Mauro Pontani

Sapienza University of Rome | la sapienza · Department of Astronautics, Electrical and Energy Engineering DIAEE

In this research, a feedback nonlinear control law was designed and tested to perform acquisition and station-keeping maneuvers for a lunar navigation constellation. Each satellite flies an Elliptical Lunar Frozen Orbit (ELFO) and is equipped with a steerable and throttleable low-thrust propulsion system. Lyapunov stability theory was employed to d...

Gateway will represent a primary logistic infrastructure in cislunar space. The identification of efficient orbit transfers capable of connecting Earth, Moon, and Gateway paves the way for enabling refurbishment, servicing, and utilization of this orbiting platform. This study is devoted to determining two-way minimum-time low-thrust orbit transfer...

This study presents new approaches that can be applied to large constellations for (a) the rapid determination of routing nodes and (b) identification of optimal routing paths in relation to specific objectives. Problem (a) is solved through the stereographic projection of the satellites orbits onto the equatorial plane, which leads to analytical f...

In recent years, lunar constellation design and deployment has attracted a strong interest from the scientific community and some major space agencies. In fact, a similar space infrastructure will represent a valuable asset for navigation and telecommunications purposes, useful to many robotic and human activities on the lunar surface. This study f...

The NASA’s Artemis project intends to bring humans back to the Moon in the next decade. A key element of the project will be the Lunar Gateway, a space station placed in a peculiar, near rectilinear Halo orbit in the vicinity of a collinear libration point in the Earth–Moon system. This study focuses on the high-fidelity description of the relative...

Gateway represents a key element of the Artemis program for the upcoming lunar exploration aimed at establishing a sustainable presence by the mid-2030s. This paper investigates minimum-fuel bi-impulsive orbit transfers from Gateway to low lunar orbits (LLOs) with a maximum time of flight of 48 h. Two distinct scenarios are analyzed: (i) target orb...

This work focuses on minimum-time low-thrust orbit transfers from a prescribed low Earth orbit to a specified low lunar orbit. The well-established indirect formulation of minimum-time orbit transfers is extended to a multibody dynamical framework, with initial and final orbits around two distinct primaries. To do this, different representations, u...

The Gateway will represent a primary space system useful for the Artemis program, Earth-Moon transportation, and deep space exploration. It is expected to serve as a staging location on the way to the lunar surface. This study focuses on low-thrust transfer dynamics, from the Near-Rectilinear Halo Orbit traveled by Gateway to a specified Low-altitu...

In this paper, the problem of guiding a vehicle from the entry interface to the ground is addressed. The Space Shuttle Orbiter is assumed as the reference vehicle and its aerodynamics data are interpolated to properly simulate its dynamics. The transatmospheric guidance is based on an open-loop optimal strategy which minimizes the total heat input...

On-orbit servicing is one of the most challenging tasks of the recent space era. Space Manipulator Systems (SMS) can represent viable technological solutions for several space operations, such as in-situ refueling, repairing of operating spacecraft, or debris grappling. Regardless of the specific task, SMS must approach the target object and then e...

Low-thrust propulsion allows substantial propellant saving if compared to high-thrust systems. However, multirevolution orbit transfers are affected by the unavailability of electrical power along eclipse arcs. This research addresses the identification of minimum-time low-thrust Earth orbit transfers with spacecraft eclipsing. Two different indire...

In the next decades, both space agencies and private competitors are targeting the lunar environment as a scientific and technological resource for future space missions. In particular, the confirmed existence of water-ice deposits in the vicinity of the poles (predominantly the south pole) makes polar or near-polar low lunar orbits attractive for...

This research describes a near-optimal feedback guidance, based on nonlinear orbit control, for low-thrust Earth orbit transfers. Lyapunov stability theory leads to proving that although several equilibria exist, only the desired operational conditions are associated with a stable equilibrium. This ensures quasi-global asymptotic convergence toward...

This research is focused on the problem of agile attitude maneuvering, aimed at the precise pointing of a satellite forming a typical constellation in low Earth orbit. We consider two different operational scenarios: (a) pointing toward a specific ground station, located on the Earth surface (for downlink data routing), and (b) pointing toward a co...

Recent space projects are designed by satellite constellations with a large number of spacecraft, a global character (i.e., from equatorial to high inclination orbits), and the possibility to transfer information to different satellites of the constellation (inter satellite link) in order to deliver the information to the ground as soon as possible...

