Space Exploration

Pre-Apollo programs

Mercury

The initial U.S. effort to launch a human into space was known as Project Mercury. It was carried out by NASA, which had been given that responsibility over air force objections. NASA engineers, led by Robert Gilruth and Maxime Faget, designed a small cone-shaped capsule for the mission. Compared with the nearly five-metric-ton Vostok, it weighed 1.94 metric tons. Unlike the Soviet approach, in which a cosmonaut was orbited on the first human spaceflight, NASA planned several suborbital test flights in which an astronaut would be in space for only a few minutes of his 15-minute up-and-down ride. Only after the Mercury equipment was checked and the effects of suborbital flight on the human body were measured would the United States commit to an orbital flight attempt. The Mercury capsule would parachute with its passenger all the way back to Earth's surface, to land in the ocean and be recovered by navy ships. Also in contrast to Vostok, the Mercury capsule was designed to allow the astronaut to control some aspects of its flight while in space.

The United States used chimpanzees, rather than dogs, as test subjects prior to human flights. In what was intended to be the final test flight before a human launch, the chimpanzee Ham rode a suborbital trajectory on January 31, 1961, using a Redstone rocket developed by Braun's team. Because the flight had experienced minor problems, Braun insisted on one more test flight with an unoccupied dummy spacecraft. If instead, as originally scheduled, that March 1961 flight had carried an astronaut, the United States would have been first with a human in space, although not in orbit. Alan B. Shepard, Jr., made the first manned Mercury flight atop a Redstone rocket on May 5, 1961. A second suborbital Mercury mission, carrying Virgil I. Grissom, followed in July.

John H. Glenn, Jr., became the first American astronaut to orbit Earth in his three-orbit mission on February 20, 1962. His Mercury spacecraft was launched by a modified air force Atlas ICBM. Three more one-man Mercury orbital flights, carrying astronauts M. Scott Carpenter, Walter M. Schirra, Jr., and L. Gordon Cooper, Jr., were conducted, the last being a 22-orbit mission in May 1963.
 
Gemini and Voskhod

In 1961 President Kennedy announced that the United States would send people to the Moon "before this decade is out." In order to test many of the techniques that would be needed to carry out a lunar mission, particularly rendezvousing and docking two objects in space, the United States in late 1961 decided to develop a two-person spacecraft called Gemini. The Gemini spacecraft was much more complex than the rudimentary Mercury capsule and, at 3.81 metric tons, was twice as heavy. Another converted air force ICBM, a Titan II, was used to launch the Gemini spacecraft.

The first manned Gemini mission lifted into space in March 1965; nine more missions followed, the last in November 1966. On the second mission in June 1965, Edward H. White II became the first American astronaut to operate outside a spacecraft. His 20-minute space walk—also known as extravehicular activity (EVA)—was without incident. Although problems developed on many of the Gemini flights, the program demonstrated that people could live and work in space for as long as 14 days, more than the time needed for a round trip to the Moon. It also showed that astronauts could carry out rendezvous in space and could make useful observations of Earth, both visually and photographically.

As plans in the United States for multiple-astronaut missions became known, the Soviet Union worked to maintain its lead in the space race by modifying the Vostok spacecraft so that it could carry as many as three persons. Korolyov could accomplish this only by having the crew fly without wearing spacesuits. The redesigned spacecraft was known as Voskhod. There were two Voskhod missions, one with three people aboard in October 1964 and another with a two-man crew in March 1965. On the second mission, cosmonaut Aleksey Leonov became the first human to leave an orbiting spacecraft, less than three months before White. His 12-minute EVA was full of problems, and his reentry of the Voskhod spacecraft was particularly difficult.

Soyuz

Korolyov and his associates began work in 1962 on a second-generation spacecraft, to be called Soyuz. It was to be a much more complex vehicle than Vostok, holding as many as three people in an orbital crew compartment, with a separate module for crew reentry and a third section containing spacecraft equipment and rocket engines for in-orbit and reentry maneuvers. Soyuz was to be capable not only of flights in Earth orbit but also, in modified versions, of flights around the Moon and even a lunar landing.

