How can I create a jetpack?

I want to create a jetpack. My jetpack model is done and I have it as a tool but I dont know how to function it via script (a tool). I know how to detect a key clicker. I want to detect when a player presses a spacebar, for example, I know how to do that and I can do it, I can print it to check if it works. But, its a jetpack so I dont know how to make it fly. Do I use BodyForce on the Y Axis to make it go up when I press spacebar? If so how can I add that into my detection script?