Francesco Topputo

Francesco Topputo
Politecnico di Milano | Polimi · Department of Aerospace Engineering

PhD

About

200
Publications
58,595
Reads
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2,260
Citations
Citations since 2016
124 Research Items
1668 Citations
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Introduction
Prof. Topputo is a Full Professor of Space Systems at Politecnico di Milano, Italy, and holds a position as Visiting Professor at TU Delft, The Netherlands. His core research activities involve spacecraft flight dynamics, interplanetary CubeSat mission and system design, autonomous guidance, navigation, and control. Dr. Topputo is an ERC laureate (CoG 2019) and has been PI in 14 research projects, with over €4.1M research grants allocated to work under his direction. He leads the Deep- space Ast
Additional affiliations
December 2012 - present
Politecnico di Milano
Position
  • Research Assistant

Publications

Publications (200)
Article
Full-text available
The increase in number of interplanetary probes has emphasized the need for spacecraft autonomy to reduce overall mission costs and to enable riskier operations without ground support. The perception of the external environment is a critical task for autonomous probes, being fundamental for both motion planning and actuation. Perception is often ac...
Article
Full-text available
Stand-alone deep-space CubeSats are the future of the space sector. For limited budget reasons, these spacecraft need to follow operational-compliant (OC) trajectories: transfers with thrusting and coasting periods imposed at pre-defined time instants. Traditional trajectory optimisation algorithms exhibit convergence problems when handling discont...
Article
Full-text available
Asteroids and comets are triggering interest due to the richness of precious materials, their scientific value as well as for their potential hazardousness. Owing to their significant diversity, minor bodies do not exhibit uniform shapes: they can range from spherical to irregularly shaped objects with rocky, uneven, and cratered surface. Nowadays,...
Article
The paper describes a general modelling procedure to build a simulation tool to investigate contact motion of a CubeSat on an asteroid surface. We investigate landing performance and landing success for the case of elastic rocky terrain and flat surfaces. As a case study, we focus on the disposal of ESA’s Hera Milani CubeSat by landing on the moon...
Preprint
Full-text available
The capability to detect boulders on the surface of small bodies is beneficial for vision-based applications such as hazard detection during critical operations and navigation. This task is challenging due to the wide assortment of irregular shapes, the characteristics of the boulders population, and the rapid variability in the illumination condit...
Preprint
Full-text available
The capability to detect boulders on the surface of small bodies is beneficial for vision-based applications such as navigation and hazard detection during critical operations. This task is challenging due to the wide assortment of irregular shapes, the characteristics of the boulders population, and the rapid variability in the illumination condit...
Preprint
Full-text available
Deep learning architectures such as convolutional neural networks are the standard in computer vision for image processing tasks. Their accuracy however often comes at the cost of long and computationally expensive training, the need for large annotated datasets, and extensive hyper-parameter searches. On the other hand, a different method known as...
Conference Paper
Full-text available
A new era of space exploitation is fast approaching. An exponential number of CubeSats, shoe-boxed spacecraft, will be launched into space, owing to their low cost compared to traditional probes. At the current pace, piloting CubeSats from the ground with standard radiometric tracking will become unsustainable. This work tackles the problem from th...
Conference Paper
Full-text available
As the number of interplanetary space missions keeps increasing thanks to the reduction of spacecraft development and integration costs, there is the urge of avoiding the saturation of the ground infrastructure required to operate satellites. The aim of the EXTREMA project, which has received fundings from the European Research Council, is to solve...
Conference Paper
Missions around small bodies present many challenges from their design to the operations, due to the highly non-linear and uncertain dynamics, the limited ∆v budget and constraints coming from orbit determination and mission design. Within this context, mathematical tools to enhance the understanding of the dynamics behavior can be proven useful to...
Conference Paper
Optical-based navigation in a binary system such as the Didymos one poses new challenges in terms of image processing capabilities , in particular for what concerns the recognition between the primary and secondary bodies. In this work, the baseline object recognition algorithm used in the Milani mission to distinguish between Didymos and Dimorphos...
Conference Paper
CubeSats represent the new frontier of space exploration, as they provide cost savings in terms of production and launch opportunities by being able to be launched as opportunity payloads. In addition, interest in minor bodies is gradually increasing because of the richness and exploitability of the materials present throughout their surface, the s...
Article
Full-text available
Deep-space CubeSats missions require careful trade-offs on design drivers such as mass, volume, and cost, while ensuring autonomous operations. This work elaborates the possibility of off-loading the reaction wheels without the need of carrying a bulky and expensive reaction control system or the field-dependent magnetotorquers. The momentum accumu...
Article
Full-text available
Ballistic capture orbits offer safer Mars injection at longer transfer time. However, the search for such an extremely rare event is a computationally intensive process. Indeed, it requires the propagation of a grid sampling the whole search space. This work proposes a novel ballistic capture search algorithm based on Taylor differential algebra pr...
