Orientador: Rodolpho Vilhena de Moraes / Banca: Othon Cabo Winter / Banca: Claudia Celeste Celestino / Resumo: No presente trabalho é abordada a manobra orbital Terra-Lua - Terra com o objetivo de um menor consumo de combustível. Inicialmente o satélite executa uma órbita em torno da Terra. Em um certo instante um impulso é efetuado para efetuar uma manobra não con-focal em que o satélite é transferido para uma órbita de transferência geocêntrica até um ponto da esfera de influência da Lua. A partir deste ponto o satélite é transferido para uma órbita hiperbólica em torno da Lua, e, no perilúnio desta órbita um novo impulso é dado transferindo o satélite para uma órbita lunar. A seguir é efetuada a manobra de volta em que o satélite é transferido para a órbitra geocêntrica de transferência, e no pericentro desta o satélite é transferido para a sua órbita inicial em torno da Terra. O caso não coplanar e a influência das perturbações devidas ao achatamento da Terra e a atração gravitacional da Lua também são analisados. / Abstract: In the present work an Earth-Moon-Earth orbital maneuver is studied with the purpose of minimum fuel consumption. Initially it is considered an artificial satellite orbiting around the Earth. In a certain instant an impulse is effected to effect a not cofocal maneuver where the satellite is transferred to an orbit of geocentric transference until a point of the sphere of influence of the Moon. From this point the satellite is transferred to a hyperbolic orbit around the Moon, and, in the perilúnio of this orbit a new impulse is given transferring the satellite to a lunar orbit. To follow the maneuver is effected in return where the satellite is transferred to geocentric orbit of transference, and in pericentro of this the satellite is transferred to its initial orbit around the Earth. The non-coplanar case and the influence of the disturbances due to the flattening of the Earth and the gravitational attraction of the Moon also are analyzed. / Mestre

Made available in DSpace on 2014-06-11T19:25:29Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-02-19Bitstream added on 2014-06-13T19:12:14Z : No. of bitstreams: 1 jacob_rr_me_guara.pdf: 637187 bytes, checksum: 24c38b78cd04acc4d1694e9912f95502 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / No presente trabalho é abordada a manobra orbital Terra-Lua - Terra com o objetivo de um menor consumo de combustível. Inicialmente o satélite executa uma órbita em torno da Terra. Em um certo instante um impulso é efetuado para efetuar uma manobra não con-focal em que o satélite é transferido para uma órbita de transferência geocêntrica até um ponto da esfera de influência da Lua. A partir deste ponto o satélite é transferido para uma órbita hiperbólica em torno da Lua, e, no perilúnio desta órbita um novo impulso é dado transferindo o satélite para uma órbita lunar. A seguir é efetuada a manobra de volta em que o satélite é transferido para a órbitra geocêntrica de transferência, e no pericentro desta o satélite é transferido para a sua órbita inicial em torno da Terra. O caso não coplanar e a influência das perturbações devidas ao achatamento da Terra e a atração gravitacional da Lua também são analisados. / In the present work an Earth-Moon-Earth orbital maneuver is studied with the purpose of minimum fuel consumption. Initially it is considered an artificial satellite orbiting around the Earth. In a certain instant an impulse is effected to effect a not cofocal maneuver where the satellite is transferred to an orbit of geocentric transference until a point of the sphere of influence of the Moon. From this point the satellite is transferred to a hyperbolic orbit around the Moon, and, in the perilúnio of this orbit a new impulse is given transferring the satellite to a lunar orbit. To follow the maneuver is effected in return where the satellite is transferred to geocentric orbit of transference, and in pericentro of this the satellite is transferred to its initial orbit around the Earth. The non-coplanar case and the influence of the disturbances due to the flattening of the Earth and the gravitational attraction of the Moon also are analyzed.

