Falcon Heavy to launch next month from Apollo 11 pad at the Cape. Will have double thrust of next largest rocket. Guaranteed to be exciting, one way or another.

— Elon Musk (@elonmusk) December 2, 2017

Payload will be my midnight cherry Tesla Roadster playing Space Oddity. Destination is Mars orbit. Will be in deep space for a billion years or so if it doesn’t blow up on ascent.

— Elon Musk (@elonmusk) December 2, 2017

Musk has been known to indulge in goofy jokes on- and offline, but he has apparently confirmed to The Verge and other outlets that the plan is serious. We’ve reached out to both SpaceX and Tesla to see what they have to say.

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The plan isn’t quite as bizarre or self-indulgent as it sounds. The first launch of the Falcon Heavy will be a test flight, and SpaceX is notorious for offbeat payloads on its vessels’ maiden voyages. Moreover, Musk has reiterated multiple times – including in last night’s tweet – that there’s a pretty solid chance the Heavy will just explode somewhere along the way, in part because precise calibration of the engines is hard to do before the live fire.

It’s one of the very few times Musk has chosen to downplay expectations rather than being wildly overoptimistic about a project — and that includes the often-delayed timetable for the Heavy test launch itself. So, he might be even more pessimistic about the launch’s prospects than he’s letting on.

In other words: Musk isn’t talking about landing the car on Mars and sending it off to do (autonomous) doughnuts below Olympus Mons. There’s a good chance it’ll just wind up as orbital wreckage. (That might be why he’s probably talking about a 2011 first-gen roadster, not the 2020 model, which currently only exists as a prototype). And though Musk writes that the “destination is Mars orbit,” that probably doesn’t mean putting the car in orbit around Mars, which commenters on Twitter have already pointed out would require specialized equipment on the car itself. A successful launch would instead likely end with the payload meandering indefinitely somewhere in the vicinity of Mars’ path around the sun.

The symbolism on Earth is much more powerful, though, particularly for Musk’s personal image. It’s Musk at his joyful, nerdy, wildly ambitious best, a real-life Tony Stark playing with his mind-boggling toys with the unbridled enthusiasm of a 5-year-old. It also sums up just how much Musk has managed to accomplish in the past 15 years, and why he is now the most admired leader in technology.