Great actors, nice set-up and decors, original enough idea, a slow but relatively realistic start... so what went wrong? For one, it never really picks up rhythm. But mostly, it's because it loses any form of realism. You can either get crazy sci-fi stuff and you make a Guardians of the Galaxy or Star Wars film and no one will care about the tech aspects, or you can claim to make it right and hire Nasa consultants and whatnot. But not both. It's far from being as stupid as Ad Astra for instance, but still big enough mistakes to make you lose interest. Nearly ALL the issues the crew has (I won't spoil) would have been avoided with some common sense and more "space realism". And if a movie relies on its characters to be far stupider or careless than they should be to move the plot, there's a problem. Too bad, it could really have been nice.