbine blades, volume 1

    NASA Technical Reports Server (NTRS)

    Sink, L. W.; Hoppin, G. S., III; Fujii, M.

    1979-01-01

    A low cost process of manufacturing high stress rupture strength directionally-solidified high pressure turbine blades was successfully developed for the TFE731-3 Turbofan Engine. The basic processing parameters were established using MAR-M 247 and employing the exothermic directional-solidification process in trial castings of turbine blades. Nickel-based alloys were evaluated as directionally-solidified cast blades. A new turbine blade, disk, and associated components were then designed using previously determined material properties. Engine tests were run and the results were analyzed and compared to the originally established goals. The results showed that the stress rupture strength of exothermically heated, directionally-solidified MAR-M 247 turbine blades exceeded program objectives and that the performance and cost reduction goals were achieved.

  4. Low-cost DH and quantum well laser array development

    NASA Technical Reports Server (NTRS)

    Linden, Kurt J.; Geoffroy, Leo M.; Pesarcik, Scott F.; Magee, Carl J.

    1989-01-01

    The intial results of a program aimed at developing low-cost diode laser arrays for use as solid-state laser pumps are reported. MOCVD is used to demonstrate excellent run-to-run reproducibility in emission wavelength, threshold current density, and quantum efficiency. For this first experimental series, J(th) values of approximately 1310 Amps/sq cm were obtained for broad-area unthinned devices from the growth runs. Differential quantum efficiencies of between 41 percent and 47 percent were measured on the non-facet-coated devices from all four runs. Single quantum well, separate confinement heterostructure lasers fabricated from wafers grown in the same MOCVD reactor exhibited near single-mode emission, with J(th) values of approximately 300 Amps/sq cm. Photoluminescence data confirm quantum well widths of 80 A and 150 A for two different MOCVD growth runs.

  5. Arduino: a low-cost multipurpose lab equipment.

    PubMed

    D'Ausilio, Alessandro

    2012-06-01

    Typical experiments in psychological and neurophysiological settings often require the accurate control of multiple input and output signals. These signals are often generated or recorded via computer software and/or external dedicated hardware. Dedicated hardware is usually very expensive and requires additional software to control its behavior. In the present article, I present some accuracy tests on a low-cost and open-source I/O board (Arduino family) that may be useful in many lab environments. One of the strengths of Arduinos is the possibility they afford to load the experimental script on the board's memory and let it run without interfacing with computers or external software, thus granting complete independence, portability, and accuracy. Furthermore, a large community has arisen around the Arduino idea and offers many hardware add-ons and hundreds of free scripts for different projects. Accuracy tests show that Arduino boards may be an inexpensive tool for many psychological and neurophysiological labs. PMID:22037977

  6. Low cost point focus solar concentrator, phase 1

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Design concepts and plans for mass-production facilities and equipment, field installation, and maintenance were developed and used for cost analysis of a pneumatically stabilized plastic film point focus solar concentrator which has potential application in conjunction with Brayton cycle engines or supply of thermal energy. A sub-scale reflector was fabricated and optically tested by laser ray tracing to determine focal deviations of the surface slope and best focal plane. These test data were then used for comparisons with theoretical concentrator performance modeling and predictions of full-scale design performance. Results of the economic study indicate the concentrator design will have low cost when mass-produced and has cost/performance parameters that fall within current Jet Propulsion Laboratory goals.

  7. Low-cost interferometric TDM technology for dynamic sensing applications

    NASA Astrophysics Data System (ADS)

    Bush, Jeff; Cekorich, Allen

    2004-12-01

    A low-cost design approach for Time Division Multiplexed (TDM) fiber-optic interferometric interrogation of multi-channel sensor arrays is presented. This paper describes the evolutionary design process of the subject design. First, the requisite elements of interferometric interrogation are defined for a single channel sensor. The concept is then extended to multi-channel sensor interrogation implementing a TDM multiplex scheme where "traditional" design elements are utilized. The cost of the traditional TDM interrogator is investigated and concluded to be too high for entry into many markets. A new design approach is presented which significantly reduces the cost for TDM interrogation. This new approach, in accordance with the cost objectives, shows promise to bring this technology to within the threshold of commercial acceptance for a wide range of distributed fiber sensing applications.

  8. Low cost composite structures for superconducting magnetic energy storage systems

    SciTech Connect

    Rix, C. ); McColskey, D. ); Acree, R. )

    1994-07-01

    As part of the Superconducting Magnetic Energy Storage/Engineering Test Model (SMES-ETM) programs, design, analysis, fabrication and test programs were conducted to evaluate the low cost manufacturing of Fiberglass Reinforced Plastic (FRP) beams for usage as major components of the structural and electrical insulation systems. These studies utilized pultrusion process technologies and vinylester resins to produce large net sections at costs significantly below that of conventional materials. Demonstration articles incorporating laminate architectures and design details representative of SMES-ETM components were fabricated using the pultrusion process and epoxy, vinylester, and polyester resin systems. The mechanical and thermal properties of these articles were measured over the temperature range from 4 K to 300 K. The results of these tests showed that the pultruded, vinylester components have properties comparable to those of currently used materials, such as G-10, and are capable of meeting the design requirements for the SMES-ETM system.

  9. Low cost composite structures for superconducting magnetic energy storage systems

    NASA Astrophysics Data System (ADS)

    Rix, Craig; McColskey, David; Acree, Robert

    1994-07-01

    As part of the Superconducting Magnetic Energy Storage/Engineering Test Model (SMES-ETM) program, design, analysis, fabrication and test programs were conducted to evaluate the low cost manufacturing of Fiberglass Reinforced Plastic (FRP) beams for usage as major components of the structural and electrical insulation systems. These studies utilized pultrusion process technologies and vinylester resins to produce large net sections at costs significantly below that of conventional materials. Demonstration articles incorporating laminate architectures and design details representative of SMES-ETM components were fabricated using the pultrusion process and epoxy, vinylester, and polyester resin systems. The mechanical and thermal properties of these articles were measured over the temperature range from 4 K to 300 K. The results of these tests showed that the pultruded, vinylester components have properties comparable to those of currently used materials, such as G-10, and are capable of meeting the design requirements for the SMES-ETM system.

  10. Low cost flatbed scanner label-free biosensor

    NASA Astrophysics Data System (ADS)

    Aygun, Ugur; Avci, Oguzhan; Seymour, Elif; Sevenler, Derin D.; Urey, Hakan; Ünlü, M. Selim; Ozkumur, Ayca Yalcin

    2016-03-01

    In this paper, we demonstrate utilization of a commercial flatbed document scanner as a label-free biosensor for highthroughput imaging of DNA and protein microarrays. We implemented an interferometric sensing technique through use of a silicon/oxide layered substrate, and easy to implement hardware modifications such as re-aligning moving parts and inserting a custom made sample plate. With a cost as low as 100USD, powered by a USB cable, and scan speed of 30 seconds for a 4mm x 4 mm area with ~10μm lateral resolution, the presented system offers a super low cost, easy to use alternative to commercially available label-free systems.

  11. Fast, Dense Low Cost Scintillator for Nuclear Physics

    SciTech Connect

    Woody, Craig

    2009-07-31

    We have studied the morphology, transparency, and optical properties of SrHfO{sub 3}:Ce ceramics. Ceramics can be made transparent by carefully controlling the stoichiometry of the precursor powders. When fully dense, transparent samples can be obtained. Ceramics with a composition close to stoichiometry (Sr:Hf ~ 1) appear to show good transparency and a reasonable light yield several times that of BGO. The contact and distance transparency of ceramics hot-pressed at about 1450ºC is very good, but deteriorates at increasingly higher hot-press temperatures. If these ceramics can be produced in large quantities and sizes, at low cost, they may be of considerable interest for PET and CT.

  12. Low-Cost, Large C-SiC Blisk Fabrication

    NASA Technical Reports Server (NTRS)

    Kowbel, W.; Effinger, M.

    2008-01-01

    C-SiC composites offer unique properties for propulsion applications. However, fabrication of low-cost, thick, large scale C-SiC disk for integrally bladed disk (blisk) applications has not been established yet. MER has demonstrated a new process to address this issue. Polymer-based processing was employed for interfacial coatings, consolidation and densification. Up to 40" O.C., 2" thick C-SiC composite processing was established, yielding in excess of 1.8 g/cu cm density. Computer tomography (CT) scans on the 40" O.D., 2" thick C-SiC disk showed no visible delamination, and good density uniformity. Stress-rupture testing in air was conducted at 2200 F, 2400 F and 2550 F.

  13. Low cost bare-plate solar air collector

    SciTech Connect

    Maag, W.L.; Wenzler, C.J.; Rom, F.E.; VanArsdale, D.R.

    1980-09-01

    The purpose of this project was to develop a low cost, bare-plate collector, determine its performance for a variety of climatic conditions, analyze the economics of this type of solar collector and evaluate specific applications. Two prototype collectors were designed, fabricated and installed into an instrumented test system. Tests were conducted for a period of five months. Results of the tests showed consistent operating efficiencies of 60% or greater with air preheat temperature uses up to 20/sup 0/F for one of the prototypes. The economic analyses indicated that an installed cost of between $5 and $10 per square foot would make this type of solar system economically viable. For the materials of construction and the type of fabrication and installation perceived, these costs for the bare-plate solar collector are believed to be attainable. Specific applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

  14. Low cost solar array project 1: Silicon material

    NASA Technical Reports Server (NTRS)

    Jewett, D. N.; Bates, H. E.; Hill, D. M.

    1980-01-01

    The low cost production of silicon by deposition of silicon from a hydrogen/chlorosilane mixture is described. Reactor design, reaction vessel support systems (physical support, power control and heaters, and temperature monitoring systems) and operation of the system are reviewed. Testing of four silicon deposition reactors is described, and test data and consequently derived data are given. An 18% conversion of trichlorosilane to silicon was achieved, but average conversion rates were lower than predicted due to incomplete removal of byproduct gases for recycling and silicon oxide/silicon polymer plugging of the gas outlet. Increasing the number of baffles inside the reaction vessel improved the conversion rate. Plans for further design and process improvements to correct the problems encountered are outlined.

  15. Small, low cost, expendable turbojet engine. 2: Performance characteristics

    NASA Technical Reports Server (NTRS)

    Dengler, R. P.; Macioce, L. E.

    1976-01-01

    A small experimental axial-flow turbojet engine was tested at sea level static conditions and over a range of simulated flight conditions to evaluate its performance as well as to demonstrate the feasibility of low-cost concepts utilized in its design. Testing was conducted at engine speeds as high as 37,000 rpm and at turbine inlet temperatures as high as 1,272 K. For maximum speed the engine produced a net thrust of 3,118 newtons at sea level static operation and 2,318 newtons at its cruise condition of M0 = 0.8 and 6,096 meters. Data obtained over a range of inlet Reynolds number indexes for nominal M0 of 0.38 revealed similar effects or trends on compressor characteristics of those previously established for much larger engines.

  16. 4273π: Bioinformatics education on low cost ARM hardware

    PubMed Central

    2013-01-01

    Background Teaching bioinformatics at universities is complicated by typical computer classroom settings. As well as running software locally and online, students should gain experience of systems administration. For a future career in biology or bioinformatics, the installation of software is a useful skill. We propose that this may be taught by running the course on GNU/Linux running on inexpensive Raspberry Pi computer hardware, for which students may be granted full administrator access. Results We release 4273π, an operating system image for Raspberry Pi based on Raspbian Linux. This includes minor customisations for classroom use and includes our Open Access bioinformatics course, 4273π Bioinformatics for Biologists. This is based on the final-year undergraduate module BL4273, run on Raspberry Pi computers at the University of St Andrews, Semester 1, academic year 2012–2013. Conclusions 4273π is a means to teach bioinformatics, including systems administration tasks, to undergraduates at low cost. PMID:23937194

  17. Sensor Integration in a Low Cost Land Mobile Mapping System

    PubMed Central

    Madeira, Sergio; Gonçalves, José A.; Bastos, Luísa

    2012-01-01

    Mobile mapping is a multidisciplinary technique which requires several dedicated equipment, calibration procedures that must be as rigorous as possible, time synchronization of all acquired data and software for data processing and extraction of additional information. To decrease the cost and complexity of Mobile Mapping Systems (MMS), the use of less expensive sensors and the simplification of procedures for calibration and data acquisition are mandatory features. This article refers to the use of MMS technology, focusing on the main aspects that need to be addressed to guarantee proper data acquisition and describing the way those aspects were handled in a terrestrial MMS developed at the University of Porto. In this case the main aim was to implement a low cost system while maintaining good quality standards of the acquired georeferenced information. The results discussed here show that this goal has been achieved. PMID:22736985

  18. MESA - A new approach to low cost scientific spacecraft

    NASA Astrophysics Data System (ADS)

    Keyes, G. W.; Case, C. M.

    1982-09-01

    Today, the greatest obstacle to science and exploration in space is its cost. The present investigation is concerned with approaches for reducing this cost. Trends in the scientific spacecraft market are examined, and a description is presented for the MESA space platform concept. The cost drivers are considered, taking into account planning, technical aspects, and business factors. It is pointed out that the primary function of the MESA concept is to provide a satellite system at the lowest possible price. In order to reach this goal an attempt is made to benefit from all of the considered cost drivers. It is to be tried to work with the customer early in the mission analysis stage in order to assist in finding the right compromise between mission cost and return. A three phase contractual arrangement is recommended for MESA platforms. The phases are related to mission feasibility, specification definition, and design and development. Modular kit design promotes flexibility at low cost.

  19. Low cost pavement marking materials based on plasticized sulfur

    NASA Astrophysics Data System (ADS)

    Dale, J. M.

    1982-04-01

    Pavement marking was made more cost effective by reducing the cost of the marking materials. A low cost marking material based on sulfur was developed. Elemental sulfur is a hard, brittle, crystalline material which, on heating, melts to a thin liquid that can be spray applied. If molten elemental sulfur is spray applied to the road as markings, it will on application solidify, crack and adhere poorly to the road. The first ten high speed trucks that ride over the markings will remove them. To make a useful sulfur based pavement marking material it was necessary to chemically modify (plasticize) the sulfur and mix it with fillers and pigments such that it had all of the characteristics desired of a pavement marking material. Yellow and white formulations were developed. For identification they were given the names YS-EIGHT and WS-EIGHT for the yellow and white formulations.

  20. Low-cost inertial navigation for moderate-g missions

    NASA Technical Reports Server (NTRS)

    Merhav, S.

    1979-01-01

    A low cost inertial navigation system (INS) concept is described for flight missions characterized by moderate accelerations and limited attitude variations. These missions involve general aviation aircraft, helicopters, or remotely piloted vehicles. The significance of the moderate acceleration and limited attitude is reviewed with respect to platform mechanization and instrumentation. A hybrid mechanization, partially gimballed and partially strapdown, is presented. The INS is implemented by an unbalanced two axis gimbal system and controlled by a two degree of freedom gyro. The INS provides locally level two axis acceleration information along with pitch and roll measurements. Heading information is provided by a second gyro mounted in the inner gimbal. The system error model is equivalent to that of a conventional platform with a tilt error determined by the integral of the gyro drift rate and an equivalent accelerometer type errors are also cancelled. Rapid gyro-compassing, implemented with opened gimbal control loops, and a strapdown procedure provides calibration of gyro drift rate biases.

  1. UV-LED exposure system for low-cost photolithography

    NASA Astrophysics Data System (ADS)

    Yapici, Murat Kaya; Farhat, Ilyas

    2014-03-01

    This paper reports the development of a low-cost, portable, light-emitting diode (LED)-based UV exposure system for photolithography. The major system components include UV-LEDs, microcontroller, digital-to-analog (D/A) converter and LED control circuitry. The UV-LED lithography system is also equipped with a digital user interface (LCD and keypad) and permits accurate electronic control on the exposure time and power. Hence the exposure dose can be varied depending on process requirements. Compared to traditional contact lithography, the UV-LED lithography system is significantly cheaper, simple to construct using off-the shelf components and does not require complex infrastructure to operate. Such reduction in system cost and complexity renders UV-LED lithography as a perfect candidate for micro lithography with large process windows typically suitable for MEMS, microfluidics applications.

  2. Low-cost packaging of high-performance optoelectronic components

    SciTech Connect

    Lowry, M.; Lu, Shin-Yee; Pocha, M.; Strand, O.T.

    1994-08-01

    Optoelectronic component costs are often dominated by the costs of attaching fiber optic pigtails--especially for the case of single transverse mode devices. We present early results of our program in low-cost packaging. We are employing machine-vision controlled automated positioning and silicon microbench technology to reduce the costs of optoelectronic components. Our machine vision approach to automated positioning has already attained a positional accuracy of less than 5 microns in less than 5 minutes; accuracies and times are expected to improve significantly as the development progresses. Complementing the machine vision assembly is our manufacturable approach to silicon microbench technology. We will describe our silicon microbench optoelectronic device packages that incorporate built-in heaters for solder bonding reflow.

  3. Low cost lift-off process optimization for MEMS applications

    NASA Astrophysics Data System (ADS)

    Pandey, Shilpi; Bansal, Deepak; Panwar, Deepak; Shukla, Neha; Kumar, Arvind; Kothari, Prateek; Verma, Seema; Rangra, K. J.

    2016-04-01

    The patterning of thin films play major role in the performance of MEMS devices. The wet etching gives an isotropic profile and etch rate depends on the temperature, size of the microstructures and repetitive use of the solution. Even with the use of selective etchants, it significantly attacks the underlying layer. On the other side, dry etching is expensive process. In this paper, double layer of photoresist is optimized for lift-off process. Double layer lift-off technique offers process simplicity, low cost, over conventional single layer lift-off or bilayer lift-off with LOR. The problem of retention and flagging is resolved. The thickness of double coat photoresist is increased by 2.3 times to single coat photo resist.

