9.4: In the Space Age

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From the beginning of spaceflight, the Moon was a prime target, but this chapter in space exploration is too long to be covered here in any detail. The first spacecraft to reach the Moon were Luna 1, 2, and 3 of the Soviet Union, in 1959. Of these, Luna 3 rounded the Moon, took photographs of the far side which is not seen from Earth, and later scanned and transmitted those images (see Figure \(\PageIndex{1}\) below); unfortunately, their quality was poor. In the decade that followed, 19 other Soviet missions were aimed at the Moon.

In 1970 a Soviet spacecraft landed and returned a rock sample, and later that year a remotely controlled “Lunokhod" (literally: moon-walker, shown in Figure \(\PageIndex{2}\) below) vehicle was landed, exploring its surroundings for nearly a year. Other sample returns and Lunokhods followed, the series ending in 1976. However, failures marked tests of a large rocket developed for human Moon flights, ending any plans of manned lunar exploration by the Soviet Union.

Early attempts by the US to send unmanned spacecraft to the Moon (1958-64) either failed or returned scanty data. In July 1964, however, Ranger 7 returned clear TV pictures of its impact on the Moon, as did Rangers 8 and 9. Of the 7 “soft landers" in the “Surveyor" series (1966-8), 5 performed well and sent back data and pictures. In November 1969, after Apollo 12 landed 500 feet (160 meters) from the “Surveyor 3" lander, astronauts retrieved its camera and brought it back to Earth. In addition to the Surveyor project, 5 lunar orbiters photographed the Moon and helped produce accurate maps of its surface.

On May 25, 1961, about one month after Russia's Yuri Gagarin became the first human to orbit the globe, US president John F. Kennedy proposed to the US Congress “that this nation should commit itself to achieving the goal, before this decade is out, of landing a man on the Moon and returning him safely to Earth. "

The Apollo missions followed, with Apollo 8 rounding the Moon in 1968 and Apollo 11 finally landing there, on July 20, 1969 (pictured in Figure \(\PageIndex{3}\) below). Five other lunar landings followed, the last of them in December 1972. Only Apollo 13 failed to land, its crew members narrowly escaping with their lives after an explosion aboard their craft on the way to the Moon.