Abstract: System for retaining or releasing a number of panels piled onto a supporting structure, such as solar panels of a spacecraft which can be deployed from the piled condition and retracted. The panels each comprise a number of passages at a distance of the edge defining a number of channels through the piled panels. A retainer extending through each channel, comprises operating elements at one side connected to control means attached to the supporting structure and at the other side connected to one or more seizing elements, which under control of said control means and through said operating elements can be moved from a retaining condition in which they seize the outer panel of the pile to a releasing condition in which they do not obstruct the deployment of the panels.