Spelling suggestions: "subject:"sounding rocket""
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Automatização aplicada a lançadores de foguete de sondagem para compensação da influência dos ventos /Garcia, Alexandre. January 2007 (has links)
Resumo: As ações do responsável pela segurança de vôo, em lançamentos de foguetes, são fundamentais para minimizar riscos relacionados à vida, ao meio ambiente e a bens materiais. Nesse contexto está incluída a atividade de cálculo da posição do lançador, para compensação da influência do vento na trajetória de foguetes nãocontrolados. Atualmente, a execução dessa tarefa e a realimentação das informações referentes ao posicionamento do lançador não são realizadas de forma automática. Esse é um dos motivos pelos quais é necessário realizar o ajuste final do lançador, aproximadamente cinco a sete minutos antes do lançamento. No intervalo de tempo até o lançamento, o vento pode mudar de velocidade e direção, promovendo situação com potencial suficiente para causar desvio na trajetória do foguete, com conseqüente aumento da dispersão do seu ponto de impacto. O objetivo desse trabalho é propor uma arquitetura de sistema para automatizar o ajuste da posição em azimute e elevação de lançadores de foguetes de sondagem não-controlados. Os ensaios realizados com o protótipo de lançador mostraram que a proposta deste trabalho é capaz de realizar automaticamente o posicionamento de lançadores durante campanhas de lançamento, para compensar a influência do vento na trajetória do foguete, com o objetivo de diminuir a dispersão de impacto de foguetes não-controlados. / Abstract: The actions taken by the person responsible for flight safety in rocket launch are fundamental to minimize risks related to life, environment and material assets. This context includes the calculation of the launcher's position to compensate for wind influence on the unguided rocket trajectory. Currently, the accomplishment of such task and the feedback of data regarding launcher's positioning are not performed automatically. This is one of the reasons why it is necessary to make the final adjustment of the launcher approximately five to seven minutes before such launch. Within the time interval until the launch, wind speed and direction may change and give rise to a situation with enough potential to cause a deviation in the rocket's trajectory with the consequential increase in the dispersion of its point of impact. The purpose of this work is to propose a system architecture able to automate the adjustment of the position in azimuth and the elevation of unguided sounding rocket launchers. The tests made on the prototype launcher showed that the proposal of this work can automatically make the positioning of the launchers during launch campaigns to compensate for wind influence on the rocket's trajectory in order to reduce dispersion of impact of unguided rockets. / Orientador: Mauro Hugo Mathias / Coorientador: Francisco Carlos Parquet Bizarria / Banca: José Elias Tomazini / Banca: João Zangrandi Filho / Banca: Hilton Cleber Pietrobom / Banca: Viktor A. Pastoukhov / Doutor
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Automatização aplicada a lançadores de foguete de sondagem para compensação da influência dos ventosGarcia, Alexandre [UNESP] 11 September 2007 (has links) (PDF)
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garcia_a_dr_guara.pdf: 2102089 bytes, checksum: 0317ee56928eede236168b36cbbd28b5 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Agência Espacial Brasileira (AEB) / As ações do responsável pela segurança de vôo, em lançamentos de foguetes, são fundamentais para minimizar riscos relacionados à vida, ao meio ambiente e a bens materiais. Nesse contexto está incluída a atividade de cálculo da posição do lançador, para compensação da influência do vento na trajetória de foguetes nãocontrolados. Atualmente, a execução dessa tarefa e a realimentação das informações referentes ao posicionamento do lançador não são realizadas de forma automática. Esse é um dos motivos pelos quais é necessário realizar o ajuste final do lançador, aproximadamente cinco a sete minutos antes do lançamento. No intervalo de tempo até o lançamento, o vento pode mudar de velocidade e direção, promovendo situação com potencial suficiente para causar desvio na trajetória do foguete, com conseqüente aumento da dispersão do seu ponto de impacto. O objetivo desse trabalho é propor uma arquitetura de sistema para automatizar o ajuste da posição em azimute e elevação de lançadores de foguetes de sondagem não-controlados. Os ensaios realizados com o protótipo de lançador mostraram que a proposta deste trabalho é capaz de realizar automaticamente o posicionamento de lançadores durante campanhas de lançamento, para compensar a influência do vento na trajetória do foguete, com o objetivo de diminuir a dispersão de impacto de foguetes não-controlados. / The actions taken by the person responsible for flight safety in rocket launch are fundamental to minimize risks related to life, environment and material assets. This context includes the calculation of the launcher’s position to compensate for wind influence on the unguided rocket trajectory. Currently, the accomplishment of such task and the feedback of data regarding launcher’s positioning are not performed automatically. This is one of the reasons why it is necessary to make the final adjustment of the launcher approximately five to seven minutes before such launch. Within the time interval until the launch, wind speed and direction may change and give rise to a situation with enough potential to cause a deviation in the rocket’s trajectory with the consequential increase in the dispersion of its point of impact. The purpose of this work is to propose a system architecture able to automate the adjustment of the position in azimuth and the elevation of unguided sounding rocket launchers. The tests made on the prototype launcher showed that the proposal of this work can automatically make the positioning of the launchers during launch campaigns to compensate for wind influence on the rocket’s trajectory in order to reduce dispersion of impact of unguided rockets.
