What effect does a hybrid motor have on a marginally stable rocket during thrust?

A hybrid motor uses a combination of solid and liquid oxidizers, which can lead to variable thrust characteristics during operation. For a rocket that is marginally stable, this variability in thrust can cause a shift in the thrust-to-weight ratio, affecting the rocket's ability to stay on a stable flight path.

When a hybrid motor is ignited, there can be a delay as the fuel and oxidizer mix and ignite, and the thrust may not immediately reach the levels expected. If the thrust does not quickly counterbalance the forces acting on the rocket, or if the thrust profile is inconsistent, the aerodynamic forces acting on the rocket could overpower its inherent stability capabilities. This can result in increased pitch or yaw motion, leading to a situation where the rocket becomes less stable during the critical moments of ascent.

Thus, for a marginally stable rocket, the fluctuations and unpredictability associated with hybrid motors can easily cause a deterioration in stability and control, making it more challenging for the rocket to maintain a straight, controlled flight path.