Lorentz-Augmented Orbit Dynamics and Mission Design
The concept of Lorentz Augmented Orbits (LAO) is explored and developed. A spacecraft with a controlled net electrostatic charge moves in a planetary magnetic field. Such a spacecraft experiences a Lorentz force. By proper control of the charge, useful changes to the spacecraft?s orbit can be made, making Lorentz propulsion a type of propellantless propulsion. The dynamics of such a system are explored in depth, using both analytical and numerical methods with a variety of magnetic field models. These dynamics are then applied to several novel mission designs. First, new Earth-synchronous orbits are developed using the Lorentz force. Under certain assumptions, a low-Earth, single-pass repeat groundtrack orbit exists for a constant spacecraft body charge-to-mass ratio. This behavior is then recovered under more realistic conditions, with a non-constant, feedback-controlled charge-to-mass ratio. The potential of the Lorentz force to expand the performance and flexibility of gravity-assist maneuvers is examined. A standard flyby maneuver is limited by timing and geometry consideration. Using an LAO can open a new range of flyby options, including temporary, reversible capture of spacecraft at a target planet, along with arbitrary direction of exit asymptote. Algorithms are developed to calculate the necessary charge-to-mass ratios. A realistic spacecraft design, using near-term technology, is developed. Mission design using the performance of this spacecraft architecture, along with a realistic geomagnetic model, is examined. The LAO approach is well suited to be used for low-Earth inclination change maneuvers. These maneuvers can save considerable propellant, at the expense of longer maneuver duration and electrical power usage. The possible role of LAOs in spacecraft formation flight is explored. The dynamics of a simple relative orbit system are derived, with their stability and controllability examined. A sample formation maneuver is presented.
Orbit Dynamics; Spacecraft Mission Design; Lorentz Force; Propellantless propulsion