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Advancing spaceborne tools for the characterization of planetary ionospheres and circumstellar environmentsDouglas, Ewan S. 04 December 2016 (has links)
This work explores remote sensing of planetary atmospheres and their circumstellar surroundings. The terrestrial ionosphere is a highly variable space plasma embedded in the thermosphere. Generated by solar radiation and predominantly composed of oxygen ions at high altitudes, the ionosphere is dynamically and chemically coupled to the neutral atmosphere. Variations in ionospheric plasma density impact radio astronomy and communications. Inverting observations of 83.4 nm photons resonantly scattered by singly ionized oxygen holds promise for remotely sensing the ionospheric plasma density. This hypothesis was tested by comparing 83.4 nm limb profiles recorded by the Remote Atmospheric and Ionospheric Detection System aboard the International Space Station to a forward model driven by coincident plasma densities measured independently via ground-based incoherent scatter radar. A comparison study of two separate radar overflights with different limb profile morphologies found agreement between the forward model and measured limb profiles. A new implementation of Chapman parameter retrieval via Markov chain Monte Carlo techniques quantifies the precision of the plasma densities inferred from 83.4 nm emission profiles. This first study demonstrates the utility of 83.4 nm emission for ionospheric remote sensing.
Future visible and ultraviolet spectroscopy will characterize the composition of exoplanet atmospheres; therefore, the second study advances technologies for the direct imaging and spectroscopy of exoplanets. Such spectroscopy requires the development of new technologies to separate relatively dim exoplanet light from parent star light. High-contrast observations at short wavelengths require spaceborne telescopes to circumvent atmospheric aberrations. The Planet Imaging Concept Testbed Using a Rocket Experiment (PICTURE) team designed a suborbital sounding rocket payload to demonstrate visible light high-contrast imaging with a visible nulling coronagraph. Laboratory operations of the PICTURE coronagraph achieved the high-contrast imaging sensitivity necessary to test for the predicted warm circumstellar belt around Epsilon Eridani. Interferometric wavefront measurements of calibration target Beta Orionis recorded during the second test flight in November 2015 demonstrate the first active wavefront sensing with a piezoelectric mirror stage and activation of a micromachine deformable mirror in space.
These two studies advance our ``close-to-home'' knowledge of atmospheres and move exoplanetary studies closer to detailed measurements of atmospheres outside our solar system.