  4. Combining advanced imaging processing and low cost remote imaging capabilities

    NASA Astrophysics Data System (ADS)

    Rohrer, Matthew J.; McQuiddy, Brian

    2008-04-01

    Target images are very important for evaluating the situation when Unattended Ground Sensors (UGS) are deployed. These images add a significant amount of information to determine the difference between hostile and non-hostile activities, the number of targets in an area, the difference between animals and people, the movement dynamics of targets, and when specific activities of interest are taking place. The imaging capabilities of UGS systems need to provide only target activity and not images without targets in the field of view. The current UGS remote imaging systems are not optimized for target processing and are not low cost. McQ describes in this paper an architectural and technologic approach for significantly improving the processing of images to provide target information while reducing the cost of the intelligent remote imaging capability.

  5. A Large Lunar Surface Testbed from Low Cost Material

    NASA Technical Reports Server (NTRS)

    Rickman, Douglas

    2014-01-01

    For users needing to simulate the lunar surface, several distinct avenues have been used. Numerous volcanic areas, including Hawaii, have been used. While providing very large areas and scenic interest, field parties to such an area is expensive and limits testing time. An alternative is to build test facilities locally. This has been done many ways, contrast GRC-1, GSC-1, BP-1 and the KSC Morpheus facility [1-4]. GRC-1 is a mixture of sand and clay; GSC-1 and BP-1 are waste materials created in the process of crushing basaltic rock. The Morpheus field used salvaged concrete and crushed quartz rock [5]. Here I report about a 30 m X 30 m test area at MSFC which was both low cost and relatively high fidelity [6].

  6. Low Cost Night Vision System for Intruder Detection

    NASA Astrophysics Data System (ADS)

    Ng, Liang S.; Yusoff, Wan Azhar Wan; R, Dhinesh; Sak, J. S.

    2016-02-01

    The growth in production of Android devices has resulted in greater functionalities as well as lower costs. This has made previously more expensive systems such as night vision affordable for more businesses and end users. We designed and implemented robust and low cost night vision systems based on red-green-blue (RGB) colour histogram for a static camera as well as a camera on an unmanned aerial vehicle (UAV), using OpenCV library on Intel compatible notebook computers, running Ubuntu Linux operating system, with less than 8GB of RAM. They were tested against human intruders under low light conditions (indoor, outdoor, night time) and were shown to have successfully detected the intruders.

  7. Glass for low-cost photovoltaic solar arrays

    NASA Technical Reports Server (NTRS)

    Bouquet, F. L.

    1980-01-01

    Various aspects of glass encapsulation that are important for the designer of photovoltaic systems are discussed. Candidate glasses and available information defining the state of the art of glass encapsulation materials and processes for automated, high volume production of terrestrial photovoltaic devices and related applications are presented. The criteria for consideration of the glass encapsulation systems were based on the low-cost solar array project goals for arrays: (1) a low degradation rate, (2) high reliability, (3) an efficiency greater than 10 percent, (4) a total array price less than $500/kW, and (5) a production capacity of 500,000 kW/yr. The glass design areas discussed include the types of glass, sources and costs, physical properties, and glass modifications, such as antireflection coatings.

  8. Low-cost EEG-based sleep detection.

    PubMed

    Van Hal, Bryan; Rhodes, Samhita; Dunne, Bruce; Bossemeyer, Robert

    2014-01-01

    A real-time stage 1 sleep detection system using a low-cost single dry-sensor EEG headset is described. This device issues an auditory warning at the onset of stage 1 sleep using the "NeuroSky Mindset," an inexpensive commercial entertainment-based headset. The EEG signal is filtered into low/high alpha and low/high beta frequency bands which are analyzed to indicate the onset of sleep. Preliminary results indicate an 81% effective rate of detecting sleep with all failures being false positives of sleep onset. This device was able to predict and respond to the onset of drowsiness preceding stage 1 sleep allowing for earlier warnings with the result of fewer sleep-related accidents. PMID:25571009

  9. Low-cost home experiments and demonstrations in optics

    NASA Astrophysics Data System (ADS)

    Mejías, P. M.; Martínez-Herrero, R.; Serna, J.; Piquero, G.

    2005-10-01

    More than 60 demonstrations and basic experiments in Optics have been compiled. They can be carried out by secondary and university students in the classroom or at home, and have been conceived considering low cost and easy-to-get materials. The goal is to offer didactic resources, showing that Optics can be taught in an attractive and amusing way. The experiments try to stimulate scientific curiosity, and generate interest in the observation of our physical world. The work could be collected as a book, where each demonstration would be contained in one or two pages, including a title, a list of the required materials and a concise explanation about what to do and observe. Associated with the experimental content, we propose a web page, namely, http://www.ucm.es/info/expoptic, that accepts experiments sent by anyone interested in Optics, which can be used as a forum to interchange information on this educational topic.

  10. New low-cost MEMS capacitive pressure sensor concept

    NASA Astrophysics Data System (ADS)

    Wang, Yun; Cheung, Kin P.; Sheng, Kuang; Pai, Chien-Shing

    2005-01-01

    Capacitive pressure sensors based on surface or bulk MEMS technology have many attributes that make them highly desirable for many applications. The biggest technical challenge of capacitive pressure sensor technology is the creation of a reference cavity. It dictates the packaging approach and therefore the cost of the sensor. In this paper we introduce a new design of capacitive pressure sensor that takes advantage of a novel new wafer level packaging technology - A thin-film sealing technology that allows independent pressure control from high vacuum to high pressure. The new technology seals the vacuum cavity formed by standard surface micro machining technology by a brief melting of a metal layer using a pulsed laser. The ability to form reference vacuum cavity without the need for fusing or bonding with another structure allows the design to be simplified, leading to low cost and high yield.

  11. Design of a low-cost bamboo well.

    PubMed

    Shakya, S K; Singh, S R; Anjaneyulu, B; Vashisht, A K

    2009-01-01

    Bamboo wells are an economical alternative for water supply wells in developing countries. The design of the bamboo well described in this article was developed based on field tests. Following field experiments, the screen in the bamboo well was fabricated with seven 3-m-long bamboo strips, each 2 cm wide and 1 cm thick. The strips were bolted on 1-cm-wide mild steel rings spaced 30 cm along the length of the bamboo strips, with 9-cm-long galvanized iron pipe end pieces. Pipes used in the bamboo well were fabricated by wrapping polythene sheets on the bamboo screens. Excellent performance, low cost, and good service life justify the use of a bamboo well for ground water withdrawal in developing countries. PMID:19210565

  12. Simulating low-cost cameras for augmented reality compositing.

    PubMed

    Klein, Georg; Murray, David W

    2010-01-01

    Video see-through Augmented Reality adds computer graphics to the real world in real time by overlaying graphics onto a live video feed. To achieve a realistic integration of the virtual and real imagery, the rendered images should have a similar appearance and quality to those produced by the video camera. This paper describes a compositing method which models the artifacts produced by a small low-cost camera, and adds these effects to an ideal pinhole image produced by conventional rendering methods. We attempt to model and simulate each step of the imaging process, including distortions, chromatic aberrations, blur, Bayer masking, noise, sharpening, and color-space compression, all while requiring only an RGBA image and an estimate of camera velocity as inputs. PMID:20224133

  13. Get away special the low-cost route to orbit

    NASA Technical Reports Server (NTRS)

    Prouty, C.

    1986-01-01

    NASA has established the Get Away Special (GAS) program as a means for providing anyone who wishes the opportunity to place a small self-contained experimental payload aboard a Space Shuttle mission for a very low cost. The GAS program is now well established, and has a respectable history with 53 payloads flown to date. The GAS experimenters are a diverse group who have demonstrated that people from all walks of life, and from many nations, are interested in working in space. This paper traces the history of the program from its concept through the development phase to the present time, and takes a brief look at the future. It also addresses the steps involved in making a payload reservation and the programmatic and technical relationships that are established between NASA and GAS customers.

  14. Demonstration of the Low-Cost Virtual Collaborative Environment (VCE)

    NASA Technical Reports Server (NTRS)

    Bowers, David; Montes, Leticia; Ramos, Angel; Joyce, Brendan; Lumia, Ron

    1997-01-01

    This paper demonstrates the feasibility of a low-cost approach of remotely controlling equipment. Our demonstration system consists of a PC, the PUMA 560 robot with Barrett hand, and commercially available controller and teleconferencing software. The system provides a graphical user interface which allows a user to program equipment tasks and preview motions i.e., simulate the results. Once satisfied that the actions are both safe and accomplish the task, the remote user sends the data over the Internet to the local site for execution on the real equipment. A video link provides visual feedback to the remote sight. This technology lends itself readily to NASA's upcoming Mars expeditions by providing remote simulation and control of equipment.

  15. Low cost open data acquisition system for biomedical applications

    NASA Astrophysics Data System (ADS)

    Zabolotny, Wojciech M.; Laniewski-Wollk, Przemyslaw; Zaworski, Wojciech

    2005-09-01

    In the biomedical applications it is often necessary to collect measurement data from different devices. It is relatively easy, if the devices are equipped with a MIB or Ethernet interface, however often they feature only the asynchronous serial link, and sometimes the measured values are available only as the analog signals. The system presented in the paper is a low cost alternative to commercially available data acquisition systems. The hardware and software architecture of the system is fully open, so it is possible to customize it for particular needs. The presented system offers various possibilities to connect it to the computer based data processing unit - e.g. using the USB or Ethernet ports. Both interfaces allow also to use many such systems in parallel to increase amount of serial and analog inputs. The open source software used in the system makes possible to process the acquired data with standard tools like MATLAB, Scilab or Octave, or with a dedicated, user supplied application.

  16. Mercury content in low cost skin lightening cream products.

    PubMed

    Naser, J; Kirm, I

    2012-04-01

    Skin lightening creams were randomly collected from local markets in Sultanate of Oman for analysis of mercury (II) content. All the products collected were of low cost imported materials from different countries. Cream samples were digested in nitric acid and hydrogen peroxide at elevated temperature using a microwave digester. The mercury content was measured using Flow Injection Atomic Spectroscopy (FIAS)-Mercury Hydride System. Out of forty cream samples analyzed, about one fourth of the samples contained higher levels of mercury which is more than the maximum mercury content of 1 microg/g permitted by the Food and Drug Administration regulation. The mercury level in the analyzed samples is found to be in the range from 0.02 to 25.7 microg/g. Among the analyzed skin lightening cream samples half of the materials did not have any detectable mercury content. PMID:24749377

  17. Low-Cost Peptide Microarrays for Mapping Continuous Antibody Epitopes.

    PubMed

    McBride, Ryan; Head, Steven R; Ordoukhanian, Phillip; Law, Mansun

    2016-01-01

    With the increasing need for understanding antibody specificity in antibody and vaccine research, pepscan assays provide a rapid method for mapping and profiling antibody responses to continuous epitopes. We have developed a relatively low-cost method to generate peptide microarray slides for studying antibody binding. Using a setup of an IntavisAG MultiPep RS peptide synthesizer, a Digilab MicroGrid II 600 microarray printer robot, and an InnoScan 1100 AL scanner, the method allows the interrogation of up to 1536 overlapping, alanine-scanning, and mutant peptides derived from the target antigens. Each peptide is tagged with a polyethylene glycol aminooxy terminus to improve peptide solubility, orientation, and conjugation efficiency to the slide surface. PMID:26490468

  18. A low cost, high performance remotely controlled backhoe/excavator

    SciTech Connect

    Rizzo, J.

    1995-12-31

    This paper addresses a state of the art, low cost, remotely controlled backhoe/excavator system for remediation use at hazardous waste sites. The all weather, all terrain, Remote Dig-It is based on a simple, proven construction platform and incorporates state of the art sensors, control, telemetry and other subsystems derived from advanced underwater remotely operated vehicle systems. The system can be towed to a site without the use of a trailer, manually operated by an on board operator or operated via a fiber optic or optional RF communications link by a remotely positioned operator. A proportional control system is piggy backed onto the standard manual control system. The control system improves manual operation, allows rapid manual/remote mode selection and provides fine manual or remote control of all functions. The system incorporates up to 4 separate video links, acoustic obstacle proximity sensors, and stereo audio pickups and an optional differential GPS navigation. Video system options include electronic panning and tilting within a distortion-corrected wide angle field of view. The backhoe/excavator subsystem has a quick disconnect interface feature which allows its use as a manipulator with a wide variety of end effectors and tools. The Remote Dig-It was developed to respond to the need for a low-cost, effective remediation system for use at sites containing hazardous materials. The prototype system was independently evaluated for this purpose by the Army at the Jefferson Proving Ground where it surpassed all performance goals. At the time of this writing, the Remote Dig-It system is currently the only backhoe/excavator which met the Army`s goals for remediation systems for use at hazardous waste sites and it costs a fraction of any known competing offerings.

  19. Investigation of a low cost method to quantify cosmetic defect.

    PubMed

    Shannon, Thomas; Chockalingam, Nachiappan

    2012-01-01

    For many patients, the motivation in seeking treatment is the improvement of their appearance rather than to correct an underlying skeletal deformity, so cosmetic concerns and the psychosocial impacts of adolescent idiopathic scoliosis are important factors in the clinical decision-making process. In the current environment of evidence based medicine there is a growing need to quantify back surface shape and general body asymmetry with the objective of producing an agreed scoring to be used in developing treatment plans and assessing outcomes but to date many clinics continue to rely on qualitative or expensive methods to describe cosmetic deformity. In November 2010, Microsoft® Corporation launched the low cost Kinect™ camera with 18 million units sold (as at January 2012) throughout the world. The device incorporates proprietary light coding technology that reconstructs the three dimensional location of an estimated 50,000 projected points illuminating objects within its field of view in approximately 1/30th of a second. The aim of the research was to investigate the capabilities of a low cost, reliable and inherently safe apparatus based on Kinect depth sensing and video technology to simultaneously acquire back surface shape and the locations of bony landmarks with the goal of providing data to describe cosmetic defect. Work has been completed using both the apparatus and a commercially available optical motion capture system (Vicon Motion Systems, Oxford, U.K.) to acquire data from a test object representing an unaffected human torso. Results were obtained to compare tri-dimensional bony landmark reconstruction accuracy and combined with analyses of point cloud data to describe back shape. Early indications are that the proposed apparatus has potential to be a clinically useful tool. PMID:22744509

  20. LOW-COST LED LUMINAIRE FOR GENERAL ILLUMINATION

    SciTech Connect

    Lowes, Ted

    2014-07-31

    During this two-year Solid-State Lighting (SSL) Manufacturing R&D project Cree developed novel light emitting diode (LED) technologies contributing to a cost-optimized, efficient LED troffer luminaire platform emitting at ~3500K correlated color temperature (CCT) at a color rendering index (CRI) of >90. To successfully achieve program goals, Cree used a comprehensive approach to address cost reduction of the various optical, thermal and electrical subsystems in the luminaire without impacting performance. These developments built on Cree’s high- brightness, low-cost LED platforms to design a novel LED component architecture that will enable low-cost troffer luminaire designs with high total system efficacy. The project scope included cost reductions to nearly all major troffer subsystems as well as assembly costs. For example, no thermal management components were included in the troffer, owing to the optimized distribution of compact low- to mid-power LEDs. It is estimated that a significant manufacturing cost savings will result relative to Cree’s conventional troffers at the start of the project. A chief project accomplishment was the successful development of a new compact, high-efficacy LED component geometry with a broad far-field intensity distribution and even color point vs. emission angle. After further optimization and testing for production, the Cree XQ series of LEDs resulted. XQ LEDs are currently utilized in Cree’s AR series troffers, and they are being considered for use in other platforms. The XQ lens geometry influenced the independent development of Cree’s XB-E and XB-G high-voltage LEDs, which also have a broad intensity distribution at high efficacy, and are finding wide implementation in Cree’s omnidirectional A-lamps.

  1. Synthesis and characterization of low cost magnetorheological (MR) fluids

    NASA Astrophysics Data System (ADS)

    Sukhwani, V. K.; Hirani, H.

    2007-04-01

    Magnetorheological fluids have great potential for engineering applications due to their variable rheological behavior. These fluids find applications in dampers, brakes, shock absorbers, and engine mounts. However their relatively high cost (approximately US600 per liter) limits their wide usage. Most commonly used magnetic material "Carbonyl iron" cost more than 90% of the MR fluid cost. Therefore for commercial viability of these fluids there is need of alternative economical magnetic material. In the present work synthesis of MR fluid has been attempted with objective to produce low cost MR fluid with high sedimentation stability and greater yield stress. In order to reduce the cost, economical electrolytic Iron powder (US 10 per Kg) has been used. Iron powder of relatively larger size (300 Mesh) has been ball milled to reduce their size to few microns (1 to 10 microns). Three different compositions have been prepared and compared for MR effect produced and stability. All have same base fluid (Synthetic oil) and same magnetic phase i.e. Iron particles but they have different additives. First preparation involves organic additives Polydimethylsiloxane (PDMS) and Stearic acid. Other two preparations involve use of two environmental friendly low-priced green additives guar gum (US 2 per Kg) and xanthan gum (US 12 per Kg) respectively. Magnetic properties of Iron particles have been measured by Vibrating Sample Magnetometer (VSM). Morphology of Iron particles and additives guar gum and xanthan gum has been examined by Scanning Electron Microscopy (SEM) and Particles Size Distribution (PSD) has been determined using Particle size analyzer. Microscopic images of particles, MH plots and stability of synthesized MR fluids have been reported. The prepared low cost MR fluids showed promising performance and can be effectively used for engineering applications demanding controllability in operations.

