The Falcon Heavy basically consists of a strengthened Falcon 9 core with two additional Falcon 9 boosters. Each Falcon 9 booster has nine Merlin engines, so for this 12-second test to be successful all 27 rocket engines had to ignite simultaneously. Falcon Heavy is the most powerful rocket since the Saturn V.
This will be a must-see event, the odds of something going wrong are high but if things go as planned the first Falcon Heavy launch will deliver a Tesla Roadster into a precessing Earth-Mars orbit around the Sun. Once the three boosters have done their job, they will perform a re-entry burn and will attempt to land on a ground-based or sea-based landing platform. Landing a single rocket is a feat that has been achieved by no one else than SpaceX, so doing the same trick with three rockets will be quite a sight to behold!
No launch date has been set yet, but Elon Musk promises it should happen in a week or so.
Falcon Heavy hold-down firing this morning was good. Generated quite a thunderhead of steam. Launching in a week or so. pic.twitter.com/npaqatbNir
— Elon Musk (@elonmusk) 24 januari 2018
My raw video of the #SpaceX Falcon Heavy static-fire at Kennedy Space Center. Come for the cloud plumes, stay for the sound.
— Robin Seemangal (@nova_road) 24 januari 2018
A French space reporter just yelled "It's like the 4th of July!" pic.twitter.com/vJssukqgIz