Massimiliano Vasile

University of Strathclyde · Department of Mechanical and Aerospace Engineering

This paper proposes a method to generate trajectories that are optimal with respect to multiple objectives and robust against epistemic uncertainty. Epistemic uncertainty is modelled with probability boxes and trajectories are optimised with respect to the lower expectations on cost functions and constraint satisfaction. The paper proposes an appro...

This paper presents a novel approach to the robust solution of optimal impulsive control problems under aleatory and epistemic uncertainty. The novel approach uses belief Markov decision processes to reformulate the control problem in terms of uncertainty distributions, called beliefs, rather than the realisations of the system states. This formula...

This paper introduces three types of dynamical indicators that capture the effect of uncertainty on the time evolution of dynamical systems. Two indicators are derived from the definition of Finite Time Lyapunov Exponents while a third indicator directly exploits the property of the polynomial expansion of the dynamics with respect to the uncertain...

This paper presents a decision support system that can automatically allocate collision avoidance manoeuvres in the event of a high risk close encounter between two space objects. Decisions are supported by an Intelligent Classification System that combines Dempster-Shafer theory of evidence with Machine Learning to automatically classify conjuncti...

This paper presents some initial results on the use of hyperspectral imaging technology and machine learning to characterise the surface composition of space objects and reconstruct their attitude motion. The paper provides a preliminary demonstration that hyperspectral and multispectral analysis of the light absorbed, emitted and reflected by spac...

Traditional radar sensors used for surveillance rely on monostatic radar principles. However, recently the use of remote radio frequency telescopes as bistatic receivers represents an interesting way to reuse existing facilities while providing additional information to improve tracking accuracy. In this paper we study the benefits of using such a...

This paper aims to provide an overview of the environmental footprint of the UK Space Energy Initiative (SEI) technology roadmap based on the CASSIOPeiA solar power satellite (SPS) system using the life cycle assessment (LCA) methodology. The information covers the time period from 2022 to 2080 and is relevant for five stratospheric SPS prototypes,...

This paper will present the results of an environmental impact assessment scoping report which was conducted to gain a professional scoping opinion on the development of a hypothetical offshore rectenna site located in the Highlands and Islands local authority region to enable space-based solar power to the UK. The construction, operational and dec...

Appendix associated with "Life Cycle Engineering of Space Systems: Preliminary Findings".

Within the space sector, the application of Environmental Life Cycle Assessment (E-LCA) is beginning to emerge as a credible and compelling method for scientifically quantifying environmental impacts of space missions. However, E-LCA does not fully align with the concept of triple bottom line sustainability, whilst the combination of all three sust...

The application of Life Cycle Engineering (LCE) within the concurrent engineering process presents a viable method for assessing environmental, social and economic impacts of space missions. Despite this, the novelty of the concept within space mission design has meant that the approach has not yet been widely implemented. This paper successfully d...

The dynamics of a CubeSat orbiting a binary asteroid system can be quite complex due to the irregular gravitational fields of the two bodies and the significant effect of the Solar radiation pressure. Furthermore, the large distance to Earth and the small size of the bodies result in difficulties in the observational process and brings about signif...

This paper will present the results of an environmental impact assessment scoping report which was conducted to gain a professional scoping opinion on the development of a hypothetical offshore rectenna site located in the Highlands and Islands local authority region to enable space-based solar power to the UK. The construction, operational and dec...

This paper aims to provide an overview of the environmental footprint of the UK Space Energy Initiative (SEI) technology roadmap based on the CASSIOPeiA solar power satellite (SPS) system using the life cycle assessment (LCA) methodology. The information covers the time period from 2022 to 2080 and is relevant for five stratospheric SPS prototypes,...

Development of versatile in-space manufacturing technologies is vital for space missions to manufacture parts and tools during long space missions or emergencies. Powder-Bed Additive Manufacturing (PBAM) is a promising manufacturing technology which uses powders as the feedstock material to 3D print a final product from a CAD model. PBAM is believe...

In this paper we study the benefits of using multi-static radar for manoeuvre detection in satellites. We present the conditions in which a multi-static radar is advantageous for this purpose, and show concrete results. Moreover, multiple manoeuvre detection methods from the literature are applied to this problem, and their accuracy is compared. Th...

The motion around binary asteroid Didymos under environment and state uncertainties is investigated using polynomial expansions. • For regions where the SRP has a significant effect, terminator orbits are found to be robust against uncertainties. • When orbiting close to the body, resonances with the rotation of the primary and the orbit of the sec...

Within the space sector, the application of Environmental Life Cycle Assessment (E-LCA) is beginning to emerge as a credible and compelling method for scientifically quantifying environmental impacts of space missions. However, E-LCA does not fully align with the concept of triple bottom line sustainability, whilst the combination of all three sust...