Conference Paper
Full-text available
A framework is presented where a nonlinear dynamical system is transformed into a higher-dimensional bilinear system using the Koopman operator theory. The nonlinear dynamics are projected onto a set of orthogonal polynomials via the Galerkin method to obtain the evolution of the eigenfunctions, so that the time evolution of any observable is descr...
Conference Paper
Full-text available
A novel homotopic approach for convex low-thrust trajectory optimization is developed to improve convergence, accuracy, and computational effort compared to state-of-the-art methods. The homotopy is included in the optimization process where the homotopic parameter is updated continuously based on the constraint violation. This method is applied to...
Article
The Lunar Meteoroid Impacts Observer (LUMIO) is a CubeSat mission to observe, quantify, and characterize the meteoroid impacts on the lunar farside by detecting their flashes. This complements the knowledge gathered by Earth-based observations of the lunar nearside, thus synthesizing global information on the lunar meteoroid environment and contrib...
Preprint
Full-text available
In this paper, a practical approach to the trajectory design for asteroid exploration missions with CubeSats is presented. When applied trajectories are sought, operative concerns and uncertainties affecting the spacecraft dynamics must be considered during the design process. Otherwise, trajectories that are possible on paper might become unfeasib...
Article
Landing on small-bodies is a very challenging problem that requires high degrees of robustness and autonomy. Being able to perform simulations with great flexibility and accuracy is paramount for the development and design of landing systems. To this end, contact dynamics plays a fundamental role and is often handled by complex tools that require l...
Article
The Lunar Meteoroid Impacts Observer (LUMIO) is a CubeSat mission to observe, quantify, and characterize the meteoroid impacts by detecting their flashes on the lunar farside. It complements lunar nearside observations performed by ground-based observatories to yield global information synthesis on the lunar meteoroid environment. Predicting LUMIO’...
Article
In this paper a novel paradigm for Mars missions is modeled, optimized, and assessed. This concept consists of a maneuver that combines aerocapture and ballistic capture upon Mars arrival, labeled aeroballistic capture. The idea is reducing the overall cost and mass by exploiting the interaction with the planet atmosphere as well as the complex sun...
Conference Paper
Full-text available
Hera is the European contribution to the ESA-NASA collaboration AIDA. During the mission, two CubeSats will be released in the proximity of the binary asteroid 65803-Didymos: Milani and Juventas. In this work, an updated overview about the Milani mission analysis and navigation assessment are presented. The mission profile and the trajectories are...
Conference Paper
Full-text available
Minor bodies show great variability in shape and surface morphological features. Since in the proximity of these bodies the dynamic is highly non-linear, communication windows with Earth could not be sufficient to navigate around them. Moreover, there is a growing demand for the reduction of costs deriving from ground-stations operations. As a resu...
Article
In this work, an orbit determination algorithm suitable for CubeSats onboard implementation is developed, which simulates optical autonomous navigation accomplished by a stand-alone platform. An extended Kalman filter featuring line-of-sight acquisitions of planets is selected as the state estimator, and its performances are tested on a Raspberry P...
Article
The Earth-Moon system is constantly bombarded by meteoroids of different size and impact speed. Observation of the impacts on the Moon can enable thorough characterization of the Lunar meteoroid flux, which is similar to that of the Earth. While Earth-based Lunar observations are restricted by weather, geometric and illumination conditions, a Lunar...
Article
Full-text available
Ground facilities relying on traditional radiometric tracking are reaching saturation due to the growth of satellites launched into space. As such, autonomous navigation is one of the main enabling technologies for sustainable deep-space missions. This paper tackles the deep-space optical navigation problem exploiting multiple beacons to estimate t...
Conference Paper
Full-text available
Ballistic capture corridors allow a spacecraft to be temporarily captured about a planet without any thrust firing. They represent a promising approach for future deep-space small-satellites missions, where only limited fuel can be carried onboard. In an effort to enable autonomous interplanetary CubeSats, a guidance algorithm based on convex optim...
Conference Paper
The adoption of CubeSats marks the beginning of new momentum in interplanetary exploration, owing to their low cost as compared to standard missions. Yet, the proliferation of deep-space CubeSats will cause the saturation of the ground networks, hindering the traditional navigation through ground-based radiometric tracking. The solution to this iss...
Conference Paper
Milani is a 6U CubeSat that will visit the Didymos binary system as part of the Hera mission. Its objectives are both scientific and technological: to study and characterize the asteroid environment, and to demonstrate the use of CubeSat technologies for interplanetary missions. The latter includes optical-based autonomous navigation algorithms in...
Conference Paper
Image processing and vision-based navigation algorithms require images for design , testing, and validation. For space exploration purposes, it is complex if not impossible to retrieve realistic images. To mitigate this, two approaches can be used: high-fidelity rendering of celestial bodies or hardware-in-the-loop testing. In this work, we focus o...
