Life Rush by Hieu Dang

The Earth and its water are contaminated. There is a limited amount of usable water for humans and living creatures on the Globe to survive. A space agency has decided to send astronauts to the stars seeking new, uncontaminated water sources.
A high school student whose dad is a cosmologist sneaked into the company at night with his lovely magic fish, taking into his own hands the task of saving the world and his fish friend. With his knowledge of dad’s astronomy lessons, the fish's help, and the tools he’ll find during the trip, he will have enough hints to reach the water.