By giving the guns targeting data by shooting enough asteroids to recalibrate the system they are able to shoot automatically, and your work is done.
So while you are still shooting the asteroids it doesn't feel as tedious and actually feels like something an engineer might have to do in this situation. Instead, in the remake, it has been changed to redirecting certain sections of the ship's power to the ADS systems before going out into space and manually recalibrating the guns yourself. This entire section has been changed entirely from doing a turret section and protecting the ship by shooting asteroids before they can destroy the hull. One controversial section of the original Dead Space required Isaac to use the ship's ADS guns manually to protect the Ishimura from asteroids in Chapter Four in the form of a turret section.