The first hydrogen fuel cell patents appeared in the patent office during 1890's, and every decade up until the oil crisis of the 1970's, which birthed some hydrogen conversion power system patents as well. This book is focused on Hydrogen technology that can be applied to home, automobile and aerospace engines. It s fully endorsed to have hydrogen power as either a primary or secondary power system for an aerospace craft, as NASA does. I have released the various hydrogen conversion patents that have gone public domain here.