Archivo Digital UPM: No conditions. Results ordered -Date Deposited. 2020-02-22T13:52:14ZEPrintshttp://oa.upm.es/style/images/logo-archivo-digital.pnghttp://oa.upm.es/2019-03-26T11:00:38Z2019-03-26T11:00:38Zhttp://oa.upm.es/id/eprint/52092This item is in the repository with the URL: http://oa.upm.es/id/eprint/520922019-03-26T11:00:38ZExploration of the Jupiter Plasma Torus with a self-powered electrodynamic tethersThe dynamics and power generation of an electrodynamic tether (EDT) placed in the three body system formed by Jupiter, Io and the spacecraft are analyzed. In the region surrounding Io?s orbital path, a region of increased electron density called the plasma torus offers a suitable location to operate an EDT. The electrodynamic interaction between the conducting cable of the EDT and the strong magnetic field of the planet leads to non-negligible electrodynamic force, that perturbs the natural three body motion. New equilibrium positions are found in the synodic frame, which coincide with the classical triangular Lagrangian points only when the electrodynamic force vanishes. The locations of equilibrium positions are computed as a function of tether length, width and spacecraft mass. While in this equilibrium position, the tethered system can generate kilowatts of electrical power without deorbiting the system, the energy coming from to the super-rotating plasma sphere of Jupiter. The motion around the new equilibrium positions is evaluated, for both small linear motion confined to a neighborhood of the equilibrium point, and for large amplitude non-linear motions. As an application of this study, a misión profile capable to explore the whole plasma torus is presented. This plasma torus explorer can perform an internal ?scan? of the torus itself while generating electrical power useful for loads on board the spacecraft.Davide CurreliEnrico C. LorenziniClaudio BombardelliManuel Sanjurjo RivoFernando R. LucasJesus Pelaez AlvarezDaniel J. ScheeresMartín Lara2019-03-26T10:49:12Z2019-03-26T10:49:12Zhttp://oa.upm.es/id/eprint/52186This item is in the repository with the URL: http://oa.upm.es/id/eprint/521862019-03-26T10:49:12ZJovian capture of a spacecraft with a self-balanced electrodynamic bare tetherThe exploration of Jupiter and the Jovian system is severely restricted by the scarcity of power, the most limiting factor of scientific missions. Electrodynamic tethers has been proposed as an efficient solution to provide power to the spacecraft. Furthermore, they are pointed out as suitable propulsive devices to perform orbit manoeuvres in the Jovian world. In this paper, the Jovian capture of a spacecraft using a self-balanced electrodynamic tether is analyzed in detail. Different models of current collection are used. A dynamic description of the evolution from the arrival hyperbolic to the final ¿captured¿ orbit is carried out. 2Jesus Pelaez AlvarezManuel Sanjurjo RivoD.J. Scheeres2019-03-26T10:38:17Z2019-03-26T10:38:17Zhttp://oa.upm.es/id/eprint/52187This item is in the repository with the URL: http://oa.upm.es/id/eprint/521872019-03-26T10:38:17ZDeflexión de asteroides por medio de fuerzas electromagnéticas durante un fly-by a la TierraEn los últimos años, se han dirigido muchos esfuerzos a tratar de evitar un posible impacto sobre la superficie terrestre de un asteroide. Se han propusto nuevas estrategias y tecnologías en este campo, investigando la utilización de aplicaciones innovadoras para ese propósito. En este contexto, este trabajo explora la posibilidad de utilizar las fuerzas que actuarían sobre el asteroide durante un fly-by a la Tierra debido a la interacción con el campo magnético terrestre. Entre estas interacciones, este artículo se centra en la fuerza de Lorentz, valorando bajo qué hipótesis y condiciones podría proporcionar una deflexión efectiva de la órbita del asteroide.Manuel Sanjurjo RivoJesus Pelaez AlvarezD. IzzoO. PurcellD.J. Scheeres2019-03-18T12:28:56Z2019-03-18T12:28:56Zhttp://oa.upm.es/id/eprint/52119This item is in the repository with the URL: http://oa.upm.es/id/eprint/521192019-03-18T12:28:56ZGenerator regime of self balanced electrodynamic bare tethersThe generator regime of electrodynamic bare tethers working at inclined orbits is analyzed. Without damping or some kind of control the attitude dynamics of these tethers is unstable. However, the instability disappears, or reduces drastically, when the tether is self balanced, that is, when the Lorentz torque about the system center of mass vanishes. The aim of the paper is to describe in detail the main parameters involved