What is an example of a passive recovery system?

A passive recovery system is one that does not require active control or intervention to function; it relies on the natural behavior of the rocket or recovery device. Tumble recovery is a prime example of this, as it utilizes the physical characteristics of the rocket to stabilize and descend safely back to the ground. When a rocket tumbles, it can orient itself in such a way that increases its drag and slows its descent, allowing the rocket to land with minimal damage.

In contrast, parachute deployment involves an active mechanism that requires the rocket to trigger a parachute to open, which is not considered passive. Rocket engine cut-off implies a controlled action taken by the rocket system to stop propulsion, and remote control landing involves direct human control to guide the rocket back, making both of these active recovery systems.