Abstract
Actual rocket bodies have a finite bending stiffness. Low bending stiffness reduces the pitching moment of the body in comparison with the case where the rocket body is assumed to be rigid and this tendency becomes stronger as the velocity increases. This paper treats the case of the single step rocket of finite bending stiffness and gives an approximate equation of the righting pitching movent. This approximation is expected to be also applicable to multi-step rockets.
