A Comparison of the Gradient and Newton-Raphson Techniques for Reentry Trajectory Optimization.
AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OHIO SCHOOL OF ENGINEERING
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The report contains a two-dimensional optimization analysis of reentry trajectories for minimization of space vehicle heating and maximization of terminal range, conducted for a lifting body reentry vehicle with a maximum lift-to-drag of three. Based on this analysis there appears to be a conflict between heat minimization and range maximization in that a high angle-of-attack is required to minimize the heating rate and a lower angle-of-attack is required to maximize range. Two optimization techniques were compared, a Newton-Raphson method and a steepest-descent gradient method. A modification of the gradient technique, which was based upon the variational Hamiltonian, was applied after convergence to a near-optimal solution, resulting in an improved control profile. Author
- Spacecraft Trajectories and Reentry
- Manned Spacecraft