Dual deployment in model rocketry is where you eject two parachutes out o' t' rocket. Aye aye! 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. T' use o' two chutes usin' this method prevents t' rocket from driftin' too far. Well, blow me down! In this video (Part 4 o' 5), we'll talk about how t' use your computer t' set t' altitudes that t' parachutes will be deployed.