In the fifth season of 'For All Mankind,' Costa Ronin takes on the role of Leonid 'Lenya' Polivanov, the governor of Mars. Ronin describes the challenges and excitement of joining a well-established series, noting that the growth of the Martian colony brings increased political intrigue and responsibility. He approaches his character with a deep understanding of his backstory, having researched the Soviet space program to authentically portray a cosmonaut turned politician. Ronin emphasizes the show's commitment to realism, highlighting the detailed set design that makes the Martian environment believable. He also shares a humorous anecdote about learning to tie a tie specifically for his character, illustrating his dedication to the role. The series presents Polivanov as a complex figure, navigating political ambitions while leveraging his past experiences as a cosmonaut. With season five currently streaming on Apple TV, Ronin's portrayal adds a rich layer to the show's exploration of life beyond Earth.