Satellite Constellation Orbit Design to Enable a Space-Based Radio Interferometer

Two different design methods for a networked constellation of N small satellites
are presented. In the first method, the (linear) Clohessy-Wilthsire equations are
used as an initial design tool, followed by conversion to a two-body model. Discrepancies
between the linear and nonlinear solutions are minimized in the conversion
process. The second method utilizes invariant manifold theory, by perturbing
a reference trajectory in different directions along the center eigenvectors. Both
methods require 5N parameters to fully define a constellation. In a relative, rotating
frame of the reference path, the spacecraft appear as periodic ellipses of
varying sizes. Deployment, reconfiguration using propulsive maneuvers, and station
keeping costs for an example mission scenario are addressed.