To have it work in MC 1.9:
Change 'Direction:[]' to 'Direction:[0.0,0.0,0.0]'
This is my first tutorial on a mechanism I discovered a while back; I call it the Fireball cascade. This mechanism can be exploited for many things such as:
-a guided rocket launcher weapon
-flying machines (pod racing!)
-pong/tennis/soccer games
-firebending
-3D-drawing
-trick-shots
I couldn't find any other videos on this mechanic and decided to post my own video explaining it. I hope you find it useful and I'm curious as to what other applications you can find for the fireball mechanic in Minecraft!
The "one" command block command can be found here:
http://pastebin.com/4SEhQ7rk
Thanks to LolKittyFufu, KateTheAwesome, Fregaropa & Mantisropa for testing it.