Dual deployment in model rocketry is where you eject two parachutes out of the rocket. A small one at apogee (the peak of the trajectory) so that the rocket comes down quickly. But to keep it from touching down too fast, you pop out a big chute when the rocket is close to the ground. The use of two chutes using this method prevents the rocket from drifting too far. In this video (Part 4 of 5), we'll talk about how to use your computer to set the altitudes that the parachutes will be deployed.