It might be the weirdest part of the atmosphere, 15 miles above the polar regions, where vast stratospheric clouds of nitric acid and water vapour shimmer in iridescent pink, while human-made chemicals play havoc with the ozone layer.
Scientists long to study the stratosphere at close range. But this is almost the edge of space, far too high for a conventional airplane in level flight.
How to get there?
In a glider.
Without the weight of engines or fuel, a glider can be lifted by natural atmospheric phenomena, engineers say. So a team of scientists, aviation buffs and entrepreneurs is building a two-seat sailplane designed to withstand the peculiar hazards of stratospheric flight. The journey is scheduled for August 2015.
The glider will be shipped by freighter to El Calafate, Argentina, where winds from the Pacific Ocean are deflected by the Andes Mountains to create a standing wave, like the waves of water that form over rocks in a mountain stream, with updrafts of 30 ft per second.
“These mountain waves get so steep and energetic, they turn into white water,” said Edward J Warnock, an aerospace engineer, who is chief executive of the Perlan Project, the non-profit organisation that is building the glider, Perlan II.
A single-engine plane, probably a crop duster, will tow the glider to meet these waves, at about 10,000 ft. Where the waves weaken, at about 60,000 ft, the glider is supposed to intercept another phenomenon, the polar vortex—circulating winds that act like a giant cyclone during the austral winter, delivering a strong uplift. If it can catch that current, the glider will soar still higher, into the Perlan Clouds, and higher, into the ozone hole, where the chemical reactions that disrupt the ozone layer take place (Perlan is the Icelandic word for “pearl”, describing the clouds’ sunlit glow).
The aim is to go to 90,000 ft, or 17 miles up, and set a new altitude record for a glider. The plane’s predecessor, Perlan I, set the record of 50,726 ft on August 30, 2006.
Perlan II will cost an estimated $7.5 million, of which $3.5 million has already been spent; the project is still trying to raise the balance. The organisers include Dennis Tito, the pension fund manager who paid $20 million to visit the International Space Station, and, until he was killed in the 2007 crash of his single-engine plane, Steve Fossett, the aeronaut and sailor who flew Perlan I.