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

The characteristic that describes the thrust curve of a regressive motor burn is a high initial thrust relative to the ending thrust. This type of burn profile is typically seen in rocket motors that experience a rapid decrease in mass flow rate as the fuel is consumed. The regressive burn means that the combustion process is designed to produce a significant amount of thrust at the beginning of the burn, which can correctly provide the necessary lift-off acceleration.

The high initial thrust is crucial for overcoming the inertia of the rocket and achieving flight, making the performance during the initial phase considerably more powerful than at the end. As the motor burns, the thrust tapers off significantly, resulting in a thrust curve that drops as the fuel is depleted. Understanding this characteristic is vital for application in rocketry, where managing the thrust profile directly impacts rocket performance and stability during ascent.

Other options highlight different types of thrust behavior that do not align with the behavior of a regressive burn. A uniform thrust profile would suggest consistency throughout the burn, while a sudden increase in thrust does not match the expected profile of a regressive motor, which does not typically exhibit this behavior. A gradual decline in thrust could pertain to different burn profiles but does not capture the high initial launch phase characteristic of