An analysis of the static and dynamic characteristics of a decoupled landing entry vehicle

A theoretical analysis of the static and dynamic characteristics of an entry vehicle utilizing the decoupled landing concept has been conducted. A hypersonic arbitrary-body aerodynamic computer program was used to determine the aerodynamics of the basic body. Three theories were used and compared with data obtained for a Mach number equal to nineteen. Several stabilizing devices were investigated to determine which were the most effective in providing static stability. To evaluate the lateral-directional handling qualities, a ω_Θ/ω_d coupling parameter along with the parameter abs(Θ/β) were derived to be applicable during hypersonic entry. Equations were also derived for determining the contribution of the stabilizing devices to the dynamic stability derivatives. In the evaluation of the vehicle dynamic characteristics linearized equations of motion for the longitudinal and lateral directional modes were used at several points along a maximum performance trajectory. The parameters considered throughout the trajectory were the period and the time to damp to one-half amplitude.