Optimal design of space transfer orbit of transatmospheric vehicle

The optimal design of the minimum-time space transfer orbit of transatmospheric vehicle presents many difficulties; only after many setbacks did we come to a fairly satisfactory method of its solution. Our method makes use of the merits of two algorithms: first order gradient algorithm and conjugate gradient algorithm. The first order gradient algorithm was used to determine the transfer time. Its optimized control value was used as the initial control value needed to get the conjugate gradient algorithm started more efficiently. The conjugate gradient algorithm was then so used as to satisfy gradually the terminal conditions and the constraining relationships of control in order to optimize the transfer process precisely. A simulation example shows preliminarily that our proposed method is feasible and converges relatively fast for this kind of two-point boundary value problem.