Drifting between these two levels are the ten thousand floating cities of Venus."The first paragraph is completely accurate. The second is not, of course, but Landis, who has worked as a scientist at NASA for 26 years, has spent the last decade and a half attempting to change that.
At NASA, the idea of sending humans to Mars and Venus was first proposed in the run-up to Neil Armstrong's historic moonwalk, during the Apollo program, when the space agency was giddy with exploration and rich in funds. Public support for the space agency was also on its way to heights it would never otherwise reach. It had begun sending probes to Venus in 1961, as part of the Mariner program. For the humans-to-Venus proposals, which would repurpose Apollo hardware, engineers determined that the three astronauts on board would only have time for between 45 minutes and two days for close observations. Even with nuclear engines (also theoretical) this wouldn't be enough time to make the 400-day trip worth it. Going the extra distance to Mars, meanwhile, was considered practically impossible. To explore these planets, robots would have to be enough.
Venus's gravity is 90 percent of Earth's, and it's easier to get to than Mars, reachable in just five months as opposed to nine for Mars.
"The surface environment of Venus is a warning," Carl Sagan wrote. "Something disastrous can happen to a planet rather like our own."
The Terraforming Options
In 2010, the Nobel prize-winning atmospheric chemist Paul Crutzen proposed releasing massive amounts of sulfur dioxide high in the Venusian atmosphere, which he argued would lower surface temperatures and slow the runaway greenhouse effect by re-creating conditions similar to a massive volcanic eruption on Earth. The idea echoed his now famous proposal for Earth: pumping gas into the atmosphere to stave off the effects of global warming—a kind of plan B for the climate that helped propel the geoengineering craze.In the early 1990s, a scientist named Paul Birch proposed a different terraforming approach to Venus's CO2 problem: infusing the planet's atmosphere with 40,000,000,000,000,000,000 kg of hydrogen obtained, somehow, from the gas giants Jupiter and Saturn. According to Birch, the hydrogen would react with all the excess carbon dioxide in the atmosphere in a process called a Bosch reaction, producing elemental carbon and incredible amounts of water—by his estimate, enough water to cover 80 percent of the Venusian surface. This process would reduce atmospheric pressure to a mere 3 bar, roughly three times that of Earth, and this nitrogen rich atmosphere would continually decrease in pressure as the nitrogen dissolved into the newly created oceans.
In more expansive visions, pumping Venus full of sulfur dioxide or hydrogen—or surrounding it in Sun shields—could terraform its climate into submission.
The Cloud Options
What about the prospect of entire colonies plummeting dozens of miles to the surface while burning up in clouds made of sulfuric acid? Landis didn't seem too phased."Well of course anything humans do has some risk," he said. "But you'd want to make your cities quite robust. Obviously, the larger a balloon is the more time you have to deal with a leak. If you have a tiny balloon, a child's balloon, it pops instantly. You'd want a giant balloon with multiple different chambers in it [for these floating cities]. It'd be huge compared to any balloon we've ever had on earth. It would absolutely dwarf the Hindenburg."
"You'd really have to do this for the long term exploration of space. This is where the future is. We're moving out into the solar system." —Dale Arney
'Beautiful, you think, yes? Like the wonderful jellyfishes of your blue planet's oceans. Can you believe that half a million people live there?'"