The space elevator is a glorious science fiction idea that's never gotten past the concept stage, mostly because it's impossible to build one right now. Recognising this, a Canadian space firm is hoping to test the waters with a slightly scaled-down version — a space tower, if you will, that only rises into the stratosphere. Only.
Thoth Technology, Inc has been granted US and UK patents for an inflatable structure that can take astronauts up into the stratosphere, 20 kilometres above the Earth. From there, they'd be launched into space. In theory, this sounds like a grand idea: If we didn't have to bring our rockets back to ground on the regular, we'd skirt a good chunk of our planet's gravity and save money on fuel. Here's The Guardian on the idea:
Traditionally, regions above 50km in altitude can only be reached by rocket ships, where mass is expelled at a high velocity to achieve thrust in the opposite direction. Quine said in the patent that rocketry is "extremely inefficient" and that a space elevator would take less energy. In the patent, Quine explained that rocket ships expend more energy because they "must counter the gravitational force during the flight by carrying mass in the form of propellant and must overcome atmospheric drag". In contrast, by using an elevator system, "the work done is significantly less as no expulsion mass must be carried to do work against gravity, and lower ascent speeds in the lower atmosphere can virtually eliminate atmospheric drag". "Part of the limitation on space travel is the cost of getting to space," Quine told the Guardian. "The tower could change space travel because professional rockets are very energy intensive and not very environmentally friendly."
Sounds like a pretty solid argument for trying to build the world's tallest tower. But is this idea more feasible than the sky-high, carbon nanofiber-reinforced designs science fiction writers and physicists have been wheeling out to conferences for decades? Probably not.
There's still the wee problem of finding a material that can support itself to these extreme heights. And while the stratosphere is a much less ambitious target than space itself, you're still going to have to contend with some tremendously powerful air currents up there. The jet stream, which circles mid to high-latitudes of our planet at a height of approximately 9.6 to 14.5 kilometres, can reach blistering speeds of up to 442.5 kilometres per hour.
Still, given that we haven't made any tangible progress on space elevators since Arthur C. Clarke was writing on the subject in the '70s, I'm all for folks attempting to simplify the idea. And hey, I'd shell out good money to drink a beer in the world's tallest sky-bar. Wouldn't you?