A TRINITY -Jack R

A TRINITY -Jack R. Holt AN UNSUCCESSFUL FLIGHT God protects children and fools. -American Proverb When I was a boy in Oklahoma, I was very interested in chemistry and some of its ramifications (especially those that make noise). I worked hard to perfect black gunpowder so that it would sound as good as the firecrackers that were so easily obtained in Oklahoma in those days. Bottle rockets, too, were some of my favorite pastimes. It was just a small step from there to an interest in model rockets. Not only because I enjoyed working with cardboard tubes, glue, and balsa wood, but also because the space race was in full swing during the later years of the 1960’s. Thus, I built and launched a number of model rockets. A group of us became interested in building our own rocket, not “just one from a kit”. So, we secured a large cardboard tube that carpet came rolled on, and we cut it into about a 4-foot section to make a really big rocket. FIGURE 1. A more recent rocket flight. We had been experimenting with a standard rocket fuel of sulfur and zinc. We meas- ured small aliquots (about a square centimeter) to a lid to measure a timed burn. We had 1 having trouble keeping a sustained burn, and the speed of the combustion was disappoint- ing. So, one of us had the idea of mixing the zinc-sulfur with the flash powder that we had perfected earlier. After a few experiments with the burning rate, we were ready to go. We had invented a new rocket fuel. The next step was to fill the tube with the new chemical mixture. The volumes of the components that we needed for the carpet tube rocket were expensive, so we all worked and contributed to the purchase of chemicals for this project. We used an evil-smelling solvent to allow for the even mixture of the components, which we poured into the tube in liter-sized aliquots. We needed to allow the solvent to evaporate between our repeated applications of the same procedure. The evaporation occurred at about the same rate that we earned money to buy more supplies. Anyway, after several trips to the local chemical supply house, we had finished filling the rocket motor compartment in the carpet tube. We packed the fuel around a metal rod down the center of the tube to provide for an empty column through the solid fuel for an even burn. After nearly a week more, the solid fuel had hardened and was ready for the application of fins and a nose cone. We even had grandiose schemes of using a hollow nose cone and launching a mouse. Fortu- nately for the mouse, we did not have time. Anyway, after attaching the fins of heavy cardboard and a solid wooden nose cone, we drove to a launching site outside of Tulsa. After we admired the impressive rocket, we slipped a long piece of dynamite fuse up through the hole in the solid fuel (yes, you could order such things as dynamite fuse through the mail in those days). We made sure that a generous amount of fuse stuck out of the rocket so that we could be well protected in case the fuel exploded. I can’t recall who lit the fuse, but I do remember waiting an eternity until the sputtering flame approached the rocket. The fuel ignited, and a large flame enveloped the whole lower part of the rocket which then began to rise very slowly. Then, it turned on its side and began to fly parallel to the ground, skipping over it in an irregular way. By that time the fins were bent and on fire, too. After it bounced off the ground, rocks, and a tree or two, the prodigal rocket came to rest with its nose cone stuck in the ground at a 45-degree angle. What remained of the crumpled tube billowed smoke and flame until at last, mercifully, only the cardboard was burning. We emerged from our protection cautiously, and advanced slowly toward the wreck. Our initial reconnoiter revealed several of our mistakes - not the least of which was that we started too big, too grand with our first experimental rocket. Also, although we spent much time in our research of rocket fuel, we had spent little to no time on the mechanics of rocket flight and rocket design. After all, the kits had always determined the design. We just assumed that if we made a bigger rocket, it would fly higher than its smaller counterparts. We should have made an effort to learn something about rocket stability. Anyway, I don’t know about the others, but this experience made such an impression on me that I stopped building model rockets altogether for more than 20 years. Had we not given up, one or more of us might have taken the path described by Homer Hickam in Rocket Boys. His group called the “Big Creek Missile Agency” suffered many more pro- found setbacks than we did, but learned from their difficulties. We did not. Our great intentions like our great invention went up in smoke that day in the summer of 1967. 2 BY THE GRACE OF INVENTION Thus we live only by the grace of invention: not merely by such invention as has already been made, but by our hope of new and nonexisting inventions for the future. -Norbert Wiener (1954) About the same time as the great rocket debacle, my grandfather perfected a locking mechanism that could move easily over a rod, but lock in place with the movement of the hand. This could be applied to music stands, lab stools, and nutcrackers, just to name a few. He applied for and received a patent on the invention, but nothing came of it. I still have the prototype of the nutcracker that produces whole pecan kernels with almost every pull of the lever. All of us in the family were excited about his invention, but the world did not seem to be. Many inventions, even successful ones, are ultimately failures and go up in smoke. Norbert Wiener (1894-1964), an American mathematician who among other things worked on the mathematics of and their applications to rocket guidance systems during World War II, considered the problem of invention and the means to nurture it. He wrote the manuscript of his ideas about invention in 1954, but it languished among his papers until 1993, 29 years after his death. Wiener considered the useful modern inventions to be applications of scientific concepts. Indeed, he did not seem to differentiate between science and technology, but saw them as part of a continuum. Wiener defined four stages in the process of invention: the intellectual, technical, social, and economic stages. He contended that these had to occur in this order for them to be successful, a success based on the invention’s benefit to society rather than to the individual inventor or entrepre- neur. Except for a few outdated examples, and repeated references to the antagonism between the Soviet Union and the United States, Wiener’s ideas are as relevant today as they were in 1954. At its most fundamental level, the intellectual stage is the idea, the concept. The idea of my grandfather’s locking device (and less so for our solid fuel rocket) is the insight in how to solve a practical problem. Here, I refer to the theoretician as the thinker or the person with the idea but not necessarily the means to bring that idea to fruition. By and large, scientists, engineers, and all manner of technicians are used to this type of thinking. Most of their ideas are tossed about and thrown away. Some ideas survive. FIRE ARROWS, ROCKETS INVENTED Invention is a heroic thing and placed above the reach of a low and vulgar genius. It re- quires an active, a bold, a nimble, a restless min; a thousand difficulties condemned with which a mean heart would be broken. - Thomas Sprat (1667) The one or ones who first had the idea of the rocket are lost in a time without science, but they seem to have appeared in China, probably not long after the invention of gunpowder. The first Chinese rockets probably evolved from firecrackers made from sec- tions of bamboo stuffed with black gunpowder and were as unpredictable as mine was. Likely, these were thrown into fires to make the explosive bang required during festivals and celebrations. Some probably did not explode, but shot out of the fire as small rockets. Regardless of the particulars, the Chinese repelled the Mongols in 1232 with rocket- propelled arrows, which spat flame and startled their enemies. The fire arrow was a lar- 3 ger version of the bottle rocket that I used as a boy. It had a tube filled with black gunpowder and used a trailing stick as a guidance mechanism (see Figure 2). Anyway, the fire arrows were effective in repelling the Mongols because of the terror that they in- spired rather than their accuracy. Wan-Hu, a Chinese official, got the idea that he could fly if he sat in a chair propelled by fire arrows. The story goes that he attached 47 fire arrow rockets to a chair with two large kite-like wings mounted above it. After the arrows were lit, Wan-Hu disappeared forever in a thunderclap of fire and smoke. FIGURE 2. Fire arrows. The top illustration shows a rocket stabilized by a trailing stick.

Load more