The Mercury Program

Podcast Transcript

In the late 1950s, the United States found itself trailing in the Space Race as the Soviet Union achieved one milestone after another.

In response, NASA launched Project Mercury, an ambitious effort to put an American into space using little more than experimental rockets, cramped capsules, and sheer determination.

Explosions, near disasters, and political pressure surrounded every mission, yet the program would lay the foundation for landing humans on the Moon.

Learn more about the Mercury Program and America’s first manned space flights on this episode of Everything Everywhere Daily.

When the USSR launched Sputnik on October 4, 1957, it sent the United States into a panic. The Soviet launch shocked the United States politically and culturally. Americans feared that the Soviet Union had surpassed them technologically and militarily, especially because the rockets capable of launching satellites could also deliver nuclear weapons.

The Americans who had already been working on sending an artificial satellite into orbit had been shown up in a public and historically humiliating fashion.

The Eisenhower administration responded on multiple fronts. In July 1958, Congress passed the National Aeronautics and Space Act, creating NASA, the National Aeronautics and Space Administration, which officially opened its doors on October 1, 1958.

One of its first and most urgent mandates was to put an American in space before the Soviets could do so.

Before NASA existed, the U.S. Air Force had been developing its own human spaceflight concept, called Man In Space Soonest (MISS). When NASA was established, it absorbed much of this work. The new civilian agency moved with unusual speed: on November 26, 1958, less than two months after NASA’s founding, the agency formally approved Project Mercury, named after the swift messenger god of Roman mythology.

The program’s stated goals were straightforward but technically staggering for the time:

Place a human being into orbital flight around the Earth.
Investigate the human body’s ability to function in space.
Recover both the astronaut and the spacecraft safely.

The implied goal, unstated in official documents, was equally important: beat the Soviets.

No one knew for certain whether a human could survive weightlessness for extended periods. Scientists debated whether astronauts might become disoriented, lose consciousness, or even go insane in zero gravity.

The first order of business was to create a space capsule, which had never been done before. The Mercury capsule was designed by a team led by Max Faget. Faget’s design was deliberately simple and conservative, a truncated cone with a heat shield on the blunt end, chosen because blunt-body reentry was better understood and more controllable than a pointed shape.

The capsule measured just 9 feet 5 inches tall and 6 feet 2.5 inches in diameter at its base, and weighed roughly 3,000 pounds. It was, by any measure, tiny, barely larger than a phone booth. The astronaut lay on a form-fitted couch in a semi-reclined position. There was almost no room to move. Early astronauts noted, only half-jokingly, that you didn’t climb into a Mercury capsule; you wore it.

The spacecraft had approximately 120 controls, 55 electrical switches, 30 fuses, and 35 mechanical levers. Despite this complexity, the capsule was designed so that in an emergency, an unconscious astronaut could complete the mission automatically.

Every aspect of the mission had to be invented from scratch, including tracking systems, spacesuits, recovery operations, and astronaut training procedures.

The other important thing was finding astronauts to put inside the capsule.

NASA’s criteria were strict: candidates had to be military test pilots, under 40 years old, under 5 feet 11 inches tall, to fit in the capsule, with at least 1,500 hours of flight time and a bachelor’s degree in engineering or equivalent.

From 508 military test pilots screened, 110 were selected for further evaluation. Those men endured days of physical examinations, psychological tests, and stress assessments. The final seven were chosen in February 1959 and announced to the public on April 9, 1959. NASA introduced the world to the Mercury Seven, the first American astronauts.

The public’s embrace of the Mercury astronauts was immediate and overwhelming. Life magazine purchased exclusive rights to their personal stories, and the seven men became the most famous Americans alive. They were fighter pilots, family men, and heroes, exactly the image a nervous nation needed.

Before sending humans into space, NASA conducted a series of uncrewed test flights. These missions tested launch vehicles, heat shields, escape systems, and recovery procedures. Several flights failed. Rockets exploded, capsules malfunctioned, and systems failed unexpectedly. One major problem involved the launch vehicles themselves.

The Redstone rocket used for suborbital flights and the Atlas rocket intended for orbital missions both had reliability problems. Atlas missiles in particular had a disturbing tendency to explode during testing. Convincing astronauts to sit atop these rockets required enormous confidence and courage.

NASA also used animals in early tests. Monkeys such as Sam, Miss Sam, Ham, and Enos were launched to evaluate the effects of spaceflight on living creatures. Ham the chimpanzee became especially famous after successfully performing tasks during a suborbital flight in January 1961. His mission demonstrated that a living being could function in space and survive the stresses of launch and reentry.

In 1961, as NASA was preparing for its first astronaut flight, on April 12, Soviet Cosmonaut Yuri Gagarin became the first human in space, completing a full orbit of the Earth.

Americans were once again humiliated. President Kennedy, in office for less than three months, faced a crisis of confidence in American technological prowess. Despite this blow to American prestige, NASA continued to execute its plan methodically.

The first crewed Mercury mission was Mercury-Redstone 3, better known as Freedom 7, which was launched on May 5, 1961. Alan Shepard became the first American in space.

