Something can't be "don't working", but can "don't work".
SRB's have little no throttle control, by the way, unless you mean thrust vectoring.
It's called shortening a sentence so you don't have to write the whole thing.
bad grammar... something can't be "dont working".. Also has no control. I would recommend having a game improving simulation before posting it. I could find at least 50 other simulations exactly like this. Make something unique and different from the rest.