He discussed technical details about the giant rocket that he says will take passengers to the Red Planet, the road map for getting to its first launch, and insights into SpaceX’s broader strategy in an “Ask Me Anything” forum on Reddit Saturday.

Musk was his typical freewheeling self during the AMA, quoting the cartoon Bob the Builder and responding to a question about spaceship design with the highly technical insight that “tails are lame.”

He also gamely responded to questions about tangential details of settling Mars, including speculation that settlers might use a compressed version of the Internet. Musk observed that data would take between 3 and 22 minutes to travel between Earth and Mars. “So you could Snapchat, I suppose. If that’s a thing in the future,” he wrote.

More substantively, Musk clarified the scope of SpaceX’s ambitions on Mars. Though he has shared images of vast Martian cities in his presentations on Mars colonization, he said SpaceX isn’t focused on building those cities itself.

“Our goal is get you there and ensure the basic infrastructure for propellant production and survival is in place. A rough analogy is that we are trying to build the equivalent of the transcontinental railway. A vast amount of industry will need to be built on Mars by many other companies and millions of people.”

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That means SpaceX will be designing and building things like systems for creating fuel from Martian resources, work that Musk said is “pretty far along.” But they won’t be focused on issues like how colonists grow food.

Musk also reiterated previous claims that SpaceX is designing the new Mars rocket – still code-named BFR, which stands for exactly what you think it does – to be as safe and reliable as today’s commercial airliners. That will be crucial if plans to use the BFR for transportation around Earth come to fruition.

Musk also shared some details about the game plan for testing the BFR ahead of its first scheduled flight in 2022.

“[We] will be starting with a full-scale Ship doing short hops of a few hundred kilometers in altitude and lateral distance,” Musk wrote. “Those are fairly easy on the vehicle, as no heat shield is needed, we can have a large amount of reserve propellant and don’t need the high area ratio, deep space Raptor engines.

“[The] next step will be doing orbital velocity Ship flights, which will need all of the above.”

SpaceX’s progress on its Falcon 9 rocket in recent years – especially its unprecedented success in landing and reusing rockets – has fascinated observers and re-energized public dialogue about space.