Article
In this work data-driven image processing options for a CubeSat mission around a binary asteroid system are investigated. The methods considered belong to two main branches of image processing methods: centroid and artificial intelligence. The former is represented by three variations of centroiding methods, and the latter by three neural networks...
Conference Paper
View Video Presentation: https://doi.org/10.2514/6.2022-1193.vid Image processing and vision-based navigation algorithms require images for design, testing, and validation. For space exploration purposes, it is complex if not impossible to retrieve realistic images. To mitigate this, two approaches can be used: high-fidelity rendering of celestial...
Conference Paper
Full-text available
View Video Presentation: https://doi.org/10.2514/6.2022-1892.vid Different discretization and trust-region methods are assessed and compared for the low-thrust fuel-optimal trajectory optimization problem using successive convex programming. In particular, the differential and integral formulations of the adaptive pseudospectral Legendre--Gauss--Ra...
Conference Paper
View Video Presentation: https://doi.org/10.2514/6.2022-2381.vid Milani is a 6U CubeSat that will be part of the Hera mission around the Didymos binary system. Its objectives are both scientific and technological: to study and characterize the Didymos environment, and to demonstrate the use of CubeSat technologies for interplanetary missions. The l...
Article
Full-text available
Ballistic capture is a phenomenon by which a spacecraft approaches its target body, and performs a number of revolutions around it, without requiring manoeuvres in between. Capture orbits are characterized by specific dynamics, defining regions that guide transport phenomena. Because of the limitations associated with existing approaches, the devel...
Preprint
Full-text available
A robust algorithm to solve the low-thrust fuel-optimal trajectory optimization problem for interplanetary spacecraft is developed in this paper. The original nonlinear optimal control problem is convexified and transformed into a parameter optimization problem using an arbitrary-order Gauss-Lobatto discretization scheme with nonlinear control inte...
Conference Paper
Full-text available
A new era of space exploitation is fast approaching. CubeSats have performed a revolution in the way satellites are deployed in interplanetary missions. The exploitation of standardized dimensions and Commercial-Off-The-Shelf components has boosted their utilization by reducing mission costs and development time. The cutting down on the space entry...
Conference Paper
Full-text available
The space industry has recently witnessed a significant decrease of the overall costs of space missions, thanks to the miniaturization of satellites and their components. CubeSats have granted institutions and small companies access to space. However, space operations are still entirely performed from ground, limiting the potentiality of such space...
Conference Paper
Full-text available
A new space era is fast approaching. In this decade, CubeSats have granted affordable access to space due to their reduced manufacturing costs compared to traditional missions. Although most of miniaturized spacecraft has thus far been deployed into near-Earth orbits, soon a multitude of CubeSats will be employed for deep-space missions as well. By...
Article
Full-text available
The Miniaturised Asteroid Remote Geophysical Observer (M-ARGO) mission is designed to be ESA’s first stand-alone CubeSat to independently travel in deep space with its own electric propulsion and direct-to-Earth communication systems in order to rendezvous with a near-Earth asteroid. Deep-space Cubesats are appealing owing to the scaled mission cos...
Article
A novel methodology for a combined systems-trajectory optimization for a geostationary equatorial orbit (GEO) platform is proposed to obtain comprehensive design solutions. A combined chemical-electric propulsion system is used to execute hybrid high-thrust/low-thrust trajectory transfer to GEO, thereby balancing the overall system mass and transfe...
Article
The dynamical environment in the close-proximity of small celestial bodies is characterized by a very weak and irregular gravity field. In this low-acceleration deep-space environment, small dynamical perturbations might affect significantly the dynamics of a spacecraft hovering near the surface of such objects. This poses a challenge to the effici...
Conference Paper
The proliferation of deep-space probes is posing new challenges in navigating them with ground-in-the-loop methods. Ground tracking stations will reach saturation owing to the escalation of small satellites in deep space. Thus, autonomous guidance, navigation, and control methods that are independent from ground communications are necessary for fut...
Conference Paper
Full-text available
Hera is the European contribution to the ESA-NASA collaboration AIDA. During the mission, two CubeSats will be released in proximity of the binary asteroid 65803-Didymos: Milani and Juventas. In this work, some challenging aspects of the mission analysis of Milani are presented. Original trajectory design solutions are devised as a response to dema...
Conference Paper
Full-text available
Current deep-space missions heavily count on ground-based operations. Although reliable, ground slots will saturate soon, so hampering the current momentum in space exploration. EXTREMA, a project awarded an ERC Consolidator Grant in 2019, enables self-driving spacecraft, challenging the current paradigm and aiming, among others, at autonomously en...
