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Fanizza, Vincenzo (author)Performing crucial activities for space exploration, e.g., debris removal and on-orbit servicing, systems for Rendezvous and Proximity Operations (RPO) are required to be autonomous and scalable. Within this context, learning-based relative navigation has gained significant traction due to the latest advancements in AI and the cost-effectiveness...master thesis 2023
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Bezsilla, Janos (author)Nowadays, many space missions require highly accurate pointing for Earth observation or cosmic vision purposes. However, the vibration environment from a spacecraft's structure and reaction wheels can cause disturbances in its line-of-sight stability and severely impact image quality. Additionally, these effects are not known precisely due to...master thesis 2023
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Atmaca, D. (author), Pontani, Mauro (author)This research proposes a near-optimal feedback guidance based on nonlinear control for low-thrust Earth orbit transfers. For the numerical simulations, two flight conditions are defined: (i) nominal conditions and (ii) nonnominal conditions that account for the orbit injection errors and the stochastic failures of the propulsion system....conference paper 2023
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Bieber, M.T. (author), Verhagen, W.J.C. (author), Cosson, Fabrice (author), Santos, Bruno F. (author)Spacecraft systems collect health-related data continuously, which can give an indication of the systems’ health status. While they rarely occur, the repercussions of such system anomalies, faults, or failures can be severe, safety-critical and costly. Therefore, the data are used to anticipate any kind of anomalous behaviour. Typically this is...journal article 2023
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Feijen, Joris (author)The performance requirements of optical instruments in space telescopes become increasingly demanding. Designing thermoelastic structures is key to account for thermal distortions to achieve the required performance, and modal analysis is required to ensure their survival. This thesis investigates how topology optimization can improve upon...master thesis 2022
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Casals Sadlier, Juliette (author)The implementation of a model-free, off-policy, actor-critic deep reinforcement learning algorithm consistent of two separate agents to a six-degree-of freedom spacecraft docking maneuver to develop a control policy is carried out in the research presented in this article. Reinforcement learning has the ability to learn without instruction, this...master thesis 2022
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Stolk, Toon Stolk (author)There is no denying that the ever-increasing demand in space endeavours calls for more sustainable exploitation of the space environment. Approaches to mitigate space debris, such as ADR, are frequently suggested. Most of these proposals suggest a single sensor approach to provide accurate and continuous shape and pose estimation of the target....master thesis 2022
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Bezsilla, János (author), Takarics, Bela (author), Vanek, Bálint (author), Guo, J. (author)This article focuses on the validation of a classical PID controller scheme for flexible spacecraft with regards to the effect of parameter uncertainty on system stability and pointing precision. A high-fidelity simulation environment with external disturbances was built in Simulink using a control-oriented model of an Earth-observing...journal article 2022
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Shao, X. (author), Yao, Weiran (author), Li, Xiaolei (author), Sun, Guanghui (author), Wu, Ligang (author)This letter investigates the direct trajectory optimization of the free-floating space manipulator (FFSM). The main purpose is to plan the joint space trajectories to reduce the spacecraft motion due to the joint rotation during the FFSM performing tasks. To improve the calculation efficiency, the adaptive Radau pseudospectral method (A-RPM)...journal article 2022
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Molera Calvés, G. (author), Pogrebenko, S. V. (author), Wagner, J. F. (author), Cimò, G. (author), Gurvits, L. (author), Bocanegra-Bahamón, T. M. (author), Duev, D. A. (author), Nunes, N. V. (author)We present a software package for single-dish data processing of spacecraft signals observed with VLBI-equipped radio telescopes. The Spacecraft Doppler tracking (SDtracker) software allows one to obtain topocentric frequency detections with a sub-Hz precision and reconstructed and residual phases of the carrier signal of any spacecraft or...journal article 2021
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Ali Nawaz, Ali (author)Though NanoSats are becoming increasingly capable of featuring active payloads, and acquiring inertial data at arcsec level precision; the payload operational duty-cycle largely remains limited by its data downlink capabilities. NanoSat laser communication terminal (LCT) promises 1 Gbps data downlink capabilities. However, LEO to ground free...master thesis 2020
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Ardaens, J.H. (author)Rendezvous in orbit has recently regained considerable attention, as it is required to enable on-orbit servicing or active debris removal activities. The pressing need for the realization of suchmissions falls within the more general societal attempt to make human activities more sustainable, avoiding wasting valuable resources and ensuring that...doctoral thesis 2020
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Karagiannis, A. (author)The Micropropulsion Group of the department of Space Systems Engineering of the Delft University of Technology is developing resistojet thrusters for small satellites operating on the vapourisation of liquid water via an electric heater and its subsequent expansion via a nozzle into vacuum for the generation of thrust. As the water vapour...master thesis 2020
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Chaves Jimenez, A. (author)Spacecraft orbit and attitude dynamics have been classically seen as two separated<br/>subjects, since the effect of attitude in orbit dynamics was deemed too small to be<br/>considered, or simply, modeled as noise in the estimation process for most satellites.<br/>In the eighties, a study by [1] showed that for a very large spacecraft,...doctoral thesis 2020
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Lopez-Encarnacion, E. (author), Fonod, R. (author), Bergner, P. (author)Fast and large-angle attitude slew maneuvers often imply simultaneous use of multiple actuators such as thrusters and reaction wheels (RWs). A fault in any of these actuators might lead to partial or full damage of sensitive spacecraft instruments. In this paper, a model-based Fault Detection and Isolation (FDI) strategy is proposed, which aims...conference paper 2019
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Maene, Jochim (author)The past decade has seen a continuous increase of Earth observation missions, since they are regarded as an important tool to address global problems such as climate change or disaster mitigation. A commercial trend exists now towards higher resolution imagery, which drives the use of agile satellites. Nevertheless, a disadvantage of agile...master thesis 2019
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López I de la Encarnación, Eric (author)Current and future space missions require agile and reliable spacecraft capable of trailing and keeping the required attitude. Most of the agile spacecraft missions are near-Earth based but some are placed far away from Earth and its influence. One example of such missions is the Athena mission, which requires the spacecraft to perform fast and...master thesis 2019
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Khamis, Karim (author)Miniaturization of spacecraft has been gaining wide interest in the space industry, given its potential for reducing space missions' costs and providing a novel approach to enhancing and facilitating spaceflight. Recently, a lot of research has been successfully put into this field along with the advancements that make it more feasible, though a...master thesis 2019
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Ripoll Sanchez, Andrés (author)There is no doubt that the smallest spacecraft platforms (CubeSats, NanoSats and microsats) are revolutionizing the market. The possibilities of developing spacecraft through standard platforms, commercial of the shelf components and then reduced the costs of development has allowed new organizations to enter the space section. On top of that,...master thesis 2019
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Bocanegra Bahamon, T.M. (author)The thesis that you are about to read deals with the implementation of a technique to study atmospheres of planets or moons in the Solar System. We use radio telescopes on Earth to track spacecraft that are orbiting planets, and use the signal the spacecraft emits, as it crosses the planet’s atmosphere, to investigate its physical...doctoral thesis 2019