This paper reviews context and results of a software tool, named SaTrade, for Model Based System Engineering in System Design of a CubeSat. This tool helps designers to go through system design trade offs easily in System and Subsystem Levels. To achieve this, Modeling for subsystem design has been made using Block Diagram Definitions and implemented in codes with Inputs from System Design and Outputs to Subsystem specifications and Design Integration. Another Feature of SaTrade is change and modification control and management, where it can be from Requirements or other Inputs from System Design or Interfaces. Changes will be affected on the System Design to allow the Designers follow the process by simulations for Integrity check and Evaluation. The first version of SaTrade focuses on Satellite Structure Design and Configuration Management more, using its Neural Network Algorithms dedicated for this purpose, however, it is intended to make paperless automated design available for the whole CubeSat System in the next version.