By Michael Shinabery, New Mexico Museum of Space History
The most recent of 27 missions to Venus, the European Space Agency's Venus Express, entered planetary orbit on April 11, 2006. The ESA launched Venus Express on a Soyuz-Fregat rocket, from Russia's Baikonur Cosmodrome, in November 2005. Today, according to the website sci.esa.int, studies of the atmosphere, cloud layer, and surface geology continue. A Jan. 7, 2011 ESA report said data gathered in conjunction with ESA Cluster satellites orbiting Earth, have "improve(d) models of the interaction of Earth and Venus with the solar wind." The result is better "understanding the effects of charged particles on orbiting spacecraft."
The Soviet Union launched the first Venus mission, Venera 1, on Feb. 12, 1961, said nssdc.gsfc.nasa.gov. While "communications failed" en route, the craft did achieve the first-ever flyby.
Next, the United States' Mariner 2 lifted off, in August 1962. Solarviews.com said "the world's first successful interplanetary spacecraft" weighed 450 pounds, and carried "six scientific instruments" including "a two-way radio." On Dec. 14, Mariner 2 arrived and began scanning the "surface with infrared and microwave radiometers, capturing data that showed Venus's surface to be about (800 degrees Fahrenheit)." Three weeks later, Mariner 2 went "off the air."
If man ever did step onto Venus, he "would find É no liquid water, probably no oxygen, and of course not
even plant life," said "The View From Planet Earth" (William Morrow/1981). "He would suffer agonies as sulphuric acid droplets burned his flesh, and he would be crushed by atmospheric pressure."
"The Venusian atmosphere is about one hundred times as massive as that of the Earth," said "New Worlds: Discoveries from Our Solar System" (Anchor Press/Doubleday/1979). "While Earth's atmosphere contains only about 0.03 per cent carbon dioxide, that of Venus is almost all carbon dioxide."
The second Soviet probe, Zond 1, left April 2, 1964, but lost contact, solarviews.com said. The next year, on Nov. 12, Venera 2 lifted off carrying television broadcast equipment, but "communications failed just before arrival." Four days later the Soviets launched Venera 3, hoping for a controlled surface landing. Yet again contact failed, and on March 1, 1966 the craft crashed, becoming the first "to impact on the surface of another planet."
Venera 4 arrived Oct. 18, 1967. Solarviews.com said the payload included thermometers, a barometer, radio transmitters, and cosmic ray detectors. "This was the first probe to be placed directly into the atmosphere and to return atmospheric data." Parachuting to the surface, atmospheric pressure "crushed" the spacecraft. Such pressure also destroyed the Venera 5 and 6 missions in May 1969.
One day after Venera 4 arrived, Mariner 5 entered orbit. Nssdc.gsfc.nasa.gov said Mariner 5 was "a refurbished backup spacecraft for the Mariner 4 (Mars) mission." Its instrumentation "measured both interplanetary and Venusian magnetic fields, charged particles, and plasmas, as well as the radio refractivity and UV emissions of the Venusian atmosphere."
The Soviets launched 16 Venera probes; of them, Venera 7, in December 1970, was "the first successful landing of a spacecraft on another planet," solarviews.com said. The craft "used an external cooling device which allowed it to send back 23 minutes of data." Venera 8, after landing in July 1972, "returned data for 50 minutes." Subsequent craft managed to survive even longer.
The Venera 9 and 10 landers, in October 1975, transmitted the first photographs, which were black-and-white, revealing a rocky, eroded terrain.
"Dmitryi Gregoryev, chairman of an international space mineralogy commission, commented: 'It looks É (like) some unknown force has scattered the rocks over the planet's surface,' " said New Worlds: Discoveries from Our Solar System." " 'It could also be that these are outbursts from giant meteorite craters.' "
Prior to the Venera 9 and 10 landings," "New Worlds: Discoveries from Our Solar System" said astronomers believed "only about 1 percent of sunlight É could penetrate through the thick cloud cover and reach the ground. The surface of Venus would be extremely gloomy, hardly the place to take photographs. For this reason, both É were equipped with powerful floodlights."
Venera 12 recorded "electrical discharges, probably from lightning," in December 1978, solarviews.com said. Following the final Venera mission in 1983, the Soviets launched Vegas 1 and 2 in 1984. Upon delivering landers, both aimed for a Halley's Comet flyby.
The U.S. sent Pioneer Venus 1, a.k.a. the Pioneer 12 orbiter, in May 1978. Arriving on Dec. 4, solarviews.com said it transmitted for 14 years, becoming "the first spacecraft to use radar in mapping the planet's surface."
"Radar tells us that Venus is cratered, that it possesses a mountain higher than Everest, and the largest canyon known," said "The View From Planet Earth."
In 1992, "fuel ran out and atmospheric entry destroyed the spacecraft," said nssdc.gsfc.nasa.gov.
Pioneer Venus 2 or Pioneer 13, launched in August 1978, was also known as the Pioneer Venus Multiprobe, said nssdc.gsfc.nasa.gov. After parachuting four probes that distinctly defined atmospheric layers, the craft burned up.
Galileo, launched in May 1989, was a U.S.-European effort "to study Jupiter's atmosphere," but "used gravity assist techniques to pick up speed by flying past Venus," solarviews.com said. The Space Shuttle Atlantis launched the final U.S. mission, Magellan, in May 1989. Magellan radar-mapped "99 percent of the planet's surface" through "thick clouds of carbon dioxide that makes the surface invisible to optical instruments." In 1994, "controllers directed the orbiter into the atmosphere, where it burned up."
"What went wrong that Venus is so unlike Earth?" "New Worlds: Discoveries from Our Solar System," asked. "Perhaps, being closer to the sun, any water vapour released by volcanism failed to condense into droplets of water, so there was nothing to stop the atmosphere of carbon dioxide growing and growing. É Decidedly the name-givers erred. Mars the 'firey' turns out to be freezing, and the planet associated with a nude goddess rising from the Mediterranean is hidden in cloud, dry and blazingly hot."