  2. Low Cost Thin Film Building-Integrated Photovoltaic Systems

    SciTech Connect

    Dr. Subhendu Guha; Dr. Jeff Yang

    2012-05-25

    The goal of the program is to develop 'LOW COST THIN FILM BUILDING-INTEGRATED PV SYSTEMS'. Major focus was on developing low cost solution for the commercial BIPV and rooftop PV market and meet DOE LCOE goal for the commercial market segment of 9-12 cents/kWh for 2010 and 6-8 cents/kWh for 2015. We achieved the 2010 goal and were on track to achieve the 2015 goal. The program consists of five major tasks: (1) modules; (2) inverters and BOS; (3) systems engineering and integration; (4) deployment; and (5) project management and TPP collaborative activities. We successfully crossed all stage gates and surpassed all milestones. We proudly achieved world record stable efficiencies in small area cells (12.56% for 1cm2) and large area encapsulated modules (11.3% for 800 cm2) using a triple-junction amorphous silicon/nanocrystalline silicon/nanocrystalline silicon structure, confirmed by the National Renewable Energy Laboratory. We collaborated with two inverter companies, Solectria and PV Powered, and significantly reduced inverter cost. We collaborated with three universities (Syracuse University, University of Oregon, and Colorado School of Mines) and National Renewable Energy Laboratory, and improved understanding on nanocrystalline material properties and light trapping techniques. We jointly published 50 technical papers in peer-reviewed journals and International Conference Proceedings. We installed two 75kW roof-top systems, one in Florida and another in New Jersey demonstrating innovative designs. The systems performed satisfactorily meeting/exceeding estimated kWh/kW performance. The 50/50 cost shared program was a great success and received excellent comments from DOE Manager and Technical Monitor in the Final Review.

  3. Low-cost uncooled VOx infrared camera development

    NASA Astrophysics Data System (ADS)

    Li, Chuan; Han, C. J.; Skidmore, George D.; Cook, Grady; Kubala, Kenny; Bates, Robert; Temple, Dorota; Lannon, John; Hilton, Allan; Glukh, Konstantin; Hardy, Busbee

    2013-06-01

    The DRS Tamarisk® 320 camera, introduced in 2011, is a low cost commercial camera based on the 17 µm pixel pitch 320×240 VOx microbolometer technology. A higher resolution 17 µm pixel pitch 640×480 Tamarisk®640 has also been developed and is now in production serving the commercial markets. Recently, under the DARPA sponsored Low Cost Thermal Imager-Manufacturing (LCTI-M) program and internal project, DRS is leading a team of industrial experts from FiveFocal, RTI International and MEMSCAP to develop a small form factor uncooled infrared camera for the military and commercial markets. The objective of the DARPA LCTI-M program is to develop a low SWaP camera (<3.5 cm3 in volume and <500 mW in power consumption) that costs less than US $500 based on a 10,000 units per month production rate. To meet this challenge, DRS is developing several innovative technologies including a small pixel pitch 640×512 VOx uncooled detector, an advanced digital ROIC and low power miniature camera electronics. In addition, DRS and its partners are developing innovative manufacturing processes to reduce production cycle time and costs including wafer scale optic and vacuum packaging manufacturing and a 3-dimensional integrated camera assembly. This paper provides an overview of the DRS Tamarisk® project and LCTI-M related uncooled technology development activities. Highlights of recent progress and challenges will also be discussed. It should be noted that BAE Systems and Raytheon Vision Systems are also participants of the DARPA LCTI-M program.

  4. Using Low Cost Environmental Sensors in Geoscience Education

    NASA Astrophysics Data System (ADS)

    Leeman, J.; Ammon, C. J.; Anandakrishnan, S.

    2014-12-01

    Advances in process technology have drastically reduced the cost of manufacturing almost every type of sensor and micro-controller, putting low-to-mid grade sensor technology in the reach of educators and hobbyists. We demonstrate how a low cost magnetometer and an Arduino micro-controller can be used in education. Students can easily connect the sensor to the Arduino and collect three-component magnetic field data. Experiments can easily be turned into long-term monitoring projects by connecting sensors to the internet and providing an Internet-of-Things interface to store and to display the data in near-real time. Low-cost sensors are generally much noisier than their research grade counterparts, but can still provide an opportunity for students to learn about fundamental concepts such as signal quality, sampling, averaging, and filtering and to gain hands-on, concrete experience with observations. Sensors can be placed at different locations and compared both qualitatively and quantitatively. For example, with an inexpensive magnetometer, students can examine diurnal magnetic field variations and look for magnetic storms. Magnetic field orientation can be calculated and compared to the predicted geomagnetic field orientation at a given location. Data can be stored in simple text files to facilitate analysis with any convenient package. We illustrate the idea using Python notebooks, allowing students to explore the data interactively and to learn the basic principles of programming and reproducible research. Using an Arduino encourages students to interact with open-source data collection hardware and to experiment with ways to quickly, cheaply, and effectively measure the environment. Analysis of these data can lead to a deeper understanding of both geoscience and data processing.

  5. Parametric perfusion imaging based on low-cost ultrasound platform.

    PubMed

    Gu, Xiaolin; Zhong, Hui; Wan, Mingxi; Hu, Xiaowen; Lv, Dan; Shen, Liang; Zhang, Xiaomei

    2010-01-01

    In this study, we attempted to implement parametric perfusion imaging to quantify blood perfusion based on modified low-cost ultrasound platform. A novel ultrasound contrast-specific imaging method called pulse-inversion harmonic sum-squared-differences (PIHSSD) was proposed for improving the sensitivity for detecting contrast agents and the accuracy of parametric perfusion imaging, which combined pulse-inversion harmonic (PIH) with pulse-inversion sum-squared-differences (PISSD) threshold-based decision. PIHSSD method just involved simple operations including addition and multiplication and was easy to realize. The sequences of contrast images without logarithmic compression were used to acquire time intensity curves (TICs) from numerous equal-sized regions-of-interest (ROI) covering the entire image plane. Parametric perfusion images were obtained based on the parameters extracted from the TICs, including peak value (PV), area under curve (AUC), mean transit time (MTT), peak value time (PVT), peak width (PW) and climbing rate (CR). Flow phantom was used for validation and the results suggested that PIHSSD method provided 9.6 to 20.3 dB higher contrast-to-tissue ratio (CTR) than PIH method. The results of the experiments of rabbit kidney also showed that the CTR of PIHSSD images was higher than that of PIH images, and the parametric perfusion images based on PIHSSD method provided more accurate quantification of blood perfusion compared with those based on PIH and PISSD methods. It demonstrated that the parametric perfusion imaging achieved good performance though implemented on low-cost ultrasound platform. (E-mail: mxwan@mail.xjtu.edu.cn). PMID:19931972

  6. THEOS-2 Orbit Design: Formation Flying in Equatorial Orbit and Damage Prevention Technique for the South Atlantic Magnetic Anomaly (SAMA)

    NASA Astrophysics Data System (ADS)

    Pimnoo, Ammarin

    2016-07-01

    Geo-Informatics and Space Technology Development Agency (GISTDA) has initiative THEOS-2 project after the THEOS-1 has been operated for more than 7 years which is over the lifetime already. THEOS-2 project requires not only the development of earth observation satellite(s), but also the development of the area-based decision making solution platform comprising of data, application systems, data processing and production system, IT infrastructure improvement and capacity building through development of satellites, engineering model, and infrastructures capable of supporting research in related fields. The developing satellites in THEOS-2 project are THAICHOTE-2 and THAICHOTE-3. This paper focuses the orbit design of THAICHOTE-2 & 3. It discusses the satellite orbit design for the second and third EOS of Thailand. In this paper, both THAICHOTE will be simulated in an equatorial orbit as a formation flying which will be compared the productive to THAICHOTE-1 (THEOS-1). We also consider a serious issue in equatorial orbit design, namely the issue of the geomagnetic field in the area of the eastern coast of South America, called the South Atlantic Magnetic Anomaly (SAMA). The high-energy particles of SAMA comprise a radiation environment which can travel through THAICHOTE-2 & 3 material and deposit kinetic energy. This process causes atomic displacement or leaves a stream of charged atoms in the incident particles' wake. It can cause damage to the satellite including reduction of power generated by solar arrays, failure of sensitive electronics, increased background noise in sensors, and exposure of the satellite devices to radiation. This paper demonstrates the loss of ionizing radiation damage and presents a technique to prevent damage from high-energy particles in the SAMA.

  7. Low Cost Surveying Using AN Unmanned Aerial Vehicle

    NASA Astrophysics Data System (ADS)

    Pérez, M.; Agüera, F.; Carvajal, F.

    2013-08-01

    Traditional manned airborne surveys are usually expensive and the resolution of the acquired images is often limited. The main advantage of Unmanned Aerial Vehicle (UAV) system acting as a photogrammetric sensor platform over more traditional manned airborne system is the high flexibility that allows image acquisition from unconventional viewpoints, the low cost in comparison with classical aerial photogrammetry and the high resolution images obtained. Nowadays there is a necessity for surveying small areas and in these cases, it is not economical the use of normal large format aerial or metric cameras to acquire aerial photos, therefore, the use of UAV platforms can be very suitable. Also the large availability of digital cameras has strongly enhanced the capabilities of UAVs. The use of digital non metric cameras together with the UAV could be used for multiple applications such as aerial surveys, GIS, wildfire mapping, stability of landslides, crop monitoring, etc. The aim of this work was to develop a low cost and accurate methodology in the production of orthophotos and Digital Elevation Models (DEM). The study was conducted in the province of Almeria, south of Spain. The photogrammetric flight had an altitude of 50 m over ground, covering an area of 5.000 m2 approximately. The UAV used in this work was the md4-200, which is an electronic battery powered quadrocopter UAV developed by Microdrones GmbH, Germany. It had on-board a Pextax Optio A40 digital non metric camera with 12 Megapixels. It features a 3x optical zoom lens with a focal range covering angles of view equivalent to those of 37-111 mm lens in 35 mm format. The quadrocopter can be programmed to follow a route defined by several waypoints and actions and it has the ability for vertical take off and landing. Proper flight geometry during image acquisition is essential in order to minimize the number of photographs, avoid areas without a good coverage and make the overlaps homogeneous. The flight

  8. AIRQino, a low-cost air quality mobile platform

    NASA Astrophysics Data System (ADS)

    Zaldei, Alessandro; Vagnoli, Carolina; Di Lonardo, Sara; Gioli, Beniamino; Gualtieri, Giovanni; Toscano, Piero; Martelli, Francesca; Matese, Alessandro

    2015-04-01

    Recent air quality regulations (Directive 2008/50/EC) enforce the transition from point-based monitoring networks to new tools that must be capable of mapping and forecasting air quality on the totality of land area, and therefore the totality of citizens. This implies new technologies such as models and additional indicative measurements, are needed in addition to accurate fixed air quality monitoring stations, that until now have been taken as reference by local administrators for the enforcement of various mitigation strategies. However, due to their sporadic spatial distribution, they cannot describe the highly resolved spatial pollutant variations within cities. Integrating additional indicative measurements may provide adequate information on the spatial distribution of the ambient air quality, also allowing for a reduction of the required minimum number of fixed sampling points, whose high cost and complex maintenance still remain a crucial concern for local administrators. New low-cost and small size sensors are becoming available, that could be employed in air quality monitoring including mobile applications. However, accurate assessment of their accuracy and performance both in controlled and real monitoring conditions is crucially needed. Quantifying sensor response is a significant challenge due to the sensitivity to ambient temperature and humidity and the cross-sensitivity to others pollutant species. This study reports the development of an Arduino compatible electronic board (AIRQino) which integrates a series of low-cost metal oxide and NDIR sensors for air quality monitoring, with sensors to measure air temperature, relative humidity, noise, solar radiation and vertical acceleration. A comparative assessment was made for CO2, CO, NO2, CH4, O3, VOCs concentrations, temperature and relative humidity. A controlled climatic chamber study (-80°C / +80°C) was performed to verify temperature and humidity interference using reference gas cylinders and

  9. Development of a Low-Cost Rotary Steerable Drilling System

    SciTech Connect

    Roney Nazarian

    2012-01-31

    The project had the goal to develop and commercialize a low-cost rotary steerable system (LCRSS) capable of operating downhole at conventional pressures and temperatures to reduce operating costs by a minimum of 50% and lost-in-hole charges by at least 50% over the currently offered systems. The LCRSS system developed under this project does reduce operating costs by 55% and lost-in-hole charges by at least 50%. The developed product is not commercializable in its current form. The overall objective was to develop and commercialize a low cost rotary steerable system (LCRSS) capable of operating downhole at conventional pressures and temperatures (20,000 psi/150 C) while reducing the operating costs by 50% and the lost-in-hole charges by 50% over the currently available systems. The proposed reduction in costs were to be realized through the significant reduction in tool complexity, a corresponding increase in tool reliability as expressed in the mean-time between failure (MTBF), and a reduction in the time and costs required to service tools after each field operation. Ultimately, the LCRSS system was to be capable of drilling 7 7/8 in. to 9 5/8 in. borehole diameters. The project was divided into three Phases, of which Phases I & II were previously completed and reported on, and are part of the case file. Therefore, the previously reported information is not repeated herein. Phase III included the fabrication of two field ready prototypes that were to be subjected to a series of drilling tests at GTI Catoosa, DOE RMOTC, and at customer partnering wells, if possible, as appropriate in the timing of the field test objectives to fully exercise all elements of the LCRSS. These tests were conducted in an iterative process based on a performance/reliability improvement cycle with the goal of demonstrating the system met all aspects required for commercial viability. These tests were conducted to achieve continuous runs of 100+ hours with well trajectories that fully

  10. Orbital Observatory for Planetary Science on Low Cost Autonomous Platform

    NASA Astrophysics Data System (ADS)

    Tavrov, Alexander; Bisikalo, Dmitry; Vedenkin, Nikolay; Korablev, Oleg; Markov, Alexander; Kiselev, Alexander; Kokorich, Mikhail

    The Space Research Institute of Russian Academy of Science (IKI RAS) and Dauria Aerospace are currently developing the middle class space telescope project aiming to observe Solar system planets by a long term spectroscopy and polarimetry monitoring, as well aiming to extra solar planets (exoplanets) engineering and scientific goals. The spacecraft is scheduled to be launched in 2017. It is planned first to be delivered on board of the ISS by the Progress spacecraft, then it will be released to the desired orbit approx. 550 km by the Progress in the way to its final destination. The “Planetary monitoring” telescope has a 0.6 meter primary mirror diameter Telescope currently includes 5 science instruments: NIR: 1000..4000 nm high-resolution spectrometer with the spectral resolution of R>10000; Visible Field camera with filters wheel; UV-VIS field resolved Fourier spectrometer; UV-VIS spectropolarimeter; Stellar coronagraph linked with a low-resolution spectrometer. The scientific goals of the “Planetary monitoring” telescope are devoted to explore not yet well studied questions on Mars (methane, ozone, dust and clouds, isotope ratio of HDO/H2O), on Venus (UV absorber, night glow, atmosphere dynamics), icy and gaseous Solar system planets, Jovian moons, Lunar exosphere, comets, meteorites. This telescope aims also for engineering development of exoplanet study by stellar coronagraphy linked with a low-resolution spectrometry. This Orbital Observatory mission uses the first low cost small satellite platform developed by the Dauria Aerospace® - Russian private company and reuses the Progress to elevate the observatory orbit. The Progress launches four times per year to provide supplies and scientific instruments to the ISS. The Progress is capable of raising the height of the orbit for the piggyback scientific missions; therefore, the implementation of the Orbital Observatory mission is considered not just as a development of a successful science mission so it

  11. Low-Cost High-Pressure Hydrogen Generator

    SciTech Connect

    Cropley, Cecelia C.; Norman, Timothy J.

    2008-04-02

    Electrolysis of water, particularly in conjunction with renewable energy sources, is potentially a cost-effective and environmentally friendly method of producing hydrogen at dispersed forecourt sites, such as automotive fueling stations. The primary feedstock for an electrolyzer is electricity, which could be produced by renewable sources such as wind or solar that do not produce carbon dioxide or other greenhouse gas emissions. However, state-of-the-art electrolyzer systems are not economically competitive for forecourt hydrogen production due to their high capital and operating costs, particularly the cost of the electricity used by the electrolyzer stack. In this project, Giner Electrochemical Systems, LLC (GES) developed a low cost, high efficiency proton-exchange membrane (PEM) electrolysis system for hydrogen production at moderate pressure (300 to 400 psig). The electrolyzer stack operates at differential pressure, with hydrogen produced at moderate pressure while oxygen is evolved at near-atmospheric pressure, reducing the cost of the water feed and oxygen handling subsystems. The project included basic research on catalysts and membranes to improve the efficiency of the electrolysis reaction as well as development of advanced materials and component fabrication methods to reduce the capital cost of the electrolyzer stack and system. The project culminated in delivery of a prototype electrolyzer module to the National Renewable Energy Laboratory for testing at the National Wind Technology Center. Electrolysis cell efficiency of 72% (based on the lower heating value of hydrogen) was demonstrated using an advanced high-strength membrane developed in this project. This membrane would enable the electrolyzer system to exceed the DOE 2012 efficiency target of 69%. GES significantly reduced the capital cost of a PEM electrolyzer stack through development of low cost components and fabrication methods, including a 60% reduction in stack parts count. Economic

  12. Recovery Act: Low Cost Integrated Substrate for OLED Lighting Development

    SciTech Connect

    Benton, Scott; Bhandari, Abhinav

    2012-12-26

    PPG pursued the development of an integrated substrate, including the anode, external, and internal extraction layers. The objective of PPG's program was to achieve cost reductions by displacing the existing expensive borosilicate or double-side polished float glass substrates and developing alternative electrodes and scalable light extraction layer technologies through focused and short-term applied research. One of the key highlights of the project was proving the feasibility of using PPG's high transmission Solarphire® float glass as a substrate to consistently achieve organic lightemitting diode (OLED) devices with good performance and high yields. Under this program, four low-cost alternatives to the Indium Tin Oxide (ITO) anode were investigated using pilot-scale magnetron sputtered vacuum deposition (MSVD) and chemical vapor deposition (CVD) technologies. The anodes were evaluated by fabricating small and large phosphorescent organic lightemitting diode (PHOLED) devices at Universal Display Corporation (UDC). The device performance and life-times comparable to commercially available ITO anodes were demonstrated. A cost-benefit analysis was performed to down-select two anodes for further low-cost process development. Additionally, PPG developed and evaluated a number of scalable and compatible internal and external extraction layer concepts such as scattering layers on the outside of the glass substrate or between the transparent anode and the glass interface. In one external extraction layer (EEL) approach, sol-gel sprayed pyrolytic coatings were deposited using lab scale equipment by hand or automated spraying of sol-gel solutions on hot glass, followed by optimizing of scattering with minimal absorption. In another EEL approach, PPG tested large-area glass texturing by scratching a glass surface with an abrasive roller and acid etching. Efficacy enhancements of 1.27x were demonstrated using white PHOLED devices for 2.0mm substrates which are at par with

