Even though "Stargate SG-1" will be shutting down after its final 10 episodes air beginning in April, TV won't lose its favorite astrophysicist.

Amanda Tapping, who plays "SG-1's" Lt. Colonel Samantha Carter, will head over to the Pegasus galaxy to join the "Stargate Atlantis" cast this fall for the show's fourth season.

Tapping will join new cast members as well as returning ones, such as Jewel Staite ("Firefly," "Serenity"), reprising her role as physician Dr. Keller. As Lt. Carter, Tapping will bring her Gate expertise, in-depth scientific knowledge and military training to the expedition, all of which will be tested when they encounter a new race.

Production on the new season will begin production in Vancouver next month.

The final "SG-1" episodes and the remainder of season three of "Atlantis" will return to Sci Fi on April 13, leading into the series debut of "Painkiller Jane."

"SG-1" castmember Claudia Black will also travel, outside of the "Stargate" franchise but staying with the Sci Fi family. Black, will make a guest appearance on the channel's new original series "The Dresden Files." She will portray Liz Fontaine, an Erin Brockovich-style private eye who gives Harry (Paul Blackthorne) some competition and a bit of chemistry when they investigate a murder case. The episode, titled "The Other Dick," will air on Sunday, March 25.