The first TV adaptation of Arthur C. Clarke’s acclaimed science fiction novel Childhood’s End and the space thriller The Expanse will pack a one-two sci-fi punch on Syfy December 14, the network says.

The three-night Childhood’s End arrives nearly a year after Deadline reported that the six-hour television event had been greenlit by Syfy and Universal Cable Productions. The network said the program will air over three consecutive nights, from Monday, December 14 through Wednesday, December 16, 8-10PM ET/PT.

The 10-episode Expanse will bow with a two-night premiere, December 14 and 15, 10 PM ET/PT. The drama, set 200 years in the future, comes from Alcon TV and is based on the best-selling book series of the same name. Following its premiere, the series will take a regular Tuesdays 10PM slot. Syfy, calling Expanse the “most ambitious series” in the network’s history, chronicles mankind’s colonization of the solar system, and stars Thomas Jane (Hung) as a tough detective and Steven Strait (Magic City) as a rogue ship’s captain. The two characters team up to search for a missing woman, but the tale “evolves into a race across the solar system to expose the greatest conspiracy in human history.”

Childhood’s End follows the peaceful invasion of Earth by alien overlords, who promise to eliminate poverty, war and sickness – ushering in an age of peace, health and security for humans, though some earthlings suspect a stiff price to pay. The three-night series was one of several long-form projects announced at Syfy’s 2013 upfront,

Executive produced by award-winning producers Akiva Goldsman (Lone Survivor, A Beautiful Mind, I Am Legend) and Michael De Luca (Captain Phillips, Moneyball, The Social Network), the Childhood’s End cast includes Charles Dance (Game of Thrones), Mike Vogel (Under the Dome), Daisy Betts (The Last Resort), Yael Stone (Orange is the New Black), Julian McMahon (Nip/Tuck), Osy Ikhile (The Fear) and Colm Meaney (Star Trek: The Next Generation).

Childhood’s End is adapted by Matthew Graham, creator of BBC’s Life on Mars and Ashes to Ashes, who serves as writer/executive producer. Alissa Phillips (Moneyball, Mob City) is co-executive producer. Universal Cable Productions is the studio.

The Expanse is based on a best-selling book series, and also stars Shohreh Aghdashloo, Dominique Tipper, Cas Anvar, Wes Chatham and Florence Faivre. Jonathan Banks, Paulo Costanzo, and Jay Hernandez will guest star during the series’ first season. Terry McDonough (Breaking Bad, Suits) directed the first two episodes, with Mark Fergus and Hawk Ostby writing the pilot and serving as exec producers and showrunners, alongside fellow executive producer Naren Shankar.

The space thriller is financed and produced by Alcon Television Group (ATG), a division of Alcon Entertainment. Alcon co-founders and co-CEOs Andrew Kosove and Broderick Johnson serve as executive producers along with former president of Alcon Television Sharon Hall. Alcon Television executive Ben Roberts serves as co-producer. Sean Daniel and Jason Brown of the Sean Daniel Company developed the original pitch as a direct-to-series project, with Fergus and Ostby. Daniel and Brown are executive producers. Ben Cook serves as a producer.

The book series authors, Daniel Abraham and Ty Franck (under the pen name James S. A. Corey), are show producers.