in the dynamics of this kind of tethers and also their influence on the balance condition. In addition a strategy will be proposed to keep the tether balanced taking into account the whole trajectory followed by the system during the deorbiting process.Jesus Pelaez AlvarezManuel Sanjurjo Rivo2019-03-18T11:06:39Z2019-03-18T11:06:39Zhttp://oa.upm.es/id/eprint/52190This item is in the repository with the URL: http://oa.upm.es/id/eprint/521902019-03-18T11:06:39ZAsymptotic solution for the low-thrust restricted two-body problemA semi-analytical solution of the restricted two-body problem subject to an arbitrary low thrust is developed. The multiple scales perturbation method is used to split the problem into ?slow? and ?fast? scales. The small parameter that permits this approach is the ratio between thrust and gravitational acceleration. The thrust is expressed as a Fourier series expansion in terms of the fast scale, in which the coefficients are allowed to vary in the ?slow? scale. The spectral analysis of the equations of motion gives rise to reduced dynamics of the ?slow? motion. The results of the integration of this dynamical model are validated against the integration of the complete dynamics. Moreover, the preliminary results show that the propagation of the reduced dynamics are comparatively much more efficient than the complete dynamics, and show also the expected small errors of the method.Manuel Sanjurjo RivoClaudio BombardelliJesus Pelaez Alvarez2019-03-06T09:35:57Z2019-03-06T09:35:57Zhttp://oa.upm.es/id/eprint/52202This item is in the repository with the URL: http://oa.upm.es/id/eprint/522022019-03-06T09:35:57ZAccurate and fast orbit propagation with a new complete set of elementsIn year 2000 a house-made orbital propagator was developed by the SDG-UPM (former Grupo de Dinámica de Tethers) based in a set of redundant variables including Euler parameters. This propagator was called DROMO? and it was mainly used in numerical simulations of electrodynamic tethers. It was presented for the first time in the international meeting V Jornadas de Trabajo en Mecánica Celeste, held in Albarracín, Spain, in 2002 (see reference (1). The special perturbation method associated with DROMO can be consulted in the paper.2 In year 1975, Andre Deprit in reference 3 proposes a propagation scheme very similar to the one in which DROMO is based, by using the ideal frame concept of Hansen. The different approaches used in references 3 and 2 gave rise to a small controversy. In this paper we carried out a different deduction of the DROMO propagator, underlining its close relation with the Hansen ideal frame concept, and also the similarities and the differences with the theory carried out by Deprit in 3. Simultaneously we introduce some improvements in the formulation that leads to a more synthetic propagatorHodei Urrutxua CereijoManuel Sanjurjo RivoJesus Pelaez Alvarez2019-02-25T11:03:09Z2019-02-25T11:03:09Zhttp://oa.upm.es/id/eprint/52201This item is in the repository with the URL: http://oa.upm.es/id/eprint/522012019-02-25T11:03:09ZDROMO propagator revisitedIn year 2000 a house-made orbital propagator was developed by the SDG-UPM (former Grupo de Dinámica de Tethers) based in a set of redundant variables including Euler parameters. This propagator was called DROMO? and it was mainly used in numerical simulations of electrodynamic tethers. It was presented for the first time in the international meeting V Jornadas de Trabajo en Mecánica Celeste, held in Albarracín, Spain, in 2002 (see reference (1). The special perturbation method associated with DROMO can be consulted in the paper.2 In year 1975, Andre Deprit in reference 3 proposes a propagation scheme very similar to the one in which DROMO is based, by using the ideal frame concept of Hansen. The different approaches used in references 3 and 2 gave rise to a small controversy. In this paper we carried out a different deduction of the DROMO propagator, underlining its close relation with the Hansen ideal frame concept, and also the similarities and the differences with the theory carried out by Deprit in 3. Simultaneously we introduce some improvements in the formulation that leads to a more synthetic propagatorH. UrrutxuaManuel Sanjurjo RivoJesús Peláez Álvarez2019-02-11T11:16:16Z2019-02-11T11:16:29Zhttp://oa.upm.es/id/eprint/52054This item is in the repository with the URL: http://oa.upm.es/id/eprint/520542019-02-11T11:16:16ZNovel dynamical model for an object-oriented space tether simulatorThis paper presents a novel dynamical model for space tether dynamics