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Planetary Missions
Mariner
The first inter-planetary mission was the United States' Mariner program, designed to fly by Mercury, Venus and Mars. Mariner 2(1962) and Mariner 5(1967) passed Venus within 22,000 miles and 2,500 miles respectively, measuring its' temperature and atmospheric density. Mariners 4 in 1964 and 6 and 7 in 1969, took photographs of the Martian surface and made significant analyses of the atmosphere.
Mariners 6 and 7 made thermal maps of Mars by means of infrared radiometers. Mariner 9, launched on May 1971 and was placed in orbit of Mars in November. This was the first time a man-made satellite orbitted another planet. Various measurements were taken and large areas of Mars were mapped, and the planet's two moons, Phobos and Deimos, were photographed.
Mariner 10(launched 1973) flew by Mercury thrice and on its third attempt radioed back to Earth the first close-up pictures of the surface, as well as analyses of the atmosphere and magnetic field. |
Venera
Venera was the name give to Soviets series of probes sent to explore the planet Venus. Venera 2 (launched in 1965) flew to within 25,000 miles of Venus in February 1966. Venera 3 crash-landed on its surface the following month, becoming the first spacecraft to strike another planet.
Launched in 1967, the Venera 4 (1967) analyzed the chemical composition of Venus' upper atmosphere and provided the first direct measurements for a model of the planet's atmospheric makeup. Venera 7(1970) and 8(1972) detected the prescence of Uranium and Thorium on the Venutian surface.
Venera 9 and 10(both 1975) sent back the first closeup photographs of the planet's surface. Venera 11 and 12(both 1978) measured the chemical components of the planet's lower atmosphere. In 1971, the Soviets launched two capsules to Mars, which both ejected landing capsules which stopped transmitting data after landing.
Viking
Viking-I blast-off
In 1975 the US launched the Viking missions. The main objective of the mission was to find the possibility of life on Mars. Other objectives included taking high-res photographs of the Martian surface and determining the structure and composition of the atmosphere and surface. Viking 1 took off on August 20, 1975 and reached Mars on June 19, 1976.
Viking 2 followed closely behind it, launching on September 9, 1975 and arriving at Mars on August 7, 1976. Both the crafts were made up of two parts - the orbiter and the lander. The landers imaged the surface, took surface samples, deployed seismometers and studied the atmospheric composition and weather. The orbiters began mapping the surface of Mars as soon as they deployed the landers.
The Viking 2 orbiter circled Mars at a higher inclination than Viking 1 orbiter, allowing it to closely observe the polar regions. Although other life-forms were obviously not found the Viking missions were highly successful and gave scientists a tremendous amount of knowledge about Mars.
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