Recently, Peter has been trying to fly a kite that his mom gave him last year as a birthday gift. In addition to just getting it up in the air, he'd heard a radio story about using kites to launch objects with little parachutes and wanted to try it. You get the kite aloft and then hook the thing on the string, and the parachute acts to pull it all the way up. Then you jimmy the kitestring to release the object and it comes floating gently down.
On Labor Day we gave it a shot. Peter worked on getting the kite in the air—it's a box kite with no tail, so it's a little unstable—while I went to the concession stand on the Coney Island boardwalk and got a few napkins from which to fashion a canopy. The napkins were rectangular instead of square, and we didn't have the dental floss we'd wanted to use for shrouds, but I gave it my best shot. Peter had brought a small assortment of washers, paperclips, rubber bands, and binder clips. It brought me back to my Odyssey of the Mind days.
All four parachutes we tried on Labor Day had the same basic design: a square canopy constructed of two napkins, joined side-by-side using three paperclips; four shrouds, each consisting of a broken rubber band and running from one of the canopy's corners to the harness; and, at the harness, a hook made from another paperclip, used to run the parachute up the kite.
In the first design, the shrouds were joined to the canopy and harness with binder clips, and the hook carried a couple washers to weigh it down. This proved too heavy to even climb the kitestring: the wind would catch the parachute, but the weight of the binder clips on the canopy prevented it from going anywhere.
For the second attempt, I replaced the binder clips at the corners of the canopy with regular paperclips, and knotted the ends of the rubber band shrouds to the paperclips. This one actually moved! However, when it reached the kite and was shaken free, three of the shroud anchors came loose and the whole contraption came nose-diving down.
Peter thought the weight of the harness was to blame for Mark 2's disintegration, and I had to agree. I removed the washers from the harness and we tried again. It failed in the same way! I was beginning to think we might be out of luck: the paperclips just didn't grip onto the napkins firmly enough to sufficiently anchor the shrouds.
We gave it another shot with a bare-bones approach that eschewed the harness's binder clip, instead knotting the rubber bands directly to the hook. It worked, floating down gracefully and landing completely intact! Coincidentally, a couple friends had showed up just prior to this attempt: as far as they were concerned, we'd nailed it right away!
I think we had one more successful flight before it got tangled up at the top and fell apart on launch. I was in the ocean at the time, so I'm not exactly sure what went wrong.
The next day, while I'm supposed to have been working, I put together a slightly different design that I hope will hold up a little better.
My first improvement was to start with better materials for the canopy. I had some paper napkins at home that unfolded into nearly perfect squares and were also noticeably tougher than the ones we'd used at the beach. I placed one napkin over another at a 45-degree angle, and marked where the corners of the lower one exceeded the edges of the upper. I cut along those lines and was left with a regular octagon.
Peter had originally wanted to use dental floss for the shrouds, but we'd forgotten to bring any to the beach. For this design, I measured out four lengths of floss, each twice the diameter of the canopy. Each would run between two opposing corners and then they'd all meet at a single point where we could attach the harness.
To keep the floss from tearing through the paper, I reinforced each corner with two strips of masking tape.
I tied a small rubber band around the meeting point of the four shroud lines. Any payload or release mechanism can just loop into the rubber band. We probably won't get a chance to test this model until the weekend, but I'm optimistic!