David O'Leary Creator, Co-Executive Producer, Writer Aidan Gillen Dr. J. Allen Hynek Actor Michael Malarkey Capt. Michael Quinn Actor Neal McDonough Gen. James Harding Actor Michael Harney Gen. Hugh Valentine Actor Laura Mennell Mimi Hynek Actor Ksenia Solo Susie Miller Actor Atlee Smallman Frankie Porter Guest Star Robert Zemeckis Executive Producer Jack Rapke Executive Producer Jackie Levine Executive Producer Sean Jablonski Executive Producer, Writer Barry Jossen Executive Producer Arturo Interian Executive Producer