Mar One has outlined the next phase of the candidate selection process for its project to send colonists on a one-way mission to Mars. The non-profit organization will subject candidates to a series of challenges and interviews that will trim the pool from 100 to 24.

In an online article entitled "Screening from 100 to 24,” Norbert Kraft, Chief Medical Officer of Mars One, outlines rounds three and four for candidate selection. According to Kraft, round three will take five days and concentrate on group dynamics challenges and observe the candidates as they break up into teams of 10 to 15 and learn to work together solving problems.

After the pool has been reduced to 40, they will then move onto round four where they'll be required to spend nine days in an isolation unit and their numbers will be further cut to 30. This will be followed by a four-hour Mars Settler Suitability Interview that will see the remaining candidates reduced to a pool to 24, who will be will be offered full-time employment with Mars One.

"It is very important that the candidates are observed closely to examine how they act in situations of prolonged close contact with one another," says Kraft. "During the journey to Mars and upon arrival, they will spend 24 hours a day with each other. It is during this time that the simplest things may start to become bothersome. It takes a specific team dynamic to be able to handle this and it is our job to find those that are best suited for this challenge."

Announced in 2012, the Mars One project aims to land four colonists on Mars in 2025, where they would remain for the rest of their lives with additional colonists sent as Earth and Mars come back into the right launch position every 18 months or so. Living in habitats set up previously by unmanned rovers, the colonists would live off the land for their raw materials, while being the focus of a reality television show beamed back to Earth.

In recent months, the credibility of the project has been called into question as problems were identified with its technology, discrepancies in its selection statistics noted, and difficulties in its business model uncovered. However, Mars One is pushing ahead, with the next selection rounds scheduled for September 2016.