Ultra lightweight folding panel structure

DETAILED DESCRIPTION Our invention is for an improved deployable panel structure which includes a plurality of ultra lightweight integrally stiffened panels, hinges connecting the panels so as to control folding and unfolding kinematics, and a cabling system for the collection of power from solar cells.
The cabling system is mounted upon the panels, integrally formed with the panel and hinge structures, is of minimum weight for the electrical power transmitted and the cabling causes minimum interference with the operation and mechanical properties of the hinges and panels.
Since the size and weight available aboard spacecraft is severely limited, a primary goal in the design of spaceborne solar cell power systems is the maximization of the ratio of deployed area (and therefore power generated for a given state of the art in solar cells) to collapsed volume and total solar panel weight.
The use of large arrays aboard recoverable spacecraft such as the space shuttle also requires that advanced solar arrays of the type contemplated must be capable of being refolded in order to prevent the loss of the array upon return to earth.
One method by which this invention uniquely satisfies these requirements is by incorporating panel structures which are formed of ultra lightweight, integrally stiffened insulative material of the type normally used to electronically isolate the solar cells, thereby utilizing the same material as a structural and insulative mounting, or substrate, for the solar cells.
This material, in this application Kapton, a high dielectric constant plastic film, is utilized in two layers bonded by a compatible adhesive.
Each layer of film has parallel stiffening ribs formed into its surface so as to provide bending stiffness in the direction of the ribs.
The two layers of reinforced film are then bonded on the surface opposite the ribs formed in the film at a 90 degree angle to one another so that the composite film substrate has substantial bending stiffness in both orthogonal planes vastly greater than an unreinforced substrate