During boost, a rocket powered by a solid rocket motor tends to become which of the following?

During boost, a rocket powered by a solid rocket motor tends to become which of the following?

• A. Less stable in flight
• B. More stable in flight
• C. No change in stability
• D. Unstable

Answer: (B)

During boost, stability in a rocket is governed by where the center of gravity sits relative to the center of pressure. For a stable flight, the center of gravity should be ahead of the center of pressure, and the farther apart they are (a larger static margin), the more stable the rocket will be. With a solid motor, the propellant is located toward the tail. As the motor burns, mass at the tail decreases, causing the center of gravity to move forward toward the nose. The center of pressure, determined mainly by aerodynamics, stays essentially the same during the burn. That forward shift in CG increases the static stability margin, making the rocket more resistant to disturbances during the boost. So, the rocket tends to become more stable during boost.

During boost, stability in a rocket is governed by where the center of gravity sits relative to the center of pressure. For a stable flight, the center of gravity should be ahead of the center of pressure, and the farther apart they are (a larger static margin), the more stable the rocket will be.

With a solid motor, the propellant is located toward the tail. As the motor burns, mass at the tail decreases, causing the center of gravity to move forward toward the nose. The center of pressure, determined mainly by aerodynamics, stays essentially the same during the burn. That forward shift in CG increases the static stability margin, making the rocket more resistant to disturbances during the boost.

So, the rocket tends to become more stable during boost.