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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mission Analysis of the Nanosatellite Sonate

Hermannsdörfer, Nadine January 2017 (has links)
The objective of this thesis is the development of a software application facilitating a quick and extensive mission analysis including all subsystems of the satellite. Furthermore mission analysis for the Sonate mission is done, utilizing the developed program. Usually mission analysis is done by applying separately different tools which are specific for each subsystem. The drawback of this method is that the system is not analyzed as a whole; rather all subsystems are investigated separately from each other. In case one or more system parameters should change, the effect of this variation onto other parts of the system will not directly be accessible and visible. A simulation tool considering all these subsystems overcomes this weaknesses and helps to develop a balanced system. Different system configurations and operation scenarios can be evaluated quickly and compared to each other in order to find an optimal solution. The simulation system developed during this thesis exhibits a client-server structure, where the subsystems are separated modules acting as clients. The program has a highly modular structure which renders it possible to have an arbitrary extension in the future. Aside from the server, connecting all modules, the following modules were implemented: orbital dynamics module containing orbit propagation and attitude determination power subsystem consisting of the subparts power production, power consumption and power storage archiving module saving all results generated for further evaluation simulation clock providing the simulation time configuration module with a GUI to facilitate the configuration of all simulation parameters simple thermal module providing temperatures for the satellite panels Mission analysis was done for the Sonate satellite utilizing the developed program in order to find a configuration for the solar panels of the satellite such that all the subsystems of the satellite can be supplied with sufficient power during the mission.
2

Théorie analytique fermée d'un satellite artificiel lunaire pour l'analyse de mission.

De Saedeleer, Bernard 28 June 2006 (has links)
Le but de ce travail est de développer un outil d'aide à l'analyse de mission pour un satellite artificiel autour de la Lune. Nous développons tout d'abord une théorie analytique qui décrit suffisamment bien la dynamique du satellite lunaire : nous considérons les quatre perturbations majeures de natures différentes qui l'influencent, ainsi que leurs différents couplages. Les résultats sont obtenus sous forme fermée, sans aucun développement en série de l'excentricité ni de l'inclinaison de l'orbite du satellite : la solution s'applique donc à une large gamme de valeurs. Nous utilisons la méthode des Transformées de Lie pour moyenniser deux fois l'Hamiltonien du problème, dans des variables canoniques, ce qui permet d'intégrer des orbites avec un temps de calcul réduit d'un facteur environ 200 000. Grâce à cela, nous produisons des cartes inédites d'espaces de phase (a,i) qui permettent de sélectionner les paramètres orbitaux selon les besoins de la mission lunaire. De nombreuses vérifications analytiques par rapport à la littérature ont été réalisées, et se sont avérées concluantes; la qualité des deux moyennisations a également été vérifiée. Le logiciel développé est souple et permet un traitement automatisé; les intégrations sont automatiquement vérifiées. Nous avons aussi apporté quelques améliorations significatives au manipulateur algébrique des FUNDP, comme l'ajout de fractions symboliques. Par ailleurs, nous résolvons le problème zonal complet du satellite artificiel, étudions l'effet de C22 sur l'inclinaison critique ainsi que l'effet de la Terre sur les durées de vie orbitales limitées de certains satellites lunaires. The aim of this work is to develop a tool helpful to mission analysis of a lunar artificial satellite. We first develop an analytical theory which sufficiently well describes the dynamics of the lunar satellite : we consider the four main perturbations of various kind which influence it, together with their several coupling. The results are obtained in closed form, without any series expansion in eccentricity nor inclination of the orbit of the satellite : so the solution applies for a wide range of values. We use the Lie Transform method for averaging twice the Hamiltonian of the problem, in canonical variables, which allows to integrate orbits with a CPU time reduced by a factor of about 200 000. Thanks to that, we produce unpublished (a,i) phase space maps from which the orbital parameters can be selected on the basis of the needs of the lunar mission. Many conclusive analytical checks with the literature have been performed, and both averaging processes have been checked. The software developed is flexible and allows an automated treatment; the integrations are automatically checked. We also improved significantly the algebraic manipulator of the FUNDP, like the inclusion of symbolic fractions. Moreover, we solve the complete zonal problem of the artificial satellite, we study the effect of C22 on the critical inclination, and also the effect of the Earth on the limited orbital lifetimes of some lunar satellites.
3

