Luc Besson had to persuade his producers to get Rihanna to star in 'Valerian and the City of a Thousand Planets'. The iconic 'Fifth Element' filmmaker knew from the start that he wanted to cast the 'Unfaithful' hitmaker in the pivotal role as Bubble in his new sci-fi film, but Besson had to persuade his producers to reach out as they were unsure they could get her in the independent film.