Since the Mariner 4, 6, 7, and 9, the United States succeeded in exploring Mars. On July 14-15, 1965, Mariner 4 made its first successful flyby around Mars and became the first spacecraft to take close-up images of another planet. In 1969, the Mariner-6 and Mariner-7 spacecraft were the first to study the composition of the Mars atmosphere using spectroscopic techniques and the temperature of the planet's surface. On November 14, 1971, Mariner - 9 entered Mars orbit and became the first artificial satellite of another planet. The spacecraft continued to explore the planet. In the following years, its data and surface images became the basis for the choice of landing sites for the “Viking” robotic space probes series. In order to explore the surface of Mars, on August 20 and September 9, 1976, NASA successfully landed two identical spacecraft, Viking 1 and Viking 2. The space probes were the first to have successfully taken photographs from the surface of Mars. They carried out experiments to determine the gas composition of the planet measured atmospheric pressure and temperature and compiled an atmospheric density profile. They also took soil samples for analyzing if there was the presence of life. Experiments revealed relatively high chemical activity of the soil, but they could not find unambiguous traces of the vital activity of microorganisms. The duration of the Viking research program was planned to be about 3 months, but each space probe worked much longer - from 4 to 6 years.Teksty umieszczone na naszej stronie są własnością wytwórni, wykonawców, osób mających do nich prawa.
