Gabriella Gaias

Politecnico di Milano | Polimi · Department of Aerospace Engineering

Autonomous spacecraft proximity operations represent a key enabler for future mission architectures such as in-orbit servicing, active debris removal, objects' inspection, and in-orbit assembly. This work addresses safety concepts for the relative trajectory guidance design applicable to challenging proximity operations in the close-range domain. T...

This work addresses the design of an extended Kalman filter for pose estimation to support close-range navigation with respect to a noncooperative target satellite. The filter estimates the relative pose, relative angular rate and linear velocity, inertia ratios, and pose of the target principal axes frame, where the noisy pose to a point of refere...

This paper presents a strategy for optimal manoeuvre design of multi-satellite formation flying in low Earth orbit environment, with the aim of providing a tool for mission operation design. The proposed methodology for formation flying manoeuvres foresees a continuous low-thrust control profile, to enable the operational phases. The design is perf...

Large constellations' deployment in low Earth orbit will drastically change the space environment and economy in the upcoming decades. The sustainability of the orbital environment in the long term needs to be accounted when implementing the large constellations projects. In fact, failures among the large constellations' assets can critically endan...

This paper presents a strategy for optimal manoeuvre design of multi-satellite formation flying in low Earth orbit environment, with the aim of providing a tool for mission operation design. The proposed methodology for formation flying manoeuvres foresees a continuous low-thrust control profile, to enable the operational phases. The design is perf...

This paper presents the architecture and the algorithms implemented for the guidance, navigation, and control system of a three-satellite formation flying mission study, the Formation Flying L-band Aperture Synthesis. This mission concept is developed in the remote-sensing field, to improve the performances of Earth observation missions for land an...

It is well known that global maps of soil moisture and sea surface salinity are required to improve meteorological and climate prediction, as demonstrated by the Soil Moisture and Ocean Salinity (SMOS) satellite flying since 2009. In the context of future L-band missions for land and oceans applications, the spatial resolution should increase from...

In the framework of Active Debris Removal (ADR) missions employing rigid capture mechanism, the rotational state of the target object greatly influences the feasibility, safety and cost of the capture operations. In this work, the impingement with thruster’s plume gases is studied as a strategy to control the target tumbling motion and aid the fina...

This paper presents the analysis for the deployment and the acquisition procedures for a three-satellites formation flying, on a sun-synchronous orbit, as part of a study for a European Space Agency potential high resolution L-band radiometer mission for land and ocean applications. The methodologies for formation-flight establishment and reconfigu...

This work addresses the design of safe relative trajectories to enable satellite close proximity operations for a variety of multi-satellite missions. With regard to active debris removal and on-orbit servicing applications, first the key aspects driving the different operational concepts are identified. Afterwards, these are translated into requir...

This work presents a precise analytical model to reconstruct the line-of-sight vector to a target satellite over time, as required by angles-only relative navigation systems for application to rendezvous missions. The model includes the effects of the geopotential, featuring: the analytical propagation in the mean relative orbital elements (up to s...

This work presents a precise analytical model to reconstruct the line-of-sight vector to a target satellite over time, as required by angles-only relative navigation systems for application to rendezvous missions. The model includes the effects of the geopotential, featuring: the analytical propagation in the mean relative orbital elements (up to s...

This work addresses flight results and practical challenges of the Autonomous Vision Approach Navigation and Target Identification in-orbit demonstration. This endeavor realized a fully autonomous rendezvous to a noncooperative target in low Earth orbit, in the separation ranges between tens of kilometers to 50 m, relying exclusively on angles-only...

This work presents a practical and efficient analytical framework for the precise modeling of the relative motion in low Earth orbits. Developed to support the design and verification of relative guidance navigation and control algorithms devoted to spacecraft rendezvous for active debris removal applications, only the orbital perturbation due to n...

This paper presents three computationally-light algorithms to solve the initial relative orbit determination problem using line-of-sight measurements. A comparative assessment of their performance and robustness is assessed, based on real flight data from two different in-orbit experiments. The proposed algorithms are optimized for the challenging...

A practical and effective numerical method is presented, aiming at solving the problem of initial relative orbit determination using solely line-of-sight measurements. The proposed approach exploits the small discrepancies which can be observed between a linear and a more advanced relative motion model. The method consists in systematically perform...

This work presents a practical and efficient semi-analytical framework for the precise modelling of the relative motion in low Earth orbits. Given the treated scenario, the orbital perturbations due to non-homogeneous Earth mass distribution and aerodynamic drag are taken into account. In accord to recent successful formation-flight experiments, th...

