The colonization of Venus has been a subject of much speculation and many works of science fiction since before the dawn of spaceflight, and is still much discussed. With the discovery of Venus' hostile surface environment, attention has largely shifted towards the colonization of the Moon and the colonization of Mars. Recently however, papers have surfaced on the feasibility of colonizing Venus beginning from the less hostile cloud-tops, making surface exploration in the beginning unnecessary. This two-part approach to the exploration and colonization of the planet has refocused interest on Venus.
Colonization of Venus with present conditions
To launch a safe colonization, as the atmosphere is not at all made up of oxygen, you would need to create your own. Plants would be able to live given the chemical content of the atmosphere (mostly carbon dioxide - about 96.5% - and nitrogen- 3.5% -) they breath in the carbon dioxide and out oxygen.
A habitat filled with same composition of earth's atmosphere at sea level will float high in the dense Venus atmosphere, The atmospheric pressure at 50 km above the surface of Venus is the same as Earth sea level (1 bar). Just in the same way that weather balloons float away from the high dense gas at the surface until the internal pressure is equal with the external pressure in the upper atmosphere, a balloon habitat with the internal pressure like that of earth would rise to an altitude where the external pressure was the same, since carbon dioxide is much more dense than the Nitrogen in our atmosphere. Temperatures are perfect for Earth, just over 0°C at that altitude on Venus. Essentially, you could walk outside onto a ramp with just an oxygen tank and look over the clouds below. Ideally, these floating habitats would be self sufficient closed systems, meaning they would produce their own oxygen through photosynthesis which wouldn't be difficult in a carbon dioxide atmosphere. Water could be extracted from the sulfuric acid in the clouds below.
Terraforming of Venus
- Main article: Terraforming of Venus
Venus has been the subject of a number of terraforming proposals. The proposals seek to remove or convert the dense carbon dioxide atmosphere, reduce Venus's 500 °C (770 K) surface temperature, and establish a day/night light cycle closer to that of Earth's.
Most proposals involve deployment of a solar shade and/or a system of orbital mirrors, for the purpose of reducing insolation and providing light to the dark side of Venus. Another way to cool Venus is via a lens system where the light is bent away from the planet or even concentrated at the equator. By concentrating enoumous amounts of sunlight in a small area at the equator we could potentially cause a change in the circulation of the planets atmosphere via a huge upwelling Hadley cell structure. If the atmosphere could be turned over it would cool much quicker, its easier for heat to escape 1 bar of atmosphere than 90 for instance. Another common thread in most proposals involves some introduction of large quantities hydrogen or water. Proposals also involve either freezing most of Venus's atmospheric CO2, or converting it to carbonates, urea or other forms.