A close-up view of the unpiloted Japanese HTV-1, the first H-II Transfer Vehicle (HTV), in the grasp of the International Space Station's robotic Canadarm2. The crew of Expedition 20 used the station's robotic arm to grab the cargo craft and attach it to the Earth-facing port of the Harmony node.

Project Gemini was NASA's second human spaceflight program. It was a United States space program started in 1961 and concluded in 1966. Project Gemini was conducted between projects Mercury and Apollo. The Gemini spacecraft carried a two-astronaut crew. Ten crews flew low Earth orbit (LEO) missions between 1965 and 1966. It put the United States in the lead during the Cold War Space Race with the Soviet Union.

Its objective was to develop space travel techniques to support Apollo's mission to land astronauts on the Moon. Gemini achieved missions long enough for a trip to the Moon and back, perfected working outside the spacecraft with extra-vehicular activity (EVA), and pioneered the orbital maneuvers necessary to achieve space rendezvous and docking. With these new techniques proven in Gemini, Apollo could pursue its prime mission without doing these fundamental exploratory operations.

The astronaut corps that supported Project Gemini included the "Mercury Seven", "The New Nine", and the 1963 astronaut class. During the program, three astronauts died in air crashes during training, including the prime crew for Gemini 9. This mission was performed by the backup crew, the only time that had happened in NASA's history to that date.

Wernher von Braun (1912-1977) was a German rocket scientist and one of the most important rocket developers and champions of space exploration during the period between the 1930s and the 1970s. Von Braun is well known as the leader of what has been called the "rocket team" which developed the V-2 ballistic missile for the Nazis during World War II. As part of a military operation called Project Paperclip, he and his rocket team were scooped up from defeated Germany and sent to America where they were installed at Fort Bliss, Texas. For fifteen years after World War II, von Braun worked with the U.S. Army in the development of ballistic missiles. At Fort Bliss, they worked on rockets for the U.S. Army, launching them at White Sands Proving Ground, New Mexico. In 1950 von Braun's team moved to the Redstone Arsenal near Huntsville, Alabama, where they built the Army's Jupiter ballistic missile. In 1960, his rocket development center transferred from the Army to the newly established NASA and received a mandate to build the giant Saturn rockets. Accordingly, von Braun became director of NASA's Marshall Space Flight Center and the chief architect of the Saturn V launch vehicle, the superbooster that would propel Americans to the Moon.