simulation. The proposed model discretises the cable in a number of elastic rods, which in turn are modeled as a set of equivalent masses. The orbital propagation is performed using a classical Cowell?s method and also a special perturbation method. The implementation is done within the framework of EcosimPro, a multidisciplinary simulation tool. A validation of the model is carried out, as well as a case of application to the de-orbiting of a satellite using an electrodynamic tether.F. Rodríguez LucasManuel Sanjurjo RivoJesús Pélaez Álvarez2018-11-29T13:11:22Z2018-11-29T13:11:22Zhttp://oa.upm.es/id/eprint/52117This item is in the repository with the URL: http://oa.upm.es/id/eprint/521172018-11-29T13:11:22ZControl de amarras electrodinámicas auto equilibradasSe analiza la dinámica de amarras espaciales electrodinámicas en órbita inclinada. Su actitud presenta inestabilidades a largo plazo, en ausencia de amortiguamiento o control. No obstante, la inestabilidad desaparece, o se reduce drásticamente, cuando la amarra está auto equilibrada, esto es, cuando se anula el par de Lorentz alrededor del centro de masas del sistema. En este artículo se describen con detalle los principales parámetros involucrados en la dinámica de la amarra, y su influencia sobre la condición de auto equilibrado. El estudio, restringido al régimen generador, puede extenderse sin dificultad al régimen motor. Se propone, además, una estrategia para mantener la amarra equilibrada teniendo en cuenta, en su totalidad, la trayectoria seguida por el sistema durante la fase de descenso. La estrategia puede implementarse de forma simple y permite aumentar la controlabilidad del sistema.Manuel Sanjurjo RivoJesus Pelaez Alvarez2015-07-13T15:31:08Z2019-05-31T15:57:25Zhttp://oa.upm.es/id/eprint/36393This item is in the repository with the URL: http://oa.upm.es/id/eprint/363932015-07-13T15:31:08ZSingularities in DROMO formulation. Analysis of deep flybysThe singularities in Dromo are characterized in this paper, both from an analytical and a numerical perspective. When the angular momentum vanishes, Dromo may encounter a singularity in the evolution equations. The cancellation of the angular momentum occurs in very speci?c situations and may be caused by the action of strong perturbations. The gravitational attraction of a perturbing planet may lead to rapid changes in the angular momentum of the particle. In practice, this situation may be encountered during deep planetocentric ?ybys. The performance of Dromo is evaluated in di?erent scenarios. First, Dromo is validated for integrating the orbit of Near Earth Asteroids. Resulting errors are of the order of the diameter of the asteroid. Second, a set of theoretical ?ybys are designed for analyzing the performance of the formulation in the vicinity of the singularity. New sets of Dromo variables are proposed in order to minimize the dependency of Dromo on the angular momentum. A slower time scale is introduced, leading to a more stable description of the ?yby phase. Improvements in the overall performance of the algorithm are observed when integrating orbits close to the singularity.Javier RoaManuel Sanjurjo RivoJesús Pélaez Álvarez2015-06-17T16:56:45Z2019-05-31T14:06:23Zhttp://oa.upm.es/id/eprint/35737This item is in the repository with the URL: http://oa.upm.es/id/eprint/357372015-06-17T16:56:45ZDROMO formulation for planar motions: Solution to the Tsien ProblemThe two-body problem subject to a constant radial thrust is analyzed as a planar motion. The description of the problem is performed in terms of three perturbation methods: DROMO and two others due to Deprit. All of them rely on Hansen?s ideal frame concept. An explicit, analytic, closed-form solution is obtained for this problem when the initial orbit is circular (Tsien problem), based on the DROMO special perturbation method, and expressed in terms of elliptic integral functions. The analytical solution to the Tsien problem is later used as a reference to test the numerical performance of various orbit propagation methods, including DROMO and Deprit methods, as well as Cowell and Kustaanheimo?Stiefel methods.Hodei Urrutxua CereijoDavid Morante GonzálezJesús Peláez ÁlvarezManuel Sanjurjo Rivo2015-05-27T18:20:54Z2019-05-06T11:34:17Zhttp://oa.upm.es/id/eprint/35185This item is in the repository with the URL: http://oa.upm.es/id/eprint/351852015-05-27T18:20:54ZJovian Capture of a Spacecraft with a Self-Balanced Electrodynamic Bare TetherThis paper proposes and analyzes the use of a nonrotating tethered system for a direct capture in Jovian orbit using
