To do this thing is all what i need now

should i take the string off, so i can just jump without come back?

bungee jumping is an activity that involves jumping from a tall structure while connected to a large elastic cord. The tall structure is usually a fixed object, such as a building, bridge or crane; but it is also possible to jump from a movable object, such as a hot-air-balloon or helicopter, that has the ability to hover above the ground. The thrill comes as much from the free-falling as from the rebounds.