With Helios, NASA Flies Through Rare Air

It's not just outer space that's the final frontier. It's also the rarified climes present at 90,000-plus feet, on the whisper-thin edge of Earth's atmosphere. It is here that NASA had a later-day Mercury moment Tuesday, when its experimental Helios aircraft shattered altitude records and pointed the way toward one day flying on Mars.

The craft has a 247-foot wingspan and solar panels that power the 14 propellers that keep it aloft, and Tuesday it traveled higher (96,500 feet) than any other non-rocket-powered plane. The possible uses are twofold. NASA hopes that this test will help it to design aircraft that can fly in the thin Martian atmosphere. And some entrepreneurial sorts think that eventually a network of these high-flying birds could serve as low-cost alternatives to communications satellites.