  13. Reliability Assessment for Low-cost Unmanned Aerial Vehicles

    NASA Astrophysics Data System (ADS)

    Freeman, Paul Michael

    Existing low-cost unmanned aerospace systems are unreliable, and engineers must blend reliability analysis with fault-tolerant control in novel ways. This dissertation introduces the University of Minnesota unmanned aerial vehicle flight research platform, a comprehensive simulation and flight test facility for reliability and fault-tolerance research. An industry-standard reliability assessment technique, the failure modes and effects analysis, is performed for an unmanned aircraft. Particular attention is afforded to the control surface and servo-actuation subsystem. Maintaining effector health is essential for safe flight; failures may lead to loss of control incidents. Failure likelihood, severity, and risk are qualitatively assessed for several effector failure modes. Design changes are recommended to improve aircraft reliability based on this analysis. Most notably, the control surfaces are split, providing independent actuation and dual-redundancy. The simulation models for control surface aerodynamic effects are updated to reflect the split surfaces using a first-principles geometric analysis. The failure modes and effects analysis is extended by using a high-fidelity nonlinear aircraft simulation. A trim state discovery is performed to identify the achievable steady, wings-level flight envelope of the healthy and damaged vehicle. Tolerance of elevator actuator failures is studied using familiar tools from linear systems analysis. This analysis reveals significant inherent performance limitations for candidate adaptive/reconfigurable control algorithms used for the vehicle. Moreover, it demonstrates how these tools can be applied in a design feedback loop to make safety-critical unmanned systems more reliable. Control surface impairments that do occur must be quickly and accurately detected. This dissertation also considers fault detection and identification for an unmanned aerial vehicle using model-based and model-free approaches and applies those

  14. The Aluminum Falcon: a Low Cost Modern Commercial Transport

    NASA Technical Reports Server (NTRS)

    Bryant, Mark; Hernandez, Estela; King, Gregory; Lor, Alex Choua; Musser, Jana; Trigs, Deanne; Yee, Susan

    1994-01-01

    The American Institute of Aeronautics and Astronautics (AIAA) released a Request For Proposal (RFP) in the form of an undergraduate design competition for a 153 passenger jet transport with a range of 3,000 nautical miles. The primary requirement for this aircraft was low cost, both in acquisition and operation, with a technology availability date of the year 2000. This report presents the Non-Solo Design Group's response to the RFP, the Aluminum Falcon (AF-1). Non-Solo's approach to development was to take the best elements of seven individual preliminary designs, then combine and refine them. The resulting aircraft meets or exceeds all requirements of both the RFP and the Federal Aviation Administration (FAA). Highlights include a revolutionary wing planform, known as an M-wing, which offers many advantages over a conventional aft swept wing. For example, the M-wing lessens the travel in the aircraft center of gravity caused by fuel being stored in the wing. It also reduces the amount of torque imposed on the center wing box because more of the lifting load acts near the fuselage joint, rather than behind it. In essence, the M-wing offers the best of both worlds: using a forward swept wing root places the aerodynamic center of the wing further forward and allows the landing gear to be placed without the use of a yahudi. At the same time, with the outboard section swept backward the tip retains an amount of aeroelastic dampening that is lost on a completely forward swept wing. The result is a wing which has many advantages of a straight, unswept wings without the severe compressibility effects at high Mach numbers. Other highlights include judicious use of composites, giving recognition to the importance of weight and its effect on aircraft cost and performance, and an advanced passenger entertainment system which can be used as a source of revenue for the airlines. This aircraft meets the low-cost doctrine with an acquisition cost of $29 million and a direct

  15. Low-Cost, Lightweight Pressure Vessel Proof Test

    NASA Astrophysics Data System (ADS)

    Chanez, Eric

    This experiment seeks to determine the burst strength of the low-cost, lightweight pressure vessel fabricated by the Suborbital Center of Excellence (SCE). Moreover, the test explores the effects of relatively large gage pressures on material strain for ‘pumpkin-shaped' pressure vessels. The SCE team used pressure transducers and analog gauges to measure the gage pressure while a video camera assembly recorded several gores in the shell for strain analysis. The team loaded the vessel in small intervals of pressure until the structure failed. Upon test completion, the pressure readings and video recordings were analyzed to determine the burst strength and material strain in the shell. The analysis yielded a burst pressure of 13.5 psi while the strain analysis reported in the shell. While the results of this proof test are encouraging, the structure's factor of safety must be increased for actual balloon flights. Furthermore, the pressure vessel prototype must be subjected to reliability tests to show the design can sustain gage pressures for the length of a balloon flight.

  16. A Low-Cost Device for Automatic Photometric Titrations

    NASA Astrophysics Data System (ADS)

    Rocha, Fábio R. P.; Reis, Boaventura F.

    2000-02-01

    Electronics is an important topic in chemistry courses. However, the introduction of basic concepts is often difficult and the lab instruments are frequently seen as "black boxes". To address this problem, we propose the construction of a simple, low-cost (about $150 U.S.) automatic photometric titrator employing a light-emitting diode (LED) and a phototransistor. The electronic circuit can be assembled by the students themselves. The device was employed to implement a common procedure in chemical labs, making feasible the introduction of concepts related to electronics in undergraduate chemistry courses. The titrator is able to work automatically, since a feedback system permits stopping the addition of titrant solution when the end-point is achieved. With this demonstration, it can be stressed that automatic procedures can be implemented without expensive instruments. Additionally, a classical procedure becomes more attractive to the students and its importance to chemical analysis can be emphasized. The feasibility of the titrator was demonstrated by acid-base titrations of HCl solutions with NaOH in the presence of phenolphthalein and by iodimetric determination of ascorbic acid in vitamin C tablets and lemon juice. Precise results (0.7% relative standard deviation, n = 10) in agreement at the 95% confidence level with those attained by a conventional procedure were obtained.

  17. Low-cost single-crystal turbine blades, volume 1

    NASA Technical Reports Server (NTRS)

    Strangman, T. E.; Heath, B.; Fujii, M.

    1983-01-01

    The exothermic casting process was successfully developed into a low cost nonproprietary method for producing single crystal (SC) castings. Casting yields were lower than expected, on the order of 20 percent, but it is felt that the casting yield could be significantly improved with minor modifications to the process. Single crystal Mar-M 247 and two derivative SC alloys were developed. NASAIR 100 and SC Alloy 3 were fully characterized through mechanical property testing. SC Mar-M 247 shows no significant improvement in strength over directionally solidified (DS) Mar-M 247, but the derivative alloys, NASAIR 100 and Alloy 3, show significant tensile and fatigue improvements. The 1000 hr/238 MPa (20 ksi) stress rupture capability compared to DS Mar-M 247 was improved over 28 C. Firtree testing, holography, and strain gauge rig testing were used to evaluate the effects of the anisotropic characteristics of single crystal materials. In general, the single crystal material behaved similarly to DS Mar-M 247. Two complete engine sets of SC HP turbine blades were cast using the exothermic casting process and fully machined.

  18. Low cost split stirling cryogenic cooler for aerospace applications

    NASA Astrophysics Data System (ADS)

    Veprik, Alexander; Zechtzer, Semeon; Pundak, Nachman; Riabzev, Sergey; Kirckconnel, C.; Freeman, Jeremy

    2012-06-01

    Cryogenic coolers are used in association with sensitive electronics and sensors for military, commercial or scientific space payloads. The general requirements are high reliability and power efficiency, low vibration export and ability to survive launch vibration extremes and long-term exposure to space radiation. A long standing paradigm of using exclusively space heritage derivatives of legendary "Oxford" cryocoolers featuring linear actuators, flexural bearings, contactless seals and active vibration cancellation is so far the best known practice aiming at delivering high reliability components for the critical and usually expensive space missions. The recent tendency of developing mini and micro satellites for the budget constrained missions has spurred attempts to adapt leading-edge tactical cryogenic coolers to meet the space requirements. The authors are disclosing theoretical and practical aspects of a collaborative effort on developing a space qualified cryogenic refrigerator based on the Ricor model K527 tactical cooler and Iris Technology radiation hardened, low cost cryocooler electronics. The initially targeted applications are cost-sensitive flight experiments, but should the results show promise, some long-life "traditional" cryocooler missions may well be satisfied by this approach.

  19. Adapting smartphones for low-cost optical medical imaging

    NASA Astrophysics Data System (ADS)

    Pratavieira, Sebastião.; Vollet-Filho, José D.; Carbinatto, Fernanda M.; Blanco, Kate; Inada, Natalia M.; Bagnato, Vanderlei S.; Kurachi, Cristina

    2015-06-01

    Optical images have been used in several medical situations to improve diagnosis of lesions or to monitor treatments. However, most systems employ expensive scientific (CCD or CMOS) cameras and need computers to display and save the images, usually resulting in a high final cost for the system. Additionally, this sort of apparatus operation usually becomes more complex, requiring more and more specialized technical knowledge from the operator. Currently, the number of people using smartphone-like devices with built-in high quality cameras is increasing, which might allow using such devices as an efficient, lower cost, portable imaging system for medical applications. Thus, we aim to develop methods of adaptation of those devices to optical medical imaging techniques, such as fluorescence. Particularly, smartphones covers were adapted to connect a smartphone-like device to widefield fluorescence imaging systems. These systems were used to detect lesions in different tissues, such as cervix and mouth/throat mucosa, and to monitor ALA-induced protoporphyrin-IX formation for photodynamic treatment of Cervical Intraepithelial Neoplasia. This approach may contribute significantly to low-cost, portable and simple clinical optical imaging collection.

  20. Assessment of a Low-Cost Ultrasound Pericardiocentesis Model

    PubMed Central

    Campo dell'Orto, Marco; Hempel, Dorothea; Starzetz, Agnieszka; Seibel, Armin; Hannemann, Ulf; Walcher, Felix; Breitkreutz, Raoul

    2013-01-01

    Introduction. The use of ultrasound during resuscitation is emphasized in the latest European resuscitation council guidelines of 2013 to identify treatable conditions such as pericardial tamponade. The recommended standard treatment of tamponade in various guidelines is pericardiocentesis. As ultrasound guidance lowers the complication rates and increases the patient's safety, pericardiocentesis should be performed under ultrasound guidance. Acute care physicians actually need to train emergency pericardiocentesis. Methods. We describe in detail a pericardiocentesis ultrasound model, using materials at a cost of about 60 euros. During training courses of focused echocardiography n = 67, participants tested the phantom and completed a 16-item questionnaire, assessing the model using a visual analogue scale (VAS). Results. Eleven of fourteen questions were answered with a mean VAS score higher than 60% and thus regarded as showing the strengths of the model. Unrealistically outer appearance and heart shape were rated as weakness of the model. A total mean VAS score of all questions of 63% showed that participants gained confidence for further interventions. Conclusions. Our low-cost pericardiocentesis model, which can be easily constructed, may serve as an effective training tool of ultrasound-guided pericardiocentesis for acute and critical care physicians. PMID:24288616

  1. A Low Cost Weather Balloon Borne Solar Cell Calibration Payload

    NASA Technical Reports Server (NTRS)

    Snyder, David B.; Wolford, David S.

    2012-01-01

    Calibration of standard sets of solar cell sub-cells is an important step to laboratory verification of on-orbit performance of new solar cell technologies. This paper, looks at the potential capabilities of a lightweight weather balloon payload for solar cell calibration. A 1500 gr latex weather balloon can lift a 2.7 kg payload to over 100,000 ft altitude, above 99% of the atmosphere. Data taken between atmospheric pressures of about 30 to 15 mbar may be extrapolated via the Langley Plot method to 0 mbar, i.e. AMO. This extrapolation, in principle, can have better than 0.1 % error. The launch costs of such a payload arc significantly less than the much larger, higher altitude balloons, or the manned flight facility. The low cost enables a risk tolerant approach to payload development. Demonstration of 1% standard deviation flight-to-flight variation is the goal of this project. This paper describes the initial concept of solar cell calibration payload, and reports initial test flight results. .

  2. Development of low cost composite plates for humanitarian demining operations

    NASA Astrophysics Data System (ADS)

    Rabet, L.; Scheppers, J.; Verpoest, I.; Pirlot, M.; Desmet, B.; Gilson, L.; Pirard, P.

    2006-08-01

    Composite plates using flax fabrics and maleic anhydride modified polypropylene were fabricated on laboratory scale. The aim of the current research was to develop a low cost composite plate or a hybrid structure based on those plates and steel sheet, for making humanitarian demining clothes protecting against secondary fragmentation caused by anti-personnel blast mines. Ballistic impact tests according to STANAG 2920 were carried out for determining the v{50}-limit. So called field tests were performed by means of simulated anti-personnel mines using M112 explosive; the repeatability and the spatial distribution of the projected fragments were checked before fixing the final experimental setup. The performance of the bare composite plate was compared with the hybrid structures in terms of v{50} and in terms of damage mechanisms. All tested configurations performed amazingly well during the field tests, which was not the case for the ballistic impact tests. This led to the conclusion that v{50} might not be the best criterion to characterize protective clothing. This conclusion is sustained by energetic considerations and by field tests on plates with half the thickness of the initial plates.

  3. Calibration of Low Cost RGB and NIR Uav Cameras

    NASA Astrophysics Data System (ADS)

    Fryskowska, A.; Kedzierski, M.; Grochala, A.; Braula, A.

    2016-06-01

    Non-metric digital cameras are being widely used for photogrammetric studies. The increase in resolution and quality of images obtained by non-metric cameras, allows to use it in low-cost UAV and terrestrial photogrammetry. Imagery acquired with non-metric cameras can be used in 3D modeling of objects or landscapes, reconstructing of historical sites, generating digital elevation models (DTM), orthophotos, or in the assessment of accidents. Non-metric digital camcorders are characterized by instability and ignorance of the interior orientation parameters. Therefore, the use of these devices requires prior calibration. Calibration research was conducted using non-metric camera, different calibration tests and various software. The first part of the paper contains a brief theoretical introduction including the basic definitions, like the construction of non-metric cameras or description of different optical distortions. The second part of the paper contains cameras calibration process, details of the calibration methods and models that have been used. Sony Nex 5 camera calibration has been done using software: Image Master Calib, Matlab - Camera Calibrator application and Agisoft Lens. For the study 2D test fields has been used. As a part of the research a comparative analysis of the results have been done.

  4. Low cost biological lung volume reduction therapy for advanced emphysema

    PubMed Central

    Bakeer, Mostafa; Abdelgawad, Taha Taha; El-Metwaly, Raed; El-Morsi, Ahmed; El-Badrawy, Mohammad Khairy; El-Sharawy, Solafa

    2016-01-01

    Background Bronchoscopic lung volume reduction (BLVR), using biological agents, is one of the new alternatives to lung volume reduction surgery. Objectives To evaluate efficacy and safety of biological BLVR using low cost agents including autologous blood and fibrin glue. Methods Enrolled patients were divided into two groups: group A (seven patients) in which autologous blood was used and group B (eight patients) in which fibrin glue was used. The agents were injected through a triple lumen balloon catheter via fiberoptic bronchoscope. Changes in high resolution computerized tomography (HRCT) volumetry, pulmonary function tests, symptoms, and exercise capacity were evaluated at 12 weeks postprocedure as well as for complications. Results In group A, at 12 weeks postprocedure, there was significant improvement in the mean value of HRCT volumetry and residual volume/total lung capacity (% predicted) (P-value: <0.001 and 0.038, respectively). In group B, there was significant improvement in the mean value of HRCT volumetry and (residual volume/total lung capacity % predicted) (P-value: 0.005 and 0.004, respectively). All patients tolerated the procedure with no mortality. Conclusion BLVR using autologous blood and locally prepared fibrin glue is a promising method for therapy of advanced emphysema in term of efficacy, safety as well as cost effectiveness. PMID:27536091

  5. Low cost mobile explosive/drug detection devices

    NASA Astrophysics Data System (ADS)

    Gozani, T.; Bendahan, J.

    1999-06-01

    Inspection technologies based on Thermal Neutron Analysis (TNA®) and/or Fast Neutron Analysis (FNA) are the basis for relatively compact and low-cost, material-sensitive devices for a wide variety of inspection needs. The TNA allows the use of either isotropic neutron sources such as a 252Cf, or electronic neutron generators such as the d-T sealed neutron generator tubes. The latter could be used in a steady state mode or in slow (>μs) pulsing mode, to separate the thermal neutron capture signatures following the pulse from the combination of the FNA plus TNA signatures during the pulse. Over the years, Ancore Corporation has built and is continuing to develop a variety of inspection devices based on its TNA and FNA technologies: SPEDS—an explosive detection device for small parcels, portable electronics, briefcases and other similar carry-on items; MDS—a system for the detection or confirmation of buried mines; VEDS—a system for the detection of varied amounts of explosives and/or drugs concealed in passenger vehicles, pallets, lightly loaded trucks or containers, etc.; ACD—a device to clear alarms from a primary, non-specific explosive detection system for passenger luggage. The principle and performance of these devices will be shown and discussed.

  6. Pretreatment of Lignocellulosic Biomass with Low-cost Ionic Liquids.

    PubMed

    Gschwend, Florence J V; Brandt, Agnieszka; Chambon, Clementine L; Tu, Wei-Chien; Weigand, Lisa; Hallett, Jason P

    2016-01-01

    A number of ionic liquids (ILs) with economically attractive production costs have recently received growing interest as media for the delignification of a variety of lignocellulosic feedstocks. Here we demonstrate the use of these low-cost protic ILs in the deconstruction of lignocellulosic biomass (Ionosolv pretreatment), yielding cellulose and a purified lignin. In the most generic process, the protic ionic liquid is synthesized by accurate combination of aqueous acid and amine base. The water content is adjusted subsequently. For the delignification, the biomass is placed into a vessel with IL solution at elevated temperatures to dissolve the lignin and hemicellulose, leaving a cellulose-rich pulp ready for saccharification (hydrolysis to fermentable sugars). The lignin is later precipitated from the IL by the addition of water and recovered as a solid. The removal of the added water regenerates the ionic liquid, which can be reused multiple times. This protocol is useful to investigate the significant potential of protic ILs for use in commercial biomass pretreatment/lignin fractionation for producing biofuels or renewable chemicals and materials. PMID:27583830

  7. Low-cost automated fiber pigtailing machine. Revision 1

    SciTech Connect

    Strand, O.T.

