Just weeks after Mercury astronaut Alan Shepard became the first American astronaut, President John F. Kennedy announced the goal of sending astronauts to the Moon before the end of the decade. Building on the Mercury successes, NASA soon expanded its manned space flight program to include the development of a two-man spacecraft dubbed Gemini. It would serve as the essential bridge between the first tentative steps of Mercury and the history-making lunar landings of Apollo.

The Gemini project pushed the boundaries of manned space flight ever further. The mission objective was to “…develop further operational capability in space and to investigate the problems of working and living in space.”

Astronaut Ed White's spacewalk featured in the 1965 NASA film "Four Days of Gemini 4."; DNI; NASA; Highlights from the 1965 NASA film "Four Days of Gemini 4" featuring the return and recovery of the capsule and the implications of this historic mission.; DNI; NASA; NASA archive footage of the preparations and launch of Gemini 4, including rarely seen color sequences of Ed White's spacewalk training.; DNI; NASA; NASA film archive footage of Ed White's Gemini 4 spacewalk, with rarely seen capsule interior shots.; DNI; NASA; Highlights from the 1966 NASA film "Proud Conquest" featuring the overview and launch coverage of the joint Gemini 6 and Gemini 7 mission.; DNI; NASA; Highlights from the 1966 NASA film "Proud Conquest" featuring the historic orbital rendezvous and station keeping carried out by the two Gemini capsules.; DNI; NASA; NASA film archive footage from on-board cameras during the Gemini 6 and Gemini 7 orbital rendezvous.; DNI; NASA; NASA film archive footage from on-board cameras during Gemini 8's docking and emergency undock with the Agena Target Vehicle.; DNI; NASA; NASA film archive footage of Gemini 9's failed attempt to dock with the new ADTA target vehicle after it's shroud failed to separate.; DNI; NASA; The Gemini missions were the bridge between Mercury’s first steps and the ambitions of the Apollo program. Watch archive footage including Ed White's incredible Gemini 4 spacewalk.

Similar in design to the Mercury capsule but much larger, the new Gemini spacecraft was designed to carry two astronauts into the Earth's orbit to test long duration flight, rendezvous and dock with another craft, both vital elements of a future mission to the moon. The ten Gemini flights between March 1965 and November 1966 saw the first rendezvous in orbit of one spacecraft with another, the docking of two spacecraft together and the first space walk.

Astronaut Ed White became the first American to perform 'extravehicular activity' when he climbed out of the spacecraft for a short period of time for a spacewalk. Buzz Aldrin trumped White's original Gemini space walk duration of 22 minutes, by spending five hours and 30 minutes walking in space during the final Gemini mission.

Project Gemini sought to extend the duration of manned space flight up to two weeks, developing a spacecraft that could comfortably and effectively carry astronauts for lengthy journeys. It aimed to develop the technology to allow astronauts to interact with other spacecraft, but most importantly it acted as the link between Project Mercury and a manned mission to the moon.