Article
A method for solving zero-finding problems is developed by tracking homotopy paths, which define connecting channels between an auxiliary problem and the objective problem. Current algorithms’ success highly relies on empirical knowledge, due to manually, inherently selected homotopy paths. This work introduces a homotopy method based on the Theory...
Conference Paper
Full-text available
The low-thrust minimum-fuel trajectory optimization problem is solved in a high-fidelity model using convex optimization. The problem is convexified and dis-cretized with the Radau pseudospectral method. We apply a homotopic approach and successively increase the complexity and accuracy of the model to enhance convergence properties. Solar radiatio...
Preprint
Full-text available
Ballistic capture is a phenomenon by which a spacecraft approaches its target body, and performs a number of revolutions around it, without requiring manoeuvres in between. Capture orbits are characterized by a specific dynamics, defining regions that guide transport phenomena. Because of the limitations associated to existing approaches, the devel...
Conference Paper
Full-text available
A closed-loop guidance method for low-thrust fuel-optimal interplanetary transfers is developed. The algorithm is based on convex programming and a flipped Radau pseudospectral discretization scheme. New reference trajectories are repeatedly recomputed in certain time intervals. The state of the spacecraft is propagated during these periods using t...
Poster
Full-text available
In the current landing simulation scene, contact dynamics tools play a fundamental role. Developing them is a very complex task, howeverseveral options used in the video-game and VFX are available. In this work, a study is performed exploiting the contact physic engine in Blender to simulate the bounce-off trajectories followed after impact on diff...
Conference Paper
Full-text available
Vast amounts of meteoroids and micrometeoroids continuously enter the Earth–Moon system and consequently become a potential threat. Lunar meteoroid impacts have caused a substantial change in the lunar surface and its properties. The Moon having no atmospheric blanket to protect itself, it is subjected to impacts from meteoroids ranging from a few...
Article
The Miniaturised Asteroid Remote Geophysical Observer (M-ARGO) is planned to be the first standalone deep-space CubeSat mission to rendezvous with and characterise a near-Earth asteroid. To this aim, it is essential to assess the attainable set of target asteroids. This work presents the initial results of the mission analysis and design of M-ARGO....
Conference Paper
Full-text available
An efficient indirect method is presented to solve optimal low-thrust Earth-orbit transfers in presence of shadow eclipses. The key feature of our method is the capability to offer accurate gradients of problem functions with respect to all decision variables, which is pivotal for robust convergence. Particular attention is paid to handling the dis...
Preprint
Full-text available
CubeSats offer a flexible and low-cost option to increase the scientific and technological return of small-body exploration missions. ESA's Hera mission, the European component of the Asteroid Impact and Deflection Assessment (AIDA) international collaboration, plans on deploying two CubeSats in the proximity of binary system 65803 Didymos, after a...
Conference Paper
Full-text available
Small-bodies such as asteroids and comets exhibit great variability in surface morphological features. These are often unknown beforehand but can be exploited for hazard avoidance during landing, autonomous planning of scientific observations, and for navigation purposes. The detection and classification of such features is a laborious task that re...
Conference Paper
Full-text available
Optical navigation about small-bodies can be performed at different scales and with different techniques during proximity operations. Traditional methods however are influenced by pixel intensity due to illumination conditions and often provide a navigation solution only when coupled with filtering techniques. In this work, a navigation method for...
Conference Paper
Full-text available
A robust algorithm to solve the low-thrust fuel-optimal trajectory optimization problem for interplanetary spacecraft is developed in this work. The original nonlinear optimal control problem is convexified and transformed into a parameter optimization problem using the adaptive flipped Radau pseudospectral discretization scheme. The switching time...
Article
A novel Mars orbit insertion strategy that combines ballistic capture and aerobraking is presented. Mars ballistic capture orbits that neglect the aerodynamics are first generated, and are distilled from properly computed stable and unstable sets by using a pre-established method. A small periapsis maneuver is implemented at the first close encount...
Article
CubeSats offer a flexible and low-cost option to increase the scientific and technological return of small-body exploration missions. ESA’s Hera mission, the European component of the Asteroid Impact and Deflection Assessment (AIDA) international collaboration, plans on deploying two CubeSats in the proximity of binary system 65803 Didymos, after a...
Article
Deep-space optical navigation is among the most promising techniques to autonomously estimate the position of a spacecraft in deep space. The method relies on the acquisition of the line-of-sight directions to a number of navigation beacons. The position knowledge depends upon the tracked objects. This paper elaborates on the impact of the observat...
Conference Paper
Full-text available
The LUnar Meteoroid Impacts Observer (LUMIO) is a CubeSat mission to a halo orbit at Earth–Moon L2 that shall observe, quantify, and characterize meteoroid impacts on the Lunar farside, by detecting their flashes. In this way, LUMIO is expected to significantly contribute to Lunar Situational Awareness and to the current knowledge on the evolution...