Mercury Program

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Mercury Program

In ancient Rome, Mercury was the mythical messenger of the gods. His winged helmet and sandals represented his ability to run extremely fast. Ancient astronomers immortalized him by giving the name Mercury to the planet that circled the Sun in the shortest amount of time. In 1958 speed was very much on the minds of the managers of the National Aeronautics and Space Administration (NASA). Speed was critical to meeting the goal of the Mercury program: to launch an astronaut into orbit and safely return him to Earth.^* To achieve that goal NASA would have to accelerate a vehicle containing an astronaut, life support equipment, and other systems to more than 29,000 kilometers (18,000 miles) per hour. Speed was also critical in another sense. NASA was expected to achieve the goal of piloted orbital flight before the Soviet Union did so to help the United States gain the lead in the space race. The Soviets had unexpectedly seized the lead by launching the first artificial satellite—Sputnik—in 1957.

Success and safety were at least as important as speed. To avoid failure because of mechanical problems, NASA carried out an extensive system design and test program. To avoid failure due to human problems, NASA conducted an extensive astronaut selection and training program. As the program began, scientists knew little about how the human mind and body would react to the stress of spaceflight and the environment of space. Would an astronaut's heart stop beating from weightlessness? How would the human body be affected by the radiation in space, which was unfiltered by Earth's atmosphere? Could astronauts become so disoriented that they would be unable to accomplish their tasks while weightless?

There was so much doubt concerning humans' abilities under the conditions the astronauts would encounter that initial proposals called for astronauts to be merely passengers, the subjects of experiments rather than contributors to flight operations. Such astronauts would not have to be qualified pilots. This approach, which was dubbed "Man in a Can," was ultimately replaced by one that gave astronauts a role in flight operations, an approach that led to the decision to use highly skilled military test pilots as astronauts.

Selecting the First Astronauts

A system of record screening using preliminary criteria reduced the number of military test pilots considered from more than 500 to 110. These pilots were arbitrarily divided into three groups, two of which were brought to Washington, D.C., and briefed on the Mercury program. There were so many volunteers from the first two groups that NASA decided not to call the third to Washington. After written tests, interviews covering technical knowledge and psychological makeup, medical history reviews, and extensive medical testing, the number of potential astronauts who were qualified and interested was reduced to 31. These candidates completed a series of elaborate and frequently exotic tests to determine their physical and psychological limits under some of the extreme conditions they might encounter. Humorous examples of the testing program are depicted in the movie The Right Stuff (1983) based on Tom Wolfe's book about the space program.

With 18 finalists a NASA panel selected the first Americans to fly into space. Unable to agree upon only six astronauts as planned, they selected seven: Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Walter Schirra, Alan Shepard, and Donald Slayton—the "Mercury Seven." Their choice was announced on April 9, 1959, and the seven astronauts became instant heroes.

As concepts were developed into systems, systems were validated through testing, and astronauts were prepared by means of training and rehearsals, the Mercury program began to take shape. There first would be a series of suborbital flights using Redstone rockets (an intermediate-range rocket developed for military use) to carry the Mercury capsule and its occupant (dummy, primate, or person) on a brief up-and-down ballistic flight through space. Later, orbital flights would be made using the Atlas, a military booster with intercontinental range and more power. The first piloted flight was planned for March 1961 but was delayed until May because of technical problems. Those problems were to have an unexpected and unwanted consequence. On April 12, 1961, the Soviet Union launched cosmonaut Yuri Gagarin into a one-orbit flight around Earth. The Soviet Union thus added "first human in space" to its record of accomplishments and extended its lead in the space race against the United States.

The Mercury Flights

The first piloted suborbital Mercury flight, achieved by the astronaut Alan Shepard in the Mercury capsule named Freedom 7, did not occur until May 5, 1961. In July, Gus Grissom piloted a suborbital flight, but August brought a second Soviet flight in which the cosmonaut Gherman Titov completed seventeen orbits. The space race was in high gear, and the United States seemed to be falling farther behind. Then, on February 20, 1962, an Atlas booster propelled the Friendship 7 Mercury capsule and astronaut John Glenn to a three-orbit flight. An American had finally made it to orbit.

The American launches were conducted more publicly than the Soviet missions. The preparation, launch, flight, re-entry, and landing were followed, often with fingers crossed and breath held, by millions in America and by people around the world. Although Glenn's flight was far shorter than Titov's, it clearly put the United States back into the space race. Three months later Scott Carpenter would fly another three-orbit mission. Then came two simultaneous, long-duration Soviet missions, including one of sixty-four orbits that lasted nearly 4 days. On October 3, 1962, Wally Schirra flew a six-orbit mission in the Sigma 7. Then, on May 15, 1963, Gordon Cooper and the Faith 7 were launched into space for a twenty-two orbit mission, the last flight in the Mercury program.

The Results

The Mercury flights lifted two rhesus monkeys, two chimpanzees, and six men into space. Of the six men, four were placed in Earth orbit, with the longest and last flight, Faith 7, exceeding 34 hours. The Mercury program was a tremendous success. Although the Soviets still led in the space race, the Mercury program reduced the gap. More importantly, it fired the public's imagination and gave scientists and engineers the knowledge and experience critical for Gemini, Apollo, and the first lunar landing in 1969.

see also Animals (volume 3); Apollo (volume 3); Capsules (volume 3); Career Astronauts (volume 1); Gargarin, Yuri (volume 3); Gemini (volume 3); Glenn, John (volume 3); History of Humans in Space (volume 3); Kennedy, John F. (volume 3); Primates, Non- Human (volume 3); Nasa (volume 3); Shepard, Alan (volume 3); Space Suits (volume 3).

Timothy R. Webster