The paper provides an overview of the angles-only relative orbit determination activities conducted to support the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment. This in-orbit endeavor was carried out by the German Space Operations Center (DLR/GSOC) in autumn 2016 to demonstrate the capability to perform spaceb...

This work addresses the two-way conversion between osculating and mean orbital elements, as required by orbital elements-based onboard guidance navigation and control algorithms for near-circular formation flying missions in low Earth orbits. With regard to the non-homogenous Earth mass distribution perturbation, the developed algorithm merges a Ha...

This work addresses flight results and practical challenges of the Autonomous Vision Approach Navigation and Target Identification in-orbit demonstration. This endeavor realized a fully autonomous rendezvous to a noncooperative target in low Earth orbit, in the separation ranges between tens of kilometers to 50 m, relying exclusively on angles-only...

The paper describes the onboard vision-based navigation software employed during the DLR's AVANTI experiment and presents its flight performance. The navigation task relies on a dedicated target detection module in charge of extracting the line-of-sight observations from the images taken by a monocular camera. The recognition of the target is based...

In the last decade, the German Space Operations Center (DLR/GSOC) has been building up a unique expertise in the field of spacecraft formation flying. A total of four formations have been successfully operated from the GSOC premises, providing valuable flight data and experience. Several relevant technical contributions have also been made in the d...

This paper presents ultimate design, implementation, and in-flight performance of the spaceborne guidance, navigation, and control system that enabled the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment; a flight demonstration developed by the German Space Operations Center of DLR, German Aerospace Center and car...

This contribution addresses the realization of angles-only relative navigation systems as means to approach noncooperative target objects flying in low Earth orbits. Based on the recent in-flight experience collected during the AVANTI (Autonomous Vision Approach Navigation and Target Identification) demonstration, a critical comparison between spac...

This paper presents the in-orbit performance of the spaceborne guidance navigation and control system which enabled the AVANTI experiment, a technological demonstration conducted by the German Aerospace Center in autumn 2016. AVANTI proved the viability to perform far- to closerange autonomous proximity operations with respect to a noncooperative f...

This paper presents the key results of the angles-only relative orbit determination activities performed during the AVANTI experiment. This in-orbit endeavor was conducted by DLR in autumn 2016 and aimed at demonstrating spaceborne autonomous rendezvous to a noncooperative target using solely optical measurements. In view of the complexity of the e...

The paper presents the flight performance of the onboard vision-based navigation software employed during the AVANTI experiment. Two autonomous rendezvous to a noncooperative object have been performed in orbit, first from 13 km to 1 km separation, then from 3 km to 50 m. Despite the poor visibility conditions and the strong orbit perturbations enc...

AVANTI is a formation-flight experiment involving two noncooperative satellites. After a brief overview of the challenges that experiment design and scenario induce, this paper presents the safety concept retained to guarantee the safety of the formation. The peculiarity of the proposed approach is that it does not rely on the continuous availabili...

The Berlin InfraRed Optical System satellite, which is scheduled for launch in 2016, will carry onboard the picosatellite BEESAT-4 and release it through a spring mechanism. After separation, it will perform experimental proximity maneuvers in formation with the picosatellite solely based on optical navigation. In order to start the experiment it i...

The paper tackles the problem of estimating accurately the relative state of a CubeSat after in-orbit deployment using a camera. The objective is to provide quick and precise relative orbit information to support the ground operations during this critical phase. To that end, the separation sequence is captured by a camera whose images are processed...

This work revisits the modeling of the relative motion between satellites flying in near-circular low-Earth-orbits. The motion is described through relative orbital elements and both Earth’s oblateness and differential drag perturbations are addressed. With respect to the former formulation, the description of the $$J_2$$J2 effect is improved by in...

The Berlin Infrared Optical System satellite, which is scheduled for launch in 2016, will carry onboard a picosatellite and release it through a spring mechanism. After separation, it will perform proximity maneuvers in formation with the picosatellite solely based on optical navigation. Therefore, it is necessary to keep the distance of the two sp...

Advanced multisatellite missions based on formation-flying and on-orbit servicing concepts require the capability to arbitrarily reconfigure the relative motion in an autonomous, fuel efficient, and flexible manner. Realistic flight scenarios impose maneuvering time constraints driven by the satellite bus, by the payload, or by collision avoidance...

The BIROS satellite, which is scheduled for launch in 2015 into a low Earth orbit, will carry onboard a picosatellite and subsequently release it through a spring mechanism with a fixed velocity. In the frame of the AVANTI experiment, the BIROS satellite will perform proximity maneuvers in a mid-range formation with the picosatellite, based solely...

This paper provides the description of the Autonomous Vision Approach Navigation and Target Identification (AVANTI) experiment currently in development at the German Space Operations Center. AVANTI is one of the secondary scientific experiments to be accomplished within the FireBird mission which will launch the BIROS spacecraft in 2015. AVANTI is...

