Mercury Space Program in the 1960s

The United States’ first manned space program. The Mercury program succeeded in lifting two men into suborbital flight and four more into orbit around Earth in the early 1960’s.

Origins and History

The Mercury man-in-space program began in 1958, just after the National Aeronautics and Space Administration (NASA) began operation and more than a year after the spectacular, and to Americans, shocking success of Sputnik 1, launched by the Soviet Union. NASA named its program after the ancient Greek messenger of the gods, whose winged feet carried him between the heavens and earth with ease. Roger Gilruth, a NASA engineer who had been working on the design of a piloted spacecraft, became the head of a space task group responsible for the Mercury flights.

On October 4, 1957, the Soviet satellite Sputnik 1, which weighed only 183 pounds, had orbited Earth every ninety minutes and sent back radio signals identifying itself, allowing ground trackers to monitor its position. The Soviets had quickly followed up on the satellite’s success, lofting Sputnik 2 into orbit on November 3, 1957, just a month later. Sputnik 2 weighed 1,120 pounds and carried a dog, Laika, into orbit for almost two hundred days. To hoist a 180-pound satellite into orbit was one thing; to launch a human-made object weighing a half ton and achieve orbit at seventeen thousand miles per hour, with a live animal on board, was quite another. Sputnik 2 astounded scientists the world over and sent a message that the Soviet space effort was more advanced than that of the Americans.

Facing a clear and daunting challenge, Gilruth and other NASA scientists decided on a three-phase attack. Instead of building rockets from scratch, NASA engineers would use existing technology, modify the nose cones, and begin with what seemed the modest goal of launching a man in an arching suborbital trajectory some three hundred miles downrange from Cape Canaveral, the U.S. spaceport on the eastern coast of Florida. Phase one of the Mercury program envisioned putting a manned capsule atop a Redstone rocket, a type of military rocket that had been in use since 1953, had a range of five hundred miles, and could carry a small warhead. NASA’s first space voyager would just skim the edges of the void and return within fifteen minutes. In phase two, the capsule would make longer suborbital flights after being sent aloft by a slightly larger, more powerful booster, the Jupiter. Finally, in phase three of the Mercury program, an Atlas intercontinental ballistic missile would launch an astronaut into orbit. Gilruth projected that the third phase would take place within two years of the start of the program.

This was an ambitious plan, and Gilruth and the Mercury team almost achieved it. The Mercury capsule, only eleven feet long and six feet wide at the base, was built by the McDonnell Aircraft Corporation. The pilot, an astronaut chosen after a rigorous selection process, was a man with long experience as a test pilot for the armed forces. He sat, facing backward, in a cramped cockpit jammed with instrument panels, an onboard computer for automatic timing of the capsule’s return to Earth, and a small periscope.

This tiny spacecraft was used not only for the first suborbital flight but also for the longer orbital flights around Earth. The first U.S. manned flight took place on May 5, 1961, three years after NASA had begun its quest for parity in the space race and almost five years after the first Sputnik had been launched.

The 7 young astronauts chosen to become Mercury space voyagers were selected through an arduous process from a group of 508 highly talented fliers who also happened to be engineers. The final 7 made their debut before the U.S. public on April 9, 1959.

The first American in space, Alan B. Shepard, Jr., and the second, Virgil I. “Gus” Grissom, rodeRedstone boosters on short, suborbital flights. A mishap on landing caused Grissom’s Liberty Bell 7 to sink into the Atlantic Ocean, although Grissom was safely plucked from the sea by helicopter. The third Mercury flight was the first to orbit Earth. An Atlas booster carried John Glenn into orbit on February 20, 1962, inside the capsule he had named Friendship 7. Glenn circled Earth three times before returning to splash down in the Atlantic near the Bahamas. His flight was not without problems: His capsule’s heat-resistant shield, designed to protect him from the searing three-thousand-degree Fahrenheit heat of reentry, came loose during liftoff from Cape Canaveral, and Glenn had to ride Friendship 7 back to Earth with his retrorockets strapped to the shield. Glenn, a Marine Corps flier, watched a spectacular shower of flames shoot by his cockpit window as the capsule descended into the atmosphere. At times during reentry, he was unsure whether he was about to become a shooting star himself.

The Mercury program made three more orbital flights around Earth in 1962 and 1963. Navy Lieutenant M. Scott Carpenter completed a three-orbit flight on May 20, 1962; Lieutenant Commander Walter M. Schirra circled Earth six times on October 3, 1962; finally, on May 15-16, 1963, just six months before President John F. Kennedy’s assassination, Captain L. Gordon Cooper of the Air Force completed a twenty-two orbit flight in thirty-four hours. The seventh astronaut, Air Force Captain Donald “Deke” Slayton never flew aboard a Mercury capsule because NASA grounded him after physicians discovered a slight heart murmur in a preflight examination.

Impact

The Mercury program set the stage for further U.S. manned exploration of space. The United States also boosted its prestige, in question after a long series of Soviet space successes. Through the program, NASA engineers had solved the basic problems of manned space flight: lifting a human being into orbit, keeping the pilot alive in space, and returning capsule and crew safely to Earth. With the successful completion of this early program, the United States had committed itself to a long-term presence in outer space.

Subsequent Events

The next U.S. effort, the Gemini program of 1965-1966, launched two-person capsules into orbit around Earth. Although most of the original Mercury astronauts did not fly in space again, Grissom piloted the first Gemini mission on March 23, 1965. Then, in culmination of a decade-long effort, Apollomissions to the Moon began in 1968 with an Earth-orbit test mission and continued until December, 1972. Grissom died in a fire aboard the first Apollo capsule as it sat on a launch pad atop a huge Saturn 5 booster rocket on January 27, 1967. It was an Apollo capsule that later, on July 20, 1969, successfully landed the first human on the moon.

In the mid-1970’s, after a decade and a half of competition, the United States and the Soviet Union shifted focus and began cooperative efforts in space. Slayton flew aboard a joint Apollo-Soyuzmission with the Soviets on July 17, 1975. Slayton died of cancer in June, 1993.

Shepard died at a hospital outside Monterey, California, in July, 1998.

Additional Information

A highly readable account of the early U.S. space effort, including the Mercury program, can be found in Moon Shot: The Inside Story of America’s Race to the Moon (1994), by astronauts Shepard and Slayton. We Seven, by the Astronauts Themselves (1962), a collection of first-person narratives by the seven Mercury astronauts, takes the reader inside key missions. Roger D. Launius’s NASA: A History of the U.S. Civil Space Program (1994) provides an overview of the space effort.