..."An official NASA christening named the program Gemini, after the constellation that includes the twin stars Castor and Pollux. The name was first suggested by Alex Nagy of NASA Headquarters, and it caught on overnight"...
Astronaut - Gus Grissom
..."Alex Nagy thought that "the Twins", as Gemini, one of the 12 constellations of the zodiac was called, did a good job of symbolizing the two man crew, a rendezvous mission and it's relation to Mercury. By an unlikely coincidence, since Nagy disclaims any knowledge of astrology, Gemini as a sign of the Zodiac is controlled by Mercury. Its spheres of influence include adaptability and mobility - two features that spacecraft designers had explicity pursued - and, though its link with the third house of Zodiac, all means of communication and transportation as wel. Astrologically, at least, Gemini was a remarkably apt name, the more so since the United States is said to be very much under its influence"...
The Artwork
The insignia of the Gemini space program is a disc of dark blue as a background for a gold Zodiac Gemini symbol. A white star on each of the two vertical curves of the Gemini symbol represent the Gemini twins, Pollux and Castor.