There is so much focus on the exploration of Mars in space circles that you could almost be forgiven for forgetting that in fact Venus is the nearest planet to Earth. Nasa is very much fixed on pursuing missions to the Red Planet for now, but it has released details of an internal study that show how the organisation could approach the exploration of Venus in the future.
Nasa's concept mission to Venus is called Havoc, which stands for High Altitude Venus Operational Concept, and as concepts go, it's a pretty exciting one. The basic idea is to build a floating city of zeppelins manned by astronauts, which would hover in the planet's atmosphere.
Venus is extremely inhospitable thanks to high pressure and temperatures that can reach 500 degrees, which leave it unsuitable for human exploration. Even probes that have been sent there in the past have been destroyed by the harsh conditions on the surface.
But if the zeppelins stayed 50km above the planet's surface, they would be able to learn more about its atmosphere, as well as potentially sending rovers down to Venus itself.
In some respects, Venus is actually a more appropriate candidate for space exploration than Mars, and not just because of the shorter journey time. The fact that it is closer to the Sun means there is more potential for harnessing solar energy and less radiation than astronauts would be exposed to on Mars.
Venus' upper atmosphere is around 75 degrees and radiation levels are similar to those you'd find on Earth. Speaking to IEEE Spectrum, Nasa's Chris Jones described it as "probably the most Earth-like environment that's out there," despite there being no ground to speak of.
The many technical challenges -- deploying the zeppelins and getting the astronauts there and back to Earth following 30-day mission stints in the zeppelins, for example -- that would need to be tackled before sending humans to Venus, would need to be dealt with in several precursory missions. Eventually the aim would be to have a permanent human presence in the floating zeppelin city. The crewed zeppelins would be 130 metres long -- twice the size of a Boeing 747 -- and would be covered in 1,000 metres squared of solar panels.
The team that has worked on the concept believe that very little technological advancement need be made in order to plan and execute such a crewed mission. In fact the team believes that getting humans to Venus -- or its upper atmosphere at least -- may be easier than getting them to Mars. It is also possible that some of the breakthroughs that would be made on the Venus mission could provide a shortcut to overcoming obstacles that stand in the mway of mankind landing on the Red Planet. For now, though, Nasa's attention is focussed away from the Sun, not towards it, which means probably no floating cloud cities anytime soon.
This article was originally published by WIRED UK
