We present an alternative approach for satellite formation reconfiguration by an optimal impulsive-thrust strategy to minimize the total characteristic velocity in a near-circular-orbit. Linear transformation decouples the Hill-Clohessy-Wiltshire(HCW) dynamics into a new block-diagonal system matrix consisting of 1-dimensional harmonic oscillator and 2-dimensional subsystem. In contrast to a solution based on the conventional primer vector theory, the optimal solution and the necessary conditions are represented as times and directions of impulses. New analytical expression of the total characteristic velocity is found for each sub systems under general boundary conditions including transfer time constraint. To minimize the total characteristic velocity, necessary conditions for times and directions of impulses are analytically solved. While the solution to the 1-dimensional harmonic oscillator has been found, the solution to the 2-dimensional subsystem is currently under construction. Our approach is expected to be applicable to more challenging problems.