But Kennedy wasn't always the firm supporter of space exploration he presented to the public. Less than a year later, he began publicly broaching the subject of canceling Apollo in favor of a joint lunar program with the Soviets.

On Sept. 12, 1962, President John Kennedy said that we as a nation choose to go to the moon not because it is easy but because it is hard. Advocates of an aggressive manned spaceflight program cling to that speech, calling it the inspiration and call to action we need today to take on big audacious goals in space.

Kennedy picked the moon as a goal in the quickly escalating space race somewhat reluctantly. After conceding that space was an important arena in the Cold War, he turned to NASA and asked what it could do. The moon, administrators said, and Kennedy added the end of the decade deadline. On May 25, 1961, he stood up before congress and said that the nation should commit itself to this goal, because none would be as important.

But he wasn't that big a fan of space science, or, once it really got rolling, Apollo. This came out in a heated conversation with NASA Administrator James Webb on Nov. 21, 1962. Webb tried to impress on the President the importance of gathering scientific data before going to the moon. NASA needed to know what challenges, technical and human, would exist on this mission. Radiation and micrometeorites were real concerns. The end of the decade coincided with a peak of solar activity, and no one knew how much that would affect astronauts on a trans-lunar journey. And then there was the finicky business of landing; NASA needed to know what surface they were dealing with before building a lunar lander.

To Webb's dismay, Kennedy wasn't interested. If these science experiments would help Apollo get to the moon by the end of the decade, fine, but nothing else mattered. Just get there, he said, because Apollo couldn't fall behind schedule. He wasn't going to spend billions of dollars on superfluous science when all he needed was one man to set foot on the moon.

Working out the details of a lunar mission wasn't easy, and solving problems as they arose was an expensive affair. Throughout 1963, costs associated with Apollo (and its predecessor Gemini) rose steadily. But Cold War tensions were easing up a just little bit. Less than a year after the Cuban Missile Crisis, the 13-day standoff in October 1962 between the Soviets and Americans during which the world waited for the Cold War to become a ‘Hot War,' a ban was placed on high altitude, space, and under water nuclear testing.

On Sept. 20, 1963, Kennedy addressed the 18th assembly of the United Nations on what he hoped this nuclear test ban might lead to: international cooperation. That the West believes in the individual's freedom to choose his own future, he said, is fundamentally opposed to the view of the Soviet Union. And so long as this difference exists there are limits to agreements between nations; America must remain in a state of constant vigilance in the interest of protecting freedom. But living on the brink of mutually assured destruction was no way to live.

He called for the beginning of cooperative agreements between the US and the Soviet Union based on the "mutual interest in avoiding mutual destruction." And building on this point he made a bold suggestion: he proposed canceling Apollo in favor of a joint lunar program with the Soviets. The quest to land a man on the moon shouldn't be a competition between nations but a joint program in the mutual interest of exploring space:

Finally, in a field where the United States and the Soviet Union have a special capacity–in the field of space–there is room for new cooperation, for further joint efforts in the regulation and exploration of space. I include among these possibilities a joint expedition to the moon. Space offers no problems of sovereignty; by resolution of this Assembly, the members of the United Nations have foresworn any claim to territorial rights in outer space or on celestial bodies, and declared that international law and the United Nations Charter will apply. Why, therefore, should man's first flight to the moon be a matter of national competition? Why should the United States and the Soviet Union, in preparing for such expeditions, become involved in immense duplications of research, construction, and expenditure? Surely we should explore whether the scientists and astronauts of our two countries–indeed of all the world–cannot work together in the conquest of space, sending someday in this decade to the moon not the representatives of a single nation, but the representatives of all of our countries.

He referred to this new approach as a competition in a peaceful arena, a competition in ideas and production with a benefit for all mankind. "I welcome such a contest. For we believe that truth is stronger than error–and that freedom is more enduring than coercion. And in the contest for a better life, all the world can be a winner."

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This wasn't the first time Kennedy had approached Soviet leaders with the idea of cooperation in space, but it was his most aggressive and outright call for such a program. There's some evidence - albeit scant evidence - that Soviet leader Nikita Khrushchev did at one point consider this proposal. The potential to exchange technology and save money on development of spaceflight systems were appealing prospects.

Kennedy was set to address the Texas Democratic State Committee in Austin the day he was shot. The prepared remarks, though undelivered, show no change from his tone at Rice the year before. "We have launched into earth orbit more than 4 times... We have focused our wide-ranging efforts around a landing on the moon in this decade... And we have made it clear to all that the United States of America has no intention of finishing second in outer space."

It's unclear what would have happened had Kennedy survived the assassination attempt on Nov. 22, 1963, but the fate of Apollo was likely sealed because of his death. His call to action was too powerful, and no one wanted to let the fallen President's dreams for his nation die with him.

Image: Kennedy makes his famous speech at Rice University. Credit: Archives.gov