This weekend was our weekend to learn about model rocketry. Last November, Ian received an Estes Model Rocket Starter Kit as one of his birthday gifts. Unfortunately, the weather had already turned bad by then, so we put the thing on a shelf until Spring.
Last weekend, we unpacked the rocket and he and I spent an hour or so putting the kit together. We were very careful to follow the directions, and I took extra time on what was a pretty simple kit to show him good modeling techniques, trimming off extra “flash” from the plastic parts and the like, and taking time to test the fit before we glued things together. We even took the rocket out to the garage and gave it a few coats of clear spray paint to harden up the tube a bit and make it all nice and shiny. It was a nice looking rocket, I tell ya!
Unfortunately, some pretty severe weather ripped through our area last weekend, so the launch plans had to be scrubbed. This weekend was alright, though. It was a bit cloudy and a little breezy, but nothing I thought we couldn’t handle. So, Saturday morning, I packed Ian, Terri and our neighbor’s teenaged son into the Civic, and off we went to the high school sports complex, where I knew there was a large field.
The field was unfortunately soggy from the last week’s rains. Undeterred, we headed across the street to Alumni Park, where it looked like we’d have a clear range for the rocket to fly in. We carefully set up the launcher, put an engine into the rocket, inserted the igniter, placed the rocket on the pad, and backed up the length of the controller wires. I helped Ian hold the launch controller. I inserted the safety key and held it down, and Ian started his countdown.
10…9…8…. When he reached “one” he mashed his thumb down on the launch button. The rocket blasted off the pad with a whoosh! and flew beautifully, climbing 400… 500… 600… at least 800 feet into the cloudy sky, where with a muffled pop! the recovery charge blew, popping off the nose cone and deploying the recovery streamer.
It was beautiful. Our first launch, and everything had gone just as planned so far. We watched the rocket lazily tumble down out of the sky toward a landing point maybe 500 feet away…and plunge straight into the upper branches of a tree, instead.
It wasn’t all that tall of a tree, but the rocket had managed to hang up nearly as high as it could, draping the shock cord connecting the nose cone and the rocket body over the end of a limb. The neighbor’s boy tried to climb the tree, but he couldn’t get any higher than about halfway to the rocket. About that time the neighbor himself showed up.
Engineering ensued. Plans were formulated, attempted, and revised when they failed. Rope was obtained. Another journey up the tree was tried. Rocks and a piece of brick, attached to the rope, were thrown. Fishing line was used to try and send up a pilot line that might be used to haul up a more substantial piece of rope. Another tree was used as a primitive block and tackle in an attempt to gain enough leverage to shake the first tree enough to dislodge the rocket.
We spent over two hours. That rocket is still hanging from the tree as I write this.
It’ll probably blow down the next time we have a bit of wind or a storm. Fortunately, I drive past the spot nearly every day, so I hope I’ll be able to retrieve it one day soon.
I felt bad for Ian; it was his first rocket and we’d only flown it once. So, in the spirit of “getting back on the horse that threw you,” I went to the store last night and picked up another couple of small rockets. I figured that even if we lost one, we’d still have at least one more to work with.
I also picked up another package of engines. Unfortunately, the store didn’t have a wide selection, but they did have the largest engine recommended for the particular rockets I was buying, the “C6-7.” The package said they’d work. I really didn’t know much about engines, but that seemed right to me.
I know a lot more about rocket engines after today.
Ian and I put the two new rockets together this morning. We didn’t spend as much time on these kits; we were eager to fly. The new rockets were quite a bit smaller and simpler, in any case.
After giving the glue some time to dry, we all saddled up again and headed for the park up the street. We walked to the back of the park, and set everything up on the far side of a large open area, about 700 feet from the street. We still had an engine left over from yesterday, a “B” series engine that was close in rating to one of the recommended engines, so we used that.
Again, the rocket soared beautifully, rising so high we actually lost the rocket in the low clouds. Again, the recovery charge fired, and the recovery chute popped out. Ian and I could see the rocket, suspended beneath the red and white ‘chute as it emerged from the clouds and drifted down…clear across the field, the street, over a wall…and into the subdivision across the street.
Fortunately, we recovered the rocket after a short car trip and just a little bit of searching. It had landed gently in someone’s front yard, a good 1500 feet from our launch point.
Clearly, the local park was too small to handle our launches. I took a look at the remaining engines, the C6-7’s. According to the package, these were twice as powerful as the “B” engine we’d just used. We loaded up and moved back to the sports complex. where we had a quarter-mile length of empty parking lots to play with, and set up for another launch.
Our first launch with a C6-7 engine sent our rocket streaking high into the clouds. It turns out that “7″ in the engine designation stands for seven seconds, the time between the end of thrust from the engine until the recovery charge fires and pops out the recovery chute. The rocket, of course, keeps going up during most of this seven seconds, particularly if it’s a small rocket on a large engine. We heard the “pop” of the recovery charge firing, but we never saw the rocket again. It never emerged from the clouds. We never saw a chute.
Certainly, I thought, it wouldn’t be possible to lose three rockets in just two days. Certainly, some sort of malfunction had happened. The chute must have failed to deploy or something, and the rocket had plunged into the nearby field while we were still scanning the sky for it. It couldn’t happen again!
Well, hell yeah it can. Rocket number two, our fourth launch, soared magnificently into the heavens and disappeared, never to be seen again.
This was getting personal now. I mean, I have a damn Master’s degree! I’ve worked for the last several years in engineering firms! These are toy rockets, and a lot of other people fly them and recover them all the time! I would not be defeated! We went to lunch.
Back home, while Terri and the kids puttered around the house and played in the yard, I conducted research. I read five year-old newsgroup postings. I scanned web sites. I learned that a common outcome of using a C-6 engine in a small rocket, particularly with a parachute as the recovery mechanism, is losing a rocket if there’s even a breath of wind. I learned that a properly launched rocket, with the right size engine using a short delay on the recovery charge and a streamer instead of a parachute should land within 500 feet of the launch point. I learned that Estes streamers suck, and a three-foot long streamer cut from mylar not only works better, but is long enough to make the descending rocket easier to spot.
I went to the crafts store and spent $50 on new rockets and engines, and a long spool of red, all weather ribbon.
After dinner we headed to the local park again. We launched three times tonight, and recovered the rocket each time. We more or less trashed the small rocket I’d bought to test my new knowledge because I’d hurriedly slapped it together and a couple of problems that created eventually caused the engine to burn through the rocket tube, but we were successful each time. Most importantly, Ian now thinks rocketry is cool, and can’t wait to work on the larger rocket I bought tonight - which also launches two little glider “shuttles” off the rocket itself when it reaches the top of its flight path. My wife, of course, is even more convinced that I’m still an adolescent in a man’s body, but hey, that’s what being a dad’s all about, right?
