Groundbreaking is not the first word that comes to mind when one considers Lost in Space. But in its melding of cheesoid camp with action-adventure, it was just that. The CBS series (1965-68) detailed the exploits of the Robinson brood (June Lockhart, Guy Williams, Marta Kristen, Billy Mumy, and Angela Cartwright), who are marooned en route to Alpha Centauri after their ship is sabotaged by a stowaway. That would be Dr. Zachary Smith, played to fey perfection by Jonathan Harris. On the eve of the big-screen Space remake, the Sci-Fi Channel’s 12-episode marathon (Oct. 16, 3 p.m.-4 a.m) includes interviews with the series’ stars.