The modern space scenario, characterised by the deployment of complex constellations and multi-regime missions, demands increasingly robust and precise Flight Dynamics (FD) tools. This thesis presents the design, development, and operational validation of Validation and Element Reconstruction Algorithms (VERA), a modular software environment designed to support FD operations across diverse orbital regimes, through the sequential integration of independent functional components. The research focuses on the first building blocks of the suite: a high-fidelity numerical propagator and Two-Line Elements (TLE) Generation Module. The core of this work resides in the development and rigorous validation of the TLE Generation Module. This tool utilises a Least-Squares algorithm to reconstruct analytical orbital elements from reference trajectories.