    1996-01-01

    The goal of this 2-year ARPA-funded project was to design and build 3 low-cost machines to perform sub-micron alignment and attachments of single-mode fibers to different OE devices. These Automated Fiber Pigtailing Machines (AFPMs) are intended to be compatible with a manufacturing environment and have a modular design for maximum flexibility and standardization of parts. Machine vision enables the AFPM to perform sufficient alignment to couple light for maximization. This work was a collaboration among Uniphase Telecommunications Products (formerly United Technologies Photonics, UTP), Ortel, Newport/Klinger, the Massachusetts Institute of Technology Manufacturing Institute (MIT), and Lawrence Livermore National Laboratory (LLNL). UTP and Ortel are the industrial partners for whom two of the AFPMs were built. MIT and LLNL made up the design and assembly team of the project, while Newport/Klinger was a potential manufacturer of the AFPM and provided guidance to ensure that the design of the AFPM is marketable and compatible with a manufacturing environment. The AFPM for UTP pigtails LiNbO{sub 3} waveguide devices and the AFPM for Ortel pigtails photodiodes. Both of these machines contain proprietary information, so the third AFPM, residing at LLNL, pigtails a non-proprietary waveguide device for demonstrations to US industry and further development.

  8. Development of Low Cost Soil Stabilization Using Recycled Material

    NASA Astrophysics Data System (ADS)

    Ahmad, F.; Yahaya, A. S.; Safari, A.

    2016-07-01

    Recycled tyres have been used in many geotechnical engineering projects such as soil improvement, soil erosion and slope stability. Recycled tyres mainly in chip and shredded form are highly compressible under low and normal pressures. This characteristic would cause challenging problems in some applications of soil stabilization such as retaining wall and river bank projects. For high tensile stress and low tensile strain the use of fiberglass would be a good alternative for recycled tyre in some cases. To evaluate fiberglass as an alternative for recycled tyre, this paper focused on tests of tensile tests which have been carried out between fiberglass and recycled tyre strips. Fibreglass samples were produced from chopped strand fibre mat, a very low-cost type of fibreglass, which is cured by resin and hardener. Fibreglass samples in the thickness of 1 mm, 2 mm, 3 mm and 4 mm were developed 100 mm x 300 mm pieces. It was found that 3 mm fibreglass exhibited the maximum tensile load (MTL) and maximum tensile stress (MTS) greater than other samples. Statistical analysis on 3 mm fibreglass indicated that in the approximately equal MTL fibreglass samples experienced 2% while tyre samples experienced 33.9% ultimate tensile strain (UTST) respectively. The results also showed an approximately linear relationship between stress and strain for fibreglass samples and Young's modulus (E), ranging from 3581 MPa to 4728 MPa.

  9. Technical features of a low-cost Earthquake Alert System

    SciTech Connect

    Harben, P.

    1991-08-01

    The concept and features of an Earthquake Alert System (EAS) involving a distributed network of strong motion sensors is discussed. The EAS analyzes real-time data telemetered to a central facility and issues an areawide warning of a large earthquake in advance of the spreading elastic wave energy. A low-cost solution to high-cost estimates for installation and maintenance of a dedicated EAS is presented that makes use of existing microseismic stations. Using the San Francisco Bay area as an example, we show that existing US Geological Survey microseismic monitoring stations are of sufficient density to form the elements of a prototype EAS. By installing strong motion instrumentation and a specially developed switching device, strong ground motion can be telemetered in real-time to the central microseismic station on the existing communication channels. When a large earthquake occurs, a dedicated real-time central processing unit at the central microseismic station digitizes and analyses the incoming data and issues a warning containing location and magnitude estimations. A 50-station EAS of this type in the San Francisco Bay area should cost under $70,000 to install and less than $5000 annually to maintain.

  10. Automatic orbit ephemeris update in a low cost ground station

    NASA Astrophysics Data System (ADS)

    Ward, A. Kim; Ely, Robert J.; Holdaway, Richard

    1997-07-01

    This paper examines a method of updating the orbit ephemeris of low Earth orbit satellites based on antenna tracking error data from a single ground station. The paper describes Satellites International's low cost S-band ground station which utilizes a 2.4 m parabolic dish antenna with full azimuth and elevation drive control. The antenna incorporates a diplexing feed, with a low noise amplifier in the receive path, linked to a receiver/demodulator which downconverts and decodes the received telemetry before passing it to a telemetry depacketizer; and thence to the spacecraft control centre. The uplink telecommand data is packetized and passed to a sub-carrier generator, before being upconverted in an S-band sweeper/modulator, followed by a high power amplifier linked to the antenna feed. The antenna controller drives the antenna in a fine resolution program track mode derived from a 10-point orbit ephemeris. Tracking error data is obtained in real-time during a pass by scanning the antenna across-track and along-track with respect to the nominal satellite position. The error measurements are then fed automatically into the orbit generation software to provide an updated orbit ephemeris. The paper demonstrates that the orbit prediction accuracy obtainable using this method can achieve satisfactory mission performance.

  11. Odometry and Low-Cost Sensor Fusion in Tmm Dataset

    NASA Astrophysics Data System (ADS)

    Manzino, A. M.; Taglioretti, C.

    2016-03-01

    The aim of this study is to identify the most powerful motion model and filtering technique to represent an urban terrestrial mobile mapping (TMM) survey and ultimately to obtain the best representation of the car trajectory. The authors want to test how far a motion model and a more or less refined filtering technique could bring benefits in the determination of the car trajectory. To achieve the necessary data for the application of the motion models and the filtering techniques described in the article, the authors realized a TMM survey in the urban centre of Turin by equipping a vehicle with various instruments: a low-cost action-cam also able to record the GPS trace of the vehicle even in the presence of obstructions, an inertial measurement system and an odometer. The results of analysis show in the article indicate that the Unscented Kalman Filter (UKF) technique provides good results in the determination of the vehicle trajectory, especially if the motion model considers more states (such as the positions, the tangential velocity, the angular velocity, the heading, the acceleration). The authors also compared the results obtained with a motion model characterized by four, five and six states. A natural corollary to this work would be the introduction to the UKF of the photogrammetric information obtained by the same camera placed on board the vehicle. These data would permit to establish how photogrammetric measurements can improve the quality of TMM solutions, especially in the absence of GPS signals (like urban canyons).

  12. Nanoengineered CIGS thin films for low cost photovoltaics

    NASA Astrophysics Data System (ADS)

    Eldada, Louay; Taylor, Matthew; Sang, Baosheng; McWilliams, Scott; Oswald, Robert; Stanbery, Billy J.

    2008-08-01

    Low cost manufacturing of Cu(In,Ga)Se2 (CIGS) films for high efficiency photovoltaic devices by the innovative Field-Assisted Simultaneous Synthesis and Transfer (FASST®) process is reported. The FASST® process is a two-stage reactive transfer printing method relying on chemical reaction between two separate precursor films to form CIGS, one deposited on the substrate and the other on a printing plate in the first stage. In the second stage these precursors are brought into intimate contact and rapidly reacted under pressure in the presence of an applied electrostatic field. The method utilizes physical mechanisms characteristic of anodic wafer bonding and rapid thermal annealing, effectively creating a sealed micro-reactor that ensures high material utilization efficiency, direct control of reaction pressure, and low thermal budget. The use of two independent ink-based or PVD-based nanoengineered precursor thin films provides the benefits of independent composition and flexible deposition technique optimization, and eliminates pre-reaction prior to the second stage FASST® synthesis of CIGS. High quality CIGS with large grains on the order of several microns are formed in just several minutes based on compositional and structural analysis by XRF, SIMS, SEM and XRD. Cell efficiencies of 12.2% have been achieved using this method.

  13. Low-cost mirror substrates: manufacturing process evolution

    NASA Astrophysics Data System (ADS)

    Rosala, Francois; Meyer, Michele; Bes de Berc, Jean-Sebastien; Roussel, Andre; Beriot, Emmanuel

    1997-12-01

    In the framework of the Megajoule Laser project driven by the French Atomic Energy Board, one of the most valuable optical programs in term of material volume as well as in term of component size, the actual glasses and production means appear to be inconsistent with the economical objectives. Corning proposed an alternative, based on the use of a low cost glass, together with an evolution of the production process. Combining its experience in quality optical glasses manufacturing and its mastery of forming processes, Corning conducted a production cost reduction program; the objective of this program was to validate the concept of large slab melting (about 2000 kg each), where blocks are cut off, versus the conventional single block (about 100 kg) melting. Economical improvements are based on a reduction of lost time (mold change) and production lead- time by increasing the feeding yield, on a better glass utilization, and a reduced number of molds. The technical issues were: increase the feeding yield maintaining a given glass quality level, reduce the glass allowance, improve the materials of the molds, reinforce the thermal process control, automatism of critical operations, especially at the start-up and at the end of the mold feeding. Despite the long production cycle, about 3 months including melting and annealing, the first results carry the technological options set-up.

  14. Low-cost mirror substrates: manufacturing process evolution

    NASA Astrophysics Data System (ADS)

    Rosala, Francois; Meyer, Michele; Bes de Berc, Jean-Sebastien; Roussel, Andre; Beriot, Emmanuel

    1996-08-01

    In the framework of the megajoule laser project driven by the french atomic energy board, one of the most valuable optical programs in terms of material volume as well as in terms of component size, the actual glasses and production means appear to be inconsistent with the economical objectives. Corning proposed an alternative, based on the use of a low cost glass, together with an evolution of the production process. Combining its experience in quality optical glasses manufacturing and its mastery of forming processes, Corning conducted a production cost reduction program; the objective of this program was to validate the concept of large slab melting, where blocks are cut off, versus the conventional single block melting. Economical improvements are based on a reduction of lost time and production lead-time by increasing the feeding yield, on a better glass utilization, and a reduced number of molds. The technical issues were: increase the feeding yield maintaining a given glass quality level, reduce the glass allowance, improve the materials of the molds, reinforce the thermal process control, automatism of critical operations, especially at the start-up and at the end of the mold feeding.

  15. Low cost alternatives to commercial lab kits for physics experiments

    NASA Astrophysics Data System (ADS)

    Kodejška, Č.; De Nunzio, G.; Kubínek, R.; Říha, J.

    2015-08-01

    Conducting experiments in physics using modern measuring techniques, and particularly those utilizing computers, is often much more attractive to students than conducting experiments conventionally. However, the cost of professional kits in the Czech Republic is still very expensive for many schools. The basic equipment for one student workplace in the case of professional kits such as Vernier, Pasco or Coach costs around 800 euros. In this paper some physics experiments in which a computer, or a tablet with Microsoft Windows, is used as the measuring device, along with available physical devices such as a laser pointer, a solar cell or an electret microphone, are presented as suitable and alternative ways to carry out lab work. We show that it is possible to perform very simple school experiments (both as a central demonstration and as individual experimentation), in which high accuracy and clear final conclusions can be achieved at a very low cost. Further information is published on the specialized webpage www.sclpx.eu/index.php?lang=en. The worksheets are in Czech, but the English version is in preparation.

  16. A Novel and Low Cost Sea Ice Mass Balance Buoy.

    NASA Astrophysics Data System (ADS)

    Jackson, Keith; Meldrum, David; Wilkinson, Jeremy; Maksym, Ted; Beckers, Justin; Haas, Christian

    2013-04-01

    Understanding of sea ice mass balance processes requires continuous monitoring of the seasonal evolution of ice thickness. While autonomous ice mass balance buoys (IMBs) deployed over the past two decades have contributed to our understanding of ice growth and decay processes, deployment has been limited, in part, by the cost of such systems. Routine, basin-wide monitoring of the ice cover is realistically achievable through a network of reliable and affordable autonomous instrumentation. We describe the development of a novel autonomous platform and sensor that replaces the traditional thermistors string for monitoring temperature profiles in the ice and snow using a chain of inexpensive digital temperature chip sensors linked by a single-wire data bus. By incorporating a heating element on each sensor, the instrument is capable of resolving material interfaces (e.g. air-snow and ice-ocean boundaries) even under isothermal conditions. The instrument is small, low-cost and easy to deploy. Field and laboratory tests of the sensor chain demonstrate that the technology can reliably resolve material boundaries to within a few centimetres and over 50 scientific deployments have been made with encouraging results. The discrimination between different media based on sensor thermal response is weak in some deployments and efforts to optimise the measurement continue.

  17. Low-cost hadron colliders at Fermilab: A discussion paper

    SciTech Connect

    Foster, G.W.; Malamud, E.

    1996-06-21

    New more economic approaches are required to continue the dramatic exponential rise in collider energies as represented by the well known Livingston plot. The old idea of low cost, low field iron dominated magnets in a small diameter pipe may become feasible in the next decade with dramatic recent advances in technology: (1) advanced tunneling technologies for small diameter, non human accessible tunnels, (2) accurate remote guidance systems for tunnel survey and boring machine steering, (3) high T{sub c} superconductors operating at liquid N{sub 2} or liquid H{sub 2} temperatures, (4) industrial applications of remote manipulation and robotics, (5) digitally multiplexed electronics to minimize cables, (6) achievement of high luminosities in p-p and p-{anti P} colliders. The goal of this paper is to stimulate continuing discussions on approaches to this new collider and to identify critical areas needing calculations, construction of models, proof of principle experiments, and full scale prototypes in order to determine feasibility and arrive at cost estimates.

  18. Low Cost Polymer heat Exchangers for Condensing Boilers

    SciTech Connect

    Butcher, Thomas; Trojanowski, Rebecca; Wei, George; Worek, Michael

    2015-09-30

    Work in this project sought to develop a suitable design for a low cost, corrosion resistant heat exchanger as part of a high efficiency condensing boiler. Based upon the design parameters and cost analysis several geometries and material options were explored. The project also quantified and demonstrated the durability of the selected polymer/filler composite under expected operating conditions. The core material idea included a polymer matrix with fillers for thermal conductivity improvement. While the work focused on conventional heating oil, this concept could also be applicable to natural gas, low sulfur heating oil, and biodiesel- although these are considered to be less challenging environments. An extruded polymer composite heat exchanger was designed, built, and tested during this project, demonstrating technical feasibility of this corrosion-resistant material approach. In such flue gas-to-air heat exchangers, the controlling resistance to heat transfer is in the gas-side convective layer and not in the tube material. For this reason, the lower thermal conductivity polymer composite heat exchanger can achieve overall heat transfer performance comparable to a metal heat exchanger. However, with the polymer composite, the surface temperature on the gas side will be higher, leading to a lower water vapor condensation rate.

  19. Process for Low Cost Domestic Production of LIB Cathode Materials

    SciTech Connect

    Thurston, Anthony

    2012-10-31

    The objective of the research was to determine the best low cost method for the large scale production of the Nickel-Cobalt-Manganese (NCM) layered cathode materials. The research and development focused on scaling up the licensed technology from Argonne National Laboratory in BASF’s battery material pilot plant in Beachwood Ohio. Since BASF did not have experience with the large scale production of the NCM cathode materials there was a significant amount of development that was needed to support BASF’s already existing research program. During the three year period BASF was able to develop and validate production processes for the NCM 111, 523 and 424 materials as well as begin development of the High Energy NCM. BASF also used this time period to provide free cathode material samples to numerous manufactures, OEM’s and research companies in order to validate the ma-terials. The success of the project can be demonstrated by the construction of the production plant in Elyria Ohio and the successful operation of that facility. The benefit of the project to the public will begin to be apparent as soon as material from the production plant is being used in electric vehicles.

  20. Printable low-cost sensor systems for healthcare smart textiles

    NASA Astrophysics Data System (ADS)

    Rai, Pratyush; Kumar, Prashanth S.; Oh, Sechang; Kwon, Hyeokjun; Mathur, Gyanesh N.; Varadan, Vijay K.

    2011-04-01

    Smart textiles-based wearable health monitoring systems (ST-HMS) have been presented as elegant solutions to the requirements of individuals across a wide range of ages. They can be used to monitor young or elderly recuperating /convalescent patients either in hospital or at home, or they can be used by young athletes to monitor important physiological parameters to better design their training or fitness program. Business and academic interests, all over the world, have fueled a great deal of work in the development of this technology since 1990. However, two important impediments to the development of ST-HMS are:-integration of flexible electrodes, flexible sensors, signal conditioning circuits and data logging or wireless transmission devices into a seamless garment and a means to mass manufacture the same, while keeping the costs low. Roll-to-roll printing and screen printing are two low cost methods for large scale manufacturing on flexible substrates and can be extended to textiles as well. These two methods are, currently, best suited for planar structures. The sensors, integrated with wireless telemetry, facilitate development of a ST-HMS that allows for unobtrusive health monitoring. In this paper, we present our results with planar screen printable sensors based on conductive inks which can be used to monitor EKG, abdominal respiration effort, blood pressure, pulse rate and body temperature. The sensor systems were calibrated, and tested for sensitivity, reliability and robustness to ensure reuse after washing cycles.

  1. A Low Cost Sensor Controller for Health Monitoring

    NASA Astrophysics Data System (ADS)

    Birbas, M.; Petrellis, N.; Gioulekas, F.

    2015-09-01

    Aging population can benefit from health care systems that allow their health and daily life to be monitored by expert medical staff. Blood pressure, temperature measurements or more advanced tests like Electrocardiograms (ECG) can be ordered through such a healthcare system while urgent situations can be detected and alleviated on time. The results of these tests can be stored with security in a remote cloud or database. Such systems are often used to monitor non-life threatening patient health problems and their advantage in lowering the cost of the healthcare services is obvious. A low cost commercial medical sensor kit has been used in the present work, trying to improve the accuracy and stability of the sensor measurements, the power consumption, etc. This Sensor Controller communicates with a Gateway installed in the patient's residence and a tablet or smart phone used for giving instructions to the patient through a comprehensive user interface. A flexible communication protocol has been defined supporting any short or long term sensor sampling scenario. The experimental results show that it is possible to achieve low power consumption by applying apropriate sleep intervals to the Sensor Controller and by deactivating periodically some of its functionality.

