CAPE CANAVERAL, Fla. -- SpaceX's Falcon Heavy rocket blasted off Tuesday afternoon from the same Florida launch pad used by NASA nearly 50 years ago to send men to the moon.

With liftoff, Falcon Heavy became the most powerful rocket in use today.

Its three boosters and 27 engines roared to life at Kennedy Space Center -- just in the nick of time before the close of its 4 p.m. launch window.

Not only did the rocket lift SpaceX CEO Elon Musk's red Tesla Roadster into orbit -- with a dummy "Starman" at the wheel -- two of the three boosters came back and landed upright at Cape Canaveral.

The 15-story boosters landed at the same time, side by side.