We had 8 students again this year for our prebuild. This year I had them assemble parachutes, paper streamers, launch bags (motor, igniter, plug and wadding) for both A8-3 and B6-4 motors and fill glue bottles. This year the boys did pretty well and kept pace with the girls. They assembled 24 parachutes, 24 streamers, 48 launch bags, and filled 12 glue bottles. All in 90 minutes.
There were 68 students this year in the 6th grade and we built the same three kits we did last year - our perennials - Thing-a-ma-jig and Razor, and the Estes Alpha for the second year; thirty-four kits in all, in three classes with each class building a different rocket. And as usual, we stop the build in the middle at a point where it is useful to have the glue set and I give a short - very simple - lesson in rocketry, thrust and combustion.
Each year we have pretty much the same set of problems during the build that we need to anticipate. The biggest being the use of too much glue. I spend some time on this at the beginning of each class - i.e. not to use too much glue! For the most part the kids get it but there are always some messes that need to be cleaned up. This year however, was a challenge! One example: for the Thing-a-ma-jig, the instructions show a thin line of glue down one side of the tab holes in each of the fins. I have the kids line up the fins and run a bead of glue down the center and over the tab holes. In past years, the kids knew not to run the glue over the holes - not this year. We had to clean up many desks, each with a line of nine dollops of glue where the tab holes were. Another example: we have the kids glue the centering rings to the motor mount tube for each rocket by putting a fillet of glue above and below each ring. Several (many!) teams had glue just dripping from the assembly and John, Katy and I had to take these glue messes to the sink and wipe off the extra glue. Katy brought back a cleaned-up motor tube to one of the teams and the boy immediately started adding more glue to it! - at which, Katy blurted out, 'PUT THE GLUE BOTTLE DOWN!' I could go on!
Launch day is the big day; all the kids are excited and I'm always nervous. As we did last year, each team launched their rocket twice, first on an A8-3 and then on a B6-4. Everything was pretty much the same as last year except this year we had use of MMMSC's PA system. This helped a lot and we so thank Scott and MMMSC for its use. The A motor launch used a parachute and the B motor launch used a streamer. For each launch, 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. The parents are invited and each year more show up, with about 30 to 40 showing up this year. After all of the scheduled launches, we had a 6-way drag race with some of the kid's rockets. I then launched my Corkscrew and Frick-in-Frack. We then launched 6 Alpha's, each with 2 - 80 ft streamers. That was a hit. The motors for two of the Alphas did not ignite but it was pretty neat anyway and it got a big applause. We took our customary group picture and that was it. Of the 82 launches that morning, we had 3 lost rockets, 2 core samples and a few rockets with snapped fins - not bad.