He is Father Vincent R. Capodanno, and he was awarded the Medal of Honor posthumously for, as the saying goes, "rushing to the sound of the guns" and then disregarding Communist mortar and machine gun fire to minister to his wounded and dying Marines. Already wounded and having lost part of his right hand, Father Capodanno rushed to a wounded Marine only 15 yards in front of a machine gun and was hit with 27 rounds.
You should see the tributes to Father from his surviving Marines (click on this post's title).
Father Daniel Mode's fine book, The Grunt Padre, is about Father Capodanno.
Another Vietnam War chaplain, Father Charles Litecky, also was awarded the Medal of Honor. Sadly, he later left the priesthood, "surrendered" his MOH and became a leftist activist. Still, we honor his battlefield valor and we can keep him in our prayers.