What physical feature primarily dictates the fixed thrust-time history of a solid rocket motor?

Answer

The shape of the burning surface area within the grain

Designers tailor the internal geometry, using patterns like star configurations, to achieve the desired thrust profile, as the burning surface area controls the thrust output.

What physical feature primarily dictates the fixed thrust-time history of a solid rocket motor?
Aerospacedisadvantagerocketpropulsionsolid rocket