That was my take on the movie, R47.
Now I was just summarizing what I saw.
****MORE SPOILERS***
It was a little bit difficult trying to make out the dialogue, but the gist of the story was about Brad trying at all costs to reach his father who had lost contact with Earth, but whom he was sure is still alive in a space station orbiting Neptune.
Apparently, his father also murdered his own crew (because they wanted to abandon their mission above Neptune), and rather than letting them end the mission, he slaughtered them all in their space station.
Meanwhile, Brad is on this quest to reach his father. At some point on the way to Neptune, the people in charge of the mission decide that his father isn't alive (I forgot how this came about), and they tell him to turn around and go home. This was the first part that bugged me. So you send Brad Pitt billions of miles into space, only to tell him to turn around and go back home?? Like he was going to the corner market? Omg, that pissed me off.
Of course, Brad wasn't going to turn around, and I believe (again, it was hard to hear) that his fellow astronauts were trying to get him to turn back, which is how he ends up killing them. Also like someone upthread mentioned, there was this random monkey who ends up killing someone, and also some random dog wandering around their craft, as if he was a stray in the alleys of Cairo.
Miraculously (I use that word snarkily), he makes it to Neptune in a little shuttle all by himself, only to discover that the shuttle can't dock with the space station, because it got damaged during the trip. So he exits the shuttle into space, and the shuttle drifts off, basically stranding him at his father's space station.
He enters the space station and finds his father who is half insane, but still alive. After more boring dialogue about the whos, whats, whens, wheres, and hows of the past years of being stranded, Brad convinces his father to leave the station.
Of course, without a ship, they exit into space in just their space suits, and some sort of tether, to try and reach a nearby space station (which I assume has a craft to get them back to Earth.
In their attempt to reach the other station, something goes wrong, and the father basically says "let me go." After the gratuitous hemming and hawing, Brad reluctantly lets his father drift off into space.
There's still the matter of Brad needing to get to the other station (while drifting in outer space in just a space suit, mind you). This is where he finds a piece of space junk, and uses it to surf through an asteroid belt (with BOULDER SIZED ASTEROIDS), and he manages to dodge them all (**eyes rolling**) and target the other space station (again, while drifting in outer space) while "surfing" the piece of metal at what must be thousands of miles per hour.
Again MIRACULOUSLY, he lands with a thud on top of the other space station (which in real life would have squashed him like a bug).
The movie just glosses over this, and shows him landing back on Earth (a scene of about five seconds), and then voila! He's in a coffee shop.
More low talking.... then end of movie.
WORST MOVIE EVER.