Spacesuit Unveiled for Hi-Altitude Freefall Record Attempt
Felix Baumgartner tests the mobility of his pressure suit shell during high altitude skydive training over the Mojave desert in preparation for the Red Bull Stratos mission where he hopes to freefall back to Earth from 120,000 feet in 2010. Photo credit: Luke Aikins for Red Bull Media House
The Red Bull Stratos helmet is similar to a space helmet as it is a fiberglass shell that will protect Felix Baumgartner during his 120,000 foot freefall attempt in 2010. Credit: Red Bull Stratos
April 1, 2010 — This week the Red Bull Stratos science team has revealed the pressure helmet, and suit that will serve as Felix Baumgartner’s sole life-support system when he steps off his capsule at 120,000 feet to attempt a record-breaking freefall from the edge of space. The suit is custom made by The David Clark company which has been making suits since 1941 including launch entry suits for Space Shuttle astronauts and the iconic suit that United States Air Force Colonel (Ret.) Joe Kittinger wore on his historic Excelsior III jump in 1960.
Full-Pressure Suit Is Necessary
In the hostile stratospheric environment Felix plans to traverse, hazards include temperatures as cold as minus 56 degrees Celsius; an environment with too little oxygen to sustain human life; and air pressure so low that decompression sickness and embolism. During his ascent beneath a 30-million-cubic-foot polyethylene balloon filled with helium, Felix will depend on a sealed capsule to provide a pressurized environment; but once he depressurizes the vessel and opens the door to step off, his full-pressure suit and helmet – what engineers call a “Pilot Protective Assembly,” or PPA – will be his only life-support system until he reaches the safety of the lower atmosphere.
By attempting to break the speed of sound in freefall, Felix will be trailblazing a velocity that future astronauts and aviators may have to face: although Felix will need to optimize his flight posture to achieve Mach 1, astronauts bailing out from significantly higher altitudes would likely attain supersonic speed involuntarily.
A Full-Pressure Suit in Freefall
Although a full-pressure suit is essential for survival at high altitudes, such “space” suits have never been qualified for the kind of controlled freefall that Felix Baumgartner must execute to safely return to Earth from the edge of space. The challenges include restricted mobility that makes some physical adjustments that skydivers rely upon difficult, and others impossible. The view through the helmet visor will be limited and could be susceptible to fogging or icing from the atmosphere or perspiration. Plus the heavy gloves will limit his ability to operate or even feel his parachute controls.
Customized Full-Pressure Suit and Helmet
Mike Todd, the Red Bull Stratos Life Support Engineer, describes Felix’s PPA as “an artificial atmosphere.” The suit’s exterior is made of a material that is both fire-retardant and an insulator against extreme cold. Inside, the “bladder” (which will be filled with gases to provide pressurization before Felix exits the capsule), is composed of a selectively permeable material surrounded by link netting. When the bladder is inflated, it will provide pressure at 3.5 pounds per square inch. An integrated control valve, maintains pressure automatically at various altitudes.
The shell of the helmet is molded from composite materials. Its visor, has an integrated heating circuit that must warm it enough to avert fogging and icing, yet not melt it – a function doubly challenged by (1) a stratospheric environment that lacks air to draw away heat and (2) a potentially supersonic freefall that will encounter rapid changes in temperature. The helmet will also supply Felix with 100 percent oxygen (from cylinders he’ll wear), and it includes a microphone and earphones for communication with the Mission Control Center.
Test Jump Findings
“Every time someone jumps a system like this, there’s something to learn,” says Daniel R. McCarter, Program Manager for David Clark Company. Initial tests conducted in wind tunnels, low-pressure chambers and 25,000-foot skydives indicate that while it’s important to assess the pressure suit itself, the key to optimizing its functionality lies in seeing how the suit works with the other mission components, including the parachute rig. While the suit performed its life support function well, it did have a claustrophobic effect on Felix. In the wind tunnel Felix was able to maneuver into the high speed position he would need to go supersonic and the suit exhibited very little instability. The gloves and helmet did present a problem during test jumps which required the parachute controls to be modified so Felix could easily find the release handles.
“This is why test jumps are so valuable, because you are always discovering new things,” Felix notes. “On the ground, everything looks cool; but the picture changes when you’re in freefall. Especially when you’re the one in the pressure suit.”