Launch Vehicle Load Relief: A Historical Perspective and Some New Concepts
A review of historical flight control approaches to launch vehicle load relief is presented, with an emphasis on the capabilities and limitations of acceleration and angle-of-attack feedback schemes. The basic dynamics and control principles of a rigid rocket are used to illustrate trade-offs and design considerations. The control laws used for NASA vehicles such as Saturn I/I-B, Space Shuttle, and Ares I-X are reviewed. It is shown that modern, low-cost strapdown GPS/INS systems, combined with preflight measured winds data, can be used to provide quality estimates of the angle of attack for use in modern load relief schemes.