The objective of the activity is to increase the maturity of spacecraft guidance optimization techniques developing a prototype of a mathematical solver toolbox that is able to solve complex global optimisation problems and to apply it to a reference mission scenario, enabling a further industrial scale-up to provide a commercial product applicable to a wider range of applications of optimal guidance and control solutions.

 

Global optimisation methods allow finding a minimum on a global search space without restrictions, unlike finding only local extrema. A general mathematical toolbox for global optimisation is not presently available; all existing solvers and solution algorithms are narrowly specialized towards particular problem types or not available in a high-performance implementation. WORHP is a local optimiser, and hence it provides good results when it is restricted to a small search space by a user-provided initial guess.

 

This GSTP activity proposes to develop a prototype of a mathematical global solver toolbox to be able to solve current and upcoming spacecraft optimal guidance for space missions. The following reference mission scenario is targeted: the problem of designing low-thrust transfers to and from Cis-Lunar space and beyond, i.e. to/from Earth-Moon Lagrange Point Orbits, targeting mass-efficient strategies involving Electric Propulsion (EP) to save propellant and enable these missions.

The following interdependent tasks shall be performed:

On the software development side:

 

• Assessment of the upgrade of the optimiser WORHP with respect to global trajectory optimisation problems and study the interaction between local and global optimisation methods.

• Specification of the global solver architecture, including mathematical methods trade-off, considering the functional, operational, performance requirements of the solver by the reference mission application.

• Implementation and verification of the solver algorithms and the transcription method in a software prototype compatible with the validation framework already available.

 

On the software validation side:

• Assessment of the mission scenario complexity and simulation needs for guidance design and validation, including any benchmark solutions for validation reference.

• Requirements for software functionalities, operations, performance, and requirements for software validation (simulation and performance), for the reference scenario.

• Specification of the validation framework architecture, including mission systems and operations trade-off.

• Implementation and verification of the simulation and performance tools that constitute the validation testing framework.

• Integration and validation of the software in the testing framework to assess the performance against the requirements of the targeted problem under study.