The focus of the proposed research will be to explore accurate methods for conceptual structural sizing that are more efficient than current processes, then to reap the benefits of such methods. The primary benefit will be the reduction of mass growth that typically occurs in space systems between the time when the initial design point is selected and when the final vehicle is produced. Additionally, the development of rapid and accurate structural sizing methods will enable more advanced design techniques such as probabilistic exploration of the design space and robust design. This will enable thorough exploration of design concepts that are currently deemed too risky to explore, such as composite space structures. These goals will be accomplished through automation of the manual process for developing the internal structural architecture of a space system. This automation will be achieved by creating mathematical models that generate internal structure based on overall vehicle geometry and applied loads. By removing a significant amount of manual tweaking from the structural design loop, rapid iteration with advanced design concepts can be performed.