It may be the most exclusive school in the world.

According to Ars Technica, billionaire inventor Elon Musk has a school for kids housed somewhere inside the sprawling Hawthorne, Calif., headquarters of his rocket company, SpaceX.

The school, Ad Astra, reportedly has fewer than 50 students between 7 and 14 years old, a perpetually evolving curriculum and no formal grading.

The mysterious not-for-profit school functions like a “venture capital incubator” in which students work in teams to drill into some of the most daunting topics of our time: robotics, nuclear politics and the dangers posed by artificial intelligence, according to Ars Technica.

The latter is no surprise considering that Musk has been stridently warning about the risks posed by intelligent machines for several years now.

“I just didn’t see that the regular schools were doing the things that I thought should be done,” Musk told a Chinese TV station in 2015. “So I thought, well, let’s see what we can do. Maybe creating a school will be better.”

Musk funds the four-year-old school himself, donating $475,000 in 2014 and 2015, according to an IRS document published by Ars Technica.

Last year, Ars Technica reported, 400 families competed for 12 openings. To gain admission, would-be students must pass a reasoning test developed by child psychologists.

Ad Astra’s website features little beyond an email address and a close-up photo of a pockmarked planet from space. The school did not immediately respond to requests for comment.

“Ad Astra believes in developing future leaders through multidisciplinary problem solving and reasoning through first principles,” the school’s spartan LinkedIn page says, noting the organization has between 11 and 50 employees. “Ad Astra believes in promoting a love of learning, enduring curiosity, and unbounded imagination.”

“Ad Astra is a laboratory school that embraces advancements in the fields of science, technology, and education,” the page adds. “Ad Astra is dedicated to pushing each student to the frontier of his or her human potential.”

Ars Technica reported that Musk started the school after the Tesla chief executive decided to remove his sons from a Los Angeles private school for gifted children. Musk also lured one of his son’s teachers away to help lead the school.

“We started with eight kids in a really small conference room with transparent walls,” Joshua Dahn, head of the school, said during an interview last year with entrepreneur Peter H. Diamandis. “Generally speaking, we just keep on taking the most precocious young kid we can find who can keep up with the kids that are a bit older. That’s a 7-year-old at this point.”

“We’re pretty open to all ages,” he added.

In addition to learning to code in Scheme, Scratch and Swift, Dahn said, students study math, computer science and chemistry. Students have also spent time creating battling robots, one of which was equipped with a flamethrower — one of Musk’s favorite tools. There are no sports, music or languages taught. Musk believes computer-assisted language translation is not far from being widely available.

At lunch, students play dodgeball.

Dahn said the curriculum is mostly geared toward problem solving, whether those problems stem from physics and engineering or tough ethical questions. In one example Dahn provided, students are asked to deconstruct tripartite nuclear negotiations, with children splitting into groups representing the United States, China and North Korea.

“You give them those parameters and the negotiations take place, and you have kids that are embodying the team of North Korea and taking on that sort of identity and trying to achieve their primary objectives,” Dahn said.

“One of the North Korean team members led the world to a nuclear holocaust, essentially,” he added. “It was a truly impactful moment for that kid.”