LICIACube on DART Mission: An Asteroid Impact Captured by Italian Small Satellite Technology

In the frame of the Planetary Defense program, NASA developed the Double Asteroid Redirection Test (DART) mission and the Italian Space Agency joined the effort. DART’s spacecraft will act as a kinetic impactor by deliberately crashing into the moonlet of Didymos binary system (i.e. Didymos-B) while the effects of the impact will be observed by a small satellite, the Light Italian CubeSat for Imaging of Asteroid (LICIACube) and ground-based telescopes. LICIACube, an Italian Space Agency (ASI) mission, will fly with a relative velocity of approximately 6.5 km/s and it will document the effects of the impact, the crater and the evolution of the plume generated by the collision. LICIACube will have to maintain the asteroid\u27s pointing at an angular speed of approximately 10 deg/s to fly-by the asteroid close to the Didymos-B surface. The images acquired by LICIACube will be processed onboard through the autonomous navigation algorithm to identify the asteroid system and control the satellite attitude. They will also help the scientific community and provide feedback to the Planetary Defense program, pioneered by the Space Agencies. This deep-space mission is based on a small scale but highly technological platform, whose development is involving both the Italian technical and scientific community

Microsatellite Constellation for Mars Communication and Navigation

Exploration of Mars and establishment of human settlement have been of sharp interest for several decades. Since the turn of the century, efforts have been ramped up to make these a reality. With the execution of multiple robotic exploration missions and several more planned missions in the next two decades, as well as serious plans for human landing missions, a key need is the establishment of accurate, reliable, expansive, and cost-effective positioning and communication service for several users in the Mars environment. The Mars Communication and Navigation (MCN) mission is a multi-satellite constellation at Mars that shall provide data relay and positioning services for the identified possible users, that are orbiters, landers, ascenders, autonomous rovers, and human landing missions. The aim of MCN is to investigate and prototype key technologies for a Mars positioning and communication system using small satellites, in order to enable the development and operations of a wide range of Mars missions, providing a backbone Earth–Mars communication and navigation infrastructure. This work focuses on the critical architectural aspects of the MCN. The end-to-end (E2E) system architecture is presented, in order to provide an overview of the space and ground segments along with the operations concepts. Concerning the orbital configuration, the constellation and its deployment strategy are discussed. The MCN constellation baseline comprises 24 microsatellites operating in a Walker-like orbital configuration at Mars to provide service for more than 70 users potentially. Moreover, a Relay/Gateway link is utilized to serve as a communication bridge between Earth ground segment and the MCN constellation. Concerning the communication and navigation aspects, their architectures and possible solutions are highlighted, together with an overview of the related critical technologies required to achieve the mission objectives

The SSDC Role in the LICIACube Mission: Data Management and the MATISSE Tool

Light Italian Cubesat for Imaging of Asteroids (LICIACube) is an Italian mission managed by the Italian Space Agency (ASI) and part of the NASA Double Asteroid Redirection Test (DART) planetary defense mission. Its main goals are to document the effects of the DART impact on Dimorphos, the secondary member of the (65803) Didymos binary asteroid system, characterizing the shape of the target body and performing dedicated scientific investigations on it. Within this framework, the mission Science Operations Center will be managed by the Space Science Data Center (ASI-SSDC), which will have the responsibility of processing, archiving, and disseminating the data acquired by the two LICIACube onboard cameras. In order to better accomplish this task, SSDC also plans to use and modify its scientific webtool Multi-purpose Advanced Tool for Instruments for the solar system Exploration (MATISSE), making it the primary tool for the LICIACube data analysis, thanks to its advanced capabilities for searching and visualizing data, particularly useful for the irregular shapes common to several small bodies

