Friday night is almost here—and so is the new season of science fiction television on the SciFi Channel. New episodes of “Stargate SG-1,” “Stargate Atlantis” and “Battlestar Galactica” will air Friday, July 15 starting at 8 p.m. ET. Check out the latest issue of TV Guide for some spoilers and information on what’s going to happen in each of these favorite shows!

“Stargate SG-1” is headed into its ninth season with an infusion of new blood—Richard Dean Anderson has left the show. Taking his place will be Beau Bridges as General Hank Landry and Ben Browder as Lt. Colonel Cameron Mitchell. Lexa Doig will also join the cast as Dr. Carolyn Lam, while Lou Gossett Jr. signs on as a rising Jaffa leader named Gerak. Farscape’s Claudia Black will also appear in several episodes as a thief. In part one of “Avalon,” the season opener, the new commander takes his crew on a mission to recover an ancient treasure. Will these cast changes bring the show new life? We can’t wait to find out.

Meanwhile, the second season of “Stargate Atlantis” promises some big, exciting episodes as the stranded explorers continue to hold off the Wraith, the alien race that enjoys eating humans. New characters this season include Jason Momoa as a warrior who was captured and turned into prey by the Wraith and Colonel Steve Caldwell, commander of the Daedalus. He’s played by X-Files fan favorite Mitch Pileggi (Skinner). Friday’s episode is “Siege: Part 3,” continuing a story in which the Wraith were trying to seize the Atlantis portal to invade Earth.

We’re all eagerly awaiting the second season of “Battlestar Galactica,” too. The whole cast returns: Lee is headed for the brig, Adama has been shot, President Roslin seems to be getting more and more unstable and there’s some mystery about a Cylon baby that Sharon (one of her clones, anyway) might be carrying. So many crazy things happened at the end of the first season’s cliffhanger we’re having trouble just keeping them straight! In a new episode called “Scattered,” Roslin’s in the brig and Adama’s wounded, which means that Tigh must take the mantle of command.

In other SciFi Channel news, Dynamite Entertainment will be launching a new comic book series based on the new “Battlestar Galactica” to be published starting this fall. Also, if you’re looking to revisit the world of Joss Whedon’s “Firefly,” the SciFi Channel will be broadcasting all 14 episodes (including the three previously unaired ones) on Friday, July 22. The movie based on “Firefly,” “Serenity,” is due in theaters this September. For an episode guide, check out our archives. Finally, starting July 15 you can go to www.scifi.com to enter the "Get in the Gate" sweepstakes--a chance to win a walk-on role on one of the two "Stargate" series. Now that would be fun.