A long journey without leaving Earth (Image: ESA/Mars 500 crew)

Read more: “520 days: Surviving everyday life on a mission to Mars“

Six men will emerge from a simulated spaceship on 4 November, ending a 520-day journey without ever really leaving home.

The Mars 500 experiment kept them confined in a 72-square-metre “spaceship” in Moscow, Russia, for the most realistic mock mission to the Red Planet ever attempted.


Doctors have been monitoring the crew’s immune systems, sleep cycles, hormone levels and other vital signs that might suffer after a year and a half in a hamster cage. One intriguing study monitors salt levels in the astronauts’ urine to see if men’s hormones go through phases akin to women’s menstrual cycles.

Meanwhile, psychologists have been watching the crew’s moods to see how they hold up after being isolated for so long. As well as helping future astronauts stay upbeat, the results could help soldiers dealing with stress and fatigue.

The crew seems anxious to come home. “The goal is around the corner!” crew member Diego Urbina tweeted on 23 October. In a 13 October blog post, he mused about his experience. “Now that it is coming to an end, I am still convinced that this was not a journey into the cosmos, but a journey to know ourselves and our minds,” he wrote, “to realise how important respect and communication are in order to achieve a functional crew, how fundamental are the links to the real world, thin and fragile as they may be in this situation.”

Interactive graphic: “Mars 500: An interactive timeline“