Apollo - From the Earth to the Moon
During Eisenhower’s second term, outer space had become an arena for U.S.-Soviet competition. In 1957, the Soviet Union launched Sputnik — an artificial satellite — thereby demonstrating it could build more powerful rockets than the United States. The United States launched its first satellite, Explorer I, in 1958. But three months after Kennedy became president, the USSR put the first man in orbit. Kennedy responded by committing the United States to land a man on the moon and bring him back “before this decade is out.” With Project Mercury in 1962, John Glenn became the first U.S. astronaut to orbit the Earth.
"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." That proclamation by President John F. Kennedy before a joint session of Congress on May 25, 1961, set the stage for an astounding time in our nation's emerging space program. The goal -- fueled by competition with the Soviet Union dubbed the "space race" -- took what was to become Kennedy Space Center from a testing ground for new rockets to a center successful at launching humans to the moon.
Direct ascent was basically the method that had been described in science fiction novels and shown in Hollywood movies. A massive rocket, roughly the size of a battleship, would be fired directly to the Moon, land, and then blast off for home directly from the lunar surface. The trip would be like that of a chartered bus, moving from point A to point B and back to A again in one huge booster vehicle, the proposed twelve-million-pound-thrust Nova rocket.
Earth-Orbit Rendezvous involved launching two pieces of hardware into space independently using advanced Saturn rockets that were then under development. The two pieces would rendezvous and dock in the Earth’s orbit. The modules that had joined up during the rendezvous would allow for the assembly, fueling, and detachment of a lunar mission vehicle. That augmented ship would then proceed directly to the surface of the Moon and, after exploration, return to the Earth. The immediate advantage of Earth-orbit rendezvous was that it required a pair of less powerful rockets that were already nearing the end of their development—in other words, twice as many of his early Saturns. The whole reason for doing it via EOR would be because the boosters were still too small. The biggest pitfall, as with direct ascent, was that there was not yet any clear concept of how the spacecraft would actually make its landing.
When NASA engineers first suggested the concept of lunar-orbit rendezvous, it had been rejected out of hand for being too complicated and risky. Rendezvous appeared dangerous and impractical to some NASA engineers, but to others it was the obvious way to eliminate the need for gigantic Nova-size boosters. Foremost among the variants in this approach was direct flight's chief competitor, earth-orbit rendezvous (EOR). The von Braun group had revealed an interest in this mode when it briefed Glennan in December 1958 - long before its transfer from the Army to NASA. Von Braun had made a strong pitch for using EOR and the Juno V later Saturn booster, painting a pessimistic picture of developing anything large enough for direct ascent. Agreeing that direct flight was basically uncomplicated, von Braun nevertheless said he favored earth-orbit rendezvous because smaller vehicles could be employed.
If rendezvous had to be part of Project Apollo, critics of LOR felt that it should be done only in Earth orbit. if that rendezvous failed, the threatened astronauts could be brought back home simply by allowing the orbit of their spacecraft to deteriorate. But, if a rendezvous around the moon failed, the astronauts would be too far away to be saved. Nothing could be done.
In retrospect, LOR enjoyed several advantages over the other two options. It required less fuel, only half the payload, and less brand new technology than the other methods; it did not require the monstrous Nova rocket; and it called for only one launch from Earth whereas EOR required two. Only the small, lightweight lunar module, not the entire spacecraft, would have to land on the moon. This was perhaps LOR's major advantage. Because the lander was to be discarded after use and would not need return to Earth, NASA could tailor the design of the LEM for maneuvering flight in the lunar environment and for a soft lunar landing. In fact, the beauty of LOR was that it meant that NASA could tailor all of the modules of the Apollo spacecraft independently.
But in 1962 all these advantages were theoretical. On the other hand, the fear that American astronauts might be left in an orbiting coffin was quite real. It was a specter that haunted the dreams of those responsible for the Apollo program and one that made objective evaluation of the lunar-orbit rendezvous concept by NASA unusually difficult. But it became clear that lunar orbit rendezvous offered a chain reaction simplification on all ‘back effects': development, testing, manufacturing, erection, countdown, flight operations, etc.
Following the first space rendezvous in 1965, NASA refined its capabilities in later Gemini missions, achieving the first docking of two spacecraft. From there, Apollo missions honed NASA’s Earth orbit rendezvous skills. Apollo 10 saw the first lunar orbit rendezvous.
After Kennedy’s death, President Lyndon Johnson enthusiastically supported the space program. In the mid-1960s, U.S. scientists developed the two-person Gemini spacecraft. Gemini achieved several firsts, including an eight-day mission in August 1965 — the longest space flight at that time — and in November 1966, the first automatically controlled reentry into the Earth’s atmosphere. Gemini also accomplished the first manned linkup of two spacecraft in flight as well as the first U.S. walks in space.
The Apollo 8 astronauts flew the first lunar orbital mission after launching from Launch Pad 39A aboard a Saturn V on Dec. 21, 1968. During that historic mission, Americans sat spellbound on Christmas Eve watching a live broadcast by the astronauts orbiting the moon, as they presented amazing, never-before-seen images like "Earthrise" over the lunar surface. On 20 July 1969, an estimated 530 million people watched the televised image and heard Armstrong's words as he became the first human to set foot on the moon, fulfilling President Kennedy's challenge.
The three-person Apollo spacecraft achieved Kennedy’s goal and demonstrated to the world that the United States had surpassed Soviet capabilities in space. On July 20, 1969, with hundreds of millions of television viewers watching around the world, Neil Armstrong became the first human to walk on the surface of the moon. Neil Armstrong's "one small step" on the lunar surface in 1969 achieved a goal that sounded like science fiction just a few years earlier.
Other Apollo flights followed, but many Americans began to question the value of manned space flight. In the early 1970s, as other priorities became more pressing, the United States scaled down the space program. Some Apollo missions were scrapped; only one of two proposed Skylab space stations was built.
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