Olympian deity, god of music, poetry, medicine, etc., later identified with Helios, the sun god; the name is a Latin form of Greek Apollon, which is of uncertain origin. Beekes, after considering the alternatives, concludes, "In spite of repeated attempts, there is no IE etymology. ... The name is probably Pre-Greek, and Hitt. Appaliunaš, mentioned in a treaty between Alaksandus of Wilusa and the Hittite king, may well be the Pre-Greek proto-form Apal'un." The U.S. space program ran from 1961 to 1972.