Atmosphere of Venus
In 1761, Russian polymath Mikhail Lomonosov observed an arc of light surrounding the part of Venus off the Sun's disc at the beginning of the egress phase of the transit and concluded that Venus has an atmosphere. In 1940, Rupert Wildt calculated that the amount of CO in the Venusian atmosphere would raise surface temperature above the boiling point for water. This was confirmed when Mariner 2 made radiometer measurements of the temperature in 1962. In 1967, Venera 4 confirmed that the atmosphere consisted primarily of carbon dioxide.
Venus Atmospheric Maneuverable Platform
The aircraft is proposed to be launched as a secondary payload on another spacecraft mission to Venus, probably on Russia's Venera-D in 2026. During daytime, VAMP would be able to make continuous science measurements, while at night the vehicle would descend to 50 km altitude where it would be fully buoyant, remain at a lower-power state, and still perform modest science measurements at the float altitude. The lower cloud layer of Venus, located between 47.5 and 50.5 km altitude, is acidic, but it is considered by some astrobiologists to be a target for exploration due to the favorable conditions for microbial life, including moderate temperatures and pressures (∼60 °C and 1 atm).