Project Mercury

• 1. Introduction

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  Project Mercury began on the 7th of October 1958, with a single, blunt question: could the United States put a human being into space before the Soviet Union? The answer would take five years, twenty uncrewed test flights, and six missions flown by men who had never had a protocol written for them. No one had ever been selected as an astronaut before. No capsule like theirs had ever flown. The program would run from 1958 through 1963, costing hundreds of millions of dollars, and it would pull the United States from the shock of Sputnik toward the audacity of Apollo. What held the capsule together? Who decided who would fly? How did engineers solve problems no textbook had anticipated? And when it was over, who had actually won?

• 2. The Sputnik Shock

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  In October 1957, the Soviet Union placed the first satellite into orbit, and Americans felt a dread that had no name yet. Fear quickly acquired a label: the "missile gap." The concern was not just scientific rivalry. Because the USSR had no western-hemisphere bases from which to deploy bomber planes, Joseph Stalin had pushed for intercontinental ballistic missiles, and it was that same rocket technology that now put metal into the sky above American cities. A month after the first satellite, the Soviets launched Sputnik 2, carrying a dog. The animal was not recovered alive, but the implication was obvious: their target was human spaceflight.

  President Eisenhower could not publicly disclose military space projects, so he ordered a civilian answer. The National Advisory Committee for Aeronautics, the federal research agency known as NACA, became the foundation of a new organization. NASA opened on the 1st of October 1958, with T. Keith Glennan as its first Administrator and Hugh L. Dryden, the last Director of NACA, as his Deputy. The agency's first satellite, Pioneer 1, reached orbit that same year. The next goal was a person.

  Reaching space meant clearing the Karmán line, defined at the time as 62 miles altitude. Getting there required rocket boosters, which brought their own catalog of dangers: explosion, crushing g-forces, vibrations through a dense atmosphere, and temperatures exceeding 10,000 degrees Fahrenheit during reentry from air compression. Engineers took some comfort from early data: satellite flights suggested the micrometeoroid risk was negligible, and experiments from the early 1950s with simulated weightlessness and high g-forces suggested that known technologies could handle most of what space would throw at a human body. Reentry heating had already been studied through the nuclear warheads of ballistic missiles, which showed that a blunt, forward-facing heat shield could deflect most of the thermal energy around the craft.

• 3. Building the Capsule

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  Twelve companies bid on the Mercury spacecraft contract, set at 20 million dollars. In January 1959, McDonnell Aircraft Corporation won it. The spacecraft's principal designer was Maxime Faget, who had begun his research into human spaceflight during his time at NACA. The result was a cone-shaped capsule 10.8 feet long and 6 feet wide; with the launch escape system attached, the full stack reached 25.9 feet. The habitable volume was 100 cubic feet, barely enough for one person. Inside were 120 controls: 55 electrical switches, 30 fuses, and 35 mechanical levers. The heaviest production spacecraft, Mercury-Atlas 9, weighed 3,000 pounds fully loaded. Its outer skin was made of René 41, a nickel alloy engineered to withstand extreme temperatures.

  The capsule was built at McDonnell's facility in St. Louis, Missouri, in clean rooms and vacuum chambers. Close to 600 subcontractors contributed components; Garrett AiResearch, for instance, built the environmental control system. NASA ordered 20 production spacecraft, numbered 1 through 20. Five of them were never flown. Two were destroyed in uncrewed test flights. One, Spacecraft No. 11, sank during recovery and was pulled from the bottom of the Atlantic Ocean after 38 years.

  The spacecraft carried no on-board computer. All reentry calculations were performed by computers on the ground and then transmitted to the capsule by radio during flight. At Cape Canaveral, an IBM 709 vacuum-tube system determined whether a mid-launch abort was needed. At Goddard Space Center in Maryland, a redundant pair of transistorized IBM 7090 computers processed data from the spacecraft and relayed it to the Mercury Control Center. A Burroughs-GE system handled radio guidance for the Atlas during launch. McDonnell also built the training simulators the astronauts used, and adopted the motto "First Free Man in Space."

• 4. Choosing the Seven

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  Before Project Mercury, no process existed for selecting an astronaut. At the end of 1958, ideas ranged widely, including an open public call for volunteers that would have allowed rock climbers and acrobats to apply. NASA officials ended that conversation quickly: spaceflight required professional flight engineering, not thrill-seeking. On President Eisenhower's insistence, the pool was narrowed further to active duty military test pilots, which produced exactly 508 candidates. These were U.S. Navy, Marine Corps, or Air Force pilots with long military records.

  The requirements cut in unexpected directions. Candidates had to be between 25 and 40 years old, no taller than 5 feet 11 inches, and hold a college degree in a STEM field. The height limit was dictated by the capsule's dimensions. The degree requirement eliminated the Air Force's X-1 pilot, then-Lieutenant Colonel Chuck Yeager, the first person to exceed the speed of sound. Yeager later became a critic of the program, labeling astronauts as "spam in a can." John Glenn lacked a college degree as well, but used influential contacts to persuade the selection committee to accept him. Neil Armstrong, then a civilian NASA X-15 pilot, was also disqualified from Mercury, though he had been selected by the Air Force for its Man in Space Soonest program in 1958, which Mercury absorbed. Armstrong became NASA's first civilian astronaut in 1962 and the first person to walk on the Moon in 1969.

