Project Gemini:

The second U.S. manned space program was announced in January 1962. Its two-man crew gave it its name, Gemini, for the third constellation of the Zodiac and its twin stars, Castor and Pollux. Gemini involved 12 flights, including two unmanned flight tests of the equipment.

Like Mercury's, its major objectives were clear-cut:

• To subject man and equipment to space flight up to two weeks in duration;
• To rendezvous and dock with orbiting vehicles and to maneuver the docked combination by using the target vehicle's propulsion system;
• To perfect methods of entering the atmosphere and landing at a preselected point on land. Its goals were also met, with the exception of a land landing, which was cancelled in 1964.

The National Aeronautics and Space Administration announced December 7, 1961, a plan to extend the existing manned space flight program by development of a two-man spacecraft. The program was officially designated Gemini on January 3, 1962. It was named after the third constellation of the zodiac, featuring the twin stars Castor and Pollux. The program was operationally completed with the Gemini XII flight.

Excerpt from the Encyclopedia Britannica without permission.