Survey of Blunt Body Dynamic Stability in Supersonic Flow <s> I. Introduction <s> From Summary: "An analysis is given of the oscillating motion of a ballistic missile which upon entering the atmosphere is angularly misaligned with respect to the flight path. The history of the motion for some example missiles is discussed from the point of view of the effect of the motion on the aerodynamic heating and loading. The miss distance at the target due to misalignment and to small accidental trim angles is treated. The stability problem is also discussed for the case where the missile is tumbling prior to atmospheric entry." <s> BIB001 </s> Survey of Blunt Body Dynamic Stability in Supersonic Flow <s> I. Introduction <s> From Summary: "An analysis is given of the oscillatory motions of vehicles which traverse ascending and descending paths through the atmosphere at high speed. The specific case of a skip path is examined in detail, and this leads to a form of solution for the oscillatory motion which should recur over any trajectory. The distinguishing feature of this form is the appearance of the Bessel rather than the trigonometric function as the characteristic mode of oscillation." <s> BIB002 </s> Survey of Blunt Body Dynamic Stability in Supersonic Flow <s> I. Introduction <s> Report discussing various features of the stability of ballistic reentry shapes, including considerations for ballistic-missile and manned-satellite reentry capsules. Attainment of satisfactory stability of reentry bodies with subsonic terminal velocities was not found to be too difficult, but undesirable features that may cause marginal stability characteristics may be introduced in an effort to minimize weight. Reentry bodies with supersonic terminal velocities have fewer stability issues. <s> BIB003
N the continued exploration of our Solar System, science objectives often require for the landing of a payload on the surface of a body with a sensible atmosphere. Examples of missions falling into this category are those visiting Mars, Venus, Titan, or any mission that must return crew or science payload to Earth. Due to heating constraints, these vehicles are generally blunt in shape BIB001 . Unfortunately, these blunt shapes are generally dynamically unstable once they reach the low to mid supersonic portions of their trajectory. Thus, their oscillation amplitudes will diverge until equilibrium is attained and a limit cycle amplitude is reached. Initial investigations into the phenomenon of dynamic stability as applied to blunt bodies began in the 1950's as the development of ballistic missile and space exploration technologies gained momentum. At that point, dynamic instability was an issue familiar to the aerospace community due to its prevalence in aircraft dynamics. However, due the drastically different operational environments and geometries of entry vehicles, engineers lacked intuitive insight into the problem at the early stages. The analytical work of Allen BIB001 and Tobak BIB002 combined with extensive experimental investigations by Bird BIB003 , Fletcher  ,  , Short and Sommer  and others  -  helped to develop this intuition. These studies also highlighted the unpredictable nature of blunt body dynamic stability, its sensitivity to geometric and environmental variables, and the difficulties associated with determining the stability parameters analytically, numerically, or experimentally. Even with significant experimental effort and computational development since this early era of research, the same uncertainties regarding the driving physical mechanisms behind dynamic stability and difficulties in predicting dynamic performance persist today.