Contents -- Preface -- Introduction -- 0.1 Detailed Objectives -- 0.2 Known Results About the Stability of L45 -- 0.3 Main Difficulties of the Problem -- Chapter 1 Global Stability Zones Around the Triangular Libration Points -- 1.1 Equations of Motion -- 1.2 Results for the Restricted Circular Problem -- 1.3 Simulations for the Bicircular Problem -- 1.4 Results for the Simulations Using the JPL Model -- 1.5 Discussion and Tentative Explanations -- Chapter 2 The Normal Form Around L5 in the Three-dimensional RTBP -- 2.1 Checks of the Normal Form -- Chapter 3 Normal Form of the Bicircular Model and Related Topics -- 3.1 The Equations of the Bicircular Problem -- 3.2 Expansion of the Hamiltonian -- 3.3 Cancelling the Terms of Order One -- 3.4 Normal Form to Order Two -- 3.5 Normal Form of Terms of Order Higher than Two -- 3.6 A Test Concerning the Normal Form Around the Small Periodic Orbit Near L5 in the Bicircular Problem -- 3.7 On the Computation of Unstable Two-dimensional Tori -- 3.8 Big Tori and Stability Zones -- Chapter 4 The Quasi-periodic Model -- 4.1 The Lagrangian and the Hamiltonian -- 4.2 Some Useful Expansions -- 4.3 The Fourier Analysis -- Chapter 5 Nominal Paths and Stability Properties -- 5.1 Introduction -- 5.2 Idea of the Resolution Method -- 5.3 The Algebraic Manipulator -- 5.4 Results with the Algebraic Manipulator -- 5.5 Numerical Refinement -- 5.6 The Neighbourhood of the Almost Planar Nominal Paths -- Chapter 6 Transfer to Orbits in a Vicinity of the Lagrangian Points -- 6.1 Computations of the Transfer Orbits -- 6.2 Summary of the Results -- Appendix A Global Stability Zones Around the Triangular Libration Points in the Elliptic RTBP -- Appendix B Fourier Analysis -- B.l Introduction -- B.2 The Method.

B.3 An Application to the Analysis of Orbits of the Restricted Problem -- Appendix C Geometrical Bounds for the Dynamics: Codimension 1 Manifolds -- C.l The Center Center-stable and Center-unstable Manifolds -- C.2 On the Analytic Computation of Invariant Manifolds -- C.3 The Center-stable and Center-unstable Manifolds for L3 in the RTBP -- Appendix D Conclusions -- D.l Summary of Achievements -- D.2 On the Methodology -- D.3 On the Application of the Results to the Design of Spacecraft Missions -- D.4 Outlook -- Bibliography -- Updates with Respect to the Work Done for the European Space Agency.