Mars to Stay it is assumed the planet will be a magnet for settlers as wage costs will be high. Because of the labor shortage on Mars and its subsequent high pay-scale, Martian civilization and the value placed upon each individual's productivity is proposed as a future engine of both technological and social advancement. In the fifth chapter of "Mars Direct", Zubrin addresses the idea that radiation and zero-gravity are unduly hazardous. He claims cancer rates "do" increase for astronauts who have spent extensive time in space, but only marginally. Similarly, while zero-gravity presents challenges, near total recovery of musculature and immune system
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.