Lego Space Space subtheme in which the entire theme is "good", "bad", or "civilian". 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 the lifeforms that could possibly exist on Mars. This was the first Space theme to feature two types of minifigures: human astronauts and Martian aliens. The sets denote peaceful coexistence between the two species on the planet Mars. The "Life on Mars" theme pioneered several unique aspects in Lego in general. It was the first Lego theme to utilize a pneumatic
Mars to Stay the astronauts from the surface of Mars is one of the most difficult parts of a Mars mission, the idea of a one-way trip to Mars has been proposed several times. Space activist Bruce Mackenzie, for example, proposed a one-way trip to Mars in a presentation "One Way to Mars – a Permanent Settlement on the First Mission" at the 1998 International Space Development Conference, arguing that since the mission could be done with less difficulty and expense if the astronauts were not required to return to Earth, the first mission to Mars should be a settlement, not a visit.