SyFy premiered science fiction series The Expanse way back in 2015. Based on the hit series of novels by James S.A. Corey (Daniel Abraham and Ty Franck), the show moved to Amazon in 2019, where it's been allowed to truly explore its potential (and its newfound freedom to swear).
The series, a sprawling space opera with a high decree of scientific accuracy, was developed for television by Mark Fergus and Hawk Ostby, who are more famous as the screenwriters behind Iron Man, and Children of Men. These showrunners have serious chops.
No doubt, the series owes much of its success to the original novel series.
Introduced Avasarala Early (Change)
One of the series' most iconic characters, and most beloved, is Chrisjen Avasarala. Portrayed by Shohreh Aghdashloo, Avasarala is the UN Deputy Undersecretary for Executive Administration, a real heavy hitter back on Earth. She is at the center of the Mars/Asteroid Belt/Earth conflict.
However, in the books, Chrisjen Avasarala is not introduced until much later. In the series, she appears in the very first episode. Early on, while the series was still broadcast on SyFy, fans also complained at her cleaned up language and lack of creative swearing. But Amazon has remedied that.
Added More Artificial Gravity (Change)
In the Expanse books, much of the action (and non-action) takes place in zero gravity and low gravity environments. Makes sense, since the books' authors strive for scientific accuracy, and they take place in space. However, in the show, there are very few scenes that take place in a zero-G setting.
The reason behind this change wasn't a narrative choice, it was a practical one. Shooting so many scenes in zero gravity would have been extremely expensive, and on a TV show budget, it just wasn't tenable. But it doesn't seem to detract at all from fans' enjoyment.
Made James Holden Less Idealistic (Change)
James Holden, portrayed by actor Steven Strait, is arguably the protagonist of the entire series, and captain of the ship Rocinante. Still, despite his importance, his character is one of those with the most changes from the page to the screen, even getting an entirely new backstory.
In the books, he's very idealistic, but in the series, he's less of an idealist and more of a freedom fighter. His backstory makes him the child of anti-government radicals in Montana, where he grew up on a sort of commune. This change in motivation makes Holden easier for the audience to understand right off the bat.
Created A Belter Language (Change)
The Belter creole, Lang Belta, that features prominently in the series was in fact created for TV by linguist Nick Farmer, after he met author Ty Franck. While Franck and Abraham did reference a Belter language in the books, and mention some words and phrases, the language was never truly fleshed out until Farmer came along. And thank God he did.
Like Dothraki and Valyrian are iconic elements of Game of Thrones, like every true Star Trek fan can speak a little Klingon, Lang Belta sets The Expanse apart from the rest.
Shifted Focus Of Cibola Burn (Change)
The entirety of the fourth book in The Expanse series, Cibola Burn, takes place on the planet Ilus, a setting which does not appear in the first three seasons of the show. But the fourth season, which takes most of its story cues from Cibola Burn, still focuses heavily on Mars, Earth, and the Belt.
This change makes a lot of sense. After all, fans have spent three seasons becoming invested in the conflicts back home in Earth's solar system, so if the writers were to leave that all behind, even for one season, they could've had a mutiny on their hands.
Started Allowing Cursing On Streaming (Same)
As mentioned above, one of the biggest sticking points with fans of the book series was that none of the characters in the TV show were allowed to curse. Particularly Chrisjen Avasarala, whose potty mouth is the stuff of legends. But on cable, with a TV-14 rating, there wasn't much way around it. The language had to be clean, whether fans liked it or not.
Now, with the fourth season streaming on Amazon and a fifth season in the works, fans can rejoice, as characters are allowed to curse to their hearts' content.
Stayed True To The Tech (Same)
Yes, scientific accuracy has already been mentioned, but it really can't be brought up enough. The Expanse book series is hard science fiction (science fiction based in science fact), much like Frank Herbert's Dune and Isaac Asimov's Foundation series.
Some of the technology that appears in the book series pops up at different points throughout the show. For instance, contraband stealth tech that may be from book 5 is mentioned in the pilot episode. But overall, the technology that appears in the books is faithfully rendered in the TV series.
Found Great Actors For The Characters (Same)
One of the hardest things to translate from stage to screen is character. When a writer, or two writers, can stretch their legs to the tune of a few thousand cumulative pages, they can delve deeper into the characters than a TV series can ever hope to go, even with nearly 50 episodes under its belt.
Luckily, the series seems to have found the perfect actors to portray its characters, something which goes a long way. Great actors are able to portray deep nuance and backstory without stating things verbatim on screen. Fans praise the casting of Dominique Tipper as Naomi Nagata in particular.
Adapted One Book Per Season (Same)
One of the thing's that's so great about The Expanse is that it only tackles one book per season of the series. This really allows the series writers to get into the meat of the novel, even if some fans think that ten or thirteen episodes for each book is nowhere near enough.
In nods to the books, the finale episode in each season is named for the novel which the season adapts. The first season takes on Leviathan Wakes, the second Caliban's War, the third Abaddon's Gate, and the fourth the aforementioned Cibola Burn. Fans can only hope the series keeps running long enough to tackle all 8 books, and maybe even the 9th still to come.
Introduced The Ring In Season 4 (Same)
The fourth book marks a major shift for the series trajectory, introducing a "ring gate" which allows the characters to travel to alien galaxies. In keeping with their habit of tackling one book per season, the series writers introduced the same ring gate in season four of the TV series.
Luckily, this is exactly the sort of paradigm-shifting plot twist that lots of shows employ in their later seasons. Sometimes these twists, which generally introduce characters to a larger world than ever before, can go horribly wrong (as in Battlestar Galactica), but The Expanse seems to have handled it well.