The first launch of Soyuz, with a single cosmonaut, Vladimir Komarov, aboard, took place on April 23, 1967. Once the spacecraft reached orbit, it suffered a number of problems, which prompted ground controllers to bring Komarov back to Earth as soon as possible. After reentry, however, the spacecraft's main parachute did not fully deploy, and the Soyuz hit the ground at high speed. Komarov became the first person to perish during a spaceflight, and the accident dealt a major blow to Soviet hopes of orbiting or landing on the Moon before the United States.

After the problems with the Soyuz design were diagnosed and remedied, various models of the spacecraft served as the means of access to space for the Soviet, and then Russian, program of human spaceflight for more than 30 years. At the start of the 21st century, a version of Soyuz was used as the crew rescue vehicle—the lifeboat—for the early phase of construction and occupancy of the International Space Station.

The American commitment

In the immediate aftermath of Gagarin's orbital flight, President Kennedy was advised by his vice president, Lyndon B. Johnson, of Braun's belief that the Soviet Union, using Korolyov's existing R-7 launcher, could well succeed in sending a multiperson spacecraft into Earth orbit and perhaps even around the Moon before the United States. The first competition that the United States had a good chance of winning would be that of a manned lunar landing, because it would require each country to develop a new, more powerful rocket. On those technical grounds and because a lunar landing would be a very visible demonstration of American strength, Kennedy announced on May 25, 1961, that the United States would commit itself to a lunar landing before 1970. At that time, only one American human spaceflight, Shepard's 15-minute suborbital journey, had been made.

In response to Kennedy's decision, the United States carried out a warlike, but peaceful, mobilization of financial and human resources. NASA's budget was increased almost 500 percent in three years, and at its peak the lunar landing program involved more than 34,000 NASA employees and 375,000 employees of industrial and university contractors.

By the end of 1962, the basic elements of what was called Project Apollo were in place. The launch vehicle would be a powerful Saturn V rocket, 110.6 metres (363 feet) tall and power-driven by five huge engines generating a total of 33,000 kilonewtons (7.5 million pounds) of lifting power at takeoff—100 times the takeoff thrust of the Redstone rocket that had launched Shepard. After an intense debate, NASA chose a spacecraft configuration for Apollo that could be sent up in one launch, rather than a larger spacecraft that would need to be assembled in a series of rendezvous in Earth orbit. The Apollo spacecraft would have three sections. A Command Module would house the three-person crew on liftoff and landing and during the trip to and from the Moon. A Service Module would carry various equipment and the rocket engine needed to guide the spacecraft into lunar orbit and then send it back to Earth. A Lunar Module, comprising a descent stage and an ascent stage, would carry two people from lunar orbit to the Moon's surface and back to the Command Module. The ability of the Lunar Module's ascent stage to rendezvous and dock in lunar orbit with the Command Module after takeoff from the Moon was critical to the success of the mission. NASA also created a large new launch facility on Merritt Island, near Cape Canaveral, Florida, as the Apollo spaceport.

The Soviet response

While committing the United States to winning the Moon race, President Kennedy also made several attempts in the early 1960s to convince the Soviet leadership that a cooperative lunar landing program between their two countries would be a better alternative. No positive reply from the Soviet Union was forthcoming, however. In fact, between 1961 and 1963, there was still vigorous debate within the Soviet Union over the wisdom of undertaking a lunar program, and no final decision had been made on the question.

Meanwhile, the separate design bureaus headed by Korolyov and his rival Vladimir Chelomey competed fiercely for a lunar mission assignment, either a flight around the Moon or an actual landing. Finally, in August 1964, Korolyov received the lunar landing assignment, and soon afterward Chelomey was given responsibility for planning a circumlunar flight to be carried out before the 50th anniversary of the Bolshevik Revolution, which would take place in October 1967. In 1965 Soviet leaders decided to combine the efforts of the two rivals for the circumlunar mission, using a version of Korolyov's Soyuz spacecraft and a new rocket, the UR-500 (also called the Proton), designed by Chelomey.

