We have just uploaded details of our parachute deployment system. If the video isn't very detailed then please comment and we will put more details.How it works:
-The parachute is packed and is spring loaded for quick and reliable deployment.
-The door has an elastic band on it and when the door is shut, the elastic band stretches round the rocket.
-The elastic band hooks onto a wind up toy (remember to wind the toy around 1 or 2 times first so it doesn't stop before it releases).
-Then wind up the toy (timer) about 1 or 2 times, depending on the amount of time you want.
-The timer is held in place by a piece of wood, at launch the piece of wood is pulled out and the timer starts.
-When the timer releases the elastic band, it releases the door and the parachute deploys.
... and the rocket is safe.