In 1997, Lego finally released a space theme that was a pure, clean break from the Classic Space -> Exploriens continuum that had been their vernacular for almost 20 years. Its name was appropriate for its novelty: these were the UFO faction. Unidentified, mysterious, alien. Fond of dorky little trikes.
The UFOs were a unique faction in a number of ways compared to their predecessors. They had no human characters, their crews instead consisting of elaborately printed cyborgs and helmeted, glowy-faced aliens with names like “Alpha Draconis” and “Commander X”, whose designs recall tertiary pop culture alien races like Trek’s Breen or Wars’ Pikes.
Design-wise, the UFO ships have a number of distinguishing features. Dominated by huge printed shell pieces in light grey, they have a look that’s pretty un-Classic-Space-like, and even fairly un-Lego-like – these wedges were derided in the fandom as POOPs, for “Pieces of Only One Purpose” since due to their shape and decorations there was very little you could do with them other than make the hulls of flying saucers. Despite its vast size, the flagship 6979 Interstellar Starfighter consists of only 292 parts because the saucer body pieces are so large.
The UFO sets were also huge on gimmicks – note the magnet pieces and the light-up brick with fiber optic tubes towards the aft section of 6979. Other sets had heat-sensitive stickers that would display a logo when pressed down on with a finger.
UFO lasted until 1998, when they were supplanted by an even more alien faction.