SpaceX's maiden launch of Falcon Heavy remains go for tomorrow afternoon

Tomorrow afternoon at 1:30pm EST, SpaceX plans to launch their long-awaited Falcon Heavy rocket from Historic Launch Complex 39A (LC-39A). The 3-hour launch window extends from 1:30pm-4:30pm EST with a backup window on Wednesday. 
At liftoff, Falcon Heavy will become the most powerful operational rocket in the world by a factor of 2, being able to lift twice the payload than the Delta IV Heavy. Only the Saturn V rocket, the one that brought astronauts to the Moon, delivered more payload into orbit around the Earth. 
The Falcon Heavy is comprised of 3 Falcon 9 cores strapped together. It isn't as simple as that - the core stage had to be redesigned to withstand the extreme forces being put onto it during flight from the side cores. The side cores have the new titanium grid fins which help the boosters steer down to the landing site at Cape Canaveral. The three cores total 27 Merlin engines and produce approximately 5 Million pounds of thrust at liftoff.

The side cores on Falcon Heavy are both flight-proven boosters previously supporting the CRS-9 and Thaicom 8 missions. The 2 boosters will be attempting a landing at the 2 landing zones (LZ-1 & LZ-2) at Cape Canaveral about 8 minutes after liftoff. The core booster will attempt a landing at sea on the droneship "Of Course I Still Love You".

Falcon Heavy will launch Elon Musk's Tesla Roadster as a mass simulator. The destination of the Tesla is an Earth-Mars elliptical orbit around the Sun. It will be playing David Bowie's "Space Oddity" as it travels endlessly through space. SpaceX didn't want to just launch something boring such as water ballasts or steel, so they decided to launch something exciting that would grab people's attention.