Mirko Trisolini

Politecnico di Milano | Polimi · Department of Aerospace Engineering

This work presents the preliminary analysis of the projectile deployment by the Hayabusa2 extended mission (Hayabusa2#) after its planned rendezvous with asteroid 1998 KY26. Hayabusa2# will be the first ever mission to rendezvous with such a rapidly rotating small asteroid, posing significant engineering challenges because of its distinctive dynami...

In this paper the operational tool for the computation of the space debris index that will be released through a web-based front end by the end of 2023. The development of the software THEMIS is the results of an effort of Politecnico di Milano and Deimos UK within a project funded by the European Space Agency to track the health of the space envir...

The Hayabusa2 extended mission is planned to rendezvous with the fast-rotating asteroid 1998 KY26 in 2031. Hayabusa2# will be the first ever mission to rendezvous with such a rapidly rotating small asteroid, posing significant challenges because of its distinctive dynamical environment. In this paper we investigate potential target marker deploymen...

This work presents the model of an ejecta cloud distribution to characterise the plume generated by the impact of a projectile onto asteroids surfaces. A continuum distribution based on the combination of probability density functions is developed to describe the size, ejection speed, and ejection angles of the fragments. The ejecta distribution is...

The permanent power loss and the deviation of the trajectory of satellites impacted by centimetre and sub-centimetre sized debris have highlighted the need of taking into account such small fragments in the evolutionary models of the debris population and in the assessment of the in-orbit collision risk. When scaling down to the centimetre-millimet...

The continuously growing number of objects orbiting around the Earth is expected to be accompanied by an increasing frequency of objects re-entering the Earth’s atmosphere. Many of these re-entries will be uncontrolled, making their prediction challenging and subject to several uncertainties. Traditionally, re-entry predictions are based on the pro...

The sustainability of the space around the Earth is becoming an increasingly important issue in the space sector. Indeed, given the introduction of large constellations that place many satellites in specific orbital regions and the occurrence of breakup events (e.g., the CZ-6A breakup occurred on the 12 th of November 2022) that increase the backgr...

This work presents the model of an ejecta cloud distribution to characterise the plume generated by the impact of a projectile onto asteroids surfaces. A continuum distribution based on the combination of probability density functions is developed to describe the size, ejection speed, and ejection angles of the fragments. The ejecta distribution is...

This work presents a mission concept for in-orbit particle collection for sampling and exploration missions towards Near-Earth asteroids. Ejecta is generated via a small kinetic impactor and two possible collection strategies are investigated: collecting the particle along the anti-solar direction, exploiting the dynamical features of the L$_2$ Lag...

This work presents a mission concept for in-orbit particle collection for sampling and exploration missions towards Near-Earth asteroids. Ejecta is generated via a small kinetic impactor and two possible collection strategies are investigated: collecting the particle along the anti-solar direction, exploiting the dynamical features of the L2 Lagran...

This paper presents an improved methodology for long-term uncertainty propagation in nonlinear dynamics by combining techniques of initial multi-directional splitting and adaptive entropy-based splitting during the propagation within the Gaussian mixture model framework. An initial multi-directional splitting technique applied to the directions par...

This work presents a new mission concept for sample collection missions around asteroids. Starting from the heritage of mission Hayabusa2, a kinetic impactor is used to generate fragments, which are then collected in orbit. The work discusses the feasibility of the mission, possible collection strategies, and the preliminary concepts of operations.

This paper proposes a continuity equation-based debris’ evolutionary model for the long-term propagation of fragments’ clouds under atmospheric drag, J2 perturbation, solar radiation pressure and third-body perturbation. In particular, it focuses on enhancing the computational efficiency of the dynamical model. This purpose is achieved by cutting...

This work presents a sensitivity analysis of ejecta models used to model impact events onto small bodies in the Solar System. The application in exam is focused on kinetic impacts on Near Earth Asteroids to study the possibility of collecting the generated fragments in orbit, thus avoiding landing or touchdown operations. The sensitivity analysis s...

In the context of space sustainability and space traffic coordination and management, it is important to define an internationally recognised and accepted approach to measure the Space capacity, defined as the quantity and type of missions/objects that the Space environment can sustain. In parallel to the study on how the capacity can be measured,...

