Complex sentence: Fortunately, Mentor of Arisia assured Kit Kinnison that "operators would come into effect to prevent such an occurrence" and that untoward events would be limited to a radius of ten or fifteen parsecs.
Split into simpler sentences: Fortunately, Mentor of Arisia assured Kit Kinnison that "operators would come into effect to prevent such an occurrence". A and that untoward events would be limited to a radius of ten or fifteen parsecs.