The most immediate opportunity for the tools that will be developed under this SBIR is to assist NASA and its contractors in performing design trade studies of large mass-efficient deployable solar array systems. NASA has recently awarded two contractorsATK and DSSPhase I contracts to advance their concepts through hardware development and verification testing. One design will move forward to a multiyear Phase II flight demonstration program. The tools that will be developed under this SBIR will allow rapid design trade studies of these systems to be carried out by NASA and the manufacturers so that the designs can be optimized for critical performance requirements such as deployment reliability, stiffness, strength, and control. These studies will allow a more complete exploration of the design space and substantially reduce risk in expensive hardware manufacture and testing on these and future deployable systems. Additional areas of expressed interest for NASA include using the tools for control-structure interaction studies of structures with flexible components as well as simulating thermal-gradient effects on the structure. Control-structure interaction is important for a wide variety of NASA interests, one of which is attitude control. Using a flexible structure in the simulation of the control system dynamics will greatly enhance the accuracy of simulations and provide valuable insight into the actual performance of the control system. The tools developed in this program will have broader applications than just the design and optimization of solar array structures. Development of the toolset will provide a modular, open-architecture tool that is easily extensible and customizable to integrate with other systems, software tools, and architectures across other industries. The fundamental approach of using Modelica as the core of a lightweight, graphics-based, intuitive, and efficient computational tool for design and analysis can be extended to a wide variety of other structural analysis and design optimization applications including lightweight booms, frames, expandable/inflatable structures, and associated mechanisms. Furthermore, the underlying architecture of the toolset allows it to be easily expanded and/or customized to enable additional analysis solutions, geometry modules, control systems, interactions, and componentry relevant to a vast array of other products. The software will eventually prove to benefit the design and analysis of any product that has several disparate components that must work in an integrated way. Examples include heavy equipment, robotics (terrestrial and space-based), industrial manufacturing, spacecraft, aircraft, automotive, and energy applications.