The Earth-Mars Transfer Trajectory Optimization of Solar Sail Based on hp-Adaptive Pseudospectral Method

Table 1

Iterative steps of hp-adaptive pseudospectral method.

Step 1	Initialization. Given the initial states of the solar sail, set the number of intervals , the number of initial collocation points for each interval, the error threshold , and the relative curvature threshold .
Step 2	The optimal control problem is discretized into the NLP problem with the selected nodes and is solved.
Step 3	Determine the relation between the maximum residual and in the current interval : if , then continue to check the next interval; otherwise, proceed to step 4 or step 5.
Step 4	If , determine the new number collocation points of this mesh interval by (35), and then check the th mesh interval.
Step 5	If , then refine the th mesh interval into subintervals by (36), and set the number of collocation points on each of the subintervals to be and proceed to the next interval.
Step 6	After all mesh intervals have been updated, return to Step 2 and proceed to the next iteration.