Development of advanced multifield structural models for the study of smart wing

Dans le domaine de l’aéronautique, l’acception ‘shape morphing’ a été utilisée pour identifier ces avions qui subissent certaine modifications géométrique pour améliorer leur adaptation au différents profils de missions. Différemment de la solution classique, celle ‘shape morphing’ exige : une distribution d’actionnement avec une densité de puissance élevée, une mécanisation des structures, des revêtements souples, et le développement des loi de contrôle. Dans ce scénario, un modèle capable reconnaitre l'insertion de capteur et d'actionneur de nouvelle génération, et capable de réduire au minimum le coût du calcul devient très intéressant. Ce travail essaye d'affronter deux aspects différents du problème. Dans la première partie, la question suivante a été exploitée: pour un problème donné, géométrie, chargement, etc. .. condition aux limites, quel est le modèle le plus précis en terme de résultats, fidélité et avec le plus réduit coût de calcul? Deux approches différentes ont été utilisées pour donner une réponse. Le diagramme de la « Théorie Meilleur Plate (RTPB) » a été dessiné. Avec cet instrument il est possible, pour un problème donné, d'identifier les modèles ayants les meilleurs temps de calcul et une bonne fidélité des résultats. Dans la deuxième partie de la thèse un modèle avancé mono dimensionnel et multi domaine en éléments fini est présenté. Le modèle est capable de capturer l'insertion d'éléments piézo-électriques dans l'aile composite. Il a été développé à partir de la formulation Carrera unifiée et à partir de l'équation de comportement électro-mécanique. Une comparaison avec la bibliographie actuelle a été fait afin de valider les résultats.In the field of aeronautics, shape morphing has been used to identify those aircraft that un-dergo certain geometrical changes to enhance or adapt to their mission profile. Different formthe classical solution the shape morphing required: distributed high-power density actuation, structural mechanization, flexible skins, and control law development. In these scenario, model able to capture the insertion of new generation sensor and actuator, and able to minimize the computational cost become very interesting. These work try to affront two different aspect of the problem. In the first part the following question has been exploited: for a given problem, geometry, loading, boundary condition etc... which is the most accurate model in term of results fidelity with the lowest computational cost? Two different approaches have been used to give an answer. The Best Plate Theory Diagram (BPTD) has been drawn. Trough the BPTD it is possible, for a given problem, to identify those models with the lowest computational time and a good results fidelity. An advanced mono-dimensional multi-field FEM model is presented in the second part of the thesis. The model is able to capture the insertion of piezo-electric elements in composite wing. It has been developed starting from the Carrera Unified Formulation and from the electro-mechanical constitutive equation. Comparison with the bibliography have be done in order to validate the results.Nel campo dell’aeronautica il termine shape morphing identifica quei velivoli in grado di apportare determinati cambiamenti geometrici al fine di adattarsi a diversi profili di missione. Diversamente dalle soluzioni convenzionali la progettazione di velivoli shape morphing richiede : un’attuazione distribuita, uno skin flessibile in grado di pemettere le deformazioni e delle leggi di controllo. Divengono quindi di notevole interesse modelli in grado di cogliere l’inserzione di attuatori e sensori di nuova generazione all’interno dell’ala, e di esibire al contempo un basto costo computazionale. Nel lavoro presentato in questa tesi vengono trattati entrabi gli aspetti. Nella prima parte si è andati a dare una risposta alla segunete domanda: per un dato problema, geometria, condizioni di carico, etc..., qual è il modello più accurato, in termini di fedeltà dei risultati, che presenta il minor costo computazionale? Il problema è stato affrontato attraverso due differenti approcci, che hanno portato alla creazione della "Best Plate Theory Curve", attraverso la quale è possibile, per un dato problema, identificare il modello più idoneo in termini di fedeltà dei risultati e di costo computazionale. Nella seconda parte del lavoro viene presentato un modello mono-dimensionale multi-campo avanzato in grado di cogliere l’inserzione di elementi piezo-elettrici in ali in materiale composito. Questo elemento è stato viluppato partendo dalla Carrera Unified Formulation e dalle equazioni costitutive elettromeccaniche. Sono state effettuate poi delle validazioni attraverso confronti con la bibliografia

