In simulations scientific workflows are used to coordinate complex implementations incorporating different kinds of simulations. Typically, the amount of data to be analyzed is huge and it is impossible to store all intermediate or alternative results. Thus, the access to data services has to be coordinated such that applications read the right data and do not overwrite one another. In this paper, we present a possibility to coordinate different scientific simulations accessing and updating the same data using existing Web service technologies: We extend the concept of choreography spheres by allowing control-links between them and the property "permeability" stating whether a cross-boundary link may be traversed before the start or completion of a choreography sphere. This paper is the first presenting a state model for choreography spheres.