WARNING: Major spoilers for Ad Astra ahead.

Ad Astra takes Brad Pitt on a journey to the stars, but is really much more concerned with the smaller, the quieter, the more internal parts of his life. And as a result, when James Gray's belated sci-fi drama comes to its close, audiences will be left with a lot of questions.

In Ad Astra, Roy McBride (Pitt) is recruited by SpaceCom to help contact The Lima Project, a missing exploration ship piloted by Roy's father, Clifford (Tommy Lee Jones), presumed destroyed decades earlier. Pulse bursts have been ravaging the Earth, causing major electrical problems and putting countless lives in increasing danger, and the Lima's payload is believed to be the cause of it. Roy is secretly shipped out to Mars via the Moon where he can attempt to contact his father. Except most of that intel isn't true. SpaceCom really wants to kill Clifford, and all they need Roy for is to elicit a response so they can track his location and send a team with a nuclear bomb. Roy discovers this, sabotages the mission and goes there alone, hoping to destroy the Lima but save his father. In the end, the duo successfully destroy the Lima, Clifford is lost and Roy makes it back home.

Related: Ad Astra Cast & Character Guide

The real wrinkle in understanding Ad Astra, though, is the ending's presentation. The movie throughout has a strong internalized focus, with Pitt channeling his deep whispering from Terrence Malick's The Tree of Life, but once he sets off on his solo, possibly one-way mission, explanation and understanding become twisted and merged. Here's what Ad Astra's ending really means.

Ad Astra's Big Twist: The Lima Project Discovered Aliens Don't Exist

The Lima Project in Ad Astra

The Lima was sent out 16 years prior to the mainline events of Ad Astra captained by Clifford McBride. Its mission was to set up home at Neptune and monitor for any trace of life outside the solar system, away from the interference of the Sun and other planets.

As Earth history told it, the ship disappeared somewhere between Saturn and its destination (Uranus is conspicuous in its absence in the film), with Clifford remembered as one of humanity's greatest heroes. In reality, he was driven to madness in the deep, empty expanse of space. As it became clear to his crew that there wasn't going to be any transmissions or other indications of intelligent life beyond Earth - Ad Astra answers, with as much certainty as is possible, that aliens don't exist - they wanted to return home. Deeming them weak, he killed off mutineers, all the while keeping committed to scanning for traces of advanced life. Per Clifford when found by Roy, the Surge only began when the last of those loyal to him attempted to flee and damaged the transmitter; while that's information provided by a highly unreliable source, it fits with his tunneled-vision commitment to the mission.

At the center of The Lima Project is the question of what the mission's true purpose was and what counts as success or failure. To Clifford, he would only have completed his task when he found irrefutable evidence that life did exist - and would keep working until he hit that endpoint. That impossibility (given the movie's isolationist view), one rooted as much in faith as it is scientific rationality (indeed, aliens here are really a space-age analog for deep-seated religious belief), is what tipped him over the edge. He was an already detached man, and the hopelessness of the search gave him purpose even as it disconnected him from humanity.

Related: How Much Did Ad Astra Cost To Make?

Roy McBride's REAL Mission In Ad Astra Explained

Brad Pitt in Ad Astra

Which brings us to Roy McBride's mission in Ad Astra, a slowly unraveling puzzle box of motivation and purpose. When he's first brought into the picture, Roy is a life-committed military man - to the point his relationship with Eve (Liv Tyler) fractured some years prior - sent on a simple recovery mission; while his presence is reliant on his family connection, his motives are more distant. That's something SpaceCom rely on, masking from Roy his active role in helping them find and kill his father. They track his mental state constantly with repeated psychological assessments, testing not as much his well-being as they are his danger to the mission's completion. There's already a deep irony here, with the same distance that made Clifford kill his crew being instilled in his son so he can be stopped.

