Vintage Space. Gemini, NASA's Overlooked Middle Child.

Before NASA could land on the Moon it had to learn how to fly in space, and that became the goal of the Gemini program.
The Gemini program is the program that taught NASA how to live and work in space. It saw the first spacewalk and the first rendezvous and docking, and also put all these new abilities together by the end of the program. In 20 months, NASA went from orbital flights to having the skill set to land men on the Moon.
The program has been chronicled in a new book showcasing rare images from the program.
Credit: Amy Shira Teitel