This work presents a methodology for the computation of particle fluxes around asteroids as they are generated by a kinetic impact on the asteroid surfaces. The methodology combines the dynamical propagation of small fragments in a perturbed environment with the modelling of impact crater phenomena. The particle fluxes allow the estimation of the n...

This paper compares the continuum evolution for density equation modelling and the Gaussian mixture model on the 2D phase space long-term density propagation problem in the context of high-altitude and high area-to-mass ratio satellite long-term propagation. The density evolution equation, a pure numerical and pointwise method for the density propa...

This paper compares the continuum evolution for density equation modelling and the Gaussian mixture model on the 2D phase space long-term density propagation problem in the context of high-altitude and high area-to-mass ratio satellite long-term propagation. The density evolution equation, a pure numerical and pointwise method for the density propa...

In recent years, due to the constant increase of the density of satellites in the space environment, several studies have been focused on the development of active and passive strategies to remove and mitigate space debris. This work investigates the feasibility of developing a reliable and fast approach to analyze the re-entry of a satellite. The...

In recent years, due to the constant increase of the density of satellites in the space environment, several studies have been focused on the development of active and passive strategies to remove and mitigate space debris. This work investigates the feasibility of developing a reliable and fast approach to analyze the re-entry of a satellite. The...

This work presents the development of a statistical ejecta model to predict the ejecta characteristics due to the impact of a small kinetic impactor onto asteroids surfaces. The distribution of the ejecta in terms of particle size, ejection velocity, and ejection direction is obtained. The procedure followed to compute the parameters defining the s...

It is estimated that almost one million debris greater than 1 cm currently orbit the Earth, posing hazard to operational satellites. Therefore, the traditional piece-by-piece approach, to monitor the evolution of such small space debris, is computationally prohibitive. This problem is here addressed through an analogy with fluid dynamics, consideri...

The ability of space activities to benefit Earth and its people is now threatened by the increasing density of objects in orbit. If no mitigation measures are taken, the population could reach a level in the future at which collisions would continue to increase the number of debris in orbit, even without new launches. Addressing the need for space...

This work explores the possibility of performing in-orbit particle collection for sampling and exploration missions towards asteroids. Ejecta is generated via a small kinetic impactor and two possible collection strategies are investigated: collecting the particle at the L 2 Lagrangian point or collecting them while they orbit the asteroid and befo...

To ensure future space development and sustainable orbital exploitation, it is essential to improve the knowledge of the space environment and of the phenomena that could influence spacecraft's operations. Space debris could pose a threat to space operations, and a collision with such an object could degrade the mission performance. Space debris' e...

This work investigates the feasibility of developing a reliable and fast approach to predict and analyse the re-entry of satellites in highly elliptical orbits. We develop an interface between the long-term orbit propagation obtained through semi-analytical methods with the atmospheric destructive re-entry phase exploiting the concept of overshoot...

The paper presents a re-entry analysis of Geosynchronous Orbit (GSO) satellites on disposal trajectories that enhance the effects of the Earth oblateness and lunisolar perturbations. These types of trajectories can lead to a natural re-entry of the spacecraft within 20 years. An analysis was performed to characterise the entry conditions for these...

The paper presents a re-entry analysis of Geosynchronous Orbit (GSO) satellites on disposal trajectories that enhance the effects of the Earth oblateness and lunisolar perturbations. These types of trajectories can lead to a natural re-entry of the spacecraft within 20 years. An analysis was performed to characterise the entry conditions for these...

Space, like any other ecosystem, has a finite capacity. The continuous growth of space activities is contributing to overload this delicate ecosystem. In this paper, the THEMIS software tool will be presented, conceived to assess the impact of a space mission on the space environment and its contribution to the overall Space capacity. THEMIS is dev...

In the context of future asteroid exploration missions, within the MSCA CRADLE project in collaboration between Politecnico di Milano and JAXA, we envision the possibility to perform in-orbit collection. In this work, the dynamical behaviour of ejecta following the impact of a small kinetic impactor is analysed in the context of the circular restri...