However, in making Roy's father an object in his mind again, the mission forces him to confront feelings he's been repressing since he was a teenager. While he was initially a solider doing his job, the personal weight begins to weaken him, making Roy more emotionally engaged. There's also a decaying element of trust in the world around him. Roy has been lied to his entire life about what happened to his father twice over, and by the time he's trying to contact his estranged parent there's a sense of being a tool. Even the trials experienced on the journey to Mars - the irate test baboons and the emergency landing - are painted in a new light by the more militaristic nature of the ship's crew later: how much were they letting him be the hero in unexpected circumstances?

While it's easy to point to discovering SpaceCom's plans as being the core motivator for Roy - first that they already view Clifford as a threat, then the plan to kill him - it's a much more protracted and personal development. Indeed, he doesn't decide to go fully off mission and take control of the Cepheus until his confrontation with Helen Lantos (Ruth Negga), during which he learns of the personal costs of her losing her parents.

What Ad Astra's Ending Means

Brad Pitt as Roy McBride in Ad Astra

Understanding the complex journeys of both Roy and Clifford is essential for breaking down Ad Astra's ending. In simple terms, father and son reunite, realize their shared goal of saving humanity, the elder McBride is lost and the younger heads home a changed man. It's a pretty standard ending, one that many likely wanted from more metaphysical sci-fi such as Interstellar.

Except, as we know, neither man is truly themselves. Roy begins to lose himself with the solitude of traveling billions of miles across the solar system, reflecting constantly on his father and coming out of his shell in the process. And while Clifford was by his own admission never concerned with his loved ones, isolation has caused him to spiral away from the functioning member of society he once appeared to be. That distinction is crucial: they're in a similar headspace from similar experiences, yet the son is only there in following his father. He's been trying to be the best he could be (at his own and SpaceCom's insistence), even though that's not him. When seeing his father a man who's suffered and struggled - and a far cry from the hero he's been indoctrinated to believe with his dogmatic approach to the alien paradox - Roy is able to quantify his losses and grasp them.

Clifford also recognizes his ills in his own way, being consoled by his son over The Lima Project's perceived failure, before letting himself go - literally. He recognizes that there's nothing for him on Earth and appears to have at least some cognisant acceptance of the ill-effects of his actions, so releases himself from his son. It's a symbolic untethering, a severing of the invisible cord that has kept Roy entirely reliant on his father. Of course, by this point the son has already stepped out beyond that shadow - it is pure imagery.

Ad Astra ends on some final twisting of paternal reliance, with Roy using a latch from his father's ship to protect him as he escapes to the Cepheus through Neptune's rings, and using the subsequent explosion as propulsion to get back to Earth (a narrative choice that has questionable real-life scientific grounding). He returns home with a newfound respect for the world around him, accepting his place in the universe and reconnecting with his estranged ex-wife.

Why Ad Astra Isn't A Sci-Fi Movie

Ship Explosion in Ad Astra

For all the backdrop of exploring humanity's lonely place in the universe (the title translates from Latin as "to the stars"), Ad Astra's ending has a rather clear, grounded thematic meaning. Roy's journey brings him face-to-face with his lost father, forcing him to evaluate how his life has been shaped by the emotional and physical distance. He devoted himself to this career because of Clifford, making himself removed from those around him out of a perceived sense of greatness. Through the movie, he's made to address that part of himself, a little unwilling at first but incredibly driven once it's out of the box. This doesn't lead to an explosive confrontation because the film isn't so much about the relationship as it is its effects. The movie's closing moments see Roy, unburdened, able to be a functioning member of society and, more importantly, happy.

What's so striking about that reading is how Ad Astra would work as a discussion on the perception of masculinity passed through the generations regardless of its sci-fi trappings. Sure, the journey to the furthest reaches of the solar system makes for a visceral experience that really sells the mental toll - the lack of air or sunlight, conveyed through suffocating set design, is stifling - but that isn't essential to the movie's core themes or character developments. What's being said internally is what matters, with the staring out into space just giving visuals and voice; you could tell the story at sea or across a city and get the same resolution.

This is, in part, why for all the intricate world-building, when exactly its set remains a mystery. Or the central ships, the Cepheus and the Lima, have none of the mythological pretense associated with the genre. Ad Astra is about the smallest, most important things in a blanket of meaningless black.

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