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Sat, 28 Feb 2009

Ad Astra Per Aspera

At dinner with my family a while ago, the conversation turned to the subject of hobbies. I was bemoaning the fact that my kids' hobbies seemed to be pretty much limited to things like achieving high scores on the X-Box, or serving in a godlike capacity as the master of a group of players in an role playing world. I was gently tweaking them over the fact that these kinds of activities were primarily computer based, involved at best a limited kind of interaction with other people, and kept them glued to the computer screen for hours at a time. While advanced joystick proficiency gained by hours playing Halo 3 might make my son a good candidate for piloting a Predator done someday, beyond that these activities didn't involve many opportunities for learning much of anything.

My kids, of course, immediately challenged me right back, asking me about my hobbies: what things did I do to occupy what little free time I had?

A good question; I had to stop and think about it. As mentioned, between long hours at work and the never ending list of things to do around the house, my free time is somewhat limited. So how did I use those precious few hours each week? Somewhat to my embarrassment, I realized that, to a large extent, my spare time was in many ways being no "better" spent than that of my kids.

I have been an avid reader all my life, and, taking a quick mental inventory, I realized that I had spent a lot of my spare time with my books, mostly histories and biographies. Nothing at all to be embarrassed about per se, but the kids rightly challenged me on the zero level of interactivity involved -- in that sense, no different from their computer games.

Another frequent activity of mine was playing chess on the Internet. Chess is another long-running avocation of mine, and one that certainly scored higher from an interactivity perspective in the sense of involving other people, but again, as was pointed out to me, it wasn't like I was getting out and going to a local chess club to play in person; I was, like my kids, sitting down at the computer screen to play. I tried to argue that proficiency at chess was ultimately more useful than the ability to battle aliens or control an RP universe, but deep down even I was less than completely convinced.

What else was there? Not very much. We would occasionally take the kids camping, but as they got older, those sojourns became fewer and farther between. We used to ride bikes as a family, going for casual rides around the neighborhood, but nowadays, the bikes hibernate in the back of the garage, and the kids are far more interested in driving than cycling. That was about it. I let the dinner conversation turn to other topics, not pursuing the points I was so confidently pressing with the kids just minutes before.

Later that evening, laying in bed before falling asleep, I thought more about the ways I used to fill my spare time. At certain times in my life, I would go through phases where one activity would become my principal hobby for that period. I started assembling a mental inventory: when I was very young, drawing and coloring predominated. During those periods when I was between girlfriends (which happened more frequently and often than I really cared to remember), surfing online pornography sites was a routine way to fill my days and evenings -- but I wasn't sure if that should have been counted as an addiction instead of an avocation. I enjoyed writing, but never had the gumption to sit down and produce anything of serious length or consequence (some might suggest that my contributions to this forum have been more of the same). In the days before the widespread adoption of e-mail, I would spend time and effort on correspondence with my friends, but I could not in all honesty consider letter-writing a hobby.

Just before drifting off, I remembered one other activity on which I spent a lot of time during a nearly ten-year period, roughly from ages eight to eighteen: building and flying model rockets. No doubt an offshoot of my ongoing fascination with the race to the moon in the 1960's, over those years I had managed to amass a fairly considerable collection of both replica and fantasy rockets. These were not the Revell plastic model kits most boys worked on (although I do recall having a number of those as well), but were instead more akin to the model airplanes our fathers would have built "from scratch" in their youth by cutting, shaping, and assembling wood, paper, and bits of plastic and metal into a finished airplane.

Similarly, the flying kind of model rockets were lightweight assemblages, essentially consisting of a cardboard tube with a balsa wood nose cone and fins. The real difference came from the fact that at the base of the rocket, you could insert a solid propellant motor (essentially a large, reengineered firecracker which, instead of simply being wrapped in lightweight paper and exploding when ignited, was designed to expel the gases from the burning gunpowder in a jet out of one end to provide a few seconds of thrust). Given adequate propellant, decent aerodynamics, and no catastrophic failures, these model rockets were capable of reaching altitudes ranging from several hundred to over one thousand feet. That was the really cool difference -- with a little luck, you could actually fly your rocket up to altitudes where the Cessnas and other small planes often cruised.

In addition, I remembered that my father often used my rockets as sneaky teaching tools. "So, do you think there's any way we could figure out just how high your rockets go?" he asked me after one particularly successful flight, which reached what seemed to me to be an tremendous altitude. I immediately started thinking of schemes involving some kind of homebrew radar equipment, but he just smiled. "No, I was thinking of something simpler than that. When we get back to the house, I'll show you." And later that afternoon, at the tender age of twelve, Dad gave my my first introduction to algebra and trigonometry. He drew diagrams showing rockets shooting straight up into the sky, and me standing a known distance away from the launch pad. I would use a protractor and a piece of string with a weight tied to it to measure the angle to the highest point of the rocket's flight. Then he showed me a small booklet full of tables of numbers, telling me that by knowing how far away from the pad I was, and the angle I measured from where I stood, I could use those tables with a formula and a little bit of multiplying and dividing to calculate the rocket's approximate altitude -- my first exposure to tan(θ). Dad didn't call it that, of course, and I had no idea why the formula worked, but I took it as given that it did.

