As kids, my brothers and I would make rockets by wrapping aluminum foil around pencils to create the fuselage, which we’d fill by cutting match heads off paper matches. These would fill the cylinder from front to back. Then we’d pinch the back end of the “rocket” into a dovetail point with one or two match heads sticking out the back. Then the rocket was ready to launch.

We’d put it on a slight incline in order to create a little lift. This enhanced the dramatic effect because it didn’t really amount to the same thrill when your rocket shot off the platform and fizzled to death in the grass.

A really good rocket would shoot from five to ten feet through the air and then lie smoldering on the sidewalk or somewhere in the grass. It is a wonder we never caught anything else on fire. That didn’t happen because we were smart enough to know that any accident would mean a permanent end to our fun. It doesn’t take a rocket scientist to realize that.

These rocket-making endeavors might occupy a couple hours on a summer afternoon. Strangely enough, my parents would fund these endeavors with the purchase of boxes of “paper” matches. Or perhaps we simply raided the pantry on a whim and our mom just didn’t care as long as we were outside and keeping busy. Such were the 1960s.

Each pack contained probably 24 cardboard matches. These we’d cut off at the head, careful not to waste any of the precious “fuel” at the end by cutting them too close. Yet we also wanted to avoid leaving too much paper “waste” attached to the match heads. We learned, in other words, to respect our craft.

It’s interesting how the native instincts of a child operate on projects such as these. When given the opportunity to learn, most kids do quite well by trial and error. The same held true while learning to play basketball or baseball. Through constant repetition and experimentation, we learn to adapt our methods toward better results.

This continues all through life if we keep our childlike minds open to possibilities. During the peak training months of summer, I can often find my wife with her bike up on a stand while she hand-spins the pedals around testing the flow of the gears on the cassette. It’s a pleasing sound to hear the chain whirr and the gears shift. She says nothing for the most part while doing this exercise. Her attention is fully occupied on the task at hand. Literally.

Usually, she’ll come inside after a while and make some observation about how the drive train is operating. She’s not mechanical in terms of being Mrs. Fixit, but she sure has a sense when something is wrong. More than once she’s carted her bike into the shop for a tuneup and the mechanic confirms her suspicions.

I’m not mechanical at all. After fifteen years of cycling, I still can’t tune my derailleur or adjust the tension on the brake pads. That’s why I bring my bike to the shop for checkups. Without that, the thing would fall apart underneath me.

That doesn’t mean I’m benign to problems. I sense them well enough when things get loose or weak or the chain rattles. Parts wear out. Things get stretched. We depend on instincts in many cases. It isn’t rocket science.

Yet I think back to those early experiments with match rockets and realize that we were literally engaging in rocket science. We had to be cautious and smart with our materials. The balance in thickness of the aluminum foil we wrapped around the pencil to make the rocket had to be calculated against the total thrust and explosive power of the fuel load, which was matchheads.

My brothers were fond of engaging in such experiments. Once my brother and his friend Marty spent an hour constructing a Mega Rocket. They wrapped aluminum foil around a toilet paper roll instead of a pencil. It took almost an entire box of match packs to fill that damned rocket. It sat there on the launch pad all wrinkled and thick like a turgid penis. We all had a laugh at that.

Then Marty took a match and struck it against the black strip on the pack. It was launch time. The first match lit and sputtered at the back and then the real fire began. Inside the rocket the match heads exploded in a furious release of energy.

Then we had liftoff. It blew out the back of the rocket and blackened matchheads were left behind like the detritus of a volcanic eruption. The rocket lurched up the pad and blasted into pieces just beyond the first length of sidewalk.

We all cheered because it was a spectacular deal even if it was not an entirely successful flight. Years later when the Challenger space shuttle exploded after launch I would recall that attempt of ours to build a badass rocket. It’s not easy. These days the SpaceX crews send rockets into space with relative frequency. They have brilliant minds at work. Real rocket scientists sending hundreds of thousands of pounds of equipment out of earth’s gravity into space.

The principles at work in all this are maddeningly consistent. It’s always a question of weight versus propulsion capacity. It’s true with our bikes. It’s true with our running. It’s true in the pool. It’s all weight versus propulsion.

The matchheads we place in our bodies are the food we eat, the drinks we consume and the energy bars we pack into our bodies hoping to sail through yet another workout or race.

It’s not rocket science. But it works like that. Weight versus propulsion. Think about it next time you’re on the road or in the pool. Go light a match. Or more.