the electrodynamic force generated along the cable. A detailed dynamical model is developed showing a strong
gravitational and electrodynamic coupling between the center of mass and the attitude motions. This paper shows the feasibility of a direct capture in Jovian orbit of a rigid tethered system preventing the tether from rotating. Additional mechanical–thermal requirements are explored, and preliminary operational limits are defined to complete the maneuver. In particular, to ensure that the system remains nonrotating, a nominal attitude profile for a self-balanced electrodynamic tether is proposed, as well as a simple feedback control.Manuel Sanjurjo RivoD. ScheeresJesús Peláez Álvarez2015-01-19T17:25:34Z2015-01-19T17:25:34Zhttp://oa.upm.es/id/eprint/33435This item is in the repository with the URL: http://oa.upm.es/id/eprint/334352015-01-19T17:25:34ZSolution of optimal continuous low-thrust transfer using Lie transformsThis paper addresses the problem of optimal constant continuous low-thrust transfer in the context of the restricted two-body problem (R2BP). Using the
Pontryagin’s principle, the problem is formulated as a two point boundary value problem (TPBVP) for a Hamiltonian system. Lie transforms obtained through the Deprit method allow us to obtain the canonical mapping of the
phase flow as a series in terms of the order of magnitude of the thrust applied.
The reachable set of states starting from a given initial condition using optimal control policy is obtained analytically. In addition, a particular optimal transfer
can be computed as the solution of a non-linear algebraic equation.
Se investiga el uso de series y transformadas de Lie en problemas de optimización de trayectorias de satélites impulsados por motores de bajo empujeManuel Sanjurjo RivoD. ScheeresM. LaraJesús Peláez Álvarez2014-04-11T16:28:05Z2016-04-21T17:38:15Zhttp://oa.upm.es/id/eprint/22644This item is in the repository with the URL: http://oa.upm.es/id/eprint/226442014-04-11T16:28:05ZDynamic stabilization of L2 periodic orbits using attitude-orbit coupling effectsNumerical explorations show how the known periodic solutions of the Hill problem are modified in the case of the attitude-orbit coupling that may occur for large satellite structures. We focus on the case in which the elongation is the dominant satellite?s characteristic and find that a rotating structure may remain with its largest dimension in a plane parallel to the plane of the primaries. In this case, the effect produced by the non-negligible physical dimension is dynamically equivalent to the perturbation produced by an oblate central body on a masspoint satellite. Based on this, it is demonstrated that the attitude-orbital coupling of a long enough body may change the dynamical characteristics of a periodic orbit about the collinear Lagrangian points.Jesús Peláez ÁlvarezClaudio BombardelliM. LaraFernando R. LucasManuel Sanjurjo RivoD. CurreliEnrico C. LorenziniD. Scheeres2014-04-01T13:48:43Z2016-04-21T15:21:45Zhttp://oa.upm.es/id/eprint/15305This item is in the repository with the URL: http://oa.upm.es/id/eprint/153052014-04-01T13:48:43ZEnergy Analysis of Bare Electrodynamic TethersThe design of an electrodynamic tether is a complex task that involves the control of dynamic instabilities, optimization of the generated power (or the descent time in deorbiting missions), and minimization of the tether mass. The electrodynamic forces on an electrodynamic tether are responsible for variations in the mechanical energy of the tethered system and can also drive the system to dynamic instability. Energy sources and sinks in this system include the following: 1) ionospheric impedance, 2) the potential drop at the cathodic contactor, 3) ohmic losses in the tether, 4) the corotational plasma electric field, and 5) generated power and/or 6) input power. The analysis of each of these energy components, or bricks, establishes parameters that are useful tools for tether design. In this study, the nondimensional parameters that govern the orbital energy variation, dynamic instability, and power generation were characterized, and their mutual interdependence was established. A space-debris mitigation mission was taken as an example of this approach for the assessment of tether performance. Numerical simulations using a dumbbell model for tether dynamics, the International Geomagnetic Reference Field for the geomagnetic field, and the International Reference Ionosphere for the ionosphere were performed to test the analytical approach. The results obtained herein stress the