Taking over the "good guy" theme space race from the Space Police II was the Unitron, a more military themed group. Unitron also features elements from the classic Futuron line, as it revolved around a large monorail system powered by a 9V battery; it retained LEGO interchangeability in the form of small, sleek cockpits which could dock on the front or top of its vehicles. Unfortunately, aside from a ground installation, a large buggy, an advanced looking spaceship, and aforementioned monorail, the theme was underdeveloped, a fact that is still lamented today.
The two Unitron vehicles were 1787 Crater Cruiser and their largest starcraft 1789 Star Hawk II (both 1995) (which was only half the size for most of the other space races' largest starships). The base was 1793 Space Station Zenon (1995). The monorail system was 6991 Monorail Transport Base (1994). This set was the last LEGO monorail set released, and the only Unitron set that was released outside of America.
Dark grey quietly made an appearance as a new LEGO Space colour in Unitron minifigure torsos. Aside from the rocks they built their bases on, the colour appears in no other parts in this theme.
In Europe, Unitron had no other set then the monorail, which made the faction not credible as "good guys fighters" challenging Spyrius. Instead, catalogue pictures showed them as civilians attacked by Spyrius to steal their technology. They also faced a Spyrius assault during TV commercials.
|Image||#||Set||Number of pieces||Minifigures||Price||Release|
|1789||Star Hawk II||288||Unitron Astronaut, Unitron Chief||$27.00||1995|
|1793||Space Station Zenon||340||3||1995|
|5039||Monorail Stop/Reverse Switch for Space Track||3||1989|
|5040||Monorail 9V Motor for Space Track||1||1989|
|5041||Space Track Connector Lead 9V||1||1989|
|6347||Monorail Accessory Track||54||1991|
|6705||Space Explorers||34||Commander Cold, Spyrius Astronaut, Spyrius Chief, Spyrius Droid, Unitron Chief||1994|
|6921||Monorail Accessory Track||46||$$34.95||1988|
|6991||Monorail Transport Base||573||4||$178.00||1994|
- Only one set was released in 1994, which was the 6991 Monorail Transport Base. Coincidentally it was also the biggest set of the theme.