The most straightforward way of folding a membrane is to fold it freehand, using a reference of some sort of fold height and maintaining the existing folds by pressing them under weights, magnets, or in clips. This can be time-consuming and the quality of the folds depends on the experience and care of the people doing. We were hopeful that many of the challenges of assembling and folding prototype solar sail membranes in the lab could be overcome with enough effort and care. The authors wish to thank Mr. Kevin Mclain (Fabrication Technology Development Branch, NASA Langley Research Center) for assistance in manufacturing the paper.
How do aerospace solar arrays work?
In the realm of space technology, aerospace solar arrays are conventionally employed as efficient means of energy harvesting. The solar arrays need to be packaged in a payload capsule before launch and unfold as a standard rectangle with uniform thickness and a flat surface in orbit.
How to launch a solar array?
In preparation for launch, it is necessary to package the solar arrays in a payload capsule, which must subsequently unfold into a standard rectangular shape with uniform thickness and a flat surface while orbiting. Currently, zigzag folding is the most common method of achieving this deployment.
However tightly packaged, a folded membrane retains some air between layers of material. This raises the concern that, during spacecraft ascent, the retained air could be trapped by the membrane and inflate the stowed sail, damaging the membrane or nearby parts of the spacecraft. Ascent vent testing was performed on a PET prototype sail of design
In the realm of space technology, the utilization of solar energy to power aerospace structures is a widespread practice . To facilitate an uninterrupted energy supply for such structures, rigid solar arrays are conventionally employed as efficient means of energy harvesting.
Figure 1: Folding a solar sail prototype triangular quadrant with a 9.2-meter edge for laboratory use. Manufacturing a sail with an area of even 100 m2 for laboratory use takes substantial floor space and effort. At the highest end, the NASA's Comet Halley rendezvous solar sail mission studies in 1977 included a report on scaling
How do solar sail membranes work?
This paper presents lessons gathered from lab work with solar sail membranes at a 10-meter scale. Solar sails are a form of propellantless space propulsion that generate thrust by reflecting sunlight with a large “sail.” As this thrust is proportional to the area of the sail, the sail must be large and light weight.