Dual deployment in model rocketry is where you eject two parachutes out o' t' rocket. Blimey! A small one at apogee (the peak o' t' trajectory) so that t' rocket comes down quickly. But t' keep it from touchin' down too fast, you pop out a big chute when t' rocket is close t' t' ground. Aye aye! T' use o' two chutes usin' this method prevents t' rocket from driftin' too far. In this video (Part 4 o' 5), shiver me timbers, we'll talk about how t' use your computer t' set t' altitudes that t' parachutes will be deployed.