LAREDO: LAunching, REndezvous and DOcking Simulation Tool

Abstract : This paper intends to provide a description of the LAREDO tool including architecture, design choices and mathematical formulations. The goal of LAREDO, which is a six DOF simulator developed under Matlab/Simulink-based environment, is to reproduce the Rendezvous and Docking (RvD) sequences applicable to different exploration mission-scenarios and to provide detailed analysis of formation flyings (FF) satellite constellations using highly coupled GNC algorithms, which integrate attitude, navigation and maneuvers. Among those, it is possible to select: Earth, Moon, Mars, Venus, Deimos, Triton and Europa as final destination. Within the LAREDO simulator a launching optimization module is implemented to optimize the launching phase once it has lifted off from the Earth, Moon or Mars surfaces. This optimization is performed such that maximum payload is delivered into orbit. The tool simulates the rocket stages and also evaluates the launch opportunities for optimum launch. The orbit control can be performed by impulsive or continuous maneuvers both on circular and elliptical orbits. The type of maneuvers, their order and schedule is completely configurable by the users. The maneuvers are very accurate even under perturbations. In case the identified safety limits are trespassed, a collision avoidance maneuver (CAM) will be automatically activated, moving the spacecraft to a safety region. The simulator propagates considering various orbit perturbations (aerodynamic, non-sphericity, solar radiation and third body perturbations), communications (both with ground stations and between satellites), and provides full analysis of the trajectory. The GNC modules incorporate sensor models for LIDAR, camera, IMU and RF devices, and both orbit and attitude guidance and control. Furthermore, LAREDO offers powerful 3-D visualization of trajectories and attitude, as well as other important features such as consumed V, ground station contacts, eclipse times, and others.