Well, kiddo, there was a group of grown-ups called the L5 Society that wanted to build a big space station out in space that people could live on. They thought it would be really cool to live up there and explore the universe without ever coming back down to Earth.
They had lots of ideas about what the space station would look like and how it would be built. They wanted it to be shaped like a big wheel so that it could spin around, simulating gravity and making it feel like we're still on Earth.
But building this space station was really expensive and it needed a lot of technology that wasn't invented yet. So the L5 Society was trying to get people excited about it and find ways to fund the project.
It never actually got built, but the L5 Society was still super cool for dreaming big and wanting to explore the universe!