Venus is the second planet from the Sun, orbiting it every 224.7 Earth days. The planet is named after the Roman goddess of love and beauty. After the Moon, it is the brightest natural object in the night sky, reaching an apparent magnitude of −4.6, bright enough to cast shadows. Because Venus is an inferior planet from Earth, it never appears to venture far from the Sun: its elongation reaches a maximum of 47.8°. Venus reaches its maximum brightness shortly before sunrise or shortly after sunset, for which reason it has been referred to by ancient cultures as the Morning Star or Evening Star.
The first robotic space probe mission to Venus, and the first to any planet, began on 12 February 1961, with the launch of the Venera-1 probe. The first craft of the otherwise highly successful Soviet Venera program, Venera-1 was launched on a direct flyby trajectory, but contact was lost seven days into the mission, when the probe was about two million km from Earth. It was estimated to have passed within 100,000 km of Venus in mid-May. The American Mariner-2 succeeded in flying past the Planet in December 1962. Mariner 5 flew past Venus on June 14, 1967 while Venera-2 also flew past (without returning any data) and while Venera-3 entered the Venusian atmosphere (also without returning any data). Venera-4 succeeded in exploring the atmosphere of Venus on October 18, 1967. Two more Soviet Atmospheric probes Venera-5 & 6 followed in January 1969 before Venera-7 successfully landed on December 15, 1970.
Venera-8 arrived in July 1972 On February 5, 1974 Mariner-10 flew past Venus on it's way to Mercury. At the same time NASA's 1973 Venus Explorer Orbiter entered orbit around the Planet. In 1975 a second Venus Explorer Orbiter was launched as was a third in 1976. In 1977 two Venus flyby spacecraft were launched each deploying multiple atmospheric probes at Venus while also performing flyby science. In 1978 a Mariner-Venus-Mercury flyby probe was launched by NASA with secondary flyby science performed during the Venusian gravity assist. That same year of 1978 also saw a Venus Mariner Orbiter and a Venus Explorer Orbiter arrive around Venus. NASA's final unmanned probes in their Venus Exploration Program were two Venus Mariner Orbiters launched in 1981.
In October 1975, Venera-9 & 10 became the second spacecrafts to Orbit Venus in addition to their first deployment of a 2nd generation of sophisticated Soviet landers. Two sets of these sophisticated Orbiters/Landers were launched by the Soviets in 1978, 1982 and 1983 ending with Venera-15 and Venera-16.The Manned Exploration of Venus didn't begin until August 14, 1983 when the piloted Ares 1 & 2 spacecrafts having just returned from the first Manned Mars landing also performed the first Piloted exploration (flyby) of the Planet Venus. Radar imagers and other instruments studied the planet during the short two days of encounter while two Lander/Balloon payloads were deployed and telerobotically operated. Manned Flybys of Venus also occurred in 1986 and 1988. With the beginning of long-duration Mars missions in the late 1980s however, Gravity assists from Venus no longer became necessary for returning to Earth.
Robotic exploration of Venus also ended with the successful flyby & balloon/lander deployment following Vega 1 & 2 in 1985.
Beginning in 1999 a piloted 12-person Venus Orbit Base comprised of multiple SSMs (Space Station Modules) was launched with regular crew and cargo traffic to and from the planet via the utilization of NERVA Shuttles. Whether humans will ever be able to walk on Venus (let alone set up a surface base or colonize it) is uncertain.