  2. Simple low-cost miniaturization approach for pharmaceutical nanocrystals production.

    PubMed

    Romero, Gregori B; Keck, Cornelia M; Müller, Rainer H

    2016-03-30

    Systematic screening for optimal formulation composition and production parameters for nanosuspensions consumes a lot of time and also drug material when performed at lab scale. Therefore, a cost-effective miniaturized scale top down approach for nanocrystals production by wet bead milling was developed. The final set-up consisted of 3 magnetic stirring bars placed vertically one over the other in a 2 mL glass vial and agitated by a common magnetic stirring plate. All of the tested actives (cyclosporin A, resveratrol, hesperitin, ascorbyl palmitate, apigenin and hesperidin) could be converted to nanosuspensions. For 4 of them, the particles sizes achieved were smaller than previously reported on the literature (around 90 nm for cyclosporin A; 50 nm for hesperitin; 160 nm for ascorbyl palmitate and 80 nm for apigenin). The "transferability" of the data collect by the miniaturized method was evaluated comparing the production at larger scale using both wet bead milling and high pressure homogenization. Transferable information obtained from the miniaturized scale is minimum achievable size, improvements in size reduction by reduction of beads size, diminution kinetics and potentially occurring instabilities during processing. The small scale batches also allow identification of optimal stabilizer types and concentrations. The batch size is 0.5 mL, requiring approximately 50 mg or 5 mg of drug (5% and 1% suspension, respectively). Thus, a simple, accessible, low-cost miniaturized scale method for the production of pharmaceutical nanocrystals was established. PMID:26642945

  3. Norwich Technologies' Advanced Low-Cost Receivers for Parabolic Troughs

    SciTech Connect

    Stettenheim, Joel; McBride, Troy O.; Brambles, Oliver J.; Cashin, Emil A.

    2013-12-31

    This report summarizes the successful results of our SunShot project, Advanced Low-Cost Receivers for Parabolic Troughs. With a limited budget of $252K and in only 12 months, we have (1) developed validated optical and thermal models and completed rigorous optimization analysis to identify key performance characteristics as part of developing first-generation laboratory prototype designs, (2) built optical and thermal laboratory prototypes and test systems with associated innovative testing protocols, and (3) performed extensive statistically relevant testing. We have produced fully functioning optical and thermal prototypes and accurate, validated models shown to capture important underlying physical mechanisms. The test results from the first-generation prototype establish performance exceeding the FOA requirement of thermal efficiency >90% for a CSP receiver while delivering an exit fluid temperature of > 650 °C and a cost < $150/kWth. Our vacuum-free SunTrap receiver design provides improvements over conventional vacuum-tube collectors, allowing dramatic reductions in thermal losses at high operating temperature.

  4. Mars Relay Spacecraft: A Low-Cost Approach

    NASA Technical Reports Server (NTRS)

    SvitekT, .; King, J.; Fulton, R.; McOmber, R.; Hastrup, R.; Miller, A.

    1995-01-01

    The next phase of Mars exploration will utilize numerous globally distributed small low-cost devices including landers penetrators microrovers and balloons. Direct-to-Earth communications links if required for these landers will drive the lander design for two reasons: a) mass and complexity needed for a steerable high-gain antenna and b) power requirements for a high-power amplifier (i.e. solar panel and battery mass). Total mass of the direct link hardware for several recent small-lander designs exceeded the mass of the scientific payload. Alternatively if communications are via a Mars-orbiting relay spacecraft resource requirements for the local UHF communication link are comparatively trivial: a simple whip antenna and less than 1 watt power. Clearly using a Mars relay spacecraft (MRS) is the preferred option if the MRS mission can be accomplished in an affordable and robust way. Our paper describes a point design for such a mission launched in the s001 or 2003 opportunity.

  5. Low-cost infrared glass for IR imaging applications

    NASA Astrophysics Data System (ADS)

    Graham, Amy G.; LeBlanc, Richard A.; Hilton, Ray A., Sr.

    2003-09-01

    With the advent of the uncooled detectors, the fraction of infrared (IR) imaging system cost due to lens elements has risen to the point where work was needed in the area of cost. Since these IR imaging systems often have tight packaging requirements which drive the optical elements to have complex surfaces, typical IR optical elements are costly to manufacture. The drive of our current optical material research is to lower the cost of the materials as well as the element fabrication for IR imaging systems. A low cost, moldable amorphous material, Amtir-4, has been developed and characterized. Ray Hilton Sr., Amorphous Materials Inc., Richard A. LeBlanc, Amy Graham and Others at Lockheed Martin Missiles and Fire Control Orlando (LMMFC-O) and James Johnson, General Electric Global Research Center (GE-GRC), along with others have been doing research for the past three years characterizing and designing IR imaging systems with this material. These IR imaging systems have been conventionally fabricated via diamond turning and techniques required to mold infrared optical elements have been developed with this new material, greatly reducing manufacturing costs. This paper will outline efforts thus far in incorporating this new material into prototype IR imaging systems.

  6. Low Cost Geothermal Separators BLISS Boundary Layer Inline Separator Scrubber

    SciTech Connect

    Jung, Douglas; Wai, King

    2000-05-26

    A new compact, low cost, and high performance separator is being developed to help reduce the installed and O and M cost of geothermal power generation. This device has been given the acronym ''BLISS'' that stands for ''Boundary Layer Inline Separator Scrubber''. The device is the first of a series of separators, and in the case of injectates, scrubbers to address the cost-reduction needs of the industry. The BLISS is a multi-positional centrifugal separator primarily designed to be simply installed between pipe supports, in a horizontal position. This lower profile reduces the height safety concern for workers, and significantly reduces the total installation cost. The vessel can demand as little as one-quarter (25%) the amount of steel traditionally required to fabricate many large vertical separators. The compact nature and high separating efficiency of this device are directly attributable to a high centrifugal force coupled with boundary layer control. The pseudo isokinetic flow design imparts a self-cleaning and scale resistant feature. This polishing separator is designed to remove moderate amounts of liquid and entrained solids.

  7. Luminescent Solar Concentrators - a low cost photovoltaics alternative

    NASA Astrophysics Data System (ADS)

    van Sark, W. G. J. H. M.

    2012-10-01

    Luminescent solar concentrators (LSCs) are being developed as a potentially low cost-per-Wp photovoltaic device, suited for applications especially in the built environment. LSCs generally consist of transparent polymer sheets doped with luminescent species, either organic dye molecules or semiconductor nanocrystals. Direct and diffuse incident sunlight is absorbed by the luminescent species and emitted at redshifted wavelengths with high quantum efficiency. Optimum design ensures that a large fraction of emitted light is trapped in the sheet, which travels to the edges where it can be collected by one or more mono- or bifacial solar cells, with minimum losses due to absorption in the sheet and re-absorption by the luminescent species. Today's record efficieny is 7%, however, 10-15% is within reach. Optimized luminescent solar concentrators potentially offer lower cost per unit of power compared to conventional solar cells. Moreover, LSCs have an increased conversion efficiency for overcast and cloudy sky conditions, having a large fraction of diffuse irradiation, which is blueshifted compared to clear sky conditions. As diffuse irradiation conditions are omnipresent throughout mid- and northern-European countries, annual performance of LSCs is expected to be better in terms of kWh/Wp compared to conventional PV.

  8. Low Cost CE-NMR with Microcoils for Chemical Detection

    SciTech Connect

    Adams, K; Klunder, G; Demas, V; Malba, V; Bernhardt, A; Evan, L; Harvey, C; Maxwell, R; Herberg, J L

    2009-01-08

    Understanding speciation in solids and solutions is important for environmental and toxicological purposes. Capillary electrophoresis (CE) is a simple rapid separation technique that can be used to identify species in solution. CE is particularly is well suited for rapid separations of metal containing samples. Direct on-capillary measurement of metal compound speciation can be obtained with nuclear magnetic resonance (NMR). The development of a low-cost microcoil CE-NMR system for in situ characterization of samples of interest is discussed. High precision laser lithography is used to produce copper sputtered microcoils that have comparable resistivity and quality factors to that of hand wound microcoils. A portable NMR system coupled with a CE system has the potential to identify chemical species in aqueous solutions. In addition, transient isotachophoresis can separate and pre-concentrate samples of interest to obtain separate chemical peaks for speciation by online NMR analysis. We are developing separation assays to determine the speciation of chemical complexes in solutions with minimal perturbation to the original sample equilibrium. On-line NMR measurements will be made downstream of the UV detector.

  9. Low Cost CE-NMR with Microcoils for Chemical Detection

    SciTech Connect

    Adams, K L; Klunder, G; Demas, V; Malba, V; Bernhardt, A; Evan, L; Harvey, C; Maxwell, R; Herberg, J

    2008-07-25

    Understanding speciation in solids and solutions is important for environmental and toxicological purposes. Capillary electrophoresis (CE) is a simple rapid separation technique that can be used to identify species in solution. CE is particularly is well suited for rapid separations of metal containing samples. Direct on-capillary measurement of metal compound speciation can be obtained with nuclear magnetic resonance (NMR). The development of a low-cost microcoil CE-NMR system for in situ characterization of samples of interest is discussed. High precision laser lithography is used to produce copper sputtered microcoils that have comparable resistivity and quality factors to that of hand wound microcoils. A portable NMR system coupled with a CE system has the potential to identify chemical species in aqueous solutions. In addition, transient isotachophoresis can separate and pre-concentrate samples of interest to obtain separate chemical peaks for speciation by online NMR analysis. We are developing separation assays to determine the speciation of chemical complexes in solutions with minimal perturbation to the original sample equilibrium. On-line NMR measurements will be made downstream of the UV detector.

  10. Low-cost solar selective absorbers from Indian galena

    SciTech Connect

    Chatterjee, S. . Research and Development Div.); Pal, U. )

    1993-11-01

    The main thrust of the research is to prepare a low-cost solar-selective absorber from an indigenous semiconducting mineral, galena (galena aggregate and galena concentrate), for a solar thermoelectric generator. The authors report the results of preparation and characterization of solar-selective coatings made from galena aggregate and galena concentrate collected from the Zawar mines in Rajasthan, India. The coatings of galena are prepared by a thermal evaporation technique and exhibit high absorptivity ([alpha] [approximately] 0.95 and 0.97) in the solar spectral range and low emissivity ([epsilon]375[approximately]0.21 and 0.27) in the thermal range. Finally, these coatings were compared with synthesized PbS coating prepared in the laboratory and found to be quite comparable. The structure and composition of the coatings were studied by x-ray diffraction and electron spectroscopy for chemical analysis. Reflectance and absorption studies were made in the 0.3- to 3.1-[mu]m spectral range.

  11. In situ Measurements of Phytoplankton Fluorescence Using Low Cost Electronics

    PubMed Central

    Leeuw, Thomas; Boss, Emmanuel S.; Wright, Dana L.

    2013-01-01

    Chlorophyll a fluorometry has long been used as a method to study phytoplankton in the ocean. In situ fluorometry is used frequently in oceanography to provide depth-resolved estimates of phytoplankton biomass. However, the high price of commercially manufactured in situ fluorometers has made them unavailable to some individuals and institutions. Presented here is an investigation into building an in situ fluorometer using low cost electronics. The goal was to construct an easily reproducible in situ fluorometer from simple and widely available electronic components. The simplicity and modest cost of the sensor makes it valuable to students and professionals alike. Open source sharing of architecture and software will allow students to reconstruct and customize the sensor on a small budget. Research applications that require numerous in situ fluorometers or expendable fluorometers can also benefit from this study. The sensor costs US$150.00 and can be constructed with little to no previous experience. The sensor uses a blue LED to excite chlorophyll a and measures fluorescence using a silicon photodiode. The sensor is controlled by an Arduino microcontroller that also serves as a data logger. PMID:23783738

  12. Low cost energy storage flywheels from structural sheet molding compound

    NASA Astrophysics Data System (ADS)

    Kay, J. F.

    Compression molded structural sheet molding compound (SMC) composed of S-2 Glass and polyester resin has been used to fabricate energy storage flywheel rotors. This technique has the potential of low cost, high throughput production of rotors for the automobile industry. An isophthalic polyester resin and chopped S-2 Glass were used to mold flat, constant cross section discs 53.3 cm (21 innches) in diameter, 2.54 cm (1.0 inches) thick, and 49.5 kg (22.5 pounds) in weight. Materials characterizations have shown a tensile strength of 337 MPa (49 ksi) for the S-2 Glass reinforced rotors, which would allow the rotor to store 28.6 watt-hours per kilogram (13 watt-hours per pound) at 330 hertz when a filament wound carbon fiber/epoxy ring is fitted around the SMC core. A dynamic test of an SMC flywheel has shown an energy storage density of 27.7 watt-hours per kilogram (12.6 watt-hours per pound) at 330 hertz.

  13. Printable low-cost, sustained and dynamic cell stretching apparatus.

    PubMed

    Toume, Samer; Gefen, Amit; Weihs, Daphne

    2016-05-24

    Deformations that are applied on body tissues during daily activities, as a result of morbid conditions, or during various medical treatments, affect cell viability and biological function. Such mechanobiological phenomena are often studied in vitro, in monolayer cultures. To facilitate such studies cost effectively, we have developed a novel, printable cell stretching apparatus. The apparatus is used to apply tensile strains on cells cultured on elastic, stretchable substrata, either by sustained or by dynamic-cyclic application. Most of the apparatus parts are three-dimensionally printed (excluding motors), and stretching is automatically performed by two direct current geared motors that are controlled by a programmable microcontroller platform. To demonstrate functionality of this novel printable device, which can be produced in multiple copies in research labs at a cost of under 100 US$ per unit, including motors and controller, we performed cell culture studies monitored by fluorescence microscopy. Specifically, we have applied sustained and cyclic, radial stretching at large strains to NIH3T3 mouse fibroblasts, and have demonstrated that cell viability, adhesion and morphology were maintained following stretching. Our apparatus is designed to be low-cost, rapidly manufactured at a university or small-company setting, and simple to use and control, where its flexible, versatile design allows users to experimentally induce different stretching regimes with varying amplitudes and frequencies. PMID:27038541

  14. Producing optical (contact) lenses by a novel low cost process

    NASA Astrophysics Data System (ADS)

    Skipper, Richard S.; Spencer, Ian D.

    2005-09-01

    The rapid and impressive growth of China has been achieved on the back of highly labour intensive industries, often in manufacturing, and at the cost of companies and jobs in Europe and America. Approaches that worked well in the 1990's to reduce production costs in the developed countries are no longer effective when confronted with the low labour costs of China and India. We have looked at contact lenses as a product that has become highly available to consumers here but as an industry that has reduced costs by moving to low labour cost countries. The question to be answered was, "Do we have the skill to still make the product in the UK, and can we make it cheap enough to export to China?" if we do not, then contact lens manufacture will move to China sooner or later. The challenge to enter the markets of the BRIC (Brazil, Russia, India and China) countries is extremely exciting as here is the new money, high growth and here is a product that sells to those with disposable incomes. To succeed we knew we had to be radical in our approach; the radical step was very simple: to devise a process in which each step added value to the customer and not cost to the product. The presentation examines the processes used by the major producers and how, by applying good manufacturing practice sound scientific principles to them, the opportunity to design a new low cost patented process was identified.

  15. Modernizing Plunger Control with Low-Cost Digital Electronics

    NASA Astrophysics Data System (ADS)

    Fasano, Patrick; Kuta, Trenton; Aprahamian, Ani

    2014-09-01

    The plunger technique provides a valuable tool for measuring lifetimes of excited states in the 1-100 ps range. The plunger consists of a thin foil target and stopper foil separated by some controllable distance; beam-induced reactions occur in the target and the resulting nucleus of interest leaves the target foil and is completely stopped by the stopper foil. The Notre Dame Nuclear Science Laboratory has a plunger device which is approximately 30 years old. In the Notre Dame plunger apparatus, the separation between foils is measured via capacitance between the foils and is used to control the position of three servo motors. Our work this summer focused on a complete rebuild of the plunger control electronics including two major upgrades: (1) a precision capacitance-measuring circuit based on the phase-shift of a sinusoidal signal which follows a development in the mid 1990's, (2) and a low-cost microcontroller-based feedback loop for precisely controlling servo motors with quadrature encoder outputs. After demonstrating that the upgrades are successful, we will carry out reactions in the Nuclear Science Laboratory and measure the lifetimes of excited states in several rare earth nuclei.

  16. Potential contribution of low cost materials in clean technology

    NASA Astrophysics Data System (ADS)

    Smail, Heman A.; Shareef, Kafia M.; Ramli, Zainab

    2016-03-01

    As the world's population approaches more than 9 billion, the strain on the planet's resources is steadily increasing. This demand can only be met by improving production methods to reduce the use of chemicals and the amount of chemical waste. Zeolites are among the least-known products for environmental pollution control, separation science and technology. This study investigates whether the use of geological sources as low-cost materials are suitable for zeolite synthesis and future applications. In this investigation natural montmorillonite clay, locally available in Erbil-Kurdistan, was used as raw material. The experiments were carried out in the presence of ultrasound 30KHz at 60°C and for different crystallization times (5, 10 &15 hours) and the results were compared with those obtained by performing conventional alkaline hydrothermal static syntheses under similar conditions and crystallization time of (90 hours). The raw material as well as the products was analyzed using; Fourier Transform Infra-Red (FT-IR), X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF) spectroscopy and scanning electron microscope (SEM). The experimental data were ascertained the formation of Zeolite successfully. Crystallization by ultrasound has been demonstrated to offer the possibilities of increasing the nucleation and crystallization rates of zeolites, improving the yield and directing the synthesis towards different crystal phases.

  17. Low cost vee-trough evacuated tube collector module

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K.

