Venera

The Russian Venera probes represent a long-term commitment to exploration of the planet Venus. These probes form the majority of the 20 or so spacecraft which have visited Venus since 1970. The Russian space program sought to explore the atmosphere and surface, while the U.S. Mariner program concentrated on radar mapping of the surface from orbit. The Venera 4 through Venera 12 probes parachuted into the Venus atmosphere between 1967 and 1978. The earlier ones were crushed by the atmosphere before reaching the surface, but Venera 7 became the first spacecraft to soft-land on the planet. It survived 23 minutes, radioing back information on atmospheric pressure and temperature. A number of the later Venera craft survived for up to an hour in the harsh Venusian atmosphere and sent back photographs of the surface and analyses of the air and soil. In 1983 the Venera 15 and Venera 16 orbiters sent back detailed radar maps of large parts of the northern hemisphere of Venus. The resolution was about 2 km.