Another time Dad asked me, "Why do you think some of your rockets fly higher than others? They're about the same size and weight, and you use the same engines. Ever wonder about that?" And I hadn't, until Dad planted the bug in me, and from then on I was really curious to know. That led into a series of introductory lessons on the notions of aerodynamics and drag. Before that, I hadn't paid too much attention to some little details in constructing my models, such as making sure that the fins had tapered leading edges -- I had sometimes opted (mostly out of laziness and a desire to get the thing built as quickly as possible) to cut the fins to roughly the proper shape and not bother sanding the edges. After Dad drove me around the neighborhood with me sticking my hand out of the window and feeling the difference between holding it at right angles to the airflow and then edge-on, I at least had a simple, experiential idea that maybe my rockets with the rough and blocky shapes and surfaces would go higher if things were made smoother.

As mentioned, my rockets were of two main kinds: replicas, scale models of actual rockets of the past and present, and what I called "fantasy" rockets, which basically meant models that weren't trying to reproduce something real. In many senses, the fantasy rockets were far more fun to build and fly. Primarily, you didn't need to worry about trying to make an accurate reproduction of anything, so it didn't matter what color you painted it, or whether or not the trailing edge of the fins was exactly 1-3/16" long, or that you had positioned a decal meant to show an exhaust duct exactly halfway between the A and B fins and 1/4" from the rocket's exhaust nozzle, or even that you had decided to paint the whole thing orange and purple, and cover the rocket with automotive product decals left over from your brother's race car model kits. You had a lot of freedom after putting the basic mechanical systems in place to do pretty much whatever you wanted. (I even recall covering one entirely with glow in the dark paint, and then attempting my first (and only) night launch: neglecting to take into account that the tiny size of the rocket might make it hard to see, I shot it off the pad around 10 PM; it promptly disappeared into the night sky, no more visible than a firefly at a distance of a thousand feet, never to be seen again.)

The replica rockets, on the other hand, came with the excruciatingly detailed instructions alluded to above. Not knowing any better, the first rocket kit I ever ordered and attempted to build was a replica kit of a post-World War II vintage WAC Corporal sounding rocket. Dad was helping me, and he quickly realized that I had inadvertently gotten in over my head with this one. He took over many of the more intricate measuring and cutting steps, showing me how to measure accurately and cut precisely, demonstrating by example the carpenter's maxim I would later learn, "Measure twice, cut once." He also showed me a number of tricks and techniques using masking tape for painting neat and accurate lines and circles on the various rocket parts, also making clear to me for the first time in my life why the stuff was called "masking" tape. Ultimately, my WAC Corporal turned out to be a reasonably good replica of the real thing when I compared it to the pictures in the encyclopedia, especially considering that I was only eight years old at the time.

I had mixed feelings about the replica kits. On one hand, I enjoyed the challenge and discipline they imposed on my building. I had to learn to measure and cut accurately, how to glue things neatly, how to work with tiny brushes in close quarters to make the painting come out properly, and to ensure that all the mechanical systems worked smoothly to minimize the possibility of mishaps in flight. On the other hand, I found it difficult at times to impose the necessary self-discipline on myself to follow all the detailed instructions -- more than once I would let my impatience get the better of me, taking shortcuts and ignoring the precision work needed to make the replica look like anything more than an approximation of the real thing. That turned out to be mostly a matter of time and maturity on my part. As time went by, I found myself turning more and more often to replica kits, actually looking forward to trying to make them come out as accurately as I could.

My biggest challenge among the replica rockets I built back then was a 1:120 scale model of the Saturn V moon rocket. It was also the biggest rocket I ever tried to build: even at this scale it was about three feet long and nearly six inches in diameter. Watching the moon launches being televised from a camera five miles away, the Saturn V looked like a stately, smooth behemoth. Seeing the hundreds of separate parts in the kit, and reading over the forty or so pages of assembly instructions, I knew this one would not be done quickly or easily. Up close, you realized that the Saturn was not simply a collection of smoothly nested tubes, but was a real machine, covered with conduits, ductwork, fairings, plumbing connections, nozzles, wires, rivets, and corrugated skins. After completing the review of the parts checklist, I carefully put all the pieces back into the box and wondered just what I was getting myself into -- asking for the Saturn V kit as my "big" Christmas present that year may not have been the best decision I had ever made. And with my parents having invested a somewhat substantial amount of time and effort in obtaining this for me, I wanted to make sure I did the best job I could on it -- no glow in the dark paint or STP decals for this one!

