Deployment and Stabilization of Large Structures in Space
In this project we investigated possibilities to use electromagnetic interactions to deploy and control large structures in space.
The deployment and the stabilization of large structures in space is an active field of research, driven by the increasing number of applications thereof such as solar sails, solar arrays or scientific missions in mission analysis for more activities in this field.) Still, simple and reliable mechanisms are difficult to establish due to the special environment in space (mainly the absence of friction.) The Advanced Concepts Team investigated how electromagnetic forces could help in this situation. Basically there exists two different concepts: the use of Coulomb forces by charging parts of the structure or the use of Lorentz forces induced by a current. There exists a subtle interplay between these two forces: on the one hand it seems that both are needed for a successful deployment and stabilization, on the other hand the use of one force may induce the presence of the other. Here the main limit is the weak interaction with the plasma: if a non-closed current shall be established on parts of the structure local charging of the latter will inevitably result.
As a first step we analyzed how electromagnetic forces acting on a charged space web can help in deployment and stabilization. In our analysis we compared three different scenarios:
- Centrifugal deployment without external forces.
- Centrifugal deployment assisted by a torque acting on the central hub.
- Centrifugal deployment assisted by Lorentz forces due to charging of parts of the structure.
While the first situation is not controllable, the second and the third ones are. Within the idealized situation of a symmetrical deployment they can be shown to be stable as well. The main advantage of the Lorentz force is the ability to damp non-symmetrical perturbations, its main disadvantage is the small forces available for reasonable charging levels.