Sesha Sai Vaddi
Department of Aerospace Engineering
Texas A&M University
Dynamics and Controls of Formation Flying Satellites in Earth Orbits
Formation flying of satellites is an upcoming technology suitable for applications like SAR and space based interferometry. In this research we have analyzed different issues related to the dynamics and control of formation flying satellites. A typical formation consists of a central chief satellite swarmed by multiple deputy satellites. Bounded relative orbits between the chief and deputy are essential for formation flying. Hill's equations offer attractive solutions to the relative motion dynamics of two satellites. But these solutions break down due to the nonlinear effects of the differential gravity accelerations, eccentricity of the chief orbit and other perturbations to the two-body problem like the oblateness of the Earth. We analyze the effect of each of the above-mentioned perturbations and suggest corrective measures that prevent the breakdown. Fuel-efficient control schemes that exploit the natural solutions of the relative motion dynamics will be presented. A fuel balancing control scheme is derived for homogenizing the fuel consumption by different satellites in the formation. Some preliminary results on the formation reconfiguration problem will also be discussed.