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
Human mission to Mars considerations for using aerocapture on crewed missions is a maximum G-limit to experience, for which it was noted 5-g's (5 times Earth gravity) was a common limit to be planned for. There may be several landers, for example, separate ones for the crew, a habitat, rover, supplies, ascent vehicle, etc. Landed spacecraft on the surface of Mars: One of the big challenges to landing on Mars was overcome by Mariner 4, when it showed the properties of the atmosphere. Another was a basic survey of the planet, to know what place might be suitable to land. This has been overcome