arrow, it will go back. >> your game is literally out of this world. >> pretty much. >> interacting with other girls makes them realize they're not alone at this. i really hope to show the girls that girls can do anything they want to. >> hello, world! >> and welcome. congratulations. >> thank you. thank you. >> so what do you -- you're at stanford in your second year? >> stanford -- >> what are you studying? >> i'm studying computer science and mechanical engineering. >> i don't even know what that means. that's how dumb i am. what kind of projects are you working on? >> currently, i'm the mechanical lead for the mars rover project. we build a mars rover to compete in competition, similar to what i did in high school. so i'm really excited about that. >> that's so cool. well, congratulations or being a young wonder. we wish you the best. >> thank you very much. >> there's a lot more to christina's story. you can check it out at cnnheroes.com. we'll be right back. >> announcer: next, we honor a hero who connects sick children to the classroom and the world.