THE RED TOURIST PLANET: Elon Musk Projects First Private Trips to Mars by Middle of Next Decade.

Mr. Musk sketched out his aggressive vision of private space exploration by his company SpaceX—complete with technical details of capsules larger than superjumbo airliners and the basis of a business plan to pay for it—at an international astronautics conference in Australia on Friday.

The presentation, delivered in a folksy manner, was the serial entrepreneur’s most dramatic effort yet to provide specifics demonstrating the viability of his long-standing goal of colonizing the red planet.

To begin with, he downsized the proposed rocket from earlier ideas and made it more versatile, so it could be suitable for less-demanding missions closer to the earth as well as the moon.

Projecting the first trips to Mars by 2022 or 2024—more than a decade before the U.S. or any other government anticipate coming close—Mr. Musk’s latest plans are built around a business principle he had never publicly broached before.

Space Exploration Technologies Corp., as his company is formally called, seeks to create a single fleet of super-powerful rockets and spacecraft able to serve commercial satellite operators, U.S. government customers and Mr. Musk’s dreams of deep space exploration.

By leveraging technology from his current boosters and vehicles to build much larger, more-capable versions, Mr. Musk—who is also the co-founder of Tesla—aims to use cash flow from ongoing operations to finance his Mars ambitions. The existing hardware would be phased out and relatively quickly replaced by the multi-purpose systems.

And: “Mr. Musk acknowledged that the 2022 deadline was largely ‘aspirational,’ but added that by 2024 he was fairly confident about flying as many as half-a-dozen spacecraft to the Martian surface and starting to build a fuel depot there.”

Cue the wailing that Musk’s fuel depot will despoil the pristine Martian environment…