Lais Oliveira

The advantages that satellites, telescopes, and similar objects offer have engineers searching for the best methods of sending these objects into orbit. Such items are limited by volume and weight, which sparks the development of devices that launch in a stowed state and deploy once in space. One attractive option is the Flasher because of its great stowed volume to deployed surface area ratio. The radial folds of the pattern wrap around each other to make a kind of spiraling shape when viewed from above. This pattern works well enough when it is paper thin but the thickening process produces panel interference, an overall non-rigid surface, and manufacturing difficulties. Previous research has attempted to solve this thickness accommodation challenge, resulting in the membrane technique and the tapered panel technique.
A new area of research, the cross-frame technique, is presented as an alternative solution to thickening the Flasher pattern. Influenced by the tapered panel approach, geometric design for a single cross-frame panel consists of two arms at different levels. This creates a discretized step that provides multi-level hinge points. Unlike the tapered panel approach, the cross-frame members pass through the interior of the panel rather than border the perimeter. The panels are joined together at the middle of their shared edge, leaving the corners free from interference. Consequently, the members of the cross-frame panels can be thickened to the point where a hard stop between panels can be developed. This reduces floppiness throughout the device while in its deployed state. A 2-meter diameter prototype was created using 3D printed PLA parts and spinnaker tape. Folding tests have proven that the cross-frame method successfully avoids panel interference while maintaining a level of rigidity in the overall device. Future research includes designing stronger joints, selecting material for the members, and developing a method for inserting an optical membrane. As it is, the cross-frame technique stands as a viable thickness accommodation for the Flasher pattern as well as for other similar folding devices.