close relationships that exist among the velocity of descent, dynamic stability, and generated power. An optimal tether design requires a detailed tradeoff among these performances in a real-world scenario.Manuel Sanjurjo RivoJesús Peláez Álvarez2014-03-28T19:05:50Z2016-04-21T11:14:31Zhttp://oa.upm.es/id/eprint/21139This item is in the repository with the URL: http://oa.upm.es/id/eprint/211392014-03-28T19:05:50ZDynamic stabilization of L2 periodic orbits using attitude-orbit coupling effectsNumerical explorations show how the known periodic solutions of the Hill problem are modified in the case of the attitude-orbit coupling that may occur for large satellite structures. We focus on the case in which the elongation is the dominant satellite’s characteristic and find that a rotating structure may remain with its largest dimension in a plane parallel to the plane of the
primaries. In this case, the effect produced by the non-negligible physical length is dynamically
equivalent to the perturbation produced by an oblate central body on a mass-point satellite. Based
on this, it is demonstrated that the attitude-orbital coupling of a long enough body may change the
dynamical characteristics of a periodic orbit about the collinear Lagrangian points.Jesús Peláez ÁlvarezClaudio BombardelliM. LaraFernando R. LucasManuel Sanjurjo RivoD. CurreliEnrico C. LorenziniD. Scheeres2013-03-11T10:53:36Z2016-04-20T17:53:02Zhttp://oa.upm.es/id/eprint/9476This item is in the repository with the URL: http://oa.upm.es/id/eprint/94762013-03-11T10:53:36ZAsymptotic Solution for the Current Profile of Passive Bare Electrodynamic TethersA relatively high-accuracy analytical solution for the current and potential profile along a passive bare electrodynamic tether is provided using perturbation theory. An ad hoc nondimensional formulation of the governing local bias and orbital motion limited current collection equations allows one to approach the problem with a perturbation technique in which a parameter, epsilon, quantifies the influence of ohmic effects on the final solution. For the case of small ohmic effects an approximate solution is obtained with a third-order expansion. Conversely, the case of dominant ohmic effects is treated based on an extension of the exact analytical solution available for the particular case of zero load and negligible potential drop at the cathodic end of the tether. After computing the analytical current and potential profile the maximum and average current, the Lorentz force and torque, as well as the optimum load impedance for maximum power generation are obtained. When compared with the exact, numerically-computed solution an accuracy of better than5%is achieved for the computation of the average current across the full parameter space. The error with respect to the generated power becomes negligible when the load impedance is set to the optimum value, while it can grow to a maximum of about 30% for the less relevant case in which the load impedance of the power generation system is badly mismatched. The results, which are valid for a general rectilinear passive electrodynamic tether with constant cross section satisfying orbital motion limited theory and irrespective of the particular orbit configuration, will be of aid in the design and analysis of space missions involving bare electrodynamic tethers.Jesús Peláez ÁlvarezClaudio BombardelliManuel Sanjurjo Rivo2013-03-11T09:59:04Z2015-05-25T13:51:11Zhttp://oa.upm.es/id/eprint/9540This item is in the repository with the URL: http://oa.upm.es/id/eprint/95402013-03-11T09:59:04ZThree-Body Dynamics and Self-Powering of an Electrodynamic Tether in a PlasmasphereThe dynamics of an electrodynamic tether in a three-body gravitational environment are investigated. In the classical two-body scenario the extraction of power is at the expense of orbital kinetic energy. As a result of power extraction, an electrodynamic tether satellite system loses altitude and deorbits. This concept has been proposed and well investigated in the past, for example for orbital debris mitigation and spent stages reentry. On the other hand, in the three-body scenario an electrodynamic tether can be placed in an equilibrium position fixed with respect to the two primary bodies without deorbiting, and at the same time generate power for onboard use. The appearance of new equilibrium positions in the perturbed three-body problem allow this to happen as the electrical power is extracted at the expenses of the plasma corotating with the primary body. Fundamental differences between the classical