Whats the "Jato Rockets"

I have seen many mods use this rockets called "Jatos"
I got kind of curious of where the jatos came from?
are they from a mod which anyone can use without permission?
or are they in a secret file hidden in the game itself?
if anyone knows, please answer

 

oh im such a idiot i forgot that the hero bus exists, lol

 

Here's why it's named "JATO": https://en.wikipedia.org/wiki/JATO

 

so , this is used to be made for aicraft only?

 

thanks