To be a real astronaut just once? Leo and his big sister Laila have been dreaming of that for a long time. They never imagined they would be taken on a grand space adventure by an intelligent yet rather headstrong rocket. The siblings experience Earth from above, visit the International Space Station, float over the Moon, chat with Mars robots, and befriend a little princess far away in the vastness of our solar system. Along the way, they learn how stars are formed, what planets exist, and what makes our home planet special.