Aerodynamic flight control to provide flight control augmentation for aft cg future launch vehicles

This document reports on the past six years of the extensive and comprehensive flight mechanics — stability and control, special research project conducted at the NASA Marshall Space Flight Center where the author was the designated Principal Investigator and only investigator. The author has proposed, designed, wind-tunnel tested, and analyzed the static and dynamic stability and control characteristics of both forward and aft located, all-movable, blunt-trailing-edge, flight control augmentors (FCA's) for futm-e aft-cg large Saturn-class launch vehicles (LV's) that would not be controllable with engine gimbaling alone. To the author's knowledge, all-movable FCA's have never been used on a large Saturn-class LV. A review of our national heritage of LV's that have used aerodynamic surfaces (V-2, Pershing, Redstone, Saturn I, Saturn IB, Saturn V, X-15) and current usage of these surfaces by other nations has been conducted. Stability derivatives and control derivatives have been calculated from both wind tunnel test programs data and the U.S. Air Force DATCOM computer code. The enhanced static and dynamic flight stability of the aft-cg experimental LV, when treated with the author-designed FCA's, has been assessed and quantified using static margin and short-period damping as criteria. The increased control effectiveness of the blunt-trailing-edge FCA design was found to provide the maximum flight control augmentation. A titanium matrix composite was selected as the FCA material and a design review was held at the manufacturer, Textron Specialty Materials Company. The change in aeroelastic effects of the aft-cg LV were considered. From the NASTRAN generated modal data, significant mode shapes and response spectra have been analyzed and presented for both the original and aft-cg experimental LV.