Which of the following is NOT an acceptable rocket recovery method?

A net collection system is not an acceptable rocketry recovery method according to standard practices. Recovery systems are designed to safely bring a rocket to the ground after it has completed its flight. Each of the other options—parachute recovery systems, drogue chute recovery systems, and streamers—are well-established methods that ensure a controlled descent, helping to prevent damage upon landing.

Parachute recovery systems typically deploy at a predetermined altitude and gradually slow the rocket's descent, allowing for a safe landing. Drogue chutes are specifically used to stabilize the rocket or slow its descent during the initial phases of descent before the main recovery system deploys. Streamers, although less effective in slowing descent compared to parachutes, are also a commonly accepted method as they provide adequate drag to reduce the speed of descent.

In contrast, a net collection system is generally not suitable for most rocketry applications due to the challenge of accurately targeting and catching a descending rocket, as well as safety concerns associated with the potential impact and hazards of flying debris. Therefore, it is vital to adhere to recognized recovery methods that ensure the rocket's safe retrieval and minimize risks.