This research proposes a near-optimal feedback guidance based on nonlinear control for low-thrust Earth orbit transfers. For the numerical simulations, two flight conditions are defined: (i) nominal conditions and (ii) nonnominal conditions that account for the orbit injection errors and the stochastic failures of the propulsion system. Condition (...

Formations flying of small satellites orbiting the Moon is currently considered a promising technology to provide communication and navigation services for both in-orbit and on-ground lunar activities. Their requirements set strict constraints on the altitude of the satellites, limiting it to medium and low lunar orbits, where the effects of pertur...

Exploration of Venus is recently driven by the interest of the scientific community in understanding the evolution of Earth-size planets, and is leading the implementation of missions that can benefit from new design techniques and technology. In this work, we investigate the possibility to implement a microsatellite exploration mission to Venus, t...

Nonlinear orbit control with the use of low-thrust propulsion is proposed as an effective strategy for autonomous guidance of a space vehicle directed toward the Moon. Orbital motion is described in an ephemeris model, with the inclusion of the most relevant perturbations. Unfavorable initial conditions, associated with weak, temporary lunar captur...

The growth of the population of space debris in the geostationary ring and the resulting threat to active satellites require insight into the dynamics of uncontrolled objects in the region. A Monte Carlo simulation analyzed the sensitivity to initial conditions of the long-term evolution of geostationary spacecraft near an unstable point of the geo...

This study considers the problem of injecting a spacecraft into an elliptic, repeating-ground-track orbit about Mars, starting from a 4-sol highly elliptical orbit, which is a typical Martian capture orbit, entered at the end of the interplanetary transfer. The final operational orbit has apoares corresponding to the maximum (or minimum) latitude,...

Over the past few decades, space missions have been significantly revolutionized by the advent of small satellites [...]

This work considers the three-dimensional descent path of a space vehicle, from periselenium of its operational orbit to the lunar surface. The trajectory is split in two arcs: (1) descent path, up to an altitude of 50 m, and (2) terminal approach and soft touchdown. For phase 1, a new, three-dimensional locally-flat near-optimal guidance is introd...

The growth of the population of space debris in the geostationary ring and the resulting threat to active satellites require insight into the dynamics of uncontrolled objects in the region. A Monte Carlo simulation analyzed the sensitivity to initial conditions of the long-term evolution of geostationary spacecraft near an unstable point of the geo...

In most mission scenarios, precise orbit injection represents a crucial requirement, and affects the subsequent phases of spaceflight. This research proposes a new guidance, control, and actuation architecture for upper stage orbit injection maneuvers. A novel, explicit near-optimal guidance algorithm is developed that is based on the local project...

This work addresses the problem of attitude maneuvering of a spacecraft equipped with two flexible solar panels,in response to an alert in two distinct operational scenarios: (a) detection of an approaching debris, and (b)collision avoidance of an impacting debris. In scenario (a) the approaching debris is assumed to be off a collisioncourse with t...

The development of an effective guidance and attitude control architecture for terminal descent and landing represents a crucial issue for the design of reusable vehicles capable of performing a safe atmospheric planetary entry. The sliding mode control represents a nonlinear technique able to generate an effective real-time closed-loop guidance la...

This research addresses the design of a Mars constellation composed of 12 satellites and devoted to telecommunications. While 3 satellites travel areostationary orbits, the remaining 9 satellites are placed in three distinct quasi-synchronous, inclined, circular orbits. The constellation at hand provides continuous global coverage, over the entire...

This work deals with two distinct guidance and control architectures for autonomous lunar ascent and orbit injection: (i) Variable-Time-Domain Neighboring Optimal Guidance and Constrained Proportional Derivative attitude control (VTD-NOG&CPD) and (ii) locally-flat near-optimal guidance and nonlinear reduced-attitude control. While (i) represents a...

Modern space missions often require satellites to perform guidance, navigation, and control tasks autonomously. Despite their limited resources, small satellites are also involved in this trend, as in-orbit rendezvous and docking maneuvers and formation flying have become common requirements in their operational scenarios. A critical aspect of thes...

Growing interest in deep-space exploration using microsatellites is leading the development of novel trajectory design techniques compatible with the constraints of this class of spacecraft. The mission design discussed in this paper examines the possibility of injecting a microsatellite into a desired orbit around Mars taking advantage of multibod...

