TITLE:
Road Map to L4/L5 with a solar sail

AUTHORS:
Ariadna Farres^(1), Jeannette Heiligers^(2) and Narcis Miguel^(3)

(1) University of Maryland Baltimore County
(2) Delft University of Technology
(3) Universitat Pompeu Fabra

E-mails: ariadna.farres@maia.ub.es, narcis@maia.ub.es

ABSTRACT:
This paper explores the capability of solar sails to transfer a probe from the displaced
L1 and L2 libration points to the region of practical stability (RPS) around the triangular
equilibrium points L4 and L5 . If the sailcraft arrives inside the RPS with zero synodical
velocity, it will remain there with no need for station keeping maneuvers. Moreover, the
location of the RPS is ideal for space weather missions as the Sun can be observed from a
different angle compared to spacecraft orbiting the L1 point. The solar sail unstable manifolds
of the displaced L1 and L2 points come close to these regions providing opportunities
for natural transfer trajectories. By varying the solar sail orientation along the manifold,
the dynamics are altered and simple transfer trajectories that reach the RPS with few sail
maneuvers are enabled. However, these trajectories are not optimal from a transfer time
perspective, but they are used in this paper as an initial guess in a direct optimization
method to find minimum-time transfers between the displaced L1 and L2 points and the
RPS at L4 and L5.