We study a symmetric collinear restricted 3-body problem, where the equal m
ass primaries perform elliptic collisions, while a third massless body move
s in the line between the primaries, during the time between two consecutiv
e elliptic collisions. After desingularizing binary and triple collisions,
we prove the existence of a transversal heteroclinic orbit beginning and en
ding in triple collision. This orbit is the unique homothetic orbit that th
e problem possess. Finally, we describe the topology of the compact extende
d phase space.