This research considers the descent path of a space vehicle, from periselenium of its operational orbit to the lunar surface. The trajectory is split in two arcs: (a) approach, up to a specified altitude, and (b) terminal descent and soft touchdown. For phase (a), a new locally flat near-optimal guidance is used, which is based on iterative project...

This research is focused on the analysis, design, and numerical testing of a feedback guidance algorithm for autonomous (unmanned) close-range maneuvering of a chaser spacecraft, in the context of orbital rendezvous with a target vehicle. The relative dynamics of the two vehicles, placed in nearby low Earth orbits, is modeled using the nonlinear Ba...

This research addresses the problem of finding minimum-time low-thrust lunar orbit transfers, in the presence of eclipsing constraints on the available thrust. The problem at hand is formulated as a multiple-arc space trajectory optimization problem. Unlike former studies, no regularization or averaging is employed in the numerical solution process...

A formation of satellites operating in low Earth orbits is subject to perturbations associated to the nonuniform gravitational field of the Earth, whose entities depend on the position, resulting in a different effect on each satellite of the formation. As a result, any bounded configuration designed using the traditional methods, based on the Hill...

This research is focused on the problem of agile attitude maneuvering, aimed at precise pointing of a satellite that forms a typical constellation in low Earth orbit. Two different operational scenarios are considered: (a) pointing toward a specific ground station, located on the Earth surface (for downlink data routing), and (b) pointing toward a...

This papers introduces an analytic method to define multistage launcher trajectories to determine the payload mass that can be inserted in orbits of different semimajor axes and inclinations. This method can evaluate the gravity loss, which is the main term to be subtracted to the Tziolkowski evaluation of the velocity provided by the thrust of a l...

This study employs the circular restricted three-body problem (CR3BP) as the dynamical framework, for the purpose of investigating low-thrust orbit dynamics in the Earth–Moon system. First, the effect of low thrust on some dynamical structures that exist in the CR3BP is analyzed. Low-thrust capture and escape dynamics in the proximity of the Moon i...

Reorientation maneuvers represent a key task for large satellites. This work considers a space vehicle with solar panels and reaction wheels as actuation devices. Solar panels are modeled as flexural beams, using the modal decomposition technique. An inertia-free nonlinear attitude control algorithm, which enjoys quasi-global stability properties,...

In this work, we investigate the behavior of low-energy trajectories in the dynamical framework of the spatial elliptic restricted 4-body problem, developed using the Hamiltonian formalism. Introducing canonical transformations, the Hamiltonian function in the neighborhood of the collinear libration point L1 (or L2), can be expressed as a sum of th...

View Video Presentation: https://doi.org/10.2514/6.2022-1479.vid Nonlinear orbit control with the use of low-thrust propulsion is proposed as an effective strategy for autonomous guidance of a space vehicle directed toward the Moon. Orbital motion is described in an ephemeris model, with the inclusion of the most relevant perturbations. Unfavorable...

View Video Presentation: https://doi.org/10.2514/6.2022-0252.vid This work considers the three-dimensional descent path of a space vehicle, from periselenium of its operational orbit to the lunar surface. The trajectory is split in two arcs: (1) descent path, up to an altitude of 50 m, and (2) terminal approach and soft touchdown. For phase 1, a ne...

This research considers a constellation of 16 satellites equipped with SAR sensors and tailored to monitoring the polar ice evolution, with a suitable revisit time over the regions of interest. Satellite deployment includes three phases: (i) orbit injection, performed by the upper stage of the launch vehicle, (ii) orbit plane selection, and (iii) o...

This research considers the descent path of a space vehicle, from periselenium of its operational orbit to the lunar surface. The trajectory is split in two arcs: (a) approach, up to an altitude of 50 m, and (b) terminal descent and soft touchdown. For phase (a), a new local-flat near optimal guidance is used, which is based on iterative projection...

The detection of optimal trajectories with multiple coast arcs represents a significant and challenging problem of practical relevance in space mission analysis. Two such types of optimal paths are analyzed in this study: (a) minimum-time low-thrust trajectories with eclipse intervals and (b) minimum-fuel finite-thrust paths. Modified equinoctial e...

Accurate orbit injection represents a crucial issue in several mission scenarios, e.g., for spacecraft orbiting the Earth or for payload release from the upper stage of an ascent vehicle. This work considers a new guidance and control architecture based on the combined use of (i) the variable-time-domain neighboring optimal guidance technique (VTD-...

