When Jeff Bezos isn't doing his "day job" running Amazon, he's thinking a lot about outer space.

Onstage at Vox Media's Code Conference this week, Bezos said he thought that his rocket company, Blue Origin, was building the infrastructure necessary to help people of the future to innovate and that, ultimately, we'll need to move heavy industry away from Earth to save the planet.

Doing the heavy lifting

Bezos wants to make the future easier for space entrepreneurs.

When Bezos founded Amazon more than 20 years ago, a lot of the infrastructure he needed to build the business was already in place. There was already a method for online payments. Delivery services existed to cart goods across the country. If Amazon needed to build out all those services itself, it would have been too expensive to succeed at its core idea of making any book available online.

He believes Blue Origin's reusable rockets will be similarly valuable for the future.

"When it comes to space, I see it as my job to build infrastructure the hard way — I'm using my resources to put in place heavy-lifting infrastructure so the next generation of people can have a dynamic, entrepreneurial explosion into space," he said. "I want thousands of entrepreneurs doing amazing things in space, and to do that we need to dramatically lower the cost of access to space."

Not as Mars-focused as Elon Musk

When interviewer Walt Mossberg asked about the difference between Bezos and another giant in the space scene, Elon Musk, Bezos said Musk was much more singularly focused on colonizing Mars as a means to preserve humanity.

"I want us to go to Mars, but he's singularly focused on that," Bezos says. "I think, motivation wise, I don't find that Plan B idea motivating. I don't want a Plan B for Earth. I want Plan B to be, make sure Plan A works. I think you go to space to save Earth."

Bezos believes that the way to protect the planet is by moving heavy industry into space. His argument is that humans need sustainable energy but are unable to create it efficiently on Earth using methods like solar power — so in the next several hundred years we should move industries that take a lot of energy off the planet.

Here's his explanation:

If you take baseline global energy utilization today and grow it by just 3% a year, the power of compounding is so extraordinary that within just a few hundred years you will have to cover the whole landmass of Earth with solar cells — just 3% compounding, just a few hundred years. So, what are you going to do? I think that over the next few hundred years we need to move our heavy industry off-planet. Our Earth will be zoned residential and light industrial. And that just makes a lot of sense! You shouldn't be doing heavy industry on Earth. Resources are more plentiful in space. We can build gigantic chip factories in space, and then just send the little bits down. We don't actually need to build them here.