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Proposta de modelo para simular faltas em rede elétrica de serviço utilizada por foguetes de sondagem / Proposed model to simulate faults in the service electrical network used by sounding rocketsFábio Duarte Spina 18 December 2009 (has links)
Este trabalho apresenta propostas de modelos computacionais para representar os principais esquemas de aterramento e equipamentos presentes na rede elétrica de serviço que é utilizada por foguetes de sondagem, com a meta de permitir a verificação operacional e viabilidade técnica no contexto da distribuição de energia elétrica. Nesses modelos são simuladas as condições de operação nominal e em falta, sendo que essa última é realizada em pontos estratégicos da rede elétrica com o propósito de determinar valores máximos de corrente alcançados pelo sistema nessas condições. Os valores de corrente obtidos nessas simulações são principalmente utilizados como referência na escolha do esquema de distribuição da energia elétrica mais adequada para ser utilizado pela rede embarcada em foguetes de sondagem e na determinação de características elétricas mínimas que os equipamentos de bordo devem possuir a fim de atenderem as condições nominais e suportar as possíveis faltas que podem acometer o sistema. Os resultados satisfatórios obtidos nas simulações dos modelos computacionais elaborados para representar os esquemas de aterramento e equipamentos pertencentes à rede elétrica de serviço que é utilizada por foguetes de sondagem, apresentados neste trabalho, indicam que os modelos são consistentes e adequados aos propósitos que se destinam. / This work presents the proposals for computational models to represent the main grounding schemes and equipment used in the service electrical network used by sounding rockets with the goal of enabling the operational verification and technical viability in the context of electrical power distribution. In these models are simulated the conditions of nominal operation and in fault, and the latter is carried out at strategic points in the electrical network with the purpose of determining maximum power achieved by the system under these conditions. The current values obtained in these simulations are mainly used as a guide in choosing the distribution of power best suited to be used by the service electrical network and the determination of electrical characteristics requirements that the equipment should possess in order to meet the nominal conditions and support the possible faults that can affect the system. The satisfactory results obtained in the simulations of the computer models designed to represent the grounding schemes and equipment belonging to the service electrical network used by sounding rockets, presented in this paper indicates that the models are consistent and appropriate to the purposes intended.
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Liquid phase sintering of W-Ni-Fe composites : liquid penetration, agglomerate separation and tungsten particle growthEliasson, Anders January 2006 (has links)
The initial stage of liquid phase sintering, involving liquid penetration, agglomerate separation, particle spreading and growth has been investigated in experiments using tungsten heavy alloys. The particle composites used were produced by hot isostatic pressing (HIP) of pure powder mixtures of W-Ni-Fe-(Co). By using different HIP temperatures, volume fractions of tungsten, alloying elements like Cobalt and Sulphur or excluding Iron from the matrix, liquid penetration, agglomerate separation and particle growth conditions were affected. The investigations were performed mainly under microgravity (sounding rockets or parabolic trajectories by airplanes) but at high tungsten particle fractions, short sintering times or at infiltration of solid pure tungsten, they were performed at normal gravity. The liquid penetration of the tungsten agglomerates is explained by initial wetting under non-equilibrium conditions, due to the reaction between the liquid matrix and the particles, and a decrease of interfacial energy. The dissolving of tungsten gives a pressure drop in the penetrating liquid and a driving force for the liquid movement by a suggested parabolic penetration model. For cold worked tungsten, a penetration theory was proposed, where an internal stress release in the penetrated tungsten grains creates space for the advancing liquid. The spreading of the tungsten agglomerates is explained by an interagglomerate melt swelling due to a Kirkendall effect. The liquid matrix undergoes a volume increase since the diffusion rates of Ni-Fe are higher than for W and initial concentration gradients of W and Ni, Fe exists. The suggested model by Kirkendall are also used for an analysis of the interaction behaviour between solid particles and a solidification front and inclusion behaviour in iron base alloys during teeming and deoxidation. The average tungsten particles size decrease initially since part of the tungsten particles is dissolved when the non-equilibrium matrix phase is melting. When equilibrium is reached, the tungsten particles grow in accordance with the Ostwald ripening process by an approximately 1/3 power law. Larger particle fraction of particles showed a higher growth rate, due to shorter diffusion distances between the particles. Cobalt, Sulphur and absence of iron in the matrix were found to increase the growth rate of the tungsten particles due to a higher surface tension between the solid tungsten particles and the matrix melt. / QC 20100528
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Design and performance simulation of a hybrid sounding rocket.Chowdhury, Seffat Mohammad. January 2012 (has links)
Sounding rockets find applications in multiple fields of scientific research including
meteorology, astronomy and microgravity. Indigenous sounding rocket technologies are absent
on the African continent despite a potential market in the local aerospace industries. The UKZN
Phoenix Sounding Rocket Programme was initiated to fill this void by developing inexpensive
medium altitude sounding rocket modeling, design and manufacturing capacities. This
dissertation describes the development of the Hybrid Rocket Performance Simulator (HYROPS)
software tool and its application towards the structural design of the reusable, 10 km apogee
capable Phoenix-1A hybrid sounding rocket, as part of the UKZN Phoenix programme.
HYROPS is an integrated 6–Degree of Freedom (6-DOF) flight performance predictor for
atmospheric and near-Earth spaceflight, geared towards single-staged and multi-staged hybrid
sounding rockets. HYROPS is based on a generic kinematics and Newtonian dynamics core.