I took over an area near Dad's workbench downstairs, and after a few days of lining up the necessary tools and supplies, I started building my Saturn V. I worked slowly and carefully, often completing only one or two steps in the assembly process in any given day. Some days I wouldn't be able to complete even a single step. As I cut and sanded and shaped, it seemed like the number of parts to be assembled actually increased instead of getting smaller. Looking back, I realize now that at certain points in the process, that was probably correct: for example, from a single piece of balsa wood, I wound up cutting out and shaping more than two dozen fairings for simulated ullage motors and retrorockets on the outside of the vehicle, then putting them aside for painting and incorporation later into the finished rocket. I had more than a little trouble with cutting and gluing some of the shaped cardboard pieces -- despite practice, I still had never quite gotten the knack of cutting smooth curves with a straight X-acto knife blade, and because you only got one of each printed sheet, a slip or other mistake meant you were probably in trouble. At one point I had messed up these pieces not while cutting them out, but by not holding them firmly in position while the glue dried, leaving me with incorrectly warped shapes I had no way to disassemble and redo. Not knowing what else I could do, I wrote a contrite letter to the manufacturer explaining what I had done, and asking them to please take pity on me and send along a replacement printed sheet. I am sure I was not the first to make this plea, because the replacement arrived in a little over a week's time. After more painstaking cutting, I individually clipped the cone-shaped cutouts into shape, glued each one, and waited for the glue to dry before going on to the next one.

Painting and finishing were also complex tasks. It was easy to work on smaller models to get the base coats of paint in place -- a lot of newspaper covering the surrounding area and a good can of Krylon usually did the trick. But for a model this size, I had to figure out special jigs and rigs which would hold the Saturn firmly in place and also give me access to all the sides and surfaces I needed to reach without needing to try to touch any already-painted surfaces. Between the base coats of white paint and the final application of decals for the fine lettering and details, there was a fair amount of hand painting that had to be done in black (flat and glossy), gray, yellow, red, and orange, each of which had to be blended with other colors in order to achieve the proper shade and tone. This meant working in batches and storing the blended paint mixes over the several days it took to paint all the parts in a given color. Once I miscalculated and ran short of gray, and, no matter how many times I tried, I was unable to get any subsequent batches to turn out in quite the same shade as the first. I got close, and from any reasonable distance, you couldn't really tell, but it seemed like my eye was always drawn to those gray sections that didn't quite match each other.

Despite these difficulties (among many others), over a period of nearly six months of off-and-on work, my Saturn V kit was finally finished, and I had to admit, it had turned out pretty well. After admiring it in my bedroom for another six months or so, it was time to see if the thing would actually fly. It was a clear and chilly December afternoon when I took the Saturn and its heavy-duty launcher down the hill to the lake for which our subdivision was named. My brothers and I walked out onto the ice, out to the center of the lake, putting ourselves as far as possible from the houses and trees which crowded the shores.

A model this size was obviously not intended to set time-of-flight or altitude records, but I did want to make sure that there was enough oomph in the engines to get the thing to a high enough altitude to give the recovery system time to work -- the rocket would separate into two pieces, and each would descend under its own large nylon parachute. But if it didn't get high enough, the parachutes were likely to either not open completely or to not slow the rocket sufficiently to prevent a crash. I clipped on large, clear plastic fins in place of the tiny replica fins (the large fins being required to give the rocket sufficient stability during powered flight), inserted the engine into the Saturn, and wired up the electrical igniters to the engine and the launcher. More so than at any time I had tried this before, I was keyed up and anxious. In a tiny way, I was experiencing the same emotions that the NASA folks must go through when they have one of their rockets on the pad. You invested your time and effort in building the best rocket you could, and then you went out to the pad, pushed the button, and hoped for the best.

I armed the system, did a last check that everyone was clear of the launcher, verified that the wind wasn't gusting, made a last scan for low-flying planes, and counted down. At "zero", I pushed the ignition switch and looked up to watch. Unlike nearly all my earlier rocket flights, this one didn't shoot off the pad with a high speed swoosh. It made the usual swooshing noise, but it rose off the pad far more gradually, struggling against the Saturn's much greater weight. As it climbed, it went up straight for only about a hundred feet or so, then tilted over to one side and continued to climb at about a forty-five degree angle. The slanting course meant the rocket wouldn't come anywhere close to reaching its optimal altitude, and it was traveling closer to the woods on the far side of the lake. The rocket had already started descending when the recovery system activated, and I could already tell that it was far lower than it should have been. The two halves of the rocket separated as it continued to fall, and the large parachutes were still partially reefed as the pieces impacted the ice at the edge of the lake, traveling way too fast for a safe landing.

We ran over to the spot to survey the damage. The first stage half of the Saturn had crashed into a large rock at the side of the lake, snapping off a number of the smaller protuberances and putting a good sized dent in the main body. The upper section's parachute was snagged in a tree branch, about twenty feet in the air, swaying gently under its orange and black parachute. There were no good climb holds we could see, and no way to get it down. Perhaps one day, a properly-aimed gust of wind would blow it off the branch; with our luck, this would probably happen in mid-summer and the thing would land in the water anyway.

We picked up the pieces of the first stage that we could find, then packed up the launcher and headed for home. The Saturn V was my last model rocket of any kind. After it crashed, I just didn't have the heart for it any more.

Some hobbies enable you to reach for the stars, but occasionally, you encounter difficulties along the way.

Posted Feb 28, 2009 at 20:55 UTC, 3524 words,  [/richPermalink

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