According to the non-profit company, the selection was winnowed down from the original pool of 202,586 applicants of people from all walks of life from all over the world. However, questions remain about the viability of the project.

The third-round selection was from 660 second-round candidates and includes 50 men and 50 women, consisting of 39 from the Americas, 31 from Europe, 16 from Asia, 7 from Africa, and 7 from Oceania. It was based on online interviews with Mars One Chief Medical Officer, Norbert Kraft, that were intended to determine their understanding of the risks of the mission, team spirit, and motivation.

Announced in 2012, the Mars One project aims at landing 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.