The Expanse season 3 has been given the go ahead from Syfy, so don't worry, it will return.

With overwhelming positive reception from both viewers and critics, it's no surprise that The Expanse season 3 has become reality. The space drama has wowed fans with its complex characters, its political intrigue, its attention to scientific authenticity, and its stunningly good visual effects, and with several more books in the series that inspired the show, there's plenty more source material for the adaptation to explore in future seasons.
“The Expanse is a gorgeous, thrilling, emotional series that has quite simply raised the bar for science fiction on television,” said Chris McCumber, President, Entertainment Networks for NBCUniversal Cable Entertainment. “We, along with the fans, are looking forward to continuing the journey with our partners at Alcon Television Group and the series’ brilliant cast and crew.”
The Expanse tells the story of a colonized solar system 200 years in the future, when two strangers and their colleagues become unwittingly swept up in a vast conspiracy. Based on the New York Times bestselling book series collectively known as “The Expanse,” written by Daniel Abraham and Ty Franck (under the pen name James S. A. Corey), The Expanse stars Steven Strait, Shohreh Aghdashloo, Dominique Tipper, Cas Anvar, Wes Chatham and Frankie Adams.
Season 2 has just broken into material from the second of six Corey books, Caliban's War. Although The Expanse has been remarkably faithful to the novels, there have been plenty of changes that keep even the readers guessing. We expect that to continue in The Expanse Season 3.
The Expanse Season 3 Release Date
While it hasn't been officially announced yet, we expect The Expanse Season 3 will arrive in early 2018. We'll update this when we have confirmation.
The Expanse Season 3 Teaser
Until then, enjoy this teaser for The Expanse season 3 that Syfy put out after season 2 had its finale.