Robotics and AI-Enabled On-Orbit Operations With Future Generation of Small Satellites

The low-cost and short-lead time of small satellites has led to their use in science-based missions, earth observation, and interplanetary missions. Today, they are also key instruments in orchestrating technological demonstrations for On-Orbit Operations (O 3 ) such as inspection and spacecraft servicing with planned roles in active debris removal and on-orbit assembly. This paper provides an overview of the robotics and autonomous systems (RASs) technologies that enable robotic O 3 on smallsat platforms. Major RAS topics such as sensing & perception, guidance, navigation & control (GN&C) microgravity mobility and mobile manipulation, and autonomy are discussed from the perspective of relevant past and planned missions

Starling1: Swarm Technology Demonstration

The Starling series of demonstration missions will test technologies required to achieve affordable, distributed spacecraft (“swarm”) missions that: are scalable to at least 100 spacecraft for applications that include synchronized multipoint measurements; involve closely coordinated ensembles of two or more spacecraft operating as a single unit for interferometric, synthetic aperture, or similar sensor architectures; or use autonomous or semi-autonomous operation of multiple spacecraft functioning as a unit to achieve science or other mission objectives with low-cost small spacecraft. Starling1 will focus on developing technologies that enable scalability and deep space application. The mission goals include the demonstration of a Mobile Ad-hoc NETwork (MANET) through an in-space communication experiment and vision based relative navigation through the Starling Formation-flying Optical eXperiment (StarFOX)

Ground-Based 1U CubeSat Robotic Assembly Demonstration

Key gaps limiting in-space assembly of small satellites are (1) the lack of standardization of electromechanical CubeSat components for compatibility with commercial robotic assembly hardware, and (2) testing and modifying commercial robotic assembly hardware suitable for small satellite assembly for space operation. Working toward gap (1), the lack of standardization of CubeSat components for compatibility with commercial robotic assembly hardware, we have developed a ground-based robotic assembly of a 1U CubeSat using modular components and Commercial-Off-The-Shelf (COTS) robot arms without humans-in-the-loop. Two 16 in x 7 in x 7 in dexterous robot arms, weighing 2 kg each, are shown to work together to grasp and assemble CubeSat components into a 1U CubeSat. Addressing gap (2) in this work, solutions for adapting power-efficient COTS robot arms to assemble highly-capable CubeSats are examined. Lessons learned on thermal and power considerations for overheated motors and positioning errors were also encountered and resolved. We find that COTS robot arms with sustained throughput and processing efficiency have the potential to be cost-effective for future space missions. The two robot arms assembled a 1U CubeSat prototype in less than eight minutes

PACMAN: Position and Attitude Control with MAgnetic Navigation for CubeSats. An experiment under the ESA - Fly Your Thesis! programme

PACMAN (Position and Attitude Control with MAgnetic Navigation) è un esperimento il cui obiettivo è quello di dimostrare una tecnologia che sfrutti le interazioni magnetiche tra veicoli in assenza di gravità, per il controllo di posizione ed assetto durante le manovre di prossimità. In questa tesi viene presentato il design dell' intero esperimento, le simulazioni dinamiche del sistema e infine, viene presentata un'analisi preliminare sui dati ottenuti durante la campagna di vol

Design improvement and analysis of quadrilateral mechanism locks for microsatellite docking systems

