St arg ate ▁Atl ant is ) ▁– ▁medical ▁doctor ▁and ▁gen etic ist ▁who ▁disco vers ▁the ▁A TA ▁gene ▁and ▁serves ▁as ▁the ▁chief ▁medical ▁officer ▁for ▁the ▁Atl ant is ▁expedition ▁ ▁Dr . ▁Sam ▁Beck ett ▁( Quant um ▁Le ap ) ▁– ▁Nobel - p ri ze ▁winning ▁quantum ▁phys ic ist ▁( with ▁multiple ▁doctor ates ) ▁caught ▁in ▁his ▁own ▁time - tra vel ▁experiment ; ▁" le aping " ▁into ▁many ▁lives ▁along ▁the ▁span ▁of ▁his ▁own ▁lifetime , ▁he ▁must ▁change ▁the ▁histor ies ▁of ▁those ▁around ▁him ▁for ▁the ▁better ▁before ▁he ▁can ▁return ▁home ▁ ▁Dr . ▁Walter ▁Bishop ▁( F ring e ) ▁– ▁genius ▁and ▁literally ▁mad ▁scient ist ; ▁responsible ▁for ▁opening ▁a ▁door way ▁into ▁another ▁universe ▁in ▁order ▁to ▁save ▁an ▁alternate ▁version ▁of ▁his ▁son ▁Peter ▁from ▁dying ; ▁his ▁actions ▁resulted ▁in ▁the ▁grad ual ▁break down ▁of ▁both ▁univers es ▁and ▁in ad vert ently ▁started ▁a ▁war ▁between ▁them ▁ ▁Bra ins ▁( Th under bird s ) ▁– ▁engineer ▁ ▁Lieutenant ▁Colonel ▁Sam anth a ▁Carter , ▁Ph . D . ▁( St arg ate ▁S G - 1 ) ▁– ▁United ▁States ▁Air ▁Force ▁officer ▁and ▁ast ro phys ic ist ▁whose ▁scientific ▁knowledge ▁and ▁engineering ▁skills ▁are ▁used ▁to ▁resolve ▁various ▁thre ats ▁to ▁her ▁team ▁and ▁to ▁Earth ▁ ▁R avi ▁Ch ak rab art i ▁( i Z omb ie ) ▁- ▁medical ▁exam iner ▁for ▁the