This difference was catastrophic, introducing severe spherical aberration, a flaw in which light reflecting off the edge of a mirror focuses on a different point from the light reflecting off its center.The effect of the mirror flaw on scientific observations depended on the particular observation--the core of the aberrated PSF was sharp enough to permit high-resolution observations of bright objects, and spectroscopy was largely unaffected.. 
Over 9,000 Papers based on Hubble Data have been published in peer-reviewed journals, and Countless more have appeared in Conference Proceedings.. 