As in-orbit breakup events become more frequent and more difficult to predict and avoid, the risk of collisions of debris with active satellites grows each year, threatening the safety of space operations. By constantly monitoring known and new objects, it is possible to verify whether they were created in a fragmentation. The PUZZLE software packa...

Everyday thousands of meteoroids enter the Earth's atmosphere. The vast majority burn up harmlessly during the descent, but the larger objects survive, occasionally experiencing intense fragmentation events, and reach the ground. These events can pose a threat for a village or a small city; therefore, models of asteroid fragmentation, along with ac...

The e.Cube mission aims at contributing to the advancement of technologies and methodologies dedicated to space debris mitigation and remediation (1) to increase spacecraft autonomy in performing CAMs, (2) to support space debris modelling with in-orbit collected data about non-trackable fragment objects, (3) to characterise the atmosphere for more...

This paper aims at providing a new perspective on the attitude dynamics and control system of a new CubeSat mission concept for atmospheric data acquisition, in the region between 200 km and 100 km, for more accurate re-entry predictions. It discusses the main challenges and the feasibility of analysing the main atmospheric parameters via onboard s...

The number of breakup events (i.e., collisions and explosions) is growing in recent years, resulting in an increase in the number of uncontrollable objects orbiting around the Earth. Despite the presence of debris mitigation guidelines, defined to manage satellites during their entire lifetime, some events are still difficult to predict or even unp...

Everyday thousands of meteoroids enter the Earth's atmosphere. The vast majority burn up harmlessly during the descent, but the larger objects survive, occasionally experiencing intense fragmentation events, and reach the ground. These events can pose a non-negligible threat for a village or a small city; therefore, models of asteroid fragmentation...

In this paper we will present the design of a software to assess the impact of a space mission on the space environment and its contribution to the space overall capacity developed within an ESA-funded study by Politecnico di Milano and Deimos Space. The aim of this project is to create an open software platform for the evaluation of the impact of...

In this work, the effect of uncertainties in the re-entry and break-up of satellites is combined with a destructive re-entry analysis of object-oriented codes. The approach used to model the re-entry and propagate the relevant uncertainties is based on the continuity equation, where the uncertainty probability density is propagated alongside the tr...

In recent years, fragmentation events have become more frequent and more difficult to predict and avoid, with growing risk for the safety of space operations. The constant surveillance and tracking of space objects facilitates the prediction of such events and allows to back track new objects and identify whether they originated in such an event. T...

This work proposes a continuum-based approach for the propagation of uncertainties in the initial conditions and parameters for the analysis and prediction of spacecraft re-entries. Using the continuity equation together with the re-entry dynamics, the joint probability distribution of the uncertainties is propagated in time for specific sampled po...

This Paper proposes a continuum-based approach for the propagation of uncertainties in the initial conditions and parameters for the analysis and prediction of spacecraft reentries. Using the continuity equation together with the reentry dynamics, the joint probability distribution of the uncertainties is propagated in time for specific sampled poi...

In the past few years, the interest towards the implementation of design-for-demise measures has increased steadily. The majority of mid-sized satellites currently launched and already in orbit fail to comply with the casualty risk threshold of 10−4. Therefore, satellites manufacturers and mission operators need to perform a disposal through a cont...

In the past few years, the interest towards the implementation of design-for-demise measures has increased steadily. Most mid-sized satellites currently launched and already in orbit fail to comply with the casualty risk threshold of 0.0001. Therefore, satellites manufacturers and mission operators need to perform a disposal through a controlled re...

Highlights: - Exploiting the effects of lunisolar perturbation and the J2 effect to dispose of GEO satellites via re-entry through a mechanism of long-term eccentricity build-up. - Interfacing the long-term averaged propagation with the destructive re-entry analysis using the concept of overshoot boundary. - Statistical analysis of the condition...

The study of the fragmentation of meteorites entering the Earth's atmosphere allow to predict the consequences such events can have on the ground. Existing models for meteoroid fragmentation follow either a pancake approach, where the cloud of fragments resulting from the meteorite explosion expands together in the shape of a disk, or a discrete fr...

The effect of uncertainties in the re-entry and break-up of satellites is analyzed. Two contributions are considered: the effect of the initial uncertainties of the parent trajectory and the break-up event, characterized by high thermal and mechanical loads and tumbling motion. Specifically, this last phenomenon may cause the scattering of the comp...

