While Amanda Tapping was part of the main cast of Stargate SG-1, she made several cameo appearances in the first three seasons of Stargate Atlantis. Amanda Tapping became a member of the Atlantis main cast for 14 episodes of Season 4. She did not appear in " Travelers ", " Missing ", " Miller's Crossing ", " This Mortal Coil ", " Spoils of War " and " Harmony ".