I read this book when I was younger. The cover had a picture of an Asian girl in a spaceship and her companion was just this floating ball with a face. The main parts of the story that I recall were the girl was in her room, living her everyday life and doing homework when a spaceship showed up at her window. She got in and did some missions on the spaceship. The little companion tagged along for all of them.
One of the missions involved her going to another planet which was covered in red dirt and seemed to be abandoned. She was exploring a tower that was in a village of red dirt homes. I believe at one point on the way to this planet, she got caught up in some battle in the sky and almost had her spaceship fall out of the sky but somehow managed to fix it.