## Example: Control of a Spacecraft

**Difficulty: Intermediate **

This problem was originally presented in [1], and this implementation was adapted from [2]. This example is available via the link on the right.

The implementation of this examples will not be explained in details due to similarity with other examples. Please refer to **an example with similar complexity** for implementation instructions, or other examples in the **list of examples** with *Detailed Instructions*.

### Results from ICLOCS2

Using the Hermite-Simpson discretization scheme of ICLOCS2, the following state and input trajectories are obtained under a mesh refinement scheme starting with 20 mesh points. The computation time with IPOPT (NLP convergence tol set to 1e-09) is about **0.7 seconds**, using finite difference derivative calculations on an Intel i7-6700 desktop computer.

[1] Battin, R.H.: An Introduction to the Mathematics and Methods of Astrodynamics, Revised Edition. AIAA Education Series (1999)

[2] Knauer M., Buekens C. (2019) Real-Time Optimal Control Using TransWORHP and WORHP Zen. In: Fasano G., Pinter J. (eds) Modeling and Optimization in Space Engineering. Springer Optimization and Its Applications, vol 144. Springer, Cham