Which statement describes the thrust curve of a regressive motor burn?

The thrust curve of a regressive motor burn is characterized by a high initial thrust that is significantly greater than the thrust experienced toward the end of the burn. In a regressive burn, the fuel is burned at a decreasing rate as the combustion progresses. This results in a thrust profile where the rocket initially experiences a substantial push, which tapers off as the fuel is consumed.

This kind of thrust curve is often seen in solid rocket motors, where the burning surface area decreases over time, leading to less thrust produced as the burn continues. The high initial thrust provides a strong momentum boost at the start of the flight, critical for overcoming gravitational forces and achieving lift-off. As the burn progresses and the fuel diminishes, the thrust decreases, resulting in the overall thrust curve being regressive in nature.

Understanding this concept is essential for predicting flight dynamics and ensuring that the rocket remains within its performance envelope during ascent.