Mission Analysis For Pico-scale Satellite Based Dust Detection In Low Earth Orbits

Belli, Jacob 01 January 2013 (has links)
A conceptual dust detection mission, KnightSat III, using pico-scale satellites is analyzed. The purpose of the proposed KnightSat III mission is to aid in the determination of the size, mass, distribution, and number of dust particles in low earth orbits through a low cost and flexible satellite or a formation of satellites equipped with a new dust detector. The analysis of a single satellite mission with an on-board dust detector is described; though this analysis can easily be extended to a formation of pico-scale satellites. Many design aspects of the mission are discussed, including orbit analysis, power management, attitude determination and control, and mass and power budgets. Two of them are emphasized. The first is a new attitude guidance and control method, and the second is the online optimal power scheduling. It is expected that the measurements obtained from this possible future mission will provide insight into the dynamical processes of inner solar system dust, as well as aid in designing proper micro-meteoroid impact mitigation strategies for future man-made spacecraft.
4

Tools for optimizing the observation planning of the MATS satellite mission

Skånberg, David January 2019 (has links)
MATS Satellite
5

Stochastic feasibility assessments of orbital propellant depot and commercial launch enabled space exploration architectures

Chai, Patrick R. 07 January 2016 (has links)
The 2010 National Space Policy of the United State of America introduced by President Obama directed NASA to set far reaching exploration milestones that included a crewed mission to a Near Earth Asteroid by 2025 and a crewed mission to Martian orbit by the mid-2030s. The policy was directly influenced by the recommendations of the 2009 Review of United States Human Space Flight Plans Committee, which called for an evolutionary approach to human space exploration and emphasized the criticality of budgetary, programmatic, and program sustainability. One potential method of improving the sustainability of exploration architectures is the utilization of orbital propellant depots with commercial launch services. In any exploration architecture, upwards of seventy percent of the mass required in orbit is propellant. A propellant depot based architecture allows propellant to be delivered in small increments using existing commercial launch vehicles, but will require three to five times the number of launches as compared to the using the NASA planned 70 to 130 metric ton heavy lift launch system. Past studies have shown that the utilization of propellant depots in exploration architectures have the potential of providing the sustainability that the Review of United States Human Space Flight Plans Committee emphasized. However, there is a lack of comprehensive analysis to determine the feasibility of propellant depots within the framework of human space exploration. The objective of this research is to measure the feasibility of a propellant depot and commercial launch based exploration architecture by stochastic assessment of technical, reliability, and economic risks. A propellant depot thermal model was developed to analyze the effectiveness of various thermal management systems, determine their optimal configuration, quantify the uncertainties in the system models, and stochastically compute the performance feasibility of the propellant depot system. Probabilistic cost analysis captured the uncertainty in the development cost of propellant depots and the fluctuation of commercial launch prices, and, along with the cost of launch failures, provided a metric for determining economic feasibility. Probabilistic reliability assessments using the launch schedule, launch reliability, and architecture requirements of each phase of the mission established launch success feasibility. Finally, an integrated stochastic optimization was performed to determine the feasibility of the exploration architecture. The final product of this research is an evaluation of propellant depots and commercial launch services as a practical method to achieving economic sustainability for human space exploration. A method for architecture feasibility assessment is demonstrated using stochastic system metrics and applied in the evaluation of technical, economic, and reliability feasibility of orbital propellant depots and commercial launch based exploration architectures. The results of the analysis showed the propellant depots based architectures to be technically feasible using current commercial launch vehicles, economically feasible for having a program budget less than $4 billion per year, and have launch reliability approaching the best single launch vehicle, Delta IV, with the use of redundant vehicles. These results serve to provide recommendations on the use of propellant depots in exploration architectures to the Moon, Near Earth Objects, Mars, and beyond.The 2010 National Space Policy of the United State of America introduced by President Obama directed NASA to set far reaching exploration milestones that included a crewed mission to a Near Earth Asteroid by 2025 and a crewed mission to Martian orbit by the mid-2030s. The policy was directly influenced by the recommendations of the 2009 Review of United States Human Space Flight Plans Committee, which called for an evolutionary approach to human space exploration and emphasized the criticality of budgetary, programmatic, and program sustainability. One potential method of improving the sustainability of exploration architectures is the utilization of orbital propellant depots with commercial launch services. In any exploration architecture, upwards of seventy percent of the mass required in orbit is propellant. A propellant depot based architecture allows propellant to be delivered in small increments using existing commercial launch vehicles, but will require three to five times the number of launches as compared to the using the NASA planned 70 to 130 metric ton heavy lift launch system. Past studies have shown that the utilization of propellant depots in exploration architectures have the potential of providing the sustainability that the Review of United States Human Space Flight Plans Committee emphasized. However, there is a lack of comprehensive analysis to determine the feasibility of propellant depots within the framework of human space exploration. The objective of this research is to measure the feasibility of a propellant depot and commercial launch based exploration architecture by stochastic assessment of technical, reliability, and economic risks. A propellant depot thermal model was developed to analyze the effectiveness of various thermal management systems, determine their optimal configuration, quantify the uncertainties in the system models, and stochastically compute the performance feasibility of the propellant depot system. Probabilistic cost analysis captured the uncertainty in the development cost of propellant depots and the fluctuation of commercial launch prices, and, along with the cost of launch failures, provided a metric for determining economic feasibility. Probabilistic reliability assessments using the launch schedule, launch reliability, and architecture requirements of each phase of the mission established launch success feasibility. Finally, an integrated stochastic optimization was performed to determine the feasibility of the exploration architecture. The final product of this research is an evaluation of propellant depots and commercial launch services as a practical method to achieving economic sustainability for human space exploration. A method for architecture feasibility assessment is demonstrated using stochastic system metrics and applied in the evaluation of technical, economic, and reliability feasibility of orbital propellant depots and commercial launch based exploration architectures. The results of the analysis showed the propellant depots based architectures to be technically feasible using current commercial launch vehicles, economically feasible for having a program budget less than $4 billion per year, and have launch reliability approaching the best single launch vehicle, Delta IV, with the use of redundant vehicles. These results serve to provide recommendations on the use of propellant depots in exploration architectures to the Moon, Near Earth Objects, Mars, and beyond.
6

