Parameters influencing dynamic stability characteristics of Viking-type entry configurations at Mach 1.76.

Free-oscillation tests of three Viking-type blunt conical configurations were conducted in a wind tunnel to determine the important variables influencing their dynamic stability characteristics at Mach 1.76. The effects of sting geometry are shown to be significant at low angles of attack, while the effects of cross plane motions and tunnel vibration characteristics appear to be negligible. Variation of the reduced-frequency parameter and model base geometry caused significant effects in the data. An approximate technique was developed for converting effective data from either forced-oscillation or free-oscillation tests to values based on the instantaneous angle of attack.