The Expanse season 4 has completed filming last February. Since it is moving on to the editing room, where the rest of the show will be put together, fans have been eagerly awaiting its release.

But there's still quite a long wait for The Expanse season 4 release date on Amazon. The platform's executives revealed during the Television Critics Association Winter Press Tour that it's likely for the new installment to begin airing by the end of 2019.

Screen Rant speculated that the show might launch on the streaming platform this December to take over The Man in High Castle's release schedule. However, unlike its previous seasons, which ran weekly on Syfy, viewers of The Expanse season 4 will possibly get all 10 episodes at once.

Syfy decided not to continue with The Expanse season 4 in the middle of its third season run in the summer of 2018. However, Amazon stepped up to save the show.

"The show is extraordinary and these guys are unbelievably talented," Amazon boss Jeff Bezos said in its decision to negotiate the show's acquisition with Alcon Television Group. It also helped that fans campaigned to save the series with a petition earning over 138,000 signatures. 

Meanwhile, the sci-fi action drama could only get better from here on with the introduction of three new characters, as per Deadline. Keon Alexander, Rosa Gilmore and Jess Salguero have been cast in recurring roles for The Expanse season 4. 

Alexander will play a faction leader, while Salguero is a security officer in a corporate office. Gilmore, on the other hand, will play a refugee named Lucia Mazur and she lives in the Ring Gates.

The main cast of The Expanse season 4 is all expected to return in the new installment. Reprising their roles are Thomas Jane (as Jim Holden), Cas Anvar (as Alex Kamal), Dominique Tipper (as Naomi Nagata), Wes Chatman (as Amos Burton), Shohreh Asgdashloo (as Chrisjen Avasarala), Frankie Adams (As Bobbie Draper), and Florence Faivre (as Julie Mao). 

Mark Fergus and Hawk Ostby developed and created The Expanse season 4 based on a book series of the same title from James S.A. Corey. The show is set thousands of years into the future where humans have colonized most of the Solar System. Amid the action, suspense and drama is a story about conspiracies, which might spell the final end of humanity.