In nominal mission scenarios, geostationary satellites perform end-of-life orbit maneuvers to reach suitable disposal orbits, where they do not interfere with operational satellites. This research investigates the long-term orbit evolution of decommissioned geostationary satellite under the assumption that the disposal maneuver does not occur and t...

This research is focused on the definition, analysis, and numerical testing of an effective nonlinear orbit control technique tailored to compensating orbit perturbations, as well as possible errors at orbit injection of low- and medium-altitude Earth-orbit satellites. A general, systematic approach to real-time orbit control is presented, under th...

In nominal mission scenarios, geostationary satellites perform end-of-life orbit maneuvers to reach suitable disposal orbits, where they do not interfere with operational satellites. This research investigates the long-term orbit evolution of decommissioned geostationary satellite under the assumption that the disposal maneuver does not occur and t...

Recently, low-thrust propulsion is gaining strong interest from the research community and has already found application in some mission scenarios. This paper proposes an integrated guidance and control methodology, termed variable-time-domain neighboring optimal guidance and proportional derivative-rotation matrix (VTD-NOG and PD-RM), and applies...

Cycler mission architectures consider the use of a large space vehicle that cycles continuously between Earth and Mars, describing a near-ballistic path that includes flybys at the two planets. While this large spacecraft can be equipped with the life support system appropriate for a long interplanetary flight with a crew, taxi vehicles of reduced...

The determination of minimum-propellant-consumption trajectories represents a crucial issue for the purpose of planning robotic and human missions to the Moon in the near future. This work addresses the problem of identifying minimum-fuel orbit transfers from a specified low Earth orbit (LEO) to a low Moon orbit (LMO), under the assumption of emplo...

Lunar orbit dynamics and transfers at low altitudes are subject to considerable perturbations related to the gravitational harmonics associated with the irregular lunar mass distribution. This research proposes the combination of two techniques applied to low-thrust lunar orbit transfers, i.e. (i) the variable-time-domain neighboring optimal guidan...

Space missions designed to operate along three-dimensional quasi-periodic orbitsin the proximity of the collinear libration points have been proposed since the late60s. Because of the intrinsic instability of collinear libration point orbits, guidance laws for station-keeping must be developed to maintain the spacecraft sufficiently near the nomina...

The fast development of microsatellites and their use for deep space exploration pushed the interest toward the design of low-energy trajectories. These trajectories take advantage of the mutual action of multiple celestial bodies on the spacecraft, allowing missions with consistent savings of propellant mass, with respect to traditional ones. Beca...

Low-energy trajectories take advantage of the mutual action of multiple celestial bodies on the spacecraft, and can conclude with ballistic capture about the arrival body, thus allowing significant savings in terms of propellant consumption, if compared to more traditional transfers. Because of the chaotic nature of multibody environments, the desi...

Multistage launch vehicles are employed to place spacecraft and satellites in their operational orbits. If the rocket aerodynamics and propulsion are modeled appropriately, optimization of their ascent trajectory consists in determining the coast duration and the thrust time history that maximize the final mass at injection. This research derives a...

Earth-Mars cycling spacecraft have been proposed as a valuable option for the future exploration of Mars. Cycler mission architectures consider the use of a large space vehicle that cycles continuously between Earth and Mars, describing a near-ballistic path that includes flybys at the two planets. While this large spacecraft can be equipped with t...

Future human or robotic missions to the Moon will require efficient ascent path and accurate orbit injection maneuvers, because the dynamical conditions at injection affect the subsequent phases of spaceflight. This research is focused on the original combination of two techniques applied to lunar ascent modules, i.e. (i) the recently-introduced va...

Future human or robotic missions to the Moon will require efficient ascent path and accurate orbit injection maneuvers, because the dynamical conditions at injection affect the subsequent phases of spaceflight. This research focuses on the original combination of two techniques applied to lunar ascent modules, i.e., (1) the recently introduced vari...

This research aims at ascertaining the existence and characteristics of natural long-term capture orbits around a celestial body of potential interest. The problem is investigated in the dynamical framework of the three-dimensional circular restricted three-body problem. Previous numerical work on two-dimensional trajectories provided numerical evi...

Multistage launch vehicles of reduced size, such as ”Super Strypi” or ”Sword” are currently investigated for the purpose of providing launch opportunities for microsatellites. Currently, microsatellites are launched according to timing and orbit requirements of the main payload. The limited costs of microsatellites and their capability to be produc...

