Uchuu Kyoudai, ST&RS Recommendations
There are two main similarities between these two serialisations: an astronaut selection test and an initiative to travel to Mars.
Both are manga about people who really want to go to outer space, particulary on Mars. Though Kyodai is more serious and deep.
The dream of becoming an astronaut plays a prominent theme in both ST&RS and Ucchu Kyoudai (Space Brothers). In both series, the main male protagonist strives to meet that goal because of a past event. And doing their journey, they face obstacles that tests the limits of their potential. There is a competitive atmosphere in both series as the main characters also experiences anxiety. At the same time though, they also make new friends and enemies during their journey to make their dream into a reality. Recommended for fans of sci-fi involving characters with an ambition.