Skydive in pressurized suit

Baumgartner also recently conducted the first high-altitude skydives, up to about 26,000 feet, in which the suit was fully pressurized. These tests over Perris, Calif., featured a new chest pack system designed to be less in the way when Baumgartner needs to spot his landing. (The earlier placement also had interfered with the helmet and with his overall movement.)

In the eventual 120,000-foot jump, Baumgartner is expected to reach the Mach 1 speed of 690 miles per hour (roughly 1,000 feet per second) about 35 seconds after he vacates the capsule, and how long he maintains that speed depends on whether he needs to deploy the drogue parachute to stabilize his flight, according to the Red Bull Stratos team. To determine whether he hits or exceeds Mach 1, his support team will need not only the speed data from his chest pack, but also the atmospheric temperature data from the capsule instrumentation. (Sound travels more slowly in lower temperatures, so while the speed of sound in the subzero clime of 100,000 or so feet is 690 mph, at sea level in, say, 60-degree conditions, the speed of sound would be closer to 760 miles per hour.)