Lunisat represents a next-generation microsatellite aimed at orbiting the Moon, and equipped with dispensers for the release of nanosatellites. This research is focused on the orbital dynamics of both the main microsatellite and the nanosatellites after release. Due to the irregular concentrations of mass in the Moon, low altitude, near-circular lu...

Sounding rockets are currently deployed for the purpose of providing experimental data of the upper atmosphere, as well as for microgravity experiments. This work provides a methodology in order to design, model, and evaluate the performance of new sounding rockets. A general configuration composed of a rocket with four canards and four tail wings...

Earth-Mars cycling spacecraft have been proposed as potentially beneficial to Mars exploration. There are many types of cyclers, but their common characteristic is that they have a heliocentric trajectory that brings them close to both Earth andMars at regular intervals. As usually envisioned, a large cycler spacecraft would consist of most of the...

The theorem of mirror trajectories was proven almost six decades ago by Miele, and states that for a given path in the restricted problem of three bodies (with primaries in mutual circular orbits) there exists a mirror trajectory (in two dimensions) and three mirror paths (in three dimensions). This theorem regards feasible trajectories and proved...

The theorem of mirror trajectories, proven almost six decades ago by Miele, states that for a given path in the restricted problem of three bodies (with primaries in mutual circular orbits) there exists a mirror trajectory (in two dimensions) and three mirror paths (in three dimensions). The theorem at hand regards feasible trajectories and proved...

Minimum-time relative trajectories between two orbiting spacecraft represent a subject of great relevance in astrodynamics, also in consideration of the related applications to formation flying and proximity maneuvers involving two or more space vehicles. This work uses the Hill-Clohessy-Wiltshire linear equations of motion to model the spacecraft...

Multistage launch vehicles of reduced size, such as "Super Strypi" or "Sword", are currently investigated for the purpose of providing launch opportunities for microsatellites. This work proposes a general methodology for the accurate modeling and performance evaluation of launch vehicles dedicated to microsatellites. For illustrative purposes, the...

This work describes and applies the recently introduced, general-purpose perturbative guidance termed variable-time-domain neighboring optimal guidance, which is capable of driving an aerospace vehicle along a specified nominal, optimal path. This goal is achieved by minimizing the second differential of the objective function (related to the fligh...

In recent years, manifold dynamics has assumed an increasing relevance for analysis and design of low-energy missions, both in the Earth-Moon system and in alternative multibody environments, and several space missions have already taken advantage of the results of the related studies. Recent efforts have been devoted to developing a suitable repre...

Small satellites are revolutionizing the space industry. In particular, nanosatellites are very attractive because they enable access to space with a significant reduction of costs for satellite industries, and a shorter development time with respect to large satellites. Moreover, thanks to modern technologies, relatively complex missions can be pl...

Perturbative guidance techniques are aimed at driving a space vehicle along a prescribed, nominal path, leading to fullfilling the boundary conditions associated with the mission specifications. This work describes and applies the recently introduced, general-purpose perturbative guidance termed variable-time-domain neighboring optimal guidance, wh...

The restricted three-body problem represents the dynamical framework employed for spacecraft mission analysis, in the presence of two attracting bodies, since the 1950s. In this context, orbital motion is often chaotic, although several special solutions (equilibrium points, periodic orbits, and quasiperiodic trajectories) exist, and can be—or have...

This research describes and applies the recently introduced, general-purpose variable-time-domain neighboring optimal guidance scheme, which is capable of driving a space vehicle in the proximity of a specified nominal, optimal path. This goal is achieved by minimizing the second differential of the objective function (related to fuel consumption)...

Recently, manifold dynamics has assumed an increasing relevance for analysis and design of low-energy missions, both in the Earth–Moon system and in alternative multibody environments. This work proposes and describes an intuitive polyhedral interpolative approach for each state component associated with manifold trajectories, both in two and in th...

The determination of minimum-fuel or minimum-time relative orbit trajectories represents a classical topic in astrodynamics. This work illustrates some symmetry properties that hold for optimal relative paths and can considerably simplify their determination. The existence of symmetry properties is demonstrated in the presence of certain boundary c...

Low Earth orbit satellite constellations deserve several advantages with respect to geostationary platforms, i.e., lower costs for satellite development and launch, increased imaging resolution, as well as reduced power requirements and signal time delays. This research is concerned with low Earth orbit constellation design, based on an original me...