This choice was made for a few reasons:

* Symbolism: The constellation Gemini is represented by two stars, symbolizing the two-person crew that flew in each Gemini spacecraft.

* Continuity: The Gemini program followed the Mercury program, which was named after the planet Mercury. Both names were inspired by celestial bodies, continuing a trend of NASA programs being named after planets and constellations.

* Public Appeal: The name "Gemini" had a positive and memorable association with the constellation, which was well-known and easily understood by the public.

So, the name "Gemini" was a fitting and memorable choice that reflected the program's goals and the spacecraft's characteristics.