Comment by ndileas

It's possible...but the point of this instrument is to measure star locations very precisely. It probably has a star tracker for positioning doing what you're suggesting. If you were to use that type of positioning info you could introduce inaccuracies into the measured data eventually.

Also, every mission comes to an end eventually - better to do it in the right way and have the right amount of propellent saved for either a graveyard orbit or de-orbiting. It met the mission timeline and goals.