The Rocketry Unit is in its seventh year now at the 6th grade of the Dr. John C. Page School in West Newbury. Because of a particularly large 6th grade this year (78 students), there were four homerooms instead of the normal three with a new additional teacher, Tim Lyons, teaching science; although John was still in charge of the rocketry unit. As usual, the unit is spread out over a week, starting with a pre-build session after school. There was also a day of practicing the use of an Estes Altitrack and stop watch; a day of building and finally - launch day. If last year was the 'Year of the Glue', this year was the 'Year of the Knot' or more appropriately - "Year of the 'I couldn't tie a knot if my life depended on it!'" You can view photos (taken by Katy) in the gallery.
For the prebuild this year, we had nine students with Tim, Brenda, Barbara, and John helping out. We had the students do the usual - assemble parachutes and streamers, launch bags (motor, igniter, plug and wadding) for both A8-3 and B6-4 motors, and fill glue bottles. In addition, this year I had two boys construct two 75 ft extension cords with wire I had received from Bill a few years ago, and plugs I purchased at Home Depot. The cords were to be used for the new PA system that Guy had built for us. It took the two boys most of the 90 minutes to tangle, then untangle, and finally measure and cut the wire! I don't think either is destined for MIT's EE major!
The 78 students were split into three groups for three separate build sessions, with two or three students per team. Because of the larger-than-usual number of students that required aids and additional accommodations, there were several groups that had three students per group and we decided to go with the two easier rockets to build: Thing-a-ma-jig and Razor. As usual, the build session is 90 minutes and we stop the build in the middle at a point where it is useful to have the glue set, at which point I give a short - very simple - lesson in rocketry, thrust and combustion.
We pretty much have the same set of problems during the build with different ones rising above the others each year. To head-off the perennial excess glue problem (especially after last year), I demonstrated what a 'bead of glue' looks like to the kids and made sure each student saw it before we started building anything. This worked, and for the most part, gluing went smoothly. We had two issues to deal with this year and tying knots was one of them. The kids had little problem tying the shock cord to the nose cone of the Razor or eye hook on the Thing-a-ma-jig. But there was some confusion as to what tying a knot 'close to the end' meant and tying two pieces of string together was beyond them!
The other issue was a distinct inability to wait to hear all of the instructions before gluing parts together. We build each part of the rocket in the same manner: 1) I demonstrate how the parts will go together; 2) The kids put their parts together without glue and we sand or adjust things as needed; 3) The kids add glue and attach the parts. The kids always want to start gluing pieces together as soon as I start demonstrating and we always have to remind them not to do anything until we tell them to. This group was particularly eager and was a real challenge to get them to wait - with one student actually attempting to hide gluing a motor mount together under his desk. Looking back I did have a warning that this was going to be a problem. During the pre-build session. I asked two students to help me bring some materials from my truck up to class. The two immediately took off down the stairs and were half way down three flights before John caught them.
'Do you know what truck Dr. Maina drives?'
'No.'
'Do you know where he is parked?'
'No.'
Launch day is the big day; all the kids are excited and I'm always nervous. This year we had our own PA system which made it so much easier for everyone, including the parents to hear what was going on. The parents are invited each year and we had between 20 and 30 show up this year. The PA system was constructed for us by Guy. It was very generous of Guy and we love it.
As we did last year, each team launched their rocket twice, first on an A8-3 and then on a B6-4. The A motor launch used a parachute and the B motor flight used a streamer. For each flight, the kids recorded their tangent angle using and Estes Altitrak and timed their flights with a stopwatch at a station 200 ft from the launch pad, with the Math teacher there to help. Using those two measurements, the kids calculated their flight altitudes and average speed in ft/sec and mph. My own post analysis of the kids recordings and calculations showed that they did a decent job of measuring angles for the A motor of both rockets. But they had difficulty with the B motor, with many angels being greater than 80°. I'm not sure why. Past years did not seem to have this problem.
This year the launch ran particularly smoothly. We had an additional teacher, Tim Lyons, making a total of eight proctors and I know that helped. It could also be that we are just getting better at it. Either way, this year I found that I was not going from issue to issue or question to question as in past years. I actually got to watch some launches!
After all of the scheduled flights, we had a six-way drag race with three Razors and three Thing-a-ma-jigs. I then launched my finless rocket, Frick-in-Frack, and foam cup Lot-te. Two students each brought one of their rockets and we launched them as well. And to end the show, we launched six Thing-a-ma-jigs on Aerotech D10-3 motors, each with 2 - 80 ft streamers. That was a hit. We took our customary group picture, picked up the field and the kids headed back to class.
36 rockets built, 89 total launches, three lost rockets, a few broken fins and everyone had fun - not bad.
