Which factors most influence the coefficient of drag (Cd) for a subsonic rocket?

The coefficient of drag (Cd) for a subsonic rocket is primarily influenced by factors related to the rocket's design and operating conditions. Specifically, the speed of the rocket affects how it interacts with the air, dictating the flow characteristics around the vehicle. As the speed increases, the way air flows over the rocket changes, influencing the drag experienced.

In addition to speed, the airframe dimensions, such as its length and width, have a significant impact on the overall drag. A larger cross-sectional area will generally lead to higher drag. The shapes of the nosecone and fins are also crucial because these components affect the rocket's aerodynamic efficiency. A well-designed nosecone can reduce turbulence and result in a lower Cd, while the fin shape can either enhance or detract from stabilization and drag characteristics.

Other factors, such as altitude, wind speed, temperature, and humidity, can certainly affect the overall rocket performance, but they do not directly modify the coefficient of drag in the same way that design elements related to speed and shape do. The thrust from the engine and the burn time primarily impact the rocket's acceleration and altitude gain, rather than the aerodynamic coefficient. Thus, the most relevant factors that influence the coefficient of drag for a subsonic