with the faction's main focus being on exploration, their robot figure's name being a play on "android", and the faction's insignia resembling Starfleet's insignia. Roboforce (1997) In 1997, taking over the "good guy" role was another four-set theme, Roboforce. The sets featured numerous large robots in varying color schemes, run by similarly uniformed pilots. Neon Orange Class features humanoid robots equipped with a buzz saw or a chainsaw. The "head" of each robot was also a small spaceship that could be used as an escape pod or secondary vehicle. Neon Green Class featured animal-shaped robots. The Robo Raptor was the only set not to feature a spacecraft, while the Robo Master's small starcraft strongly resembled the Unitron Star Hawk II as a tribute to the fan favorite set. Roboforce "Robos" were powered by "secret" "robo disks", which were oddly enough rectangle-shaped power sources. The theme was only released in North America. UFO (1997–1998) UFO was the first Lego Space theme to feature non-human looking aliens. All of the UFO's minifigures were cybernetic in nature. They featured two wholly robot figures. Many of its spaceships used saucers or half-saucers as elements befitting its name. It has the smallest proportion of wheeled ground vehicles to ships (two to nine) of any Lego Space theme before or since. The UFO theme is often considered the first Space theme to heavily rely on large pieces meant to provide effects (such as curvature) that would be difficult to achieve with traditional Lego pieces, which became common over the next decade. Insectoids (1998–1999) The second alien-looking race, the Insectoids were insect-like humanoid cyborgs especially interested in "energy orbs", which included magnetic stickers so that magnets attached to cranes could lift them. According to the LEGO Group, the Insectoids had crash-landed on an alien planet filled with giant bugs. They were forced to disguise themselves and their spaceships as bugs to steal their giant egg orbs to refuel their spaceships and escape. The Insectoids are usually considered to be the last Classic Space sub-theme in which the entire theme is "good", "bad", or "civilian". With the advent of Lego Star Wars, the classic Lego Space line was ended. Life on Mars (2001) Life on Mars is a space theme released in 2001, around a time of increased curiosity about the red planet. The theme revolved around the concept of lifeforms that could possibly exist on Mars. This