The Hyperion was also the flag ship of the human contingent in the final mission of the Protoss campaign in the first part of Starcraft. Not to be too random or dorky.
Greek mythology: a Titan (the earlier Gods); was the son of Gaea and Uranus, and was the father of Helios.
Geek mythology: see Kuaru's post below.
and from Encyclopedia Mythica (great source for finding out a lot of game names):
Apollyon: "The destroyer". In the New Testament of the Bible, Apollyon is called the angel of the bottomless pit. Abaddon, a poetic name for the land of the dead in the old testament, is Apollyon's Greek translation from the Hebrew language. Apollyon, in early Christian literature, is a name for the devil. He is identified as an angel of death, "hideous to behold, with scales like a fish, wings like a dragon, bear's feet, and a lion's mouth."
Close. Helios was the sun god. If you know a little astronomy, you might have heard of the heliocentric model, aka sun-centered. Hyperion was one of the Titans, who was the father of Helios.