The relative position control of a collinear spinning three-spacecraft Coulomb formation with set charges is addressed. Such a formation is assumed to be in deep space without relevant gravitational forces present. The nonlinear control is realized through state dependent Riccati equation (SDRE) control method. Relative position control is used to keep a three-craft Coulomb formation about a desired equilibrium collinear configuration. The equations of motion of the formation are properly manipulated to obtain a suitable form for SDRE control. The state-dependent coefficient (SDC) form is then formulated to include the non-linearities in the relative dynamics. Numerical simulations illustrate effectiveness of the controllers.