Dynamics in the centre manifold around equilibrium points in periodically perturbed three-body problems

A new application of the parameterization method is pre- sented to compute invariant manifolds about the equilib- rium points of Periodically Perturbed Three-Body Problems ( PPTBP ). These techniques are applied to obtain high-order semi-numerical approximations of the center manifolds abo ut the points L 1 , 2 of the Sun-perturbed Earth-Moon Quasi- Bicicular Problem ( QBCP ), which is a particular case of PPTBP . The quality of these approximations is compared with results obtained using equivalents of previous normal form procedures. Then, the parameterization is used to ini- tialize the computation of Poincaré maps, which allow to get a qualitative description of the periodically-perturb ed dynamics near the equilibrium pointsPostprint (published version

Pseudo-heteroclinic connections between bicircular restricted four-body problems

In this paper, we show a mechanism to explain transport from the outer to the inner Solar system. Such a mechanism is based on dynamical systems theory. More concretely, we consider a sequence of uncoupled bicircular restricted four-body problems –BR4BP –(involving the Sun, Jupiter, a planet and an infinitesimal mass), being the planet Neptune, Uranus and Saturn. For each BR4BP, we compute the dynamical substitutes of the collinear equilibrium points of the corresponding restricted three-body problem (Sun, planet and infinitesimal mass), which become periodic orbits. These periodic orbits are unstable, and the role that their invariant manifolds play in relation with transport from exterior planets to the inner ones is discussed.Peer ReviewedPostprint (published version

A distributed attitude control law for formation flying based on the Cucker-smale model

In this paper we consider the attitude synchronization problem for a swarm of spacecrafts flying in formation. Starting from previous works on consensus dynamics, we construct a distributed attitude control law and derive analytically sufficient conditions for the formation to converge asymptotically towards a synchronized, non–accelerating state (possibly defined a priori). Moreover, motivated by the results obtained on a particular consensus model, first introduced by F. Cucker and S. Smale to modellize the translational dynamics of flocks, we numerically explore the dependence of the convergence process on the dimension of the formation and the relative initial conditions of the spacecrafts. Finally, we generalize the class of weights defined by the previous authors in order to dampen the aforementioned effects, thus making our control law suitable for very large formations.Postprint (published version

End-of-life disposal of libration point orbit spacecraft

In this work we investigate end-of-life trajectories for spacecraft in orbit about the Sun-Earth L 1 and L 2 libration points. A plan for decommission is often re- quired during the mission design process. We study the spacecraft's natural dynamics in both a high- delity model and the circular restricted three-body problem. In particular, we consider the role of the unstable manifold and forbidden regions in determin- ing disposal outcomes. A simple maneuver scheme to prevent returns to the Earth vicinity is also an- alyzed. We include discussion on potential collision orbit schemes.Postprint (published version

Detecting invariant manifolds using hyperbolic Lagrangian coherent structures

Using as reference test model the Planar Circular Restricted Three Body Prob- lem, this paper explores its Lagrangian Coherent Structures, as well as its Hy- perbolic Lagrangian Coherent Structures. The purpose is to identify stable and unstable manifolds acting as separatrices between orbits with different qualitative behaviour and, therefore, relevant to the dynamics of the problem. Particular at- tention is given to the manifolds associated to the collinear libration points and to the practical stability regions around the triangular equilibrium pointsPostprint (published version

Global analysis of direct transfers from lunar orbits to sun-earth libration point regimes

In this paper we look forward to obtain a global picture of simple transfer opportunities from Lunar to Sun-Earth libration orbits, useful for a preliminary design of these mission scenarios. Considering the trajectory of the Chinese Change’2 spacecraft as a reference case, the main transfer families are characterized and classified. In a second step, the results are analyzed and extended to departures from more general families of orbits about the Moon. Finally, we also include a preliminary sensitivity analysis of the first transfer correction maneuver (TCM1) to cancel injection errors. The methodology is of general applicability to the transfer analysis involving libration point final orbits in other general multi-body restricted systems.Peer ReviewedPostprint (author's final draft

Jet Transport propagation of uncertainties for orbits around the Earth

In this paper we present a tool to study the non-linear propagation of uncertainties for orbits around the Earth. The tool we introduce is known as Jet Transport and allows to propagate full neighborhoods of initial states instead of a single initial state by means of usual numerical integrators. The description of the transported neighborhood is ob- tained in a semi-analytical way by means of polynomials in 6 variables. These variables correspond to displacements in the phase space from the reference point selected in an orbit as initial condition. The basis of the procedure is a standard numerical integrator of ordinary differential equations (such as a Runge-Kutta or a Taylor method) where the usual arithmetic is replaced by a polynomial arithmetic. In this way, the solution of the variational equations is also obtained up to high order. This methodology is applied to the propagation of satellite trajectories and to the computation of images of uncertainty ellipsoids including high order nonlinear descriptions. The procedure can be specially adapted to the determination of collision probabilities with catalogued space debris or for the end of life analysis of spacecraft in Medium Earth OrbitsPostprint (published version

Tools to detect structures in dynamical systems using Jet Transport

This paper is devoted to the development of some dynamical indicators that allow the determination of regions and structures that separate different dynamic regimes in autonomous and non-autonomous dynamical systems. The underlying idea is closely related to the Lagrangian coherent structures concept introduced by Haller. In the present paper, instead of using the Cauchy-Green tensor, that determines the domains where the flow associated to a differential equation is expanding in the normal direction, the Jet Transport methodology is used. This is a semi-numerical tool, that has as basic ingredients a polynomial algebra package and a numerical integration method, allowing, at each integration step, the propagation under a flow of a neighbourhood U instead of a single initial condition. The output of the procedure is a polynomial in several variables that represents the image of U up to a selected order, containing high order terms of the variational equations. Using these high order representation, the places where the normal direction expands can be easily detected, in a similar manner as the procedures for calculating the Lagrangian coherent structures do. In order to illustrate the methodology, first the results obtained in the determination of the separatrices of the simple and the periodically perturbed pendulum are given. Later, the applications to the circular restricted three body problem are considered, where the aim is the detection of invariant manifolds of libration point orbits, as well as in the non-autonomous vector field defined by the elliptic restricted three body problem.Peer ReviewedPostprint (author's final draft