Modular Deployment Control for Complex Space Structures

As precision space systems evolve to larger sizes, packaged in ever smaller envelopes, the complexity of the mechanical stowage and deployment schemes increase correspondingly. Traditionally, control of deployment is the responsibility, not of thedeveloper of the structure, but of a higher-level integrator who has responsibility for the space electronics and software that are used to implement the deployment control scheme. As the complexity of deployment increases, however, this traditionaldivision of labor becomes increasingly problematic, especially in cases where complex issues of redundancy and stiffness during deployment become entwined in the deployment control scheme.We propose to develop a highly reliable, modular, COTS-based architecture for complex deployment control that can be purchased and integrated by the developer of the deployable structure, thus enabling the structure developer to assume completeresponsibility for implementation of successful deployment, and simplifying the interface between the deployable structure and its host payload or satellite. Further, by providing a thoroughly engineered deployment control architecture, including keyflight hardware components (such as motor controllers and servo-amps), much time and money can be saved in the development and validation of the deployment scheme over the traditional, ad hoc approach. Our proposed deployment control architecture realizes substantial benefits for complex deployable structures:¿ Reduction of cost and risk associated with the specification and implementation of correct deployment by the structural developer, instead of the system integrator.¿ Much more thorough testing of integrated software, electronics, and structure due to earlier integration at the structural contractor.¿ Reduction of cost of development due to the prior engineering of low-level software and electronic elements of deployment control, including qualification testing and documentation.¿ Increased responsiveness to and exploitation of evolving space electronic technology due to modularity and standardization of interfaces within the controller, both hardware and software.¿ Reduced costs of acquisition for deployed structure due to simpler, cleaner interfaces between the structure and the host payload or spacecraft.We will demonstrate this technology first for the PowerSail flight experiment, and then extend our applications to other contemplated deployable systems.