Writer-director James Gray’s output has been marked by its meditative quality ever since his debut feature film, “Little Odessa,” in 1995, so it’s unsurprising that his outer space exploration film, “Ad Astra,” should share so many traits in common with Stanley Kubrick’s even more contemplative sci-fi classic, “2001: A Space Odyssey.”

Casting Brad Pitt as his leading man, Gray indulges the actor’s affinity for stoically self-possessed men-of-action who threaten to be overwhelmed by their own legends, as seen in Pitt’s roles in “Legends of the Fall,” “Fight Club,” “Troy,” “The Assassination of Jesse James by the Coward Robert Ford,” and even his most recent outing, “Once Upon a Time in … Hollywood.”

Combine these two men’s filmmaking proclivities, and you get a version of “2001” in which Pitt’s character, preternaturally calm-under-pressure second-generation astronaut Roy McBride, is a living HAL 9000, whose upbringing and training have honed him into an efficient but emotionally disconnected machine, human but not humane.

Likewise, while Gray embraces Kubrick’s vision of space travel in the future as long since having become commonplace, with routine Virgin America shuttle flights to the moon, whose spaceport concourses are as choked with signs for Subway, Applebee’s, Hudson News and DHL as any commercial airport on Earth, that mundanity masks what Gray depicts as the potential for violence in the seeming tranquility of space travel.

Roy McBride’s secret mission for the U.S. military’s “Space Command” (named by Gray in a script draft for “Ad Astra” that was written before President Trump announced his proposed agency of the same name) takes him first to the dark side of the moon, where he comes under fire from gangs of pirates who roam the moon’s disputed territories like oceangoing pirates in international waters on Earth, then on a flight to Mars, during which a side-trip to respond to a mayday call results in tragedy.

The mayday is sent by a Norwegian space station, and what Roy encounters there inspires one of Pitt’s many voiceover monologues — this is a film as much about inner space as about outer space — ruminating on how often fury lurks just under the surface, as he confesses it does for him, and as he reveals it did for his father, legendary pioneering astronaut H. Clifford McBride, played pitch-perfectly by Tommy Lee Jones.

Jones previously played an astronaut in Clint Eastwood’s “Space Cowboys” in 2000, and Donald Sutherland, who costarred with Jones in that film, plays a former colleague of the elder McBride in “Ad Astra.”

With his folksy Texas drawl, his weatherbeaten wrinkles and the passion we see his character express for the search for extraterrestrial life, Jones seems like a real-life astronaut who somehow got left out of the history books, an unflappable scientist and philosopher-king who looks like he belongs on a wall of heroes alongside Buzz Aldrin.

I kind of reflexively cringe at yet another film centering its drama around the tug-of-war between stern, taskmaster fathers and striving, emotionally stunted sons, but Gray uses the dynamic between the elder and younger McBrides as a lens to explore what sorts of sacrifices one might have to make, in an era of deep space travel, not just in their relationships with others, but in the parts of their own psyche they would have to wall off, to ensure their mission readiness.

During Roy’s on-the-spot psychological evaluations, he states several times, over the course of his travels, how he remains committed to the mission, and how he intends to perform to the utmost of his abilities, in nearly word-for-word recreations of Douglas Rain’s dialogue as HAL in “2001,” and it’s only when we see his feelings emerge, from behind his deliberately placid facade, that his psych evals are determined to be questionable by Space Command.

Although “Ad Astra” champions the value of scientific exploration even in its denouement, it also hammers home the idea that, even in a vast universe where all of humanity fits onto a single pale blue dot, to quote Carl Sagan in “Cosmos,” all that we really have is each other.