On May 21, 1965, NASA released the Gemini 4 press kit. It opened with the standard mission description, in this case for a four-day orbital flight that would send commander Jim McDivitt and pilot Ed White around the Earth 62 times to evaluate "the effects of extended spaceflight on crew performance and physical condition."

Then there was an intriguing page that hinted at something bigger: "No decision has been made whether in the Gemini 4 mission the crew will engage in extravehicular activity... A decision to undertake the extravehicular test can be made as late as the day before the launch." The possibility of an EVA on Gemini 4 came as a surprise not only the American people that day, but to many within NASA as well.

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EVAs, colloquially known as spacewalks, were one of the three main program goals for NASA's Gemini program designed to support the Apollo program. If NASA was going to send men all the way to the moon, there was no point in having them sit inside and look out the window. They were going outside.

The original Gemini program plan called for a tight schedule with launches every eight to ten weeks. Every mission would add something new to NASA's repertoire with EVAs expected sometime after Gemini 6; Gemini 4 was designed for a week long endurance test using new fuel cells instead of batteries around June of 1965.

But mid-way through 1964 that schedule was starting to slip. The fuel cells weren't going to be ready for Gemini 4. The US Air Force Agena target vehicle destined for orbital rendezvous practice was also too far from flight ready to be counted on for Gemini 4.

With the mission plan in tatters, Robert Gilruth, the director of the Manned Spaceflight Center, proposed that Gemini 4 be reconfigured into the first EVA flight. It was a bold plan, moving the EVA goal forward by two flights. But if all the hardware could be certified and the crew trained in time, why not?

The new mission was already percolating when White and McDivitt were announced as the crew on July 24, 1964. The astronauts were two among the very select group of people who knew about the EVA goal for their flight. As pilot, White would be the one stepping out.

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