Pre-Apollo Manned American Space Missions
"I believe that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the moon and returning him safely to the Earth. No single space project in this period will be more impressive to mankind, or more important for the long-range exploration of space; and none will be so difficult or expensive to accomplish. ... in a very real sense, it will not be one man going to the moon; if we make this judgment affirmatively, it will be an entire nation. For all of us must work to put him there."
— President John F. Kennedy, 1961
When, in his speech before a joint session of Congress on May 25, 1961, President John F. kennedy set the goal of landing a man on the moon within the decade, only one American had been in space and much remained to be done. NASA had not yet put a man in orbit around the Earth. That would happen during the successive one-man missions of Project Mercury. But the Apollo project required a number of more advanced achievements before a lunar landing was feasible: astronauts had to show they could survive in space long enough to journey to the moon and back, requiring test missions of one to two weeks; two spacecraft had to rendezvous in space; the feasibility of docking two ships had to be proven; and astronauts had to demonstrate the ability to work in the vacuum of space, as they would on the surface of the moon.
These goals required a new program to solve the key unknowns for the lunar program. The ten two-man flights of the Gemini program, which took place in 1965 and 1966, were NASA's training ground for the moon.
A Tall Order
There were many advancements to make. The engineers had to design a rocket with enough power to send the Apollo spacecraft to the moon. The details of the lunar flight plan had to be worked out. Software for computers aboard the Apollo spacecraft and in mission control had to be written. The lunar landing module had to be designed to land on the moon and take off again. And the techniques for making a controlled, high-speed reentry into the Earth's atmosphere had to be worked out; coming in at the wrong angle could mean burning up in the Earth's atmosphere, or skipping off the atmosphere and ending up being stranded in space. It was a tall order.
The Mercury missions showed that astronauts could live in space for up to a full day. And the Gemini missions built on this experience to make spectacular progress. One of the most important advances came in December 1965 when Frank Borman and Jim Lovell crewed Gemini 7 — "two weeks in the front seat of a Volkswagen," in Borman's words -- proving that humans could endure a flight the length of a round-trip to the moon. On that same mission, Wally Schirra and Tom Stafford caught up to Borman and Lovell in Gemini 6 and they flew in formation, the first rendezvous in space. The astronauts took the opportunity to exchange some light banter. Schirra commented, "There's a lot of traffic up here." Borman quickly returned, "Call a policeman."
Tumbling Through Space
On the next Gemini mission, Neil Armstrong and David Scott docked their craft with an unmanned Agena craft before a harrowing problem with the engine cut the mission short. Television newsman Walter Cronkite remembered the mission: "Gemini 8 began to tumble and they were working frantically in the spacecraft of course, but also on Earth to try to figure out how to stop the tumbling because otherwise you could not safely reenter. And it really looked like we were going to lose a couple of astronauts and have a tremendous setback to the program. We immediately seized the air, of course, and went on with the play-by-play of what was being done to try to save these men.
"And from all over America we got complaints through our switchboards at local stations that we were interrupting the program in process at the time for this coverage. And you know what the program was? It was a science fiction piece called 'Lost In Space.' And there were audiences out there that wanted the fiction -- ignoring the tragedy that was taking place, we felt, out there."
In the end, Armstrong and Scott heroically righted their craft and made a safe landing. Later Gemini flights repeated the docking and confirmed the viability of the procedure.
Working on the Moon
Gemini astronauts tackled the goal of working in the vacuum of space with a series of space walks. Ed White had been the first American to walk in space, during Gemini 4, but NASA had difficulty replicating the ease with which White -- acclaimed by his peers as an exceptionally strong and capable astronaut -- accomplished the task. Three subsequent astronauts had been left frustrated, exhausted and drenched in sweat trying to work in space. As explained by Alan Shephard and Deke Slayton, two of the Mercury astronauts who oversaw the astronaut corps, the essential problem was, "How can we send men to the moon, no matter how well they fly their ships, if they're pretty helpless when they get there? We've racked up rendezvous, docking, double-teaming the spacecraft, starting, stopping, and restarting engines; we've done all that. But these guys simply cannot work outside their ships without exhausting themselves and risking both their lives and their mission."
Floating and Working
Finally on Gemini 12, commanded by Lovell, Edwin "Buzz" Aldrin spent a total of five hours floating and working outside the spacecraft with no difficulties. Aldrin was equipped with some helpful tools, to ease his work in open space, including removable handholds and foot restraints that could be bolted to a workstation. Taking breaks between tasks, Aldrin completed all his work as scheduled without overexertion. He even had time to wipe Lovell's window. "Hey, would you change the oil, too?" his commander asked. Aldrin's spacewalking success crowned the final Gemini mission.
Borman recalled the Gemini program as it related to the Space Race against the Soviet Union: "My personal sense was that we caught them with Gemini. Nobody really to this day gives enough credit to the Gemini program. It proved every single thing we had to do in Apollo. You know, long duration, extravehicular activities, rendezvous, and a guided reentry. We all did that in Gemini, and it was a very important building block. So, I felt that we were at least neck and neck when we came out of Gemini."