    1979-01-01

    A low cost solar collector capable of operating at 150-200 C is described. An evacuated tube receiver is combined with asymmetric vee-trough concentrators. Peak efficiencies of about 40% at 120 C and 30% at 180 C are expected. Predicted future collector cost is $70/sq m which yields an energy cost of $4.20/GJ at 120 C. During the development of the vee trough/evacuated tube collector both mathematical models to predict thermal and optical performance were developed and tests run to verify theory. The asymmetric vee trough concentrator increases the solar flux intensity for an average value of 2 for year-round performance. Optimized collector module has reflector angles of 55 deg/85 deg. The aperture plane is tilted to the latitude. The reflector is made of electropolished aluminum. The supporting frame is formed by bending sheet metal. Evacuated tube receivers are Pyrex, 15 cm diam and 2.4 m long. The module has 12 tubes on right and left sides altogether. Attainable operation at temperatures on the order of 150-200 C are suitable for absorption refrigeration and power generation via Rankine engines.

  18. Low-cost OP-FTIR spectrometer for workplace monitoring

    NASA Astrophysics Data System (ADS)

    Rentz, Julia H.; Engel, James R.; Carlson, David L.; Mansur, David J.; Vaillancourt, Robert M.; Genetti, George J.; Griffiths, Peter R.; Yang, Husheng

    2004-03-01

    OPTRA has developed a low-cost, extremely compact, rugged open-path Fourier transform infrared (OP-FTIR) spectrometer for workplace air quality monitoring. This research was funded under a United States Air Force ABIR Phase II contract. The goal of the program has been to identify and alleviate all aspects of currently available OP-FTIR systems which result in high-cost and complex user requirements. This low-resolution ssytem (Δσ = 8 cm-1) employs an uncooled DLATGS detector and a novel encoder-based reference metrology. Other design economies include a plastic injection-molded retroreflector array to return the open-path beam. This effort has included the development of a set of algorithms based on artificial neural networks (ANNs) and partial least squares (PLS) by the University of Idaho; these algorithms are specifically tailored to low-resolution systems applied to multi-component analysis of large, organic molecules characterized by broad infrared resonance bands. The algorithms, coupled with our OP-FTIR, are designed to autonomously identify and quantify a list of 105 common industrial organic molecules in the presence of varying humidity levels. Our system includes two PCI boards which host all OP-FTIR processing and servo electronics; the boards reside in a small suit-case PC along with a user-friendly Graphical User Interface.

  19. Low-cost single-crystal turbine blades, volume 2

    NASA Technical Reports Server (NTRS)

    Strangman, T. E.; Dennis, R. E.; Heath, B. R.

    1984-01-01

    The overall objectives of Project 3 were to develop the exothermic casting process to produce uncooled single-crystal (SC) HP turbine blades in MAR-M 247 and higher strength derivative alloys and to validate the materials process and components through extensive mechanical property testing, rig testing, and 200 hours of endurance engine testing. These Program objectives were achieved. The exothermic casting process was successfully developed into a low-cost nonproperietary method for producing single-crystal castings. Single-crystal MAR-M 247 and two derivatives DS alloys developed during this project, NASAIR 100 and SC Alloy 3, were fully characterized through mechanical property testing. SC MAR-M 247 shows no significant improvement in strength over directionally solidified (DS) MAR-M 247, but the derivative alloys, NASAIR 100 and Alloy 3, show significant tensile and fatigue improvements. Firtree testing, holography, and strain-gauge rig testing were used to determine the effects of the anisotropic characteristics of single-crystal materials. No undesirable characteristics were found. In general, the single-crystal material behaved similarly to DS MAR-M 247. Two complete engine sets of SC HP turbine blades were cast using the exothermic casting process and fully machined. These blades were successfully engine-tested.

  20. Application of Hamiltonian structure-preserving control to formation flying on a J 2-perturbed mean circular orbit

    NASA Astrophysics Data System (ADS)

    Xu, Ming; Zhu, Jiamin; Tan, Tian; Xu, Shijie

    2012-08-01

    involved in six foundational motions with different frequencies generated by the eigenvectors of the Floquet multipliers, rather than to track a reference relative configuration. Only the relative positions are employed for the feedback without the information from the direct measurement or the filter estimation of relative velocity. So the current controller has potential applications in formation flying for its less computation overload for on-board computer, less constraint on the measurements, and easily-achievable quasi-periodic relative trajectories.

  1. Low-cost electro-optical package for use with PCB-embedded waveguides

    NASA Astrophysics Data System (ADS)

    Weiss, Jonas; Berger, Christoph; Witzig, Martin; Morf, Thomas; Dangel, Roger; Horst, Folkert; Schmatz, Martin

    2007-09-01

    We present a novel approach for packaging high-speed opto-electronic 12x-array devices in a compact, low-cost package for waveguide-based intra-system links. In order to avoid optical signal loss and crosstalk, the mutual alignment between PCB-embedded multimode waveguides and the opto-electronic components needs to be in the order of 5-10 micrometer, which is an order of magnitude tighter than standard PCB manufacturing tolerances. Our packaging concept uses a combination of passive alignment steps, tolerance stackup reduction and a misalignment-tolerant coupling scheme in order to bridge this gap in a cost competitive way. Using flip-chip technology, the opto-electronic components are placed onto a very thin substrate with holes for the light path. The top side of the 25 μm liquid crystal polymer (LCP) substrate not only provides fast and low-loss electrical connections, but also serves as alignment reference plane for the entire module, avoiding alignment tolerance accumulation over different assembly steps. Openings for the laser beams, passive lens alignment features, centering holes for mechanical alignment pins between module and board and optional MT-guide receptacles are all laser-cut within one single process step, with a precision better than 5 μm. A similar approach is used for the PCB-side optics, and a lens-pair coupling scheme provides for a sufficiently large misalignment tolerance between the package and the PCB. Mechanical rigidity of the package and thermal protection are provided by an epoxy filled aluminum frame. We will present our design considerations, the basic package concept, the actual experimental implementation and characterization results of our first prototype package.

  2. Low-cost uncooled infrared detector arrays in standard CMOS

    NASA Astrophysics Data System (ADS)

    Eminoglu, Selim; Tanrikulu, M. Y.; Akin, Tayfun

    2003-09-01

    This paper reports the development of a low-cost 128 x 128 uncooled infrared focal plane array (FPA) based on suspended and thermally isolated CMOS p+-active/n-well diodes. The FPA is fabricated using a standard 0.35 μm CMOS process followed by simple post-CMOS bulk micromachining that does not require any critical lithography or complicated deposition steps; and therefore, the cost of the uncooled FPA is almost equal to the cost of the CMOS chip. The post-CMOS fabrication steps include an RIE etching to reach the bulk silicon and an anisotropic silicon etching to obtain thermally isolated pixels. During the RIE etching, CMOS metal layers are used as masking layers, and therefore, narrow openings such as 2 μm can be defined between the support arms. This approach allows achieving small pixel size of 40 μm x 40 μm with a fill factor of 44%. The FPA is scanned at 30 fps by monolithically integrated multi-channel parallel readout circuitry which is composed of low-noise differential transconductance amplifiers, switched capacitor (SC) integrators, sample-and-hold circuits, and various other circuit blocks for reducing the effects of variations in detector voltage and operating temperature. The fabricated detector has a temperature coefficient of -2 mV/K, a thermal conductance value of 1.8 x 10-7 W/K, and a thermal time constant value of 36 msec, providing a measured DC responsivity (R) of 4970 V/W under continuous bias. Measured detector noise is 0.69 μV in 8 kHz bandwidth at 30 fps scanning rate, resulting a measured detectivity (D*) of 9.7 x 108 cm√HzW. Contribution of the 1/f noise component is found to be negligible due to the single crystal nature of the silicon n-well and its low value at low bias levels. The noise of the readout circuit is measured as 0.76 μV, resulting in an expected NETD value of 1 K when scanned at 30 fps using f=1 optics. This NETD value can be decreased below 350 mK by decreasing the electrical bandwidth with the help of increased

  3. A very low-cost and adaptable DIY seismic station

    NASA Astrophysics Data System (ADS)

    Mendez Chazara, Nahum; Castiñeiras, Pedro

    2016-04-01

    With the advent of prototyping platforms and low-cost computers, geological do-it-yourself components and sensors can be quickly and inexpensively built. The design of the prototype can also be improved over several iterations, from high-resolution magnetometers to vertical electrical sounding instruments, opening new opportunities to gather data in the field or in the lab. One of the possibilities in the field of DIY geology is seismological research, because the availability and diversity of the parts used can come in handy when developing an instrument. Also, they are really easy to build without a very deep electronics background. Although the range in low-cost seismometers is usually restricted to local seismology, induced seismology or human activities, our approach is able to record data with sampling rates up to 500 Hz. It can record and analyze data with a resolution of 16-bit, but it can be regulated to reach 24-bit if needed. Data transfer can operate all-day with low power consumption, using around 1-Amp per hour, or even less, depending on the final setup chosen. Our first seismograph (<100€) consists of a vertical geophone with a natural frequency of 10 Hz, an Arduino or similar board, a 16-bit ADC capable of amplify and convert the output signal of the geophone. The latter, connected to a Raspberry Pi, gathers the data from the geophone using a Python script, slices it in 1-hour intervals and draws waveform and frequency spectrum graph for quick analysis with Matplotlib, a common graphing library in Python. The data can be gathered using several methods: If a Wi-Fi network is available, the instrument can be directly connected to the Internet and the data uploaded in real time. If there is no such connection available, a GSM shield can be used to upload the data, and in the worst-case scenario, the data can be accessed directly on the field via Wi-Fi or Ethernet connection if the location of the sensor make unable to connect via WiFi or GSM

  4. A Low Cost Spacecraft Architecture for Robotic Lunar Exploration Projects

    NASA Technical Reports Server (NTRS)

    Lemke, Lawrence G.; Gonzales, Andrew A.

    2006-01-01

    constitute the majority of spacecraft mass; saving development and integration cost on these elements is critical to controlling cost. Therefore, a low cost, modular design for spacecraft structure and propulsion subsystems is presented which may be easily scaled up or down for either insertion into lunar orbit or braking for landing on the lunar surface. In order to effectively use the approx.3 Mt mass-to-TLI of the EELV, two low cost spacecraft will be manifested on the same launch. One spacecraft will be located on top of the other for launch and the two will have to be released in sequence in order to achieve all mission objectives. The two spacecraft could both be landers, both orbiters, or one lander and one orbiter. In order to achieve mass efficiency, the body of the spacecraft will serve the dual purposes of carrying launch loads and providing attachment points for all the spacecraft subsystems. In order to avoid unaffordable technology development costs, small liquid propulsion components and autonomous, scene-matching navigation cameras may be adapted from military missile programs in order to execute precision soft landings.

  5. Access control violation prevention by low-cost infrared detection

    NASA Astrophysics Data System (ADS)

    Rimmer, Andrew N.

    2004-09-01

    A low cost 16x16 un-cooled pyroelectric detector array, allied with advanced tracking and detection algorithms, has enabled the development of a universal detector with a wide range of applications in people monitoring and homeland security. Violation of access control systems, whether controlled by proximity card, biometrics, swipe card or similar, may occur by 'tailgating' or 'piggybacking' where an 'approved' entrant with a valid entry card is accompanied by a closely spaced 'non-approved' entrant. The violation may be under duress, where the accompanying person is attempting to enter a secure facility by force or threat. Alternatively, the violation may be benign where staff members collude either through habit or lassitude, either with each other or with third parties, without considering the security consequences. Examples of the latter could include schools, hospitals or maternity homes. The 16x16 pyroelectric array is integrated into a detector or imaging system which incorporates data processing, target extraction and decision making algorithms. The algorithms apply interpolation to the array output, allowing a higher level of resolution than might otherwise be expected from such a low resolution array. The pyroelectric detection principle means that the detection will work in variable light conditions and even in complete darkness, if required. The algorithms can monitor the shape, form, temperature and number of persons in the scene and utilise this information to determine whether a violation has occurred or not. As people are seen as 'hot blobs' and are not individually recognisable, civil liberties are not infringed in the detection process. The output from the detector is a simple alarm signal which may act as input to the access control system as an alert or to trigger CCTV image display and storage. The applications for a tailgate detector can be demonstrated across many medium security applications where there are no physical means to prevent this

  6. Low-cost small satellites for astrophysical missions

    SciTech Connect

    Priedhorsky, W.C.

    1989-01-01

    A miniature satellite is a low-cost platform to support a small space experiment. Space astrophysics has been hindered by decades-long delays in important experiments. With miniature satellites, one hopes to reduce both experiment cost and lead time to an affordable level. Miniature satellites are not a new idea. The first scientific satellites, including Explorer I, were small and developed on a timescale of months. Important science was done by these pioneer missions. Though the easy discoveries have been made, important missions in exploration and follow-up can still be carried out from small platforms. Successful small satellite programs continue to this day. These include the OSCAR amateur radio satellite program, in which 12 small satellites, built by amateurs, have been flown over 25 years with no satellite failures (Fleeter, 1988). Two small free-flyers, GLOMAR and NUSAT, were ejected from the Shuttle in 1985. GLOMAR, a radio-relay experiment, was built in less than a year for under $1 million, and operated over a year in orbit. Small satellite projects continue to this day. Approaching launch are the Air Force STACKSAT array of 3 small satellites (P87-2), a number of other small satellites under Department of Defense auspices. The Air Force Space Test Program is developing a standard small experiment platform called STEP (Space Test Experiment Platform). NASA has started a small explorer program, beginning with SAMPEX, a solar and magnetospheric particle explorer, FAST, a fast auroral snapshot experiment, and SWAS, a submillimeter astronomy experiment. 5 refs., 2 figs., 2 tabs.

  7. A low-cost float method of harnessing wave energy

    SciTech Connect

    George, M.P.

    1983-12-01

    The author proposes in this paper a low-cost and simple method of harnessing wave energy that should enable coastal regions to be self-sufficient in electric power. The method is eminently applicable to India and such developing countries, being simple and involving a small capital investment. The method was evolved after study of the Indian West Coast fronting the Arabian Sea, and can harness about 50% of the wave energy. A log of wood about 5 metres long and 50 cm. in diameter, having a specific gravity of 0.8 to 0.9, is made to float parallel to the beach and about 50 metres away from it. Its movement is restricted to the vertical plane by means of poles. Two roller chains are attached to the ends of the log which pass over two sprocket free-wheels. When the log is lifted with the crest of the wave, the roller chain moves over the free-wheel. When the trough of the wave reaches the log, its weight is applied to the sprocket wheels through the roller chains. Each sprocket wheel rotates and the rotation is multiplied with a gear wheel. The torque from the high speed spindle of the gear is applied to a small alternating current generator. The AC output from the generator is rectified and used either for charging a battery bank, or connected to the lighting system, or supplied to electrolytic tank for producing hydrogen and other chemicals at the site. A chain of such systems along the coast can supply enough power to light the fishermen's hamlets stretching along the coast.

  8. A novel low-cost sodium–zinc chloride battery

    SciTech Connect

    Lu, Xiaochuan; Li, Guosheng; Kim, Jin Y.; Lemmon, John P.; Sprenkle, Vincent L.; Yang, Zhenguo

    2013-02-19

    The sodium-metal halide (ZEBRA) battery has been considered as one of the most attractive energy storage systems for stationary and transportation applications. Even though Na-NiCl2 battery has been widely investigated, there is still a need to develop a more economical system to make this technology more attractive for commercialization. In the present work, a novel low-cost Na-ZnCl2 battery with a thin planar β"-Al2O3 solid electrolyte (BASE) was proposed, and its electrochemical reactions and battery performance were investigated. Compared to the Na-NiCl2 chemistry, the ZnCl2-based chemistry was more complicated, in which multiple electrochemical reactions including liquid-phase formation occurred at temperatures above 253°C. During the first stage of charge, NaCl reacted with Zn to form Na in the anode and Na2ZnCl4 in the cathode. Once all the residual NaCl was consumed, further charging led to the formation of a NaCl-ZnCl2 liquid phase. At the end of charge, the liquid phase reacted with Zn to produce solid ZnCl2. To identify the effects of liquid-phase formation on electrochemical performance, button cells were assembled and tested at 280°C and 240°C. At 280°C where the liquid phase formed during cycling, cells revealed quite stable cyclability. On the other hand, more rapid increase in polarization was observed at 240°C where only solid-state electrochemical reactions occurred. SEM analysis indicated that the stable performance at 280°C was due to the suppressed growth of Zn and NaCl particles, which were generated from the liquid phase during discharge of each cycle.

  9. Low-Cost Approaches to Deep Space Missions

    NASA Technical Reports Server (NTRS)

    Squibb, G. F.; Edwards, C. D.; Schober, W. R.; Hooke, A. J.; Tai, W. S.; Pollmeier, V. M.

    2000-01-01

    The past decade has brought about a radical transformation in NASA's planetary exploration program. At the beginning of this decade, NASA was focused on the Cassini mission to Saturn. Following on the heels of the successful Voyager and Galileo missions, Cassini represents the culmination of an evolution towards successively larger, more complex, and more expensive spacecraft. The Cassini spacecraft weighs in at over 5 metric tons, and carries an entry probe and a sophisticated suite of sensors supporting 27 different science investigations enabling a comprehensive scientific investigation of Saturn with a single spacecraft. The cost of this spacecraft exceeded $2B, including the cost of the large Titan IV launch vehicle. During Cassini development, NASA realized that it could no longer afford these "flagship" missions, and the agency moved aggressively towards a "faster, better, cheaper" design philosophy of focused science goals and simpler, rapidly-developed spacecraft, allowing much more frequent launches of smaller, lower-cost missions. The Mars Global Surveyor, launched in November 1996, is an example of this new paradigm. Developed in less than 3-years, MGS is only one-fifth the mass of Cassini, and only cost on the order of $220M. The reduced spacecraft mass allows use of the smaller, lower cost Delta launch vehicle. Currently in orbit about Mars, MGS carries a focused suite of six science instruments that are currently returning high-resolution remote sensing of the Martian surface. The future calls for continued even more aggressive mass and cost targets. Examples of these next-generation goals are embodied in the Mars Micromission spacecraft concept, targeted for launch in 2003. With a mass of only 200kg, this lightweight bus can be tailored to carry a variety of payloads to Mars or other inner-planet destinations. The design of the Micromission spacecraft enable them to be launched at extremely low cost as a secondary "piggyback" payload.

