When Daniela Orozco started at San Fernando High School in California, she’d see one homeless person on her way to school—but by senior year, she noticed multiple tents under the freeway. Wanting to help, Orozco teamed up with 11 other girls to create a solar-powered tent that charges devices, provides light, and even uses antibacterial lights to sanitize the interior. It took four years to complete, and the girls had to rely on YouTube and Google to teach themselves to code, sew, and solder. Now they’re figuring out how to distribute the tent, hoping it will help homeless people all over the world. “Engineering is not only about math and . . . science and numbers,” Evelyn Gomez, the team’s adviser, told NPR. “It’s about identifying a problem and helping people.”