Distance in space is absurdly great that using regular measuring means is pretty useless. And the best way to calculate great distance is light-years. And from where Zhang Tian was, to where hi subordinates were, even lightyears were not enough to calculate the distance.
Yet, he was still able to send commands in real-time to his subordinates, all using one single item, and it was one of the rarest treasures in the world.
A Space Owl Breath.
It was a single-use item, that can be used to send commands from any part of the world to another, and can be used to send private messages, or straight up hollering words throughout the galaxy for everyone to hear.
Most didn't use this item due to how rare it is, but Zhang Tian had several of them laying next to him, uncaring if they were to break after sending a single word asking about his friend.
"What's the situation?" asked Zhang Tian through one of the Space Owl Breaths he owned.