Electric sail trajectory optimization and performance analysis

The electric sail is an innovative propulsion concept which uses the solar wind dynamic pressure to produce a thrust without the need for propellant mass. The electric sail is consisted of many metal tethers which are connected to a solar-powered electron gun. The electron gun emits electrons to maintain the tethers at a high positive potential. The electric field generated by these metal tethers reflects the solar wind ions to generate a thrust. In this paper, the Gauss pseudospectral method is proposed for the trajectory optimization of electric sail. The Gauss pseudospectral method overcomes the shortcomings of the indirect method which is sensitive to the initial value of the costate variable. Considering the case of the characteristic acceleration changed under solar storms, the electric sail trajectory is generated online based on the Gauss pseudospectral method, thus improving the adaptability to the uncertainty of the solar wind. Finally, an outer solar system exploration mission is taken as a reference mission to compare the performance of electric sail and solar sail. The simulation results show that electric sail is faster than solar sail in the outer solar system exploration mission.