As part of the first agreement between the French (CNES) and the Chinese (CNSA) space agencies in terms of space exploration, the DORN instrument will fly on board the Chinese Chang'E 6 mission in 2024. It aims to measure the amount of Radon escaping from the lunar soil to better understand what governs the concentration of this noble gas which contributes to the endogenous origin of the lunar exosphere. This instrument is an alpha-particle spectrometer able to detect the radioactive decay of two Radon isotopes and their progeny. These emissions act as a tracing signal for the processes happening in the lunar sub-surface. During the Assembly, Integration & Testing phase of the Flight Model of the instrument, different scientific concerns must be addressed to characterise the behaviour of the instrument before it is commissioned to China for its final tests and integration into the lander before the mission. This means that all the measuring process, since the alpha-particle deposits its energy into the detector until it is counted as an event in a spectral data product, has to be meticulously analysed and assessed to verify if it is compliant with the instrument's scientific requirements. Under this context, several data analysis tools have been developed to retrieve the behaviour characteristics of the instrument. Firstly, due to the changing conditions that a space mission to the lunar environment undergoes, it is needed to perform an in-flight calibration at every measurement. To this regard, a program able to obtain the calibration parameters at several temperatures within its operative range along with the spectral resolution of each detector has been developed and used during the Thermal Vacuum tests held at CNES. Secondly, the numerical pipeline, responsible for processing and storing onboard data, must undergo stress testing and be exposed to conditions resembling the lunar environment. As a result, the software's capabilities enabling the instrument to derive particle energy and eliminate undesired detections have undergone thorough testing. These tools have been used to verify the compliance of the instrument with its respective scientific requirements as well as to validate its current software version. They not only have played an important role in finalising the development of the instrument in France but will be of great use during the tests done in China and during the space operations on the Moon. / Dans le cadre du premier accord entre les agences spatiales française (CNES) et chinoise (CNSA) en matière d'exploration spatiale, l'instrument DORN volera à bord de la mission chinoise Chang'E 6 en 2024. Il vise à mesurer la quantité de Radon s'échappant du sol lunaire afin de mieux comprendre ce qui gouverne la concentration de ce gaz noble qui contribue à l'origine endogène de l'exosphère lunaire. Cet instrument est un spectromètre à particules alpha capable de détecter la désintégration radioactive de deux isotopes du radon et de ses descendants. Ces émissions agissent comme un signal de traçage des processus qui se déroulent dans la sub-surface lunaire. Au cours de la phase d'assemblage, d'intégration et d'essai du modèle de vol de l'instrument, différentes questions scientifiques doivent être abordées pour caractériser le comportement de l'instrument avant qu'il ne soit envoyé en Chine pour les essais finaux et l'intégration dans l'atterrisseur avant la mission. Cela signifie que l'ensemble du processus de mesure, depuis le dépôt de l'énergie de la particule alpha dans le détecteur jusqu'à son comptage en tant qu'événement dans un produit de données spectrales, doit être méticuleusement analysé et évalué pour vérifier s'il est conforme aux exigences scientifiques de l'instrument. Dans ce contexte, plusieurs outils d'analyse de données ont été développés pour retrouver les caractéristiques de comportement de l'instrument. Tout d'abord, en raison des conditions changeantes d'une mission spatiale dans l'environnement lunaire, il est nécessaire d'effectuer un étalonnage en vol à chaque mesure. À cet égard, un programme capable d'obtenir les paramètres d'étalonnage à plusieurs températures dans sa gamme opérationnelle ainsi que la résolution spectrale de chaque détecteur a été utilisé pendant les tests de vide thermique qui se sont déroulés au CNES. Deuxièmement, le pipeline numérique, chargé du traitement et du stockage des données à bord, doit subir des tests de contrainte et être exposé à des conditions ressemblant à l'environnement lunaire. En conséquence, les capacités logicielles permettant à l'instrument de déduire l'énergie des particules et d'éliminer les détections indésirables ont fait l'objet de tests approfondis. Ces outils ont été utilisés pour vérifier la conformité de l'instrument avec ses exigences scientifiques respectives et pour valider la version actuelle de son logiciel. Ils ont non seulement joué un rôle important dans la finalisation du développement de l'instrument en France, mais seront également très utiles lors des tests effectués en Chine et lors des opérations spatiales sur la Lune.