The space environment around the Earth is populated by more than 130 million objects of 1 mm in size and larger, and future predictions shows that this amount is destined to increase, even if mitigation measures are implemented at a far better rate than today. These objects can hit and damage a spacecraft or its components. It is thus necessary to...

The space environment around the Earth is populated by more than 130 million objects of 1 mm in size and larger, and future predictions shows that this amount is destined to increase, even if mitigation measures are implemented at a far better rate than today. These objects can hit and damage a spacecraft or its components. It is thus necessary to...

Among the mitigation measures introduced to cope with the space debris issue there is the de-orbiting of decommissioned satellites. Guidelines for re-entering objects call for a ground casualty risk no higher than 0.0001. To comply with this requirement, satellites can be designed through a design-for-demise philosophy. Still, a spacecraft designed...

The paper is concerned with examining the effects that design-for-demise solutions can have not only on the demisability of components, but also on their survivability that is their capability to withstand impacts from space debris. First two models are introduced. A demisability model to predict the behaviour of spacecraft components during the at...

The proposed study aims at implementing a density-based approach for the propagation of uncertainties in the initial conditions and parameters for the analysis and prediction of spacecraft re-entries. Using the continuity equation together with the re-entry dynamics, the joint probability distribution function of the uncertainties is propagated and...

The present study proposes a methodology based on the use of the continuity equation in the analysis of re-entry scenarios under the presence of uncertainty in the initial conditions and parameters. The prediction of re-entry trajectories is an extremely complex task. The accuracy of these predictions is influenced by the uncertainty on many factor...

The space sector is a new area of development for Life Cycle Assessment (LCA) studies. However, it deals with strong particularities which complicate the use of LCA. One of the most important is that the space industry is the only human activity crossing all stages of the atmosphere during the launch event or the atmospheric re-entry. As a result,...

In the past two decades, the attention towards a more sustainable use of outer space has increased steadily. The major space-faring nations and international committees have proposed a series of debris mitigation measures to ensure the sustainability of the space environment. Among these mitigation measures, the de-orbiting of spacecraft at the end...

The paper presents the development of a multi-objective optimisation framework to study the effects that preliminary design choices have on the demisability and the survivability of a spacecraft. Building a spacecraft such that most of it will demise during the re-entry through design-for-demise strategies may lead to design that are more vulnerabl...

In a period where the evolution of the space environment is causing increasing concerns for the future of space exploitation and sustainability, the design for demise philosophy has gained an increased interest. However, satellites designed for demise still have to survive the space environment polluted by space debris. Within this context we are d...

In the framework of space debris remediation and mitigation and eco-design of space systems, a design indicator is proposed to measure the management of end-of-life options and to compare different design options of a space mission from the perspective of the impacts of space debris. Such an indicator measures the orbital space occupied by missions...

In a period where the evolution of the space environment is causing increasing concerns for the future of space exploitation and sustainability, the design-for-demise philosophy has gained an increased interest. However, building a spacecraft such that most of it will demise through design-for-demise strategies may lead to designs that are more vul...

Among the mitigation measures introduced to cope with the space debris issue there is the de-orbiting of decommissioned satellites. Guidelines for re-entering objects call for a ground casualty risk no higher than 10⁻⁴. To comply with this requirement, satellites can be designed through a design-for-demise philosophy. Still, a spacecraft designed t...

The paper is concerned with examining the effects that design-for-demise solutions can have not only on the demisability of components, but also on their survivability that is their capability to withstand impacts from space debris. First two models are introduced. A demisability model to predict the behaviour of spacecraft components during the at...

In a period where the evolution of the space environment is causing increasing concerns for the future of space exploitation and sustainability, the design-for-demise philosophy has gained an increased interest. However, satellites designed for demise still have to survive the space environment, polluted by space debris, for many years. Within this...

A study was conducted to demonstrate a direct-drive system for a low-power hall thruster. The HT-100 Hall thruster was selected for the direct-drive demonstration. The throttling range of the thruster was approximately 100-300 W discharge power, 800-1200 s specific impulse, and 5-12mN thrust, with efficiency up to 35%. The solar array configuration...