This work describes the design of an impulsive manoeuvres’ planner meant for onboard autonomous optimum formation flying reconfigurations in near-circular orbit. The whole variation of the relative orbit is stepwise achieved through intermediate configurations, so that passive safety and delta-v consumption minimisation are pursued. The description...

The paper describes the integrated software solution retained for the design and development of the AVANTI experiment, a challenging on-board autonomous formation-flying endeavour to be conducted in 2016. This solution aims at enabling rapid prototyping by providing a powerful development, validation and testing environment, able to support simulta...

This paper presents system design and on-orbit results from the Advanced Rendezvous Demonstration using Global Positioning System and Optical Navigation (ARGON). ARGON has been conducted during the extended phase of the Prototype Research Instruments and Space Mission Technology Advancement (PRISMA) mission in April 2012. It represents one of the f...

Dieser Bericht gibt eine Zusammenfassung des PRISMA Missionsbetriebs durch das GSOC sowie eine Übersicht über die erzielten Ergebnisse. In Kapitel 3 werden zunächst die Zielsetzungen des Vorhabens sowie die Rahmenbedingungen beschrieben, unter denen das Projekt durchzuführen war. Anschließend gibt Kapitel 4 eine Übersicht über den Projektverlauf un...

This paper proposes an image processing method for far range rendezvous. A target spacecraft at distances up to $30$~km is tracked from camera images. The method is based on linking bright, connected sets of pixels over sequences of images. Stars and the target spacecraft are identified by using a star catalog and performing motion segmentation. Th...

This work describes the design of an impulsive maneuvers’ planner meant for on-board autonomous optimum formation flying reconfigurations. The whole variation of the relative orbit is stepwise achieved through intermediate configurations, so that passive safety and delta-v consumption minimization are pursued. The description of the relative motion...

The ultimate goal of this work is to demonstrate the capability of a maneuverable servicer spacecraft to rendezvous with a non-cooperative space resident object from far-range distance using optical angles-only measurements. To this end, the Advanced Rendezvous experiment using GPS and Optical Navigation (ARGON) has been executed during the extende...

This work addresses the design and implementation of a prototype relative navigation tool that uses camera-based measurements collected by a servicer spacecraft to perform far- range rendezvous with a non-cooperative client in low Earth orbit. The development serves the needs of future on-orbit-servicing missions planned by the German Aerospace Cen...

This work addresses the design and implementation of a prototype relative navigation tool that uses camera-based measurements collected by a servicer spacecraft to perform far- range rendezvous with a non-cooperative client in low Earth orbit. The development serves the needs of future on-orbit-servicing missions planned by the German Aerospace Cen...

This paper describes the Formation Flying Testbed (FFTB) developed by the German Space Operations Center (DLR/GSOC) and presents key results from its usage in the frame of formation flying missions currently operated at GSOC. The FFTB constitutes a mission-independent framework for the design, implementation, rapid prototyping, testing and validati...

This paper addresses the first steps realized to set up a hardware in-the-loop (HWIL) multi-satellite simulator aimed at the support of closed-loop real-time real-scale On-Orbit Servicing (OOS) scenarios. The driving idea of this project is to join the advantages coming from a model-based design approach with the simulating capabilities provided by...

A novel autonomous vision-based navigation system has been designed to support the upcoming AVANTI (Autonomous Vision Approach Navigation and Target Identification) experiment. AVANTI aims at demonstrating the fully autonomous approach to a noncooperative satellite using a simple camera in a safe and fuel-efficient manner. To that end, the pictures...

This work deals with the dynamics of spacecrafts information. The relative motion is described through the difference between the Eulerian orbital elements of the deputy satellite and the chief's ones. Eulerian orbital elements are defined from the constants of motion of the Intermediary Motion: they include perturbations till part of the 4th zonal...

The paper addresses a tool for optimizing the preliminary design of formation flying missions that realize spaceborne interferometric synthetic aperture radar (InSAR) instruments. The design is considered either under the single unit system sizing point of view or the formation synergies and geometry constraints. Advantages of employing microsatell...

This work addresses the problem of kinematic inversion of complex redundant mechanisms. The inverse problem for redundant mechanisms is known to be ill-posed. Using the multibody formalism and the capability to automatically write the equations of motion of mechanisms provided by general multibody software, a simple algorithm is proposed for the so...

The human planetary exploration goal asks for both a strong technology development and a great scientific knowledge enhancement that can be achieved only through a rational and well tuned sequence of different highly related missions, from demonstrators up to scientific probes, in the framework of a limited resources scenario. Therefore the program...