But the optimists think it is possible to avoid losing altitude by building a bridge between where they are and where they would like to be.

ECONOMIST: Economics focus

That wind was traveling at 120 miles an hour, so we ended up with Felix in the capsule under this 30-million-cubic-foot balloon flying at 125 miles an hour to the east, which is amazing to think about, because at that altitude, it's the equivalent of about a 50-story building.

ENGADGET: Art Thompson, Red Bull Stratos' technical project director, talks circuit breakers, wind shear and biomedical data