In the airfreight business, there is “specialty cargo,” and then there is “Elon Musk cargo” – a separate category all by itself.

In an audacious launch on Tuesday that was half technology showcase, half marketing stunt, the aerospace entrepreneur’s SpaceX company sent its unmanned “Falcon Heavy” lift vehicle – the most powerful rocket currently in existence – on its maiden voyage, carrying its payload into elliptical orbit around the sun, but also well beyond its target apogee that was supposed to reach the orbit of Mars.

The triple-booster vehicle – essentially three standard SpaceX Falcon 9 vehicles strapped together – lifted off yesterday at 3:45 p.m. ET from Launch Complex 39A at Kennedy Space Center in Florida, the same spot from which many of the NASA Space Shuttle and Apollo Moon missions were launched. While the technical feat was spectacular, the “payload” itself grabbed most of the headlines: Musk’s own cherry-red Tesla Roadster convertible automobile, with a mannequin in a spacesuit sitting in the driver’s seat. The fake spaceman was nicknamed “Starman,” after a David Bowie song of the same name.

A few minutes into the flight, the two side booster rockets were jettisoned as planned, while the central Falcon 9 vehicle continued on. But unlike the boosters of the Shuttle program, which drifted via parachute to a splashdown in the Atlantic, the spent Falcon 9 boosters fired a series of retro-rockets to turn themselves around and fly back to a powered landing at Cape Canaveral. In a scene reminiscent of a classic sci-fi movie, the two boosters, riding columns of rocket exhaust, touched down almost simultaneously in an upright position, precisely in the center of their landing pads. See a video of the epic flight sequence here, courtesy of SpaceX:

While the initial launch sequence was nearly flawless, there were some significant problems that may lead customers to question the reliability of the Falcon vehicle. First, some of the central first-stage booster’s rockets failed to ignite during its powered descent, causing the booster to miss its floating landing pad in the ocean and hit the water at about 480 kilometers per hour, destroying the vehicle.

Of much greater concern was the path of the upper stage and the Tesla car. According to a statement from SpaceX, the rocket in the upper stage of the Falcon 9 proved more powerful than expected, as a third burn of the engine sent the test payload far off-course. The elliptical orbit of the spacecraft will now carry it many millions of kilometers beyond Mars’ orbit and into the Asteroid Belt between Mars and Jupiter at its apogee before it loops back around the sun.

Here’s a live feed from SpaceX, showing the Starman in his Tesla, on his way – by accident – to the Asteroid Belt:

Tuesday’s launch was mostly a demonstration project, made obvious by the tongue-in-cheek nature of its bizarre payload. However, had this been a commercial mission, carrying a satellite or supplies to a space station, the huge miscalculation of the final orbit insertion would have been catastrophic, in a logistical sense. Clearly, some adjustments need to be made before Falcon Heavy can join the ranks of dependable space cargo workhorses, such as the Atlas, Titan, Delta, Soyuz and Space Shuttle vehicles.

After several test launches using Falcon 1 rockets, SpaceX has attempted to land boosters from 26 of the newer Falcon 9 rockets, 22 of which were considered successful. The Falcon series has been delivering both satellites and cargo to the International Space Station since 2010. Also, six of the recovered Falcon 9 boosters have been reused in subsequent missions, thus reducing the costs of each mission.

Last year, Musk said SpaceX no longer had plans to send humans to space via the Falcon Heavy configuration and intended it only to be a cargo vehicle for payloads of between 26,700 and 63,800 kilograms.