Since opening in October 2015, the Concurrent & Collaborative Design Studio (CCDS) at the University of Strathclyde has been used to foster and promote innovation in the field of aerospace engineering across a wide variety of educational and industrial projects. This paper will describe the development process of the CCDS to now, including a discus...

In this paper we study the benefits of using multi-static radar for manoeuvre detection in satellites. We present the conditions in which a multi-static radar is advantageous for this purpose, and show concrete results. Moreover, multiple manoeuvre detection methods from the literature are applied to this problem, and their accuracy is compared. Th...

Within the European space sector, heightened interest in Life Cycle Assessment (LCA) has been stimulated by an increased motivation and urgency on quantifying environmental consequences of space activities. The associated growth in the application of this method places a greater emphasis on obtaining high levels of transparency, reliability and val...

Knowledge loss occurs when experts leave a project or organisation, this is particularly in the form of tacit knowledge which those experts have gathered through experience. This experiential knowledge is inherently difficult to communicate, so new techniques are required for capture, storage and retrieval. To improve and replace an existing techni...

This paper presents preliminary results of the ESA-funded HyperClass project which aims to develop a classification system for unidentified space objects including satellites as well as probe their attitude motion by analysis of single-pixel, multi-exposure hyperspectral sensor data. A high-fidelity object-orbit-sensor model is used to generate tra...

This paper proposes a method for the robust optimisation of a number of Near Earth Object (NEO) deflection strategies under a mix of aleatory and epistemic uncertainty. The developments in this paper extend previous work by the authors in two important directions: it provides a unified framework for the treatment of aleatory and epistemic uncertain...

The paper will present a novel approach to the design optimisation of a resilient Drone Logistic Network (DLN) for the delivery of medical equipment. It is proposed a digital blueprint methodology that integrates Digital Twin (DT) models and optimisation tools, with the goal to optimise both the network topology and the delivery planning-scheduling...

This paper presents an Intelligent Decision Support System (IDSS) that can automatically assess the suitable robust deflection strategies to respond to an asteroid impact scenario. The input to the IDSS is the warning time, the orbital parameters and mass of the asteroid and the corresponding uncertainties. The output is the deflection strategies t...

This paper proposes an initial step towards the construction of a transport network connecting different orbit regimes with a Geosynchronous orbit in the Laplace plane and the Geosynchronous orbit with the Moon. This transport network will be designed to exploit a combination of natural dynamics and impulsive manoeuvres. The methodology proposed st...

The responsible management of space debris is critical for the continued use of space. The STRATHcube project purposes a CubeSat which focusses on two issues of space debris-detection and removal. There is an increasing need to detect, track and catalogue debris in the Low Earth Orbit (LEO). The first payload tracks orbital debris by using Passive...

Despite the establishment of Design for Demise (D4D) as a debris mitigation process, little is still known about the conditions under which debris fragment or survive during re-entry. STRATHcube, a student-led CubeSat project for Space Situational Awareness developed at the University of Strathclyde, aims to contribute to the development of D4D thr...

The landing of probes on minor solar system bodies allows for in depth analyses on the formation and evolution of these types of bodies. Due to the long descent time and highly non-linear environment, a minor body landing trajectory can be highly sensitive to uncertainties in the deployment state and environment parameters. In this research, a meth...

Traditionally, the propagation of uncertainty in astrodynamics has been performed with Monte Carlo (MC) methods, which incur a large computational cost and scale poorly with the size of the sample set. Polynomial Algebra (PA), a method for conducting calculations with continuous sets of values, can be used to reduce computational cost by forming a...

In this work, two novel dynamics indicators are introduced and used to characterise the uncertain dynamics around a binary asteroid. These indicators are derived from the propagated expansion of the states in polynomial series of the uncertainty in initial conditions and dynamical model parameters. Thus, each indicator encapsulates in a single scal...

Binary asteroid Didymos is the target of ESA's Hera mission, which plans to land a probe on the secondary body of the system, called Dimorphos. This procedure is planned to be performed using a ballistic landing strategy, which reduces the complexity of the spacecraft as no dedicated guidance, navigation, and control system is needed. However, thes...

In this work, two novel dynamics indicators are introduced and used to characterise the uncertain dynamics around a binary asteroid. These indicators are derived from the propagated expansion of the states in polynomial series of the uncertainty in initial conditions and dynamical model parameters. Thus, each indicator encapsulates in a single scal...

This paper presents a novel approach to the generative design optimisation of a resilient Drone Logistic Network (DLN) for the delivery of medical equipment in Scotland. A DLN is a complex system composed of a high number of different classes of drones and ground infrastructures. The corresponding DLN model is composed of a number of interconnected...