openThe rapid growth of the New Space Economy has led to an increased use of mi-crosatellites and nanosatellites, due to their lower costs and faster development. In recent years interactions between spacecrafts in terms of on-orbit servicing, assembly and active debris removal have become appealing fields of interest furthering the expansion of existing space assets and development of novel so-lutions. Amid the growing interest in the subject over the last two decades, the University of Padova has actively participated in the study and development of docking solutions, including DOCKS, the drogue-probe docking system this the-sis focuses on. Specifically, the primary objective of this work is to enhance the hard-docking part of DOCKS by introducing a redesigned quadrilateral mecha-nism with three locks. This mechanism plays a critical role in securing the dock-ing interface, ensuring a stable and reliable connection between the two space-crafts. After providing a comprehensive background on docking solutions in the introduction, highlighting the transformative role and growing importance of small satellites, the thesis objectives are outlined, and the system is character-ized through kinematic and force analysis. The proposed redesign addresses key performance limitations of the existing drogue-probe docking system, par-ticularly in terms of locking capabilities and resource utilization. It features ad-justed dimensions and actuators selection to minimize its impact on the mi-crosatellite's power consumption and weight constraints. To address scenarios where mechanism opening failure may occur, a release mechanism has been developed, providing a contingency measure by enabling the disengagement of the drogue-probe docking interface. The release mechanism's design ensures safe and controlled separation, preventing damage to the spacecraft or pay-loads. The enhancements have been evaluated through simulation, demonstrat-ing significant improvements in docking performance and resource efficiency. Future research directions include improvements in some critical aspects, such as further miniaturization of some components, an overall optimization of the mechanism and testing.The rapid growth of the New Space Economy has led to an increased use of mi-crosatellites and nanosatellites, due to their lower costs and faster development. In recent years interactions between spacecrafts in terms of on-orbit servicing, assembly and active debris removal have become appealing fields of interest furthering the expansion of existing space assets and development of novel so-lutions. Amid the growing interest in the subject over the last two decades, the University of Padova has actively participated in the study and development of docking solutions, including DOCKS, the drogue-probe docking system this the-sis focuses on. Specifically, the primary objective of this work is to enhance the hard-docking part of DOCKS by introducing a redesigned quadrilateral mecha-nism with three locks. This mechanism plays a critical role in securing the dock-ing interface, ensuring a stable and reliable connection between the two space-crafts. After providing a comprehensive background on docking solutions in the introduction, highlighting the transformative role and growing importance of small satellites, the thesis objectives are outlined, and the system is character-ized through kinematic and force analysis. The proposed redesign addresses key performance limitations of the existing drogue-probe docking system, par-ticularly in terms of locking capabilities and resource utilization. It features ad-justed dimensions and actuators selection to minimize its impact on the mi-crosatellite's power consumption and weight constraints. To address scenarios where mechanism opening failure may occur, a release mechanism has been developed, providing a contingency measure by enabling the disengagement of the drogue-probe docking interface. The release mechanism's design ensures safe and controlled separation, preventing damage to the spacecraft or pay-loads. The enhancements have been evaluated through simulation, demonstrat-ing significant improvements in docking performance and resource efficiency. Future research directions include improvements in some critical aspects, such as further miniaturization of some components, an overall optimization of the mechanism and testing

Spacecraft Rendezvous and Docking Using Electromagnetic Interactions

On-orbit operations such as refuelling, payload updating, inspection, maintenance, material and crew transfer, modular structures assemblies and in general all those processes requiring the participation of two or more collaborative vehicles are acquiring growing importance in the space-related field, since they allow the development of longer-lifetime missions. To successfully accomplish all these on-orbit servicing operations, the ability to approach and mate with another vehicle is fundamental. Rendezvous strategies, proximity procedures and docking manoeuvres between spacecraft are of utmost importance and new, effective, standard and reliable solutions are needed to ensure further technological developments. Presently, the possibility to create low-cost clusters of vehicles able to share their resources may be exploited thanks to the broadening advent of CubeSat-sized spacecraft, which are conditioning the space market nowadays. In this context, this thesis aims at presenting viable strategies for spacecraft RendezVous and Docking (RVD) manoeuvres exploiting electro-magnetic interactions. Two perspective concepts have been investigated and developed, linked together by the use of CubeSat-size testing platforms. The idea behind the first one, PACMAN (Position and Attitude Control with MAgnetic Navigation) experiment, is to actively exploit magnetic interactions for relative position and attitude control during rendezvous and proximity operations between small-scale spacecraft. PACMAN experiment has been developed within ESA Education Fly Your Thesis! 2017 programme and has been tested in low-gravity conditions during the 68th ESA Parabolic Flight Campaign (PFC) in December 2017. The experiment validation has been accomplished by launching a miniature spacecraft mock-up (1 U CubeSat, the CUBE) and a Free-Floating Target (1 U CubeSat, the FFT) that generates a static magnetic fields towards each other; a set of actively-controlled magnetic coils on board the CUBE, assisted by dedicated localization sensors, are used to control the CUBE attitude and relative position, assuring in this way the accomplishment of the soft-docking manoeuvre. The second one, TED (Tethered Electromagnetic Docking), concerns a novel docking strategy in which a tethered electromagnetic probe is expected to be ejected by a chaser toward a receiving electromagnetic interface mounted on a target spacecraft. The generated magnetic field drives the probe to the target and realizes an automatic alignment between the two interfaces, thus reducing control requirements for close approach manoeuvres as well as the fuel consumption necessary for them. After that, hard-docking can be accomplished by retracting the tether and bringing the two spacecraft in contact

Looking Back and Looking Forward: Reprising the Promise and Predicting the Future of Formation Flying and Spaceborne GPS Navigation Systems