Rozvoj malého podnikatelského subjektu / The development of small business entity

Klouda, Martin January 2007 (has links)
The master's thesis treat of procedure of a small business entity's developement. It deals with analysis of firm's enviroment and with proposal of vision, mission, goals and strategy, which should help the small business entity be successful during its transition from a starting stage to a groving stage of the life cycle. At the end a few words about implementation are added as well as possible risks which could appear.
7

Development of a Low Earth Orbit Mission Preliminary Analysis Tool / Utveckling av ett verktyg för preliminär analys av rymduppdrag i låg jordbana

Staniscia, Giada January 2019 (has links)
The objective of this project is the development of a mission analysis tool for the nanosatellite company GomSpace Sweden. Although there are many existing software, they can be quite complicated and time consuming to use. The goal of this work is to build a simple app to be used at the earliest stages of space missions in order to obtain key figures of merit quickly and easily. By comparing results, assessing the feasibility of customer needs, analysing how various parameters affect each other, it enables immediate deeper understanding of the implications of the main design decisions that are taken at the very beginning of a mission. The tool shall aid the system engineering process of determining orbit manoeuvre capability specifically for CubeSat electric propulsion systems taking into account the most relevant factors for perturbation in Low Earth Orbit (LEO), i.e. atmospheric drag and Earth’s oblateness effects. The manoeuvres investigated are: orbit raising from an insert orbit to an operating orbit, orbit maintenance, deorbiting within the space debris mitigation guidelines and collision avoidance within the 12 to 24 hours that the system has to react. The manoeuvres cost is assessed in terms of Delta v requirements, propellant mass and transfer times. The tool was developed with MATLAB and packaged as a standalone Linux application. / Målet med detta examensarbete var att utveckla ett verktyg för missionsanalys för nanosatellitföretaget GomSpace Sweden. Det finns många andra mjukvaror för att nå samma mål men de är ofta komplicerade och tidskrävande. Det specifika målet var således att skapa en enkel applikation som kan användas i de tidiga stegen av utformning av rymduppdrag för att snabbt och enkelt få fram viktiga parametrar. Genom att jämföra resultat, uppskatta genomförbarheten av kundbehov och analysera hur olika parametrar påverkar varandra kan omedelbar förståelse erhållas rörande påverkan av designbeslut som tas i början av rymduppdragen. Verktyget ska stödja systemingenjörsprocessen genom att uppskatta banförflyttningskapacitet för elektriska framdrivningssystem för CubeSats och ta i beaktande de mest relevanta faktorerna gällande störningar i låg jordbana (LEO), i.e. atmosfäriskt motstånd och effekterna av Jordens form. De undersökta manövrarna är: banhöjning från injektionsbana till operationell bana, banunderhåll, bansänkning som följer riktlinjerna för rymdskrot och kollisionsundvikande inom de 12 till 24 timmar som systemet har på sig att reagera. Kostnaden för manövrarna är uppskattade genom DeltaV-krav, massan av bränslet och förflyttningstider. Verktyget utvecklades med MATLAB och paketerades som en fristående applikation i Linux.
8