The evaluation of the on-ground casualty risk assessments due to a controlled or uncontrolled re-entry is highly sensitive to the accurate prediction of fragmentation events during an atmospheric re-entry. The main objective of this study is an investigation into the use of Peridynamics (PD) to improve the analysis of fragmentation during atmospher...

This paper presents a decision support system that can automatically allocate collision avoidance manoeuvres in the event of a high risk close encounters between two space objects. Decisions are supported by an Intelligent Classification System (ICS), which uses Machine Learning to automatically classify conjunctions according to the probability of...

This paper presents some preliminary results on the coordinated planning of collision avoidance manoeuvres in two different cases: two or more satellites belonging to the same constellation manoeuvering to avoid the collision with an inert object and two or more satellites belonging to different constellations manoeuvering to avoid a collision. In...

The progressive increase of traffic in space demands new approaches for support- ing automatic and robust operational decisions. CASSANDRA, Computational Agent for Space Situational Awareness aNd Debris Remediation Automation, is an intelligent system for Space Environment Management (SEM) intended to assist operators with the management of space t...

This paper presents a first-order approximation of ecospheric life cycle impacts from annual global space activities across two scenarios using a streamlined Life Cycle Sustainability Assessment (LCSA). The first scenario considers all space missions launched throughout the 2018 calendar year whilst the second is a futuristic scenario where afforda...

This paper presents some initial results of project HyperSST (Hyperspectral Space Surveillance and Tracking) supported by the UK Space Agency. HyperSST demonstrated the use of hyperspectral and multispectral analysis of the light absorbed, emitted and reflected by space objects to better reconstruct their composition and attitude motion. The key id...

This paper introduces three types of dynamical indicators that capture the effect of uncertainty on the time evolution of dynamical systems. Two indicators are derived from the definition of Finite Time Lyapunov Exponents while a third indicator directly exploits the property of the polynomial expansion of the dynamics with respect to the uncertain...

This paper demonstrates the capabilities of convolutional neural networks (CNNs) at classifying types of motion starting from time series, without any prior knowledge of the underlying dynamics. The paper applies different forms of deep learning to problems of increasing complexity with the goal of testing the ability of different deep learning arc...

This paper presents a novel and fast solver for the J2-perturbed Lambert problem. The solver consists of an intelligent initial guess generator combined with a differential correction procedure. The intelligent initial guess generator is a deep neural network that is trained to correct the initial velocity vector coming from the solution of the unp...

ESA's Hera mission is planning to land a probe on the surface of the secondary body of the Didymos binary asteroid system, called Dimorphos, using a ballistic landing strategy. Ballistic landings can be sensitive to uncertainties in the deployment of the lander and the environment models. Thus, the design of the ballistic landing trajectory needs t...

Space structures are often designed to serve only a single objective during their mission life; examples range from solar sails for propulsion over shields for protection to antennas and reflectors for communication and observation. By enabling a structure to deploy and change its shape to adapt to different mission stages, the flexibility of the s...

This paper presents an Intelligent Decision Support System (IDSS) that can automatically assess the suitable robust deflection strategies to respond to an asteroid impact scenario. The input to the IDSS is the warning time, the orbital parameters and mass of the asteroid and the corresponding uncertainties. The output is the deflection strategies t...

Centimetre and sub-centimetre debris fragments present a significant threat to many operational satellites in Earth orbit. When debris can be tracked, the preferred approach is collision avoidance to slightly alter the orbit of the at-risk satellite, resulting in an along-track displacement which compounds over several orbits. Although numerous str...

This paper presents a novel and fast solver for the J2-perturbed Lambert problem. The solver consists of an intelligent initial guess generator combined with a differential correction procedure. The intelligent initial guess generator is a deep neural network that is trained to correct the initial velocity vector coming from the solution of the unp...

This paper presents a novel method for multi-objective optimisation under uncertainty developed to study a range of mission trade-offs, and the impact of uncertainties on the evaluation of launch system mission designs. A memetic multi-objective optimisation algorithm, named MODHOC, which combines the Direct Finite Elements in Time transcription me...

This paper focuses on the scheduling under uncertainty of satellite tracking from a heterogeneous network of ground stations taking into account allocated resources. An optimisation-based approach is employed to efficiently select the optimal tracking schedule that minimises the final estimation uncertainty. Specifically, the scheduling is formulat...

With the increase of the traffic in orbit, there is the need to reconsider the optimisation of Collision Avoidance Manoeuvres (CAM) to account for the occurrence of multiple subsequent conjunction events. This paper proposes a method to compute the optimal CAM for a multiple encounter scenario accounting for operational constraints. The proposed me...

The dynamics of a CubeSat orbiting a binary asteroid system can be quite complex due to the irregular gravitational fields of the two bodies and the significant effect of the Solar radiation pressure. Furthermore, as the size of the bodies result in difficulties in the observational process, the modelling of the system can come with significant unc...