The mission was suborbital, meaning the spacecraft did not orbit Earth but instead followed a ballistic arc into space before returning to Earth. The flight lasted only about 15 minutes. Shepard’s primary goals were to evaluate spacecraft systems, determine whether humans could function in weightlessness, and test recovery procedures.

The mission succeeded and restored some American confidence after Gagarin’s earlier achievement.

The next mission was Mercury-Redstone 4, Liberty Bell 7, flown by Gus Grissom on July 21, 1961. Like Shepard’s flight, it was suborbital. The mission itself was largely successful, but it became famous for a near-disaster after splashdown.

The capsule’s hatch unexpectedly blew open, causing seawater to flood the spacecraft. Grissom nearly drowned while awaiting rescue, and the capsule sank to the bottom of the Atlantic Ocean. The incident created controversy for years, although later evidence strongly suggested that Grissom did not accidentally trigger the hatch himself.

The capsule sank to the bottom of the sea, but was recovered in 1999.

With Liberty Bell 7, the suborbital phase of the Mercury program was over. One reason why the Soviets beat the Americans in putting someone in orbit was that they were willing to take bigger risks. If Gagarin’s flight had failed, the failure would not have been as public as the failure of an American space flight.

These suborbital flights were part of the slower, more cautious approach that the Americans were taking. It caused them to miss several firsts in space, but contributed to their long-term success.

The next Mercury flight was to finally be the flight that equaled the achievement of the Soviets by placing a man into orbit.

Mercury-Atlas 6, Friendship 7, launched on February 20, 1962, carrying John Glenn. Glenn became the first American to orbit Earth, completing three orbits during a mission lasting nearly five hours. The flight was a major triumph for the United States. However, the mission was not without problems.

During the flight, telemetry suggested that the capsule’s heat shield might be loose. Mission controllers feared the shield could fail during reentry, which would have doomed Glenn.

To reduce the risk, they instructed him to leave the retrorocket package attached during reentry to help hold the heat shield in place. Glenn survived safely, and later analysis showed the warning sensor had malfunctioned.

With a successful orbital mission and proof that humans could survive and function in space, it was now a matter of continuing to push the boundaries and test the limits of what would be necessary for future planned programs.

Mercury-Atlas 7 followed on May 24, 1962, with Scott Carpenter aboard Aurora 7. The mission’s goals included conducting scientific experiments and further evaluating human performance in orbit.

Carpenter completed three orbits successfully but consumed more fuel than expected due to maneuvering and drifting off schedule. As a result, the spacecraft landed far from the planned recovery zone. Although Carpenter recovered safely, NASA criticized his handling of the mission because fuel management would become increasingly important in later programs.

Mercury-Atlas 8 launched on October 3, 1962, with Wally Schirra aboard the capsule dubbed Sigma 7. Schirra focused heavily on engineering precision and efficient spacecraft management. Unlike Carpenter’s mission, Sigma 7 was deliberately conservative.

Schirra minimized unnecessary maneuvers and carefully conserved fuel. The six-orbit mission was extremely successful and demonstrated that astronauts could operate effectively in space for longer durations.

The final Mercury mission was Mercury-Atlas 9, Faith 7, launched on May 15, 1963, with Gordon Cooper aboard. By this point, NASA wanted to push the limits of human endurance in space. Cooper spent more than 34 hours in orbit and completed 22 orbits around Earth.

The mission proved that astronauts could function effectively in space for over a day, an important milestone for future lunar missions. Toward the end of the flight, electrical failures forced Cooper to perform a largely manual reentry, which he executed with remarkable accuracy. The success of Faith 7 effectively concluded Project Mercury.

Of the original Mercury 7 astronauts, only one didn’t fly in the Mercury Program: Deke Slayton. In 1962, NASA doctors discovered that he had an irregular heart rhythm condition. Even though Slayton showed no symptoms and remained physically capable, NASA grounded him because the risks of a medical emergency in space were considered too great.

The decision effectively removed him from active flight status during the Mercury, Gemini, and most of the Apollo programs. Instead, Slayton became NASA’s Director of Flight Crew Operations, where he played a major role in selecting and assigning astronauts for later missions.

After years of medical evaluation, NASA finally restored his flight status in the 1970s, and he eventually flew in space during the 1975 Apollo-Soyuz Test Project, becoming one of the oldest astronauts to fly at the time.

A seventh human Mercury mission, which was planned for Alan Shepard, was canceled when NASA determined that Mercury had achieved its goals and that resources should be directed toward the Gemini and Apollo programs.

Most of the other Mercury astronauts continued their careers in some fashion.

Gus Grissom went on to command a Gemini mission and died in the Apollo 1 fire. Alan Shepard went on to command Apollo 14 in 1971 and famously hit two golf balls on the Moon.

John Glenn returned to space in 1998 aboard Space Shuttle Discovery at age 77, making him the oldest person ever to fly in space. Wally Schirra flew on Gemini 6 and Apollo 7. Gordon Cooper flew on Gemini 5. Scott Carpenter never flew again, but spent 28 days on the bottom of the ocean in the SEALAB project.

Project Mercury was a great success even though It did not beat the Soviets to orbit. It established the foundation on which Gemini and Apollo were built, and it demonstrated to the world, and to Americans themselves, that the United States had the talent, the determination, and the audacity to compete in the space age.