Integrated with these are numerical methods for solving differential equations, Monte Carlo
uncertainty modeling, genetic-algorithm driven design optimization, analytical vehicle structural
modeling, a spherical, rotating geodetic model and a standard atmospheric model, forming a
software framework for sounding rocket optimization and flight performance prediction. This
framework was implemented within a graphical user interface, aiming for rapid input of model
parameters, intuitive results visualization and efficient data handling. The HYROPS software
was validated using flight data from various existing sounding rocket configurations and found
satisfactory over a range of input conditions. An iterative process was employed in the aerostructural
design of the 1 kg payload capable Phoenix-1A vehicle and CFD and FEA numerical
techniques were used to verify its aerodynamic and thermo-structural performance. The design
and integration of the Phoenix-1A‟s hybrid power-plant and onboard electromechanical systems
for recovery parachute deployment and motor oxidizer flow control are also discussed. It was
noted that use of HYROPS in the design loop led to improved materials selection and vehicle
structural design processes. It was also found that a combination of suitable mathematical
techniques, design know-how, human-interaction and numerical computational power are
effective in overcoming the many coupled technical challenges present in the engineering of
hybrid sounding rockets. / Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.
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Performance modelling and simulation of a 100km hybrid sounding rocket.Leverone, Fiona Kay. January 2013 (has links)
The University of KwaZulu-Natal (UKZN) Phoenix Hybrid Sounding Rocket Programme was established in 2010. The programme’s main objective is to develop a sounding rocket launch capability for the African scientific community, which currently lacks the ability to fly research payloads to the upper atmosphere. In this dissertation, UKZN’s in-house Hybrid Rocket Performance Simulator (HYROPS) software is used to improve the design of the Phoenix-2A vehicle, which is intended to deliver a 5 kg instrumentation payload to an apogee altitude of 100 km.
As a benchmarking exercise, HYROPS was first validated by modelling the performance of existing sub-orbital sounding rockets similar in apogee to Phoenix-2A. The software was found to approximate the performance of the published flight data within 10%. A generic methodology was then proposed for applying HYROPS to the design of hybrid propellant sounding rockets. An initial vehicle configuration was developed and formed the base design on which parametric trade studies were conducted. The performance sensitivity for varying propulsion and aerodynamic parameters was investigated. The selection of parameters was based on improving performance, minimising cost, safety and ease of manufacturability. The purpose of these simulations was to form a foundation for the development of the Phoenix-2A vehicle as well as other large-scale hybrid rockets.
Design chamber pressure, oxidiser-to-fuel ratio, nozzle design altitude, and fin geometry were some of the parameters investigated. The change in the rocket’s propellant mass fraction was the parameter which was found to have the largest effect on performance. The fin and oxidiser tank geometries were designed to avoid fin flutter and buckling respectively. The oxidiser mass flux was kept below 650 kg/m2s and the pressure drop across the injector relative to the chamber pressure was maintained above 15% to mitigate the presence of combustion instability.
The trade studies resulted in an improved design of the Phoenix-2A rocket. The propellant mass of the final vehicle was 30 kg less than the initial conceptual design and the overall mass was reduced by 25 kg. The Phoenix-2A vehicle was 12 m in length with a total mass of 1006 kg. The fuel grain length of Phoenix-2A was 1.27 m which is approximately 3 times that of Phoenix-1A. The benefit of aluminised paraffin wax as a fuel was also investigated. The results indicated that more inert mass can be delivered to the target apogee of 100 km when using a 40% aluminised paraffin wax. / M.Sc.Eng. University of KwaZulu-Natal, Durban 2013.