  From 508 candidates, 110 were called for interviews. From those, 32 underwent intensive physical and mental testing: hearing, vision, tolerance of noise, vibrations, g-forces, isolation, and heat. Candidates answered more than 500 questions about themselves and described what they saw in images. Navy Lieutenant Jim Lovell, later an Apollo astronaut, did not pass the physical tests. The plan had been to select six; NASA settled on seven. On the 9th of April 1959, the agency announced: Scott Carpenter, Gordon Cooper, John Glenn, Gus Grissom, Wally Schirra, Alan Shepard, and Deke Slayton.

• 5. Training and Preparation

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  The astronauts trained in a centrifuge at the Naval Air Development Center in Warminster, Pennsylvania, simulating the g-force curves of both launch and reentry. They were taught special breathing techniques for loads above 6 g. Weightlessness training began in the back seat of a two-seat fighter and moved to padded cargo aircraft flown in parabolic arcs. At the Lewis Flight Propulsion Laboratory in Cleveland, they practiced controlling a spinning spacecraft in the Multi-Axis Spin-Test Inertia Facility, known as the MASTIF, using an attitude controller handle identical to the one in the capsule. Star and Earth recognition training took place in planetaria and simulators, preparing them to orient the spacecraft by sight.

  The astronauts were not passive passengers in the design process. They insisted that manual controls and a window be built into the spacecraft. That insistence proved its value on Gordon Cooper's final Mercury flight, when a manual reentry became the only option after automatic systems failed. Fiberglass seats were custom-molded from each astronaut's suited body to distribute the g-load as precisely as possible.

  Publicity was also part of the job. The seven gave press interviews and toured manufacturing facilities to speak with the workers who built their spacecraft. Life magazine bought their personal stories and portrayed them as patriotic, family men. Life was permitted to be present with the astronauts' families during flights. The press singled out John Glenn as the most effective speaker of the group. During the project, most of the astronauts stationed their families at or near Langley Air Force Base; Glenn lived on base and traveled to Washington, D.C., on weekends to see his family.

• 6. Six Flights, Six Successes

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  Alan Shepard flew first. On the 5th of May 1961, his Freedom 7 capsule rode a Redstone rocket on a 15 minute and 28 second suborbital arc, making him the first American in space. The flight came three weeks after Soviet cosmonaut Yuri Gagarin had completed a full orbit on the 12th of April 1961, and it was not the same achievement; it was a beginning. Shepard later walked on the Moon during Apollo 14, the only Mercury astronaut to do so.

  Gus Grissom followed on the 21st of July 1961, aboard Liberty Bell 7. After splashdown, the side hatch opened unexpectedly, flooding the capsule. Grissom was safely recovered, but the spacecraft sank. Grissom died in January 1967 during a pre-launch test for Apollo 1, never reaching orbit again.

  John Glenn became the first American to orbit Earth on the 20th of February 1962, flying Friendship 7 on a Mercury-Atlas launch from Cape Canaveral. The automatic attitude control system failed during the flight; Glenn flew manually for portions of the mission. About 75,000 people watched the launch from Cocoa Beach, south of the Cape. Glenn left NASA in 1964, was later elected to the U.S. Senate, serving from 1974 to 1999, and returned to space in 1998 aboard STS-95.

  Scott Carpenter flew Aurora 7 on the 24th of May 1962. A targeting error during reentry sent the capsule 250 miles off-course, delaying recovery. It was Carpenter's only spaceflight. He later joined the Navy's "Man in the Sea" program, becoming the only person to be both an astronaut and an aquanaut.

  Wally Schirra flew Sigma 7 on the 3rd of October 1962, in a mission focused on evaluating life-support systems. The flight lasted 9 hours and 13 minutes, a new U.S. endurance record at the time. Schirra went on to fly Gemini 6A in December 1965 and command Apollo 7, becoming the only person to fly in Mercury, Gemini, and Apollo.

  Gordon Cooper closed the program on the 15th of May 1963, with a 34-hour and 19-minute flight aboard Faith 7, completing 22 orbits. His automatic reentry system failed, and he guided the capsule down manually. It was the last time an American flew alone on an entirely solo orbital mission. Deke Slayton, the seventh member of the group, was grounded in 1962 due to a heart condition; he eventually flew in 1975 on the Apollo-Soyuz Test Project.

• 7. Legacy and What Followed

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  When Project Mercury ended in May 1963, both the United States and the Soviet Union had each sent six people into space. The Soviets still led in total time spent in space; the Vostok 5 mission alone logged nearly five days and 82 orbits. Mercury had not won the race, but it had changed the terms of it.

  A few weeks after the first crewed Mercury flight, President Kennedy announced the plan for a crewed Moon landing before the end of the 1960s. The program's success also prompted the question of women astronauts. Because women had been barred from military test pilot roles, none could qualify under the original rules. NASA physician William Randolph Lovelace created a privately funded program, later labeled Mercury 13 by the media, in which thirteen American women successfully completed the physical and psychological tests. The program was quickly cancelled; no women met the formal astronaut qualifications until 1978, when several qualified for the Space Shuttle program.

  Mercury's infrastructure did not disappear. The Manned Space Flight Network of 18 ground stations, placed around the equator and made ready in 1960, served subsequent space programs until it was replaced by a satellite relay system in the 1980s. Mission Control moved from Cape Canaveral to Houston in 1965. On the 25th of February 2011, the Institute of Electrical and Electronics Engineers awarded Boeing, the successor company to McDonnell Aircraft, a Milestone Award recognizing inventions that debuted on the Mercury spacecraft. Friendship 7, Spacecraft No. 13, later traveled on what became known as its "fourth orbit," a global museum tour. A commemorative stamp honoring Mercury-Atlas 6 was issued in 1962, the first U.S. postal issue to depict a crewed spacecraft.