In what situation would a drogue parachute be used?

A drogue parachute is specifically designed to provide initial slowing and stabilization to a rocket during its descent before the main parachute is deployed. When a rocket reaches its apogee and begins to descend, the drogue parachute is deployed first to reduce the speed of the rocket and to stabilize its orientation, ensuring that it falls in a controlled manner. This deceleration is crucial as it minimizes the risk of excessive forces leading to potential structural failure upon the subsequent deployment of the main parachute.

The use of a drogue parachute is essential in high-speed descents, as it helps transition from the rapid free-fall speed to a more manageable rate, allowing the main parachute to be deployed effectively at the appropriate altitude without the risk of damage. This is vital for the successful recovery of the rocket and ensures the recovery system functions as designed.

In contrast, using a drogue during the final landing phase could lead to complications, as the main parachute should be the primary source of deceleration at that time. While drogue parachutes can provide backup support in certain circumstances, their primary role is not as a backup for the main parachute but rather to aid in the deceleration phase before the main canopy opens.