Develpoment of advanced structural multifield models for the study of smart wing

In the field of aeronautics, shape morphing has been used to identify those aircraft that undergo certain geometrical changes to enhance or adapt to their mission profile. In spite of there is not a clear definition of shape morphing, it is a general agreement that the conventional hinged control surfaces or high lift device, such as flap or slat that provide discrete geometry changes cannot be considered as morphing. Otherwise from the conventional solution the shape morphing required: distributed high-power density actuation, structural mechanization, flexible skins, and control law development. In these scenario, models able to capture the insertion of new generation sensor and actuator, and able to minimize the computational cost become very interesting. Refined plate theories offer significant advantages in terms of accuracy of the solution and detection of non-classical effects. The drawback of these theories is that a higher computational cost is incurred because of the presence of a large number of variables. Such an increase could become prohibitive in the case of the application of computational methods such as the Finite Element Method. Moreover to control the behaviour of an distributed actuated wing are necessary model with low computational times. In fact the computational time must be lower than the characteristic time of the controlled phenomenon. In this contest it is very interesting try to identify a method able to build reduced model which didn't penalize the results fidelity. The question which require an answer to identify the reduced model is: for a given problem (geometry, loading, boundary conditions, lamination lay-out) what is the most accurate theory in terms of a fixed accuracy with the lowest computational time? A method able to find an answer has been developed in the first part of this work. The Carrera Unified Formulations (CUF) give the possibility to run various theories for an assigned problem (materials, geometry, lamination lay-out, boundary conditions) at the same time. Trough the use of the CUF it is possible to introduce the so-called mixed axiomatic/asymptotic method, which is able to recognize the effectiveness of each displacement variable of an arbitrary refined plate theory. The recognizing of the effectiveness of each terms can be done in different way, evaluating the influence of each terms of the model or trough a genetic optimization method. All the two methods bring to build the Best Plate Theory Diagram (BPTD). Trough the BPTD it is possible, for a given problem, to identify those models with the lowest computational time and the best results fidelity. One-dimensional (1D) structural models, commonly known as beams, are intensively exploited in many engineering applications. Beam theories are, in fact, used to analyse the structural behaviour of slender bodies, such as columns, arches, blades, aircraft wings and bridges. In a beam model, the 3D problem is reduced to a set of variables that only depends on the beam-axis coordinate. One-dimensional structural elements obtained are simpler and computationally more efficient than 2D (plate/shell) and 3D (solid) elements. These feature make beam theories still very attractive. Classical model (Euler-Bernulli and Timoshenko) have intrinsic limitation which preclude their applications for the analysis of a wide class of engineering problems. A multi-field formulations based on an higher order structural model has been developed in the second part of this work. The structural model is based on the Carrera Unified Formulation. CUF 1D models are extremely cost competitive with respect to plate/shell and solid models with no accuracy lost. In other words CUF 1D structural elements lead to shell- and solid-like solutions with a lesser computational cost. These capabilities allow to use the 1D CUF formulation to simulate the insertion of an distributed actuation and sensing, like piezo-materials, in a wing, using a model lig

Best theory diagram for metallic and laminated composite plates

Best theory diagrams (BTDs) are reported in this article for the static analysis of metallic and laminated composite plates. A BTD is a curve that provides the minimum number of unknown variables of a structural theory for a fixed error. The error is related to a given variable with respect to an exact or quasi-exact solution. The theories that belong to the BTD have been obtained by means of the axiomatic/asymptotic technique, and a genetic algorithm has been employed to obtain the BTD. The Carrera Unified Formulation (CUF) has been employed to obtain refined models, since the CUF can generate automatically, and in a unified manner, any type of plate model. Equivalent single layer (ESL) and layer-wise (LW) kinematics are discussed. Closed-form, Navier-type solutions have been employed, and attention has therefore been restricted to simply-supported plates. The influence of various geometries, material properties, and layouts has been considered, and their influence on the BTD has been evaluated. Furthermore, some known theories have been evaluated and compared with the BTD curve. The results suggest that the BTD and the CUF can be considered as tools to evaluate the accuracy of any structural theory against a reference solution in a systematic manne