The rocket that Korolyov designed for the lunar landing effort was called the N1. Like the Saturn V, it was huge, standing 112.8 metres (370 feet) tall and having a planned takeoff thrust of 44,500 kilonewtons (10 million pounds). Instead of a few large rocket engines in its first stage, however, the N1 had 30 smaller engines. These were developed by Nikolay Kuznetsov, an aircraft-engine chief designer who had little experience with rocket engines, rather than the more capable Glushko. Korolyov and Glushko, already personal adversaries for many years, had disagreed on the proper fuel for the N1, and they finally decided that they could no longer work together. Consequently, Korolyov turned to Kuznetsov, who chose the small-engine approach.

Indecision, inefficiencies, inadequate budgets, and personal and organizational rivalries in the Soviet system thus posed major obstacles to success in the race to the Moon. To these was added the unexpected death of Korolyov, age 59, during surgery on January 14, 1966. This was a serious setback to the Soviet space program. Korolyov had been a charismatic leader and organizer. His successor, Vasily Mishin, attempted to maintain the program's momentum, but he was not the effective manager or politically sophisticated operator that Korolyov had been.
 
Interim developments

In the United States, Apollo moved forward as a high-priority program. A major setback occurred on January 27, 1967, when astronauts Grissom, White, and Roger Chaffee were killed after their Apollo 1 Command Module caught fire during a ground test. The first manned Apollo mission, designated Apollo 7 and intended to test the redesigned Command Module, was launched into Earth orbit on October 11, 1968. The launcher used was a Saturn IB, a less-powerful rocket than the Saturn V needed to reach the Moon. The mission's success cleared the way for a bold step—the first launch of a crew atop a Saturn V to the lunar vicinity. On December 21, 1968, the Apollo 8 Command and Service modules were put on a trajectory that sent them into orbit around the Moon on Christmas Eve, December 24. The three astronauts—Frank Borman, James A. Lovell, Jr., and William A. Anders—sent back close-up images of the lunar surface, read from the biblical book of Genesis, and brought back vivid colour photographs of a blue planet Earth rising over the desolate lunar landscape. By the end of the mission, it was clear that the first lunar landing was only months away.

One reason for conducting the Apollo 8 mission was to allow NASA to test most of the systems needed for a lunar landing attempt while waiting to carry out a manned trial in Earth orbit of the Lunar Module, whose development was behind schedule. Another was the concern that the Soviet Union would beat the United States in sending people to the lunar vicinity. A circumlunar mission indeed had been part of Soviet plans, but the Soyuz 1 accident had made the October 1967 deadline infeasible. During 1968 a number of test flights of a circumlunar mission were made, using the Proton launcher and a version of the Soyuz spacecraft designated Zond. In September Zond 5 carried a biological payload, including two tortoises, around the Moon and safely back to Earth, but two months later the Zond 6 spacecraft depressurized and then crashed on landing, ending any hope for a quick follow-on launch with a human crew. Plans to send cosmonauts around the Moon in a Zond spacecraft were postponed indefinitely in March 1969, but two more scientifically successful unmanned circumlunar missions, Zond 7 and Zond 8, were carried out in 1969 and 1970, respectively.

The Soviet lunar landing program went forward rather fitfully after 1964. The missions were intended to employ the N1 launch vehicle and another variation of the Soyuz spacecraft, designated L3, that included a lunar landing module designed for one cosmonaut. Although an L3 spacecraft was constructed and three cosmonauts trained for its use, the N1 rocket was never successfully launched. After four failed attempts between 1969 and 1972—including a spectacular launch-pad explosion in July 1969—the N1 program was finally canceled in May 1974, and Soviet hopes for human missions to the Moon thus ended.