An Exploratory Investigation at a Mach Number of 6.9 Into the Use of Aerodynamic Controls for Modulating the Lift-Drag Ratio of an Apollo Type Configuration

An investigation has been conducted in the Langley 11-inch hypersonic tunnel at a Mach number of 6.9 and a Reynolds number of about 440,000 to determine the suitability of various aerodynamic controls on an Apollo type capsule over an angle-of-attack range from -5° to 53°. The controls investigated consisted of several chin and afterbody flaps and a series of hinged cylinders attached to the model base. The moment reference of the basic model was located off the axis of symmetry to permit the vehicle to trim at a nominal lift-drag ratio of approximately -0.5 and then the effectiveness of the various controls in providing trim at reduced ratios was determined. The results of the study indicate that base-mounted cylindrical controls are relatively ineffective in terms of control area required. The effectiveness of the flap controls is strongly dependent on their location.