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. Ahoy! But t' keep it from touchin' down too fast, arrr, 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. Ahoy! In this video (Part 4 o' 5), arrr, we'll talk about how t' use your computer t' set t' altitudes that t' parachutes will be deployed.