Flying model rockets are lightweight rockets made of non-metallic parts such as plastic, cardboard and balsa wood. The engines are small, solid fueled and not reusable: they come in sizes ¼ A through G, with a total impulse (metric standard) ranging from 0.310 Ns to 160 Ns. They are electrically ignited. The larger engines burn for no more than about three seconds—enough to send the small rockets up to three thousand feet high. The rockets are most commonly recovered by a parachute, which is deployed by an explosive charge. The charge is released by the engine after a time delay (allowing the rocket to reach maximum altitude). Multi-stage rockets are possible; booster engines are designed without the built-in time delay, so that the next stage ignites immediately upon burn out of the previous stage.
As a child, I had longed to be able to launch rockets. I was fascinated by all things related to space and astronomy. But it wasn’t until I was in junior high that I discovered model rockets thanks to a book I checked out of the public library. Once I found out they existed, I began building and launching them.
My middle daughter’s favorite high school class this past year was her astronomy class. She was fascinated to learn about the universe, and even more excited when her teacher announced that the class would be launching model rockets. I helped her build her first rocket from an Estes kit with the name “Big Bertha.” I selected that model for her because it is a basic, simple rocket, and because it is relatively large: nearly two feet tall.
Supposedly she was part of a team of four classmates who were supposed to build the rocket. In reality, it was mostly just my daughter and I who did all the work. The only thing her classmates contributed was to chip in a bit for the cost of the rocket, and to give it the most hideous paint job imaginable: forest green with an uneven red stripe swirling around it like a candy cane.
Since it was a group effort, my daughter had to live with it.
When the day arrived to launch the rocket, I came to watch. Her teacher had several ways for the students to earn extra points from their rockets: the best looking (which they obviously didn’t get), the one that flew the highest, the one that landed closest to the launch site, and the rocket which failed most spectacularly. Besides her classmates, several other teachers and even the principal came to watch the blast offs.
We used a C engine to launch Big Bertha. It had a flawless lift off and rose nearly a thousand feet into the sky. But the parachute failed to deploy properly when the nose cone popped off. Without the parachute, it plummeted like a rock and landed near the launch site. In fact, it hit with a surprisingly loud thunk about three feet from where the principle was standing.
So my daughter and her team got extra points for having the most spectacular failure.
Surprisingly, the rocket was undamaged. So we tried launching the Big Bertha a second time. The second flight appeared to be perfect: the rocket rose rapidly, and this time, at apogee, the parachute ejected as it was supposed to. The rocket floated gently back to the ground—nowhere even close to the principal.
But when it landed, we discovered that it had been far less than a perfect flight: the engine mount had blown out the back of the rocket at the same time the chute had popped out the front. The rocket would not be able to fly again that day.
Nevertheless, my daughter and her classmates were happy for the extra points they had won thanks to almost taking out the principal. When my daughter and I got home we repainted the rocket so that it no longer looked like a bad drug trip from the 1960s—and I ordered a replacement engine mount.
I also ordered another rocket kit. It was also from Estes. Called “The Mean Machine,” it made Big Bertha look like a toy. The Mean Machine stands more than six feet tall and uses large E engines.
My daughter told people in her class about the huge rocket I had built and they did not believe her. But a couple of months later her astronomy teacher decided to launch rockets again, so my daughter told me to bring the Mean Machine. She felt vindicated when I showed up on launch day with the monster.
Aside from a minor prelaunch incident when one of the launch lugs came loose because of the wind, the maiden flight of the Mean Machine went off without incident. It soared 700 feet straight up and then landed safely on its parachute without suffering damage or frightening the principal hiding in his office.