Spacecraft Position and Attitude Formation Control using Line-of-Sight   Observations
  This paper studies formation control of an arbitrary number of spacecraft based on a serial network structure. The leader controls its absolute position and absolute attitude with respect to an inertial frame, and the followers control its relative position and attitude with respect to another spacecraft assigned by the serial network. The unique feature is that both the absolute attitude and the relative attitude control systems are developed directly in terms of the line-of-sight observations between spacecraft, without need for estimating the full absolute and relative attitudes, to improve accuracy and efficiency. Control systems are developed on the nonlinear configuration manifold, guaranteeing exponential stability. Numerical examples are presented to illustrate the desirable properties of the proposed control system. 
Tse-Huai Wu and Taeyoung Lee
math.OC