Elon Musk, the billionaire genius behind SpaceX, Tesla Motors and Solar City, did not think his kids’ school was good enough. This led him to create his own school for them, and anyone else who had an interest in the future.

The secret Los Angeles-based academy is called Ad Astra, latin for “to the stars,” and it does not have a website and you will not find it anywhere on social media. What we do know is that Ad Astra has no grade levels and all the children go through the same experiments at the same time. Musk, who has six sons, explained how the school works:

“Some people love English or languages. Some people love math. Some people love music. Different abilities, different times. It makes more sense to cater the education to match their aptitudes and abilities.”

He also introduced key learning methods within the curriculum and highlighted how traditional methods can strip children of their critical thinking skills. “It’s important to teach problem solving, or teach to the problem and not the tools…Let’s say you’re trying to teach people about how engines work. A more traditional approach would be to say, ‘we’re going to teach all about screwdrivers and wrenches.’ This is a very difficult way to do it.” Musk favors a more hands on approach — give the kids an actual engine, teach them how to use tools, and work together to disassemble it. “How are we going to take it apart? You need a screwdriver. That’s what the screwdriver is for … And then a very important thing happens: The relevance of the tools becomes apparent.”

Musk reports that the kids “really love going to school” so much that “they actually think vacations are too long; they want to go back to school.”