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Constru??o e valida??o de um receptor GPS para uso espacialAlbuquerque, Glauberto Leilson Alves de 20 November 2009 (has links)
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Previous issue date: 2009-11-20 / Global Positioning System, or simply GPS, it is a radionavigation system developed by United States for military applications, but it becames very useful for civilian using. In the last decades Brazil has developed sounding rockets and today many projects to build micro and nanosatellites has appeared. This kind of vehicles named spacecrafts or high dynamic vehicles, can use GPS for its autonome location and trajectories controls. Despite of a huge number of GPS receivers available for civilian applications, they cannot used in high dynamic vehicles due environmental issues (vibrations, temperatures, etc.) or imposed dynamic working limits. Only a few nations have the technology to build GPS receivers for spacecrafts or high dynamic vehicles is available and they imposes rules who difficult the access to this receivers. This project intends to build a GPS receiver, to install them in a payload of a sounding rocket and data collecting to verify its correct operation when at the flight conditions. The inner software to this receiver was available in source code and it was tested in a software development platform named GPS Architect. Many organizations cooperated to support this project: AEB, UFRN, IAE, INPE e CLBI. After many phases: defining working conditions, choice and searching electronic, the making of the printed boards, assembling and assembling tests; the receiver was installed in a VS30 sounding rocket launched at Centro de Lan?amento da Barreira do Inferno in Natal/RN. Despite of the fact the locations data from the receiver were collected only the first 70 seconds of flight, this data confirms the correct operation of the receiver by the comparison between its positioning data and the the trajectory data from CLBI s tracking radar named ADOUR / O Sistema de Posicionamento Global, conhecido mundialmente pala sigla GPS, ? um sistema de radionavega??o constru?do pelos norte-americanos com inten??es militares, mas que encontraram, com o passar do tempo, muitas aplica??es de uso civil. No Brasil, al?m do desenvolvimento de foguetes de sondagem, come?am a aparecer projetos de constru??o de micro e nanosat?lites. Estes ve?culos denominados espaciais ou de alta din?mica podem, quando em voo, usufruir do sistema GPS para localiza??o aut?noma e verifica??o/controle das suas trajet?rias. Apesar da enorme disponibilidade de receptores GPS no mercado civil, estes n?o podem ser utilizados em ve?culos de alta din?mica, seja por quest?es ambientais (vibra??es, temperaturas elevadas, etc.) ou por prote??o l?gica (via software). Os receptores para uso em ve?culos de alta din?mica, ou ve?culos espaciais, fazem parte de uma tecnologia restrita a poucos pa?ses, que estabelecem regras muito r?gidas para suas aquisi??es. O presente projeto objetiva construir e validar funcionamento b?sico deste receptor ao instal?-lo num foguete de sondagem e coleta de dados em voo. O software a ser utilizado no receptor j? estava dispon?vel em c?digo fonte e testado em uma plataforma de desenvolvimento denominada GPS Architect. V?rios organismos cooperaram para realiza??o projeto: AEB, UFRN, IAE, INPE e CLBI. Ap?s v?rios passos para realiza??o do projeto: defini??o das condi??es de funcionamento, escolha e aquisi??o dos componentes eletr?nicos, fabrica??o das placas de circuito impresso, montagem e testes de integra??o; o mesmo foi instalado num foguete de sondagem VS30 lan?ado a partir do Centro de Lan?amento da Barreira do Inferno em Natal/RN. Apesar da coleta parcial dos dados do receptor, por falha t?cnica do sistema de telemetria do foguete, os resultados obtidos foram suficientes para validar o funcionamento do receptor a partir da compara??o entre os dados de trajetografia fornecidos pelo receptor GPS e o radar de trajetografia do CLBI conhecido como Radar ADOUR
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Satellite meteorology in the cold war era: scientific coalitions and international leadership 1946-1964Callahan, Angelina Long 13 January 2014 (has links)
In tracing the history of the TIROS meteorological satellite system, this dissertation details the convergence of two communities: the DOD space scientists who established US capability to launch and operate these remote sensing systems and the US Weather Bureau meteorologists who would be the managers and users of satellite data. Between 1946 and 1964, these persons participated in successive coalitions. These coalitions were necessary in part because satellite systems were too big—geographically, fiscally, and technically—to be developed and operated within a single institution.
Thus, TIROS technologies and people trace their roots to several research centers—institutions that the USWB and later NASA attempted to coordinate for US R&D. The gradual transfer of persons and hardware from the armed services to the non-military NASA sheds light on the US’s evolution as a Cold War global power, shaped from the “top-down” (by the executive and legislative branches) as well as the “bottom-up” (by military and non-military scientific communities).
Through these successive coalitions, actor terms centered on “basic science” or the circulation of atmospheric data were used to help define bureaucratic places (the Upper Atmospheric Rocket Research Panel, International Geophysical Year, NASA, and the World Weather Watch) in which basic research would be supported by sustained
and collaboration could take place with international partners.
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