A PC-BASED RF TEST CONSOLE FOR INTEGRATION & TEST ON NASA’S LUNAR PROSPECTOR SPACECRAFT

Losik, Len 10 1900 (has links)
International Telemetering Conference Proceedings / October 27-30, 1997 / Riviera Hotel and Convention Center, Las Vegas, Nevada / Lunar Prospector’s project engineering staff selected a Windows PC platform as the RF test console for the Lunar Prospector spacecraft. The spacecraft test team chose the PCbased RF test console because the PC provides a low-cost, common platform with a graphical user interface. The PC provides point-and-click, menu-driven windows that are common throughout the satellite factory. The PC RF test console is being used to exercise the Lunar Prospector spacecraft RF link for RF commanding, telemetry, and ranging signals during factory test, including thermal vacuum chamber testing. For spacecraft command and control at the factory, the PC-based RF test console is networked to a UNIX workstation over RS-422. The PC RF test console and spacecraft interface are controlled through a coax switch residing in a test rack next to the workstation. The PC RF test console is connected directly to the Lunar Prospector spacecraft using coax cable through the spacecraft Telemetry, Commanding, & Ranging (TC&R) RF antenna hat for both transmit and receive functions. The PC RF test console is also connected hard-line to the spacecraft transponder through the transponder RS-422 connection. This connection provides the ability for spacecraft telemetry to be received at the PC at RF or baseband. The same hard-line spacecraft telemetry data is provided to the UNIX workstation for comparison. NASA’s Lunar Prospector project is the first of the Discovery series of “faster, better, cheaper” missions to be competitively awarded. Lunar Prospector project funding was capped by NASA to ensure that no overruns would occur. The mission was funded to support the scientific community’s desire to verify the presence of ice on the moon and collect environmental data to understand the dynamics that may have led to polar ice deposits. The Lunar Prospector mission received funding in 1996 with a launch planned for September 1997
9

Multiple CubeSat Mission for Auroral Acceleration Region Studies

Castro, Marley Santiago January 2021 (has links)
The Auroral Acceleration Region (AAR) is a key region in understanding the interactionbetween the Magnetosphere and Ionosphere. To understand the physical, spatial, and temporal features of the region, multi-point measurements are required. Distributed small-satellite missions such as constellations of multiple nano satellites (for example multi-unit CubeSats) would enable such type of measurements. The capabilities of such a mission will highly depend on the number of satellites - one reason that makes low-cost platforms like CubeSats a very promising choice. In a previous study, the state-of-the-art of miniaturized payloads for AAR measurements was analyzed and evaluated on the capabilities of different multi-CubeSat configurations equipped with such payloads in addressing different open questions in AAR. This thesis will provide the mission analysis of such a multi-CubeSat mission to the AAR and possible mission design. This includes defining the mission scenario and associated requirements, developing a mathematical description of AAR that allows for specific regions in space to be targeted, an optimisation process for designing orbits targeting these regions, conversion of a satellite formation to appropriate orbits, verifying the scientific performance of this formation and the various costs associated with entering, maintaining, and exiting these orbits.
10

Strategické řízení firmy poskytující služby / Strategic management of company providing services

KOKEŠOVÁ, Radka January 2016 (has links)
The thesis is focused on strategic management in the company providing services. The target of thesis is analyze the current situation in the company and propose possible improvements. The main target is divide into intermediate target. The first target is chose suitable model of strategic management, the second target is use strategic methods to find inner and outer company´s surroundings. The third target is apply selected model of strategic management to company. The proposed strategy, require much work within the framework of its implementation, so the schedule of strategic operations, both in content and also in terms of the time orientation.

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