Photograph courtesy NASA
NASA's first human spaceflight program was Project Mercury. This ambitious undertaking was launched in 1958—about a year after the U.S.S.R. had signified the start of the Space Age with the successful launch of the satellite Sputnik 1.
The Mercury missions began the space race in earnest and drew upon the vast resources of the U.S. government and private sector—an estimated two million Americans contributed.
Testing the limits of the human body in space was an important objective of both space programs. To this end robots and animals were blasted aloft—most notably Mercury's Ham the chimpanzee and the Soviet dog Laika. Though Ham returned to Earth and a comfortable retirement at the National Zoo in Washington, D.C., Laika died aboard Sputnik 2 in 1957.
First Humans in Space
Soviet cosmonaut Yuri Gagarin became the first person in space when he orbited the Earth in a Vostok spacecraft on April 12, 1961.
About a month later Alan Shepard, Jr. became the first American in space on May 5, 1961, when he was launched aboard Mercury-Redstone 3. His 15-minute flight, dubbed "Freedom 7," was watched by some 45 million television viewers.
Between 1961 and 1963, six manned spacecraft flew as part of the Mercury project. Mercury pilots rode in wingless capsules, which detached from their launch rocket and fell back to Earth. The small craft were designed to withstand the tremendous temperatures of reentering the planet's atmosphere and also survive a dramatic splashdown in the ocean.
Just a few weeks after Shepard's flight, President John F. Kennedy announced his intent to put a man on the moon by the end of the decade. The challenge signaled the birth of NASA's Gemini and Apollo missions.
Yet Mercury had more to accomplish. In February 1962 John Glenn became the first American to orbit the Earth on the Friendship 7 mission.
NASA's Gemini program was designed to refine spacecraft so that they could perform rendezvous, docking, and other advanced maneuvers that would be necessary to land an astronaut on the moon and return to Earth.
As the missions of this era grew longer, astronauts became more adept at living within their spacecraft and even venturing outside it. Soviet cosmonaut Aleksei Leonov became the first person to exit an orbiting spacecraft in March 1965.
The launch of the Apollo missions precipitated an American triumph in the space race and was a major first in space exploration.
On July 20, 1969, Neil Armstrong and Edwin "Buzz" Aldrin became the first people to reach the moon when they touched their lunar lander down in the Sea of Tranquility. Before the Apollo project ended in 1972, five other missions visited the moon.
The Apollo spacecraft included a command/service module, which could orbit the moon, and a lunar module that astronauts could detach, land on the moon, and then blast off to rejoin the orbiting command module for the return trip to Earth.
Later missions carried a lunar rover that could be driven across the satellite's surface and saw astronauts spend as long as three days on the moon.
The Apollo missions achieved tremendous successes, but they came with a terrible cost. Astronauts Virgil "Gus" Grissom, Edward White, and Roger Chaffee were killed in a launchpad fire during training before the first Apollo flight.
When the Apollo missions ended in 1972, the first era of human space exploration closed.
Phenomena: A Science Salon
National Geographic Magazine
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All the elements found in nature—the different kinds of atoms—were found long ago. To bag a new one these days, and push the frontiers of matter, you have to create it first.
Burn natural gas and it warms your house. But let it leak, from fracked wells or the melting Arctic, and it warms the whole planet.