The company, Mars One, announced on Tuesday its astronaut selection criteria, of which mental resilience and a strong sense of purpose are considered important traits. Mars One’s goal is to establish the first human settlement on Mars in 2023.

In the first half of 2013, Mars One will begin its global search for the best candidates for the mission. Six teams of four will be chosen from the influx of candidates, and each of which will undergo 8 years of training needed to travel to and live on Mars.