Not for the faint of heart, this outré documentary by nonfiction filmmakers Elsa Kremser and Levin Peter is generally tedious despite its frequent attempts to be both empyreal and discomfiting. In 1957, the Soviet space program sent a street dog named Laika into orbit—sadly, she never came back. Striving for celestial, the filmmakers use Laika’s myth (that she returned to Earth as a ghost and haunts the streets) to explore . . . something? Likewise, they follow two present-day Russian street dogs, the sequences of which are interspersed with disquisition—narrated with gravitas by Russian actor Aleksey Serebryakov—about Laika and other space-bound animals (dogs, chimpanzees, and even turtles) as well as archival footage of later Russian street dogs that were sent to space and did return, only to be subjected to more unethical treatment. This material, along with an extended shot where one of the present-day dogs brutally kills a cat (which the directors show in all its bone-cracking, nature-is-violent “glory”), seems designed to impart some kind of savage truth but instead just seems gratuitous. I’m sure there’s meant to be a political statement in here somewhere—about the brutality of the state, maybe—but nothing in this epical documentary evinces one. The filmmakers have somewhat intriguing ideas, but they don’t sustain their ambition, nor is it worth it for the cruelty to which they subject viewers. In Russian with subtitles.