A software interface between the MATLAB/Simulink environment and the Satellite Tool Kit Environment is introduced. This research is based on the need for validating model performance and visualizing simultaneous multiple-spacecraft proximity maneuvers for emerging missions. It is common for spacecraft systems to be modeled with MATLAB and Simulink. Furthermore, the software package Satellite Tool Kit is often used for animating and evaluating spacecraft maneuvers. In this research, a MATLAB/Satellite Tool Kit interface was developed to propagate six-degree-of-freedom spacecraft models, compared against Satellite-Tool-Kit-generated ephemeris, and animated for analysis. MATLAB script with necessary formatting is used for Satellite Tool Kit initialization and animation. The MATLAB/Satellite Tool Kit simulation interface allows variations in number, shape, and dimensions of spacecraft. Additionally, numerous model and simulation parameters can be selected and synchronized between MATLAB and Satellite Tool Kit. Furthermore, either predetermined, or randomly distributed, initial spacecraft positions and orientations are permitted by the interface. The paper gives enough details to allow the interested readers to adapt to their needs and further develop the proposed software interface.