LOS ANGELES—Twenty-five years after its 1974 debut, the science-fiction program Space: 1999 is returning to the airwaves this fall with the two-hour NBC movie Space: 1999 '99: Back To The Moonbase. "Martin Landau, Barbara Bain and all your other favorites are getting back together for more thrilling outer-space adventures in the mysterious futureworld of 1999," NBC spokesperson Lisette Harris said Tuesday.