A retrospective consideration of two 15-year old Guidance, Navigation and Control (GN&C) technology 'vision' predictions will be the focus of this paper. A look back analysis and critique of these late 1990s technology roadmaps out-lining the future vision, for two then nascent, but rapidly emerging, GN&C technologies will be performed. Specifically, these two GN&C technologies were: 1) multi-spacecraft formation flying and 2) the spaceborne use and exploitation of global positioning system (GPS) signals to enable formation flying. This paper reprises the promise of formation flying and spaceborne GPS as depicted in the cited 1999 and 1998 papers. It will discuss what happened to cause that promise to be mostly unfulfilled and the reasons why the envisioned formation flying dream has yet to become a reality. The recent technology trends over the past few years will then be identified and a renewed government interest in spacecraft formation flying/cluster flight will be highlighted. The authors will conclude with a reality-tempered perspective, 15 years after the initial technology roadmaps were published, predicting a promising future of spacecraft formation flying technology development over the next decade

The State of the Art of Information Integration in Space Applications

This paper aims to present a comprehensive survey on information integration (II) in space informatics. With an ever-increasing scale and dynamics of complex space systems, II has become essential in dealing with the complexity, changes, dynamics, and uncertainties of space systems. The applications of space II (SII) require addressing some distinctive functional requirements (FRs) of heterogeneity, networking, communication, security, latency, and resilience; while limited works are available to examine recent advances of SII thoroughly. This survey helps to gain the understanding of the state of the art of SII in sense that (1) technical drivers for SII are discussed and classified; (2) existing works in space system development are analyzed in terms of their contributions to space economy, divisions, activities, and missions; (3) enabling space information technologies are explored at aspects of sensing, communication, networking, data analysis, and system integration; (4) the importance of first-time right (FTR) for implementation of a space system is emphasized, the limitations of digital twin (DT-I) as technological enablers are discussed, and a concept digital-triad (DT-II) is introduced as an information platform to overcome these limitations with a list of fundamental design principles; (5) the research challenges and opportunities are discussed to promote SII and advance space informatics in future

Space Exploration Systems, Strategies and Solutions

The present thesis describes the PhD research activities dealing with the topic “Space Exploration Systems, Strategies and Solutions”. Traveling beyond low Earth orbit is the next step in the conquest of the solar system and so far, a human expedition to Mars is considered the most interesting goal of future human space exploration. Due to the technological and operational challenges associated with such a mission, it is necessary to define an opportune path of exploration, relying on many missions to intermediate and “easier” destinations, which would allow a gradual achievement of the capabilities required for the human Mars mission. The main scope of this research has been the development of a rigorous and versatile methodology to define and analyze evolutionary exploration scenarios and to provide a detailed technologies’ database, to support strategic decisions for human space exploration. The very innovative aspect of this work regards the development of a flexible methodology which can be followed to assess which are the next destinations for the exploration of space beyond LEO and to preliminarily define mission’s architectures, identifying the most significant needed elements and advanced technologies. The obtained results should be seen as a pure technical reference, as no cost and/or political considerations have been included, and can be exploited to opportunely drive the decisions of the agencies to place investments for the development of specific technologies and get ready for future exploration missions. The first part of the work has been devoted to the definition of a reference human space exploration scenario, which relies on both robotic and human missions towards several destinations, pursuing an increasing complexity approach and looking at a human expedition to Mars as final target. The scenario has been characterized through the assessment of the missions and the relative phases and concepts of operations. Accordingly, the needed space elements, or building blocks, have been identified. In this frame, the concept design of two specific elements has been performed: the first is a pressurized habitation module (Deep Space Habitat) for hosting astronauts during deep space missions; the second is an electrical propulsive module (Space Tug), mainly envisioned for satellites servicing. The last part of the work has focused on the analysis of innovative and enabling technologies, with particular attention to the aspects related to their on-orbit demonstration/validation, prior to their actual implementation in real exploration missions. The PhD has been sponsored by Thales Alenia Space - Italy and the overall work has been performed in different frameworks along the three years, as well as participating to several additional activities. In line with the objectives of the PhD, in 2012 a collaboration between Politecnico di Torino and Massachusetts Institute of Technology has been established (MITOR Project, managed by MIT-Italy Program), with the support of Thales Alenia Space as industrial partner. The MITOR project, titled “Human Space Exploration: from Scenario to Technologies”, has been aimed at identifying and investigating state of the art for Human Space Ex- ploration, enabling elements, subsystems and technologies with reference to a selected scenario and relevant missions and architectures. Part of the nine months activities has been carried out at MIT AeroAstro department. Besides MITOR project, the PhD activities have been carried out in synergy with some other research programs, such as ESA “Human Spaceflight & Exploration Scenario Studies” and STEPS2 project (Sistemi e Tecnologie per l’EsPlorazione Spaziale - phase 2). Furthermore, in 2013 a specific study has been performed in collabora- tion with university “La Sapienza” (Rome), “Osservatorio Astrofisico di Torino” (Astrophysical Observatory of Torino) and DLR (Deutsches Zentrum fr Luft- und Raumfahrt) in Bremen; its main objective has been the analysis of an interplanetary cubesats mission, aimed at space weather evaluations and technologies demonstration