NASA Has Explored Manned Missions To Venus

NASA recently developed a program for manned missions to explore Venus -- even though the planet's surface is 860 degrees, which NASA explains is "hot enough to melt lead." Long-time Slashdot reader Zorro shares this week's article from Newsweek:
As surprising as it may seem, the upper atmosphere of Venus is the most Earth-like location in the solar system. Between altitudes of 30 miles and 40 miles, the pressure and temperature can be compared to regions of the Earth's lower atmosphere. The atmospheric pressure in the Venusian atmosphere at 34 miles is about half that of the pressure at sea level on Earth. In fact you would be fine without a pressure suit, as this is roughly equivalent to the air pressure you would encounter at the summit of Mount Kilimanjaro. Nor would you need to insulate yourself as the temperature here ranges between 68 degrees Fahrenheit and 86 degrees Fahrenheit. The atmosphere above this altitude is also dense enough to protect astronauts from ionising radiation from space. The closer proximity of the sun provides an even greater abundance of available solar radiation than on Earth, which can be used to generate power (approximately 1.4 times greater).... [C]onceivably you could go for a walk on a platform outside the airship, carrying only your air supply and wearing a chemical hazard suit.

Venus is 8 million miles closer to Earth than Mars (though it's 100 times further away than the moon). But the atmosphere around Venus contains traces of sulphuric acid (responsible for its dense clouds), so the vessel would need to be corrosion-resistant material like teflon. (One NASA paper explored the possibility of airbone microbes living in Venus's atmosphere.) There's a slick video from NASA's Langley Research Center titled "A way to explore Venus" showcasing HAVOC -- "High Altitude Venus Operational Concept."
"A recent internal NASA study...led to the development of an evolutionary program for the exploration of Venus," explains the project's page at NASA.gov, "with focus on the mission architecture and vehicle concept for a 30 day crewed mission into Venus's atmosphere." NASA describes the project as "no longer active," though adding that manned missions to the atmosphere of Venus are possible "with advances in technology and further refinement of the concept."