Fundamentals of Spacecraft Dynamics: Mission to Mars

The objective of this spacecraft dynamics project is to apply the skills learned in Rigid Body Kinematics, Kinetics, and Control. A challenging two-spacecraft mission to Mars is considered, in which the primary mother spacecraft is in communication with a daughter spacecraft in another orbit. The objectives include defining the kinematics of the orbital frame and several desired reference frames, numerically modeling the spacecraft attitude dynamics in orbit, and implementing feedback control that then drives the various spacecraft body frames into different flight modes, including pointing toward the Sun for power generation, pointing toward nadir for science data collection, and pointing toward the mother spacecraft for communications and data transfer. Finally, an integrated mission simulation is developed that implements these attitude modes and explores the resulting closed-loop autonomous operation. Tasks 1 and 2 use 3D kinematics to generate a simulation of the mission-related orbit and the corresponding orbital frames. The induction phase ensures the correct motion of the satellite and the correct estimate of the orientation of the orbital frame relative to the planet. Tasks 3 through 5 create the necessary reference frame for the three pointing modes called Sun-Point, Nadir-Point, and GMO-Point. The attitude reference frame is a critical component to ensure that the feedback control leads the satellite to the desired attitude. The control used remains the same for all three pointing modes, but its characteristics differ because different reference frames are used. Tasks 6 through 7 create simulation routines to first estimate the attitude tracking error between the body-fixed reference frame and the defined reference frame of the current attitude mode. The inertial attitude dynamics are then estimated using numerical simulation to be able to numerically analyze the control performance. Tasks 8 through 11 simulate the closed-loop performance of the attitude control for the three attitude modes. Tasks 8 through 10 initially simulate one installation at a time, and Task 11 develops a complex mission simulation that considers autonomous switching of installation modes depending on the position of the spacecraft relative to the planet.