twobody dynamics and the new phenomena appearing in the circular restricted three-body problem perturbed by the electrodynamic force of the electrodynamic tether are shown in the paper. An interesting application of an electrodynamic tether placed in the Jupiter plasma torus is then considered, in which the electrodynamic tether generates useful electrical power of about 1 kW with a 20-km-long electrodynamic tether from the environmental plasma without losing orbital energy.D. CurreliEnrico C. LorenziniClaudio BombardelliManuel Sanjurjo RivoJesús Peláez ÁlvarezD. ScheeresM. Lara2009-09-29T16:39:27Z2016-04-20T07:02:21Zhttp://oa.upm.es/id/eprint/1839This item is in the repository with the URL: http://oa.upm.es/id/eprint/18392009-09-29T16:39:27ZSelf Balanced Bare Electrodynamic Tethers. Space Debris Mitigation and other ApplicationsThe research on electrodynamic tethers (EDT) has been a fruitful field since
the 70’s. This technology has been developed thanks to both theoretical studies
and demonstration missions. During this period, several technical issues were
identified and overcome. Among those problems, two of them would entail an
important reduction in the operational capabilities of these devices. First, the
efficient collection of electrons in rarefied plasma and, second, the dynamic
instability of EDTs in inclined orbits. The bare tether concept represents the
surmounting of the current scarcity in low density plasma. This method of
interaction with the ionosphere promises to considerably increase the intensity
along the tether. In turn, the dynamic instability could be avoided by balancing
the EDT, as it has been proposed with the Self Balanced Electrodynamic
Tether (SBET) concept. The purpose of this thesis is to prove the suitability of
both concepts working together in several space applications: from mitigation
of the space debris to capture in a Jovian orbit.
The computation of the electron collection by a bare tether is faced in first
place. The semi-analytical method derived in this work allows to calculate accurately
and efficiently the intensity which flows along a tether working on the
OML (orbit-motion-limited) regime. Then, an energy study is derived, where
the EDT is analyzed as an energy converter. This approach provides a link
among the different aspects of the problem, from both electrical and dynamical
points of view. All the previous considerations will lead to the introduction
of control laws based on the SBET concept, enhancing its capabilities. These
analysis will be tested in a couple of particular scenarios of interest.
Mitigation of space debris has become an issue of first concern for all the
institutions involved in space operations. In this context, EDTs have been
pointed out as a suitable and economical technology to de-orbit spacecrafts at
the end of their operational life. Throughout this dissertation the numerical
simulation of different de-orbiting missions by means of EDTs will allow to
highlight its main characteristics and recognize the different parameters which
are involved. The simulations will assess the suitability of electrodynamic
tethers to perform these kind of mission.
On the other hand, one of the foremost objectives within Solar System
exploration is Jupiter, its moons and their surroundings. Due to the presence
of magnetic field and plasma environment, this scenario turns out to be
particularly appropriate for the utilization of EDTs. These devices would be
capable to generate power and thrust without propellant consumption. Orbital
maneuvers and power generation will be therefore ensured. In this work,
the possibility of using self balanced bare electrodynamic tethers to perform
a capture in Jovian orbit is analyzed. In addition, within this research, the
analysis of the dynamics of a tether in the neighborhoods of a Lagrangian
point results to be interesting since it models the motion of a space system
near a Jupiter’s moon. That would allow to study the establishment of a permanent
observatory for scientific observation in Jovian orbit. The analysis of
the restricted three body problem is developed without taking into account the
electrodynamic perturbation, leaving the inclusion of this feature for further
research. Finally, within the frame of this dissertation, an additional analysis
is presented. The study is related to the possible role of EDT in geodetic missions.
The work gathered here describes an initial analysis of the capabilities
of a tethered system to recover gravitational signals by means of measuring its
tension.
Manuel Sanjurjo Rivo