Red Heavenis timely in a way that the filmmakers could not have anticipated when they started making the documentary five years ago: It gazes head-on at isolation, confinement, boredom and stress — issues that nearly everyone is confronting in some combination or another as the world goes on coronavirus lockdown. But there's a lightness to the film as it explores weighty matters, along with a dash of reality show dynamics, framing cosmic questions in a familiar format.