Abstract: Theelectricsailisaninnovativenonpropellantpropulsioninspacewhichtakesadvantageof
themomentumofthesolarwind.Theminimumtimeinterplanetarytransferproblemoftheelectricsailwasstudied.ThemissionscenariosabouttransferringfromtheEarthtotheMarsandVenuswereinvestigated,usingacontinuoussteeringlawmodel,inapolarinertialframe.Twodirectmethodsbasedontheparticleswarmoptimization(PSO)algorithmwereproposed,whichavoidedsolvingthetwopointboundaryvalueproblem(TPBVP)whichwassensitivetotheinitialvalueofthecostatevariables.Thefirstmethodusedtheshootingmethodtodiscretizedthecontrolvariables,transformingtheoptimalcontrolproblemintoaparameteroptimizationproblemofnonlinearpropramming.BasedonthePSOalgorithm,thenearoptimaltransfertrajectorywasobtained.Thesecondmethodfocusedonthecharacteristicsthatallthecontinuouscontrollawscanbefittedusingthepolynomialfunctionundercertainprecision.Acontrollawwasdesignedtoapproximatetheoptimaltransfertrajectorybasedontheanalysisoftheresultsfromthefirstmethod,andthePSOalgorithmwasusedtooptimizetheparametersofthedesignedcontrollaw.Thesimulationresultsshowthatbothmethodshavetheadvantagesoftherandominitialvariableselection,largeconvergencerangeandgoodrobustness.

Key words: Electricsail, Trajectoryoptimization, ParticleswarmalgorithmInterplanetaryexploration