The NASA Exceptional Scientific Achievement Medal (abbrv. ESAM) was established by NASA on September 15, 1961, when the original ESM was divided into three separate awards. Under its guidelines, the ESAM is awarded for unusually significant scientific contribution toward achievement of aeronautical or space exploration goals. This award may be given for individual efforts that have resulted in a contribution of fundamental importance in this field, or have significantly enhanced understanding of this field. Source: Wikipedia (en)