  10. A Robust, Low-Cost Virtual Archive for Science Data

    NASA Technical Reports Server (NTRS)

    Lynnes, Christopher; Vollmer, Bruce

    2005-01-01

    Despite their expense tape silos are still often the only affordable option for petabytescale science data archives, particularly when other factors such as data reliability, floor space, power and cooling load are accounted for. However, the complexity, management software, hardware reliability and access latency of tape silos make online data storage ever more attractive. Drastic reductions in low-cost mass-market PC disk drivers help to make this more affordable (approx. 1$/GB), but are challenging to scale to the petabyte range and of questionable reliability for archival use, On the other hand, if much of the science archive could be "virtualized", i.e., produced on demand when requested by users, we would need store only a fraction of the data online, perhaps bringing an online-only system into in affordable range. Radiance data from the satellite-borne Moderate Resolution Imaging Spectroradiometer (MODIS) instrument provides a good opportunity for such a virtual archive: the raw data amount to 140 GB/day, but these are small relative to the 550 GB/day making up the radiance products. These data are routinely processed as inputs for geophysical parameter products and then archived on tape at the Goddard Earth Sciences Distributed Active Archive (GES DAAC) for distributing to users. Virtualizing them would be an immediate and signifcant reduction in the amount of data being stored in the tape archives and provide more customizable products. A prototype of such a virtual archive is being developed to prove the concept and develop ways of incorporating the robustness that a science data archive requires.

  11. PEM Electrolyzer Incorporating an Advanced Low-Cost Membrane

    SciTech Connect

    Hamdan, Monjid

    2013-08-29

    The Department of Energy (DOE) has identified hydrogen production by electrolysis of water at forecourt stations as a critical technology for transition to the hydrogen economy; however, the cost of hydrogen produced by present commercially available electrolysis systems is considerably higher than the DOE 2015 and 2020 cost targets. Analyses of proton-exchange membrane (PEM) electrolyzer systems indicate that reductions in electricity consumption and electrolyzer stack and system capital cost are required to meet the DOE cost targets. The primary objective is to develop and demonstrate a cost-effective energy-based system for electrolytic generation of hydrogen. The goal is to increase PEM electrolyzer efficiency and to reduce electrolyzer stack and system capital cost to meet the DOE cost targets for distributed electrolysis. To accomplish this objective, work was conducted by a team consisting of Giner, Inc. (Giner), Virginia Polytechnic Institute & University (VT), and domnick hunter group, a subsidiary of Parker Hannifin (Parker). The project focused on four (4) key areas: (1) development of a high-efficiency, high-strength membrane; (2) development of a long-life cell-separator; (3) scale-up of cell active area to 290 cm2 (from 160 cm²); and (4) development of a prototype commercial electrolyzer system. In each of the key stack development areas Giner and our team members conducted focused development in laboratory-scale hardware, with analytical support as necessary, followed by life-testing of the most promising candidate materials. Selected components were then scaled up and incorporated into low-cost scaled-up stack hardware. The project culminated in the fabrication and testing of a highly efficient electrolyzer system for production of 0.5 kg/hr hydrogen and validation of the stack and system in testing at the National Renewable Energy Laboratory (NREL).

  12. Designing low cost LED display for the billboard

    NASA Astrophysics Data System (ADS)

    Hong, Yi-Jian; Uang, Chii-Maw; Wang, Ping-Chieh; Ho, Zu-Sheng

    2011-10-01

    With quickly advance of the computer, microelectronics and photonics technologies, LED display panel becomes a new electronic advertising media. It can be used to show any information whatever characters or graphics. Most LED display panels are built of many Light-Emitting Diodes arranged in a matrix form. The display has many advantages such as low power, low cost, long life and high definition. Because the display panel is asked to show rich color, the LED display panel's driving system becomes very complex. The design methodology of LED display panel's driver becomes more and more important to meet the market requirements. Cost is always the most important issue in public market domain. In this paper, we report a design methodology of LED display panel's driver based on the microprocessor control unit (MCU) system and LED display controller IC, HT1632C, to control three colors, RGB, color LED display panel and the modular panel size is 24*16 in matrix form. The HT1632C is a memory mapping LED display controller, it can be used on many applications, such as digital clock, thermometer, counter, voltmeter or other instrumentation readouts. Three pieces of HT1632C are used to drive a 24*16 RGB LED display panel, in our design case. Each HT163C chip is used to control one of the R, G and B color. As the drive mode is driven in DC mode, the RGB display panel can create and totally of seven colors under the control of MCU. The MCU generates the control signal to drive HT1632C. In this study, the software design methodology is adopted with dynamic display principle. When the scan frequency is 60Hz, LED display panel will get the clear picture and be able to display seven colors.

  13. Low-cost exterior insulation process and structure

    SciTech Connect

    Vohra, Arun

    1997-12-01

    The invention relates to a low-cost process for insulating walls comprising: (a) stacking bags filled with insulating material next to the exterior surface of a wall until the wall is covered, the stack of bags thus formed having fasteners to attach to a wire mesh (e.g., straps looped between the bags and fastened to the wall); (b) stretching a wire mesh (e.g., chicken wire or stucco netting) over the stack of bags, covering the side of the bags which is not adjacent to the wall; (c) fastening the wire mesh to stationary objects; (d) attaching the wire mesh to said fasteners on said stack of bags; and (e) applying a cemetitious material (e.g., stucco) to the wire mesh and allowing it to harden. Stacking the bags against the wall is preferably preceded by laying a base on the ground at the foot of the wall using a material such as cement or crushed stone wrapped in a non-woven fabric (e.g., geosynthetic felt). It is also preferred to erect stationary corner posts at the ends of the wall to be insulated, the top ends of the posts being tied to each other and/or tied or otherwise anchored to the wall. The invention also includes the structure made by this process. The structure comprises a stack of bags of insulating material next to the exterior wall of a building, said stack of bags of insulating material being attached to said wall and having a covering of cementitious material on the side not adjacent to said wall.

  14. Manufacturing of Monolithic Electrodes from Low-Cost Renewable Resources

    SciTech Connect

    McNutt, Nichiolas William; Rios, Orlando; Johs, Alexander; Tenhaeff, Wyatt E; Chatterjee, Sabornie; Keffer, David

    2014-01-01

    Lignin, a low-cost, biomass derived precursor, was selected as an alternative for carbon based free standing anodes in Li-ion batteries. Industrially scalable melt-spinning and melt-blowing synthesis methods were developed at Oak Ridge National Laboratory that are compatible with industrially viable production. Engineering studies predict that LCFs can be manufactured at $3/lb using these technologies, which compares favorably to $12/lb for battery grade graphite. The physical properties of lignin carbon fibers, specifically the tunable electrochemical and thermal transport, are suitable for energy storage applications as both an active material and current collector. The elimination of inactive components in the slurry-coated electrodes was enabled by LCF processing parameters modifications to produce monolithic mats in which the fibers are electrically interconnected. These mats were several hundreds of micrometers thick, and the fibers functioned as both current collector and active material by virtue of their mixed ionic/electronic conductivities. The LCFs were coated onto copper current collectors with PVDF binder and conductive carbon additive through conventional slurry processing. Galvanostatic cycling of the LCFs against Li revealed reversible capacities greater than 300 mAh/g. The coulombic efficiencies were over 99.8%. The mats were galvanostatically cycled in half cells against Li. Specific capacities as high as 250 mAh/g were achieved approximately 17% lower than the capacities of the same fibers in slurries. However, there were no inactive materials reducing the practical specific capacity of the entire electrode construction. Lithiation and delithiation of the LCFs proceeded with coulombic efficiencies greater than 99.9%, and the capacity retention was greater than 99% over 100 cycles at a rate of 15 mA/g. Research sponsored by the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for

  15. Low Cost Missions Operations on NASA Deep Space Missions

    NASA Astrophysics Data System (ADS)

    Barnes, R. J.; Kusnierkiewicz, D. J.; Bowman, A.; Harvey, R.; Ossing, D.; Eichstedt, J.

    2014-12-01

    The ability to lower mission operations costs on any long duration mission depends on a number of factors; the opportunities for science, the flight trajectory, and the cruise phase environment, among others. Many deep space missions employ long cruises to their final destination with minimal science activities along the way; others may perform science observations on a near-continuous basis. This paper discusses approaches employed by two NASA missions implemented by the Johns Hopkins University Applied Physics Laboratory (JHU/APL) to minimize mission operations costs without compromising mission success: the New Horizons mission to Pluto, and the Solar Terrestrial Relations Observatories (STEREO). The New Horizons spacecraft launched in January 2006 for an encounter with the Pluto system.The spacecraft trajectory required no deterministic on-board delta-V, and so the mission ops team then settled in for the rest of its 9.5-year cruise. The spacecraft has spent much of its cruise phase in a "hibernation" mode, which has enabled the spacecraft to be maintained with a small operations team, and minimized the contact time required from the NASA Deep Space Network. The STEREO mission is comprised of two three-axis stabilized sun-staring spacecraft in heliocentric orbit at a distance of 1 AU from the sun. The spacecraft were launched in October 2006. The STEREO instruments operate in a "decoupled" mode from the spacecraft, and from each other. Since STEREO operations are largely routine, unattended ground station contact operations were implemented early in the mission. Commands flow from the MOC to be uplinked, and the data recorded on-board is downlinked and relayed back to the MOC. Tools run in the MOC to assess the health and performance of ground system components. Alerts are generated and personnel are notified of any problems. Spacecraft telemetry is similarly monitored and alarmed, thus ensuring safe, reliable, low cost operations.

  16. Additive Manufacturing of Low Cost Upper Stage Propulsion Components

    NASA Technical Reports Server (NTRS)

    Protz, Christopher; Bowman, Randy; Cooper, Ken; Fikes, John; Taminger, Karen; Wright, Belinda

    2014-01-01

    NASA is currently developing Additive Manufacturing (AM) technologies and design tools aimed at reducing the costs and manufacturing time of regeneratively cooled rocket engine components. These Low Cost Upper Stage Propulsion (LCUSP) tasks are funded through NASA's Game Changing Development Program in the Space Technology Mission Directorate. The LCUSP project will develop a copper alloy additive manufacturing design process and develop and optimize the Electron Beam Freeform Fabrication (EBF3) manufacturing process to direct deposit a nickel alloy structural jacket and manifolds onto an SLM manufactured GRCop chamber and Ni-alloy nozzle. In order to develop these processes, the project will characterize both the microstructural and mechanical properties of the SLMproduced GRCop-84, and will explore and document novel design techniques specific to AM combustion devices components. These manufacturing technologies will be used to build a 25K-class regenerative chamber and nozzle (to be used with tested DMLS injectors) that will be tested individually and as a system in hot fire tests to demonstrate the applicability of the technologies. These tasks are expected to bring costs and manufacturing time down as spacecraft propulsion systems typically comprise more than 70% of the total vehicle cost and account for a significant portion of the development schedule. Additionally, high pressure/high temperature combustion chambers and nozzles must be regeneratively cooled to survive their operating environment, causing their design to be time consuming and costly to build. LCUSP presents an opportunity to develop and demonstrate a process that can infuse these technologies into industry, build competition, and drive down costs of future engines.

  17. Improved Recharge Estimation from Portable, Low-Cost Weather Stations.

    PubMed

    Holländer, Hartmut M; Wang, Zijian; Assefa, Kibreab A; Woodbury, Allan D

    2016-03-01

    Groundwater recharge estimation is a critical quantity for sustainable groundwater management. The feasibility and robustness of recharge estimation was evaluated using physical-based modeling procedures, and data from a low-cost weather station with remote sensor techniques in Southern Abbotsford, British Columbia, Canada. Recharge was determined using the Richards-based vadose zone hydrological model, HYDRUS-1D. The required meteorological data were recorded with a HOBO(TM) weather station for a short observation period (about 1 year) and an existing weather station (Abbotsford A) for long-term study purpose (27 years). Undisturbed soil cores were taken at two locations in the vicinity of the HOBO(TM) weather station. The derived soil hydraulic parameters were used to characterize the soil in the numerical model. Model performance was evaluated using observed soil moisture and soil temperature data obtained from subsurface remote sensors. A rigorous sensitivity analysis was used to test the robustness of the model. Recharge during the short observation period was estimated at 863 and 816 mm. The mean annual recharge was estimated at 848 and 859 mm/year based on a time series of 27 years. The relative ratio of annual recharge-precipitation varied from 43% to 69%. From a monthly recharge perspective, the majority (80%) of recharge due to precipitation occurred during the hydrologic winter period. The comparison of the recharge estimates with other studies indicates a good agreement. Furthermore, this method is able to predict transient recharge estimates, and can provide a reasonable tool for estimates on nutrient leaching that is often controlled by strong precipitation events and rapid infiltration of water and nitrate into the soil. PMID:26011672

  18. Low-cost commercial glass beads as dosimeters in radiotherapy

    NASA Astrophysics Data System (ADS)

    Jafari, S. M.; Bradley, D. A.; Gouldstone, C. A.; Sharpe, P. H. G.; Alalawi, A.; Jordan, T. J.; Clark, C. H.; Nisbet, A.; Spyrou, N. M.

    2014-04-01

    Recent developments in advanced radiotherapy techniques using small field photon beams, require small detectors to determine the delivered dose in steep dose gradient fields. Commercially available glass jewellery beads exhibit thermoluminescent properties and have the potential to be used as dosimeters in radiotherapy due to their small size (<5 mm), low cost, reusability and inert nature. This study investigated the dosimetric characteristics of glass beads. The beads were irradiated by 6 MV photons using a medical linear-accelerator and 60Co gamma rays over doses ranging from 1 to 2500 cGy. A thermoluminescence (TL) system and an electron paramagnetic resonance (EPR) system were employed for read out. Both the TL and EPR studies demonstrated a radiation-induced signal, the sensitivity of which varied with bead colour. White coloured beads proved to be the most sensitive for both systems. The smallest and therefore least sensitive bead sizes allowed measurement of doses of 1 cGy using the TL system while that for the EPR system was approximately 1000 cGy. The fading rate was found to be 10% 30 days after irradiation with both readout systems. The dose response is linear with measured dose over the dose range 1 to 2500 cGy, with an R2 correlation coefficient of greater than 0.999. The batch-to-batch reproducibility of a set of dosimeters after a single irradiation was found to be 3% (1 SD). The reproducibility of individual dosimeters was found to be 1.7%. No measurable angular dependence was found (results agreed within 1%). Dose rate response was found to agree within 1% for dose rates of 100 to 600 cGy/min. These results demonstrate the potential use of glass beads as TL dosimeters over the dose range commonly applied in radiotherapy.

  19. Low Cost Upper Stage-Class Propulsion (LCUSP)

    NASA Technical Reports Server (NTRS)

    Vickers, John

    2015-01-01

    NASA is making space exploration more affordable and viable by developing and utilizing innovative manufacturing technologies. Technology development efforts at NASA in propulsion are committed to continuous innovation of design and manufacturing technologies for rocket engines in order to reduce the cost of NASA's journey to Mars. The Low Cost Upper Stage-Class Propulsion (LCUSP) effort will develop and utilize emerging Additive Manufacturing (AM) to significantly reduce the development time and cost for complex rocket propulsion hardware. Benefit of Additive Manufacturing (3-D Printing) Current rocket propulsion manufacturing techniques are costly and have lengthy development times. In order to fabricate rocket engines, numerous complex parts made of different materials are assembled in a way that allow the propellant to collect heat at the right places to drive the turbopump and simultaneously keep the thrust chamber from melting. The heat conditioned fuel and oxidizer come together and burn inside the combustion chamber to provide thrust. The efforts to make multiple parts precisely fit together and not leak after experiencing cryogenic temperatures on one-side and combustion temperatures on the other is quite challenging. Additive manufacturing has the potential to significantly reduce the time and cost of making rocket parts like the copper liner and Nickel-alloy jackets found in rocket combustion chambers where super-cold cryogenic propellants are heated and mixed to the extreme temperatures needed to propel rockets in space. The Selective Laser Melting (SLM) machine fuses 8,255 layers of copper powder to make a section of the chamber in 10 days. Machining an equivalent part and assembling it with welding and brazing techniques could take months to accomplish with potential failures or leaks that could require fixes. The design process is also enhanced since it does not require the 3D model to be converted to 2-D drawings. The design and fabrication process

  20. A Low-Cost "Stationary Eye" in the Sky

    NASA Astrophysics Data System (ADS)

    Koch, R.; Lande, K.; Mitchell, R.; Wildenhain, P.; Hoang, N.; Langford, J.

    1997-12-01

    We are developing a stationary, near the top of the atmosphere, astronomical observing system. The platform is a high altitude robotic aircraft (THESEUS) flying in anti-sense to Earth's rotation at a latitude where the plane's speed closely matches the local ground spin velocity. Thus, either an extended day or night viewing program of a given object can be achieved. Our intention here concentrates on astronomical targets. The system consists of the following components. (1) A low cost robotic aircraft that can fly at an altitude of about 25 km. for 30 to 40 hours with differential GPS navigation. Real time control of the aircraft and the observing instruments is either by on-board computer or from the ground via low altitude, commercial satellite communications systems (Iridium, Teledesic, etc.). (2) A siderostat-fed telescope of small f-ratio is attached to the aircraft via critically damped mechanical isolators. An electronic camera at the prime focus looks at a chosen astronomical target. (3) Image smear due to aircraft engine vibration will be eliminated by a combination of critically damped mechanical isolators and electronic CCD pixel jogging. Very precise piezo- electric driven transverse translation of the CCD camera will be used to compensate for wind induced drift of the image on the focal plane. Bright field stars will be used to drive the stabilizing system. (4) Data are stored on high capacity ruggedized hard drives similar to that used by the Mars Lander. The Aurora THESEUS aircraft, whose design is based upon earlier models, is under development. The image stabilizing system components have been identified. An off-the-shelf data-storage device has been chosen. A first prototype telescope has been built and tested. Other optical configurations are possible and collaborators will be welcomed.