This paper introduces a robust Bayesian particle filter that can handle epistemic uncertainty in the measurements, dynamics, and initial conditions. The robust filter returns robust bounds on the output quantity of interest, rather than a crisp value. Particles are generated with an importance sampling technique and propagated only one time during...

The dynamics of space objects in Low-Earth Orbit are strongly determined by the effect of atmospheric drag; at the same time, the evolution of the density of the thermosphere is difficult to model, being highly dependent on both the position and the interactions with space weather, making such force a primary source of uncertainty. However, existin...

There is a growing need to detect, track and catalogue space debris in the congested Low Earth Orbit (LEO) region. A method to detect debris could be to use space-based passive bistatic radar (PBR). The STRATHcube project proposes to launch a CubeSat into LEO as a PBR technology demonstrator where a signal processing algorithm developed at the Univ...

The 'NewSpace' revolution has led to more launch opportunities and cheaper off-the-shelf components. As a consequence, the rate at which objects are being launched into orbit has significantly increased. A large proportion of these new objects are due to satellite mega-constellations, and concern is growing over the congestion of the space environm...

Space debris mitigation has become essential for the continued use of space. The removal of satellites from Low Earth Orbit by uncontrolled atmospheric re-entry is a recommended space debris mitigation practice. However, to ensure this is safe, Design for Demise processes are required to predict the risk of a satellite surviving re-entry using re-e...

Within the European space sector, heightened interest in Life Cycle Assessment (LCA) has been stimulated by an increased motivation and urgency on quantifying environmental consequences of space activities. The associated growth in the application of this method places a greater emphasis on obtaining high levels of transparency, reliability and val...

Small (<10cm) debris fragments present a significant threat to all operational satellites in orbit. Although numerous strategies for debris mitigation have been proposed, most active space-based methods involve rendezvous maneuvers with targeted pieces of debris, making them unsuitable for the cleaning up of large populations of fragments. There ar...

This paper considers the case in which the dynamics of an object in orbit is subject to a random process that can be modelled as a generic Continuous Time Random-Walk (CTRW). This model can describe the situation in which an orbiting object is subject to random, non destructive, collisions. In the limit of an infinite number of collisions the proce...

This paper presents analytical solutions for the estimation of the ΔV\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\Delta V$$\end{document} cost of the transfer of a...

Methods are proposed and compared to generate robust optimal trajectories subject to epistemic uncertainty, meaning uncertainties that derive from a lack of knowledge on system’s and launcher’s parameters. This type of uncertainty is typical of the early stage of the design process when multiple options need to be evaluated and only a partial knowl...

This paper presents a method for the design for resilience of complex systems under uncertainty. In this approach, the complexity of the system is captured by a network formulation. Each node i is completely determined by two indicators: a performance f i and a functionality c i. Both these measures depend on time, decision and uncertain variables....

This chapter presents a new robust particle filter that can handle set-valued probability measures. The method implemented in this new robust filter returns bounds on the probability associated with a given quantity of interest. The particles are generated with an importance sampling technique and propagated only once. The bounds are then computed...

Gathers lecture notes from leading experts in the field into one authoritative resource, providing readers with an essential starting point for cutting edge research Provides the most modern techniques for optimization under uncertainty, many of which are outdated or not covered in existing texts on the subject Includes never before published sec...

The Hera mission plans to release a CubeSat into orbit around the binary asteroid system Didymos to investigate these bodies in more detail. Uncertainties play a key role in designing the trajectory for the CubeSat and thus a method is needed that is able to accurately and efficiently capture all the effects of uncertainties on the dynamics of this...

The dynamics of space objects in Low Earth Orbit (LEO) is strongly determined by the effects of atmospheric drag: this complex interaction, dependent on the physical properties of the atmosphere, comprises several of the primary sources of orbit uncertainty in LEO. However, most atmospheric density models, both empirical and semi-empirical, do not...

Recently, the first treatment of the space population as a multi-layer temporal network was introduced. This model has allowed the application of network theory techniques for a holistic treatment of the space environment. In this work, we go one step further by focusing on the physical layer of the network, investigating its structure, dynamics, a...

This paper addresses the problem of automatically allocating Collision Avoidance Manoeuvres under uncertainty by a robust Bayesian framework. This framework allows propagating the objects’ uncertainty, predicting collisions, allocating manoeuvres, updating the state estimation with Bayesian inference, and redefining the manoeuvres, accounting at al...

This paper proposes a method for the solution of constrained min-max problems. The method is tested on a benchmark of representative problems presenting different structures for the objective function and the constraints. The particular min-max problem addressed in this paper finds application in optimisation under uncertainty when the constraints...