[Jeema3000]

I think I would prefer the upper atmosphere of Venus if I had to choose between the two for a one-way trip:

"At an altitude of 50 km above Venusian surface, the environment is the most Earth-like in the solar system – a pressure of approximately 1 bar and temperatures in the 0°C–50°C range. Because there is not a significant pressure difference between the inside and the outside of the breathable-air balloon, any rips or tears would cause gases to diffuse at normal atmospheric mixing rates, giving time to repair any such damages. In addition, humans would not require pressurized suits when outside, merely air to breathe, a protection from the acidic rain; and on some occasions low level protection against heat."

http://en.wikipedia.org/wiki/Colonization_of_Venus#Aerostat_...

Just don't fall off the edge... :)

[TheEzEzz]

That is the most interesting bit of space knowledge I've ever read. It certainly seems like the potential in Venus is much greater than on Mars. I wonder why the space industry is so fixated on Mars?

[rbanffy]

Keeping the habitat 50 Km from the surface for decades isn't a trivial task.

Mars also has easily accessible water and a lower gravity. All you can get from Venusian high atmosphere are the gases you capture. On Mars you can mow rocks to get stuff like, say, steel.

[InclinedPlane]

Indeed, there's not a lot to recommend a Venusian floating habitat over a pure space station, for example.

However, if you look at what's possible with Mars, things get interesting quickly. Firstly, the CO2 atmosphere and local sub-surface water ice can be used to generate rocket fuel with a very low level of infrastructure, making initial exploration dramatically more efficient. Secondly, Mars has plenty of Sun and near-Earth day/night cycle, making it straightforward to grow food there. The day/night cycle also makes relying on solar power much more feasible, and makes direct communication with Earth more reasonable (since a location on Mars and on Earth will generally have line-of-sight to each other on the order of once per day). Thirdly, local martian materials can be used to maintain a self-sufficient industrialized civilization over an indefinite period of time (local metal ores, water ice, CO2, even Uranium ores, ability to grow food, etc.)

[rbanffy]

Doing some fact checking, you could build automated processing stations on Venus that could process atmospheric CO2 and water vapor (the former is most of Venusian atmosphere and the latter about 20 ppm) into methane and O2. There is plenty of sunlight as a power source too and an abundant source of heat. The gravity well is much worse than the one you find on Mars, but, as far as an automated facility goes, it's conceivable just to leave it there for decades, let it fill itself to its full capacity over decades and just ship a couple tanks coupled to engines to low orbit (or a cycler one) where a passing spacecraft could pick them up. The empty vehicle could then return to Venus and start its cycle again.

Mars is easier, but there is a lot of Carbon on Venus and it would be nice to be able to ship it elsewhere. Maybe then we could somewhat reduce the greenhouse effect and make it more comfortable over a couple hundred thousand years.

[anigbrowl]

I've wondered about that too. While it would be hard to float any kind of space colony there even with giant dirigibles, I've always felt that Venus' thick, gaseous atmosphere offers tremendous long-term potential, and I don't understand why we don't fire more probes at it. There are extremophile bacteria on earth that live in hot or chemically hostile conditions, many of which are anaerobic. It seems like we could try some long-term terraforming efforts at little short-term cost.