On a cloudy Independence Day, over 30 people gathered on the Racecourse Park to make and launch water bottle rockets. This is our largest group event by an order of magnitude, and thanks to everyone who came. We’re currently waiting what look to be an excellent crop of pictures from @alanjames. There’s a few pics on the @northackton feed at the moment as well. When new sources of pics turn up they’ll be linked from here. The wiki page will also be updated.
To summarise the day then; we started setting up at just after 2pm, to a rain-free but very windy day (22mph according to the BBC). The first rocket was launched at about half two, and rockets were launched frequently until 4pm when the barbecues were started, which proved to be deliciously distracting. A number of families turned up, and bottles, card, and cardboard were used, under careful supervision, to make rockets for the kids, which were also launched. The wind proved to be a bit troublesome, as rocket fins would get caught by the wind and blow the rocket off course quickly.
Disappointingly the height competition did not go well as the theodolite I constructed couldn’t be used quickly enough to measure apogee well. It also may have moved when used for measurement as the angles it read seems surprisingly low. Martyn’s alternate device appeared to work more successfully, if it was in pre-war units!
After the barbecue the few remaining expressed their disappointment that it was too windy to launch chemical rockets. And then we launched some anyway! The first rocket had been launched before on a D class rocket engine. Unfortunately the C class used this time did not give it sufficient altitude, and the wind pushed the fins so that the rocket flew horizontally, and then landed before the parachute ejected. As it landed on its nosecone, this ejection charge merely blew the rocket apart, quite satisfyingly. The second rocket was much more successful. So successful in fact, that we don’t know where it landed, it was still afloat on its parachute when it left the park! So now we know, if it’s so windy the launchpad blows over, it’s too windy to launch. Everyone seemed to have a great time, and were all keen that we run another, so perhaps before September, maybe we shall run this again.