Project Gemini.

Project Gemini:
On Jan. 3, 1962, NASA announced the advanced Mercury Mark II project had been named "Gemini." After 12 missions – 2 uncrewed and 10 crewed – Project Gemini ended Nov. 15, 1966, following a nearly four-day, 59 orbit-flight. Its achievements included long-duration spaceflight, rendezvous and docking of two spacecraft in Earth orbit, extravehicular activity, and precision-controlled re-entry and landing of the spacecraft.

Poster designed by Kennedy Space Center Graphics Department/Greg Lee. Credit: NASA