Red Bull Stratos is a mission to the edge of space in which Felix Baumgartner will ascend to 120,000 feet in a helium balloon and come down to Earth in free fall, collecting useful scientific data and setting four world records as he does so:
1. Break the speed of sound unaided
2. Free fall from the highest altitude
3. Longest free-fall time
4. Highest manned balloon flight
The Red Bulletin is following the mission closely, each issue focusing on a specific topic. All back issues can be downloaded for the iPad.
This month we speak with Jonathan Clark, medical director of Red Bull Stratos, about the dangers to Baumgartner’s body.
THE RED BULLETIN: Which stages of Red Bull Stratos are the most dangerous, from a medical point of view?
JONATHAN CLARK: The start is quite precarious. Below 1,000 feet, the parachute doesn’t have the chance to open and slow the free fall. If the balloon envelope were to tear at the start, the odds would be stacked heavily against Felix. He needs 13 seconds to get out of the capsule -- at such a low altitude that’s too long. For this reason he’s buckled into a modified race truck seat with safety harnesses to make things as safe as possible. During the launch we have all rescue teams on standby at the start. I would even go so far as to say that the phase from zero to 1,000 feet is the most dangerous.
From what height could Felix exit without experiencing problems?
From 4,000 feet we’re on the safe side. From that point on he would have enough time to get out of the capsule, even if the balloon envelope ripped.
But then other problems await him further up...
Above the Armstrong Line at 63,000 feet, the pressure is so low that water in the blood “boils” away, as it were. That’s exactly what happened to Joe Kittinger’s hand when he jumped [due to a fault in the pressure suit]. It happened to a person during a spacesuit test, and to another in a vacuum chamber. It also sealed the fate of the crew on the Soviet spaceship Soyuz 11 in 1971: The cosmonauts weren’t wearing pressure suits, the capsule lost pressure, and in five minutes they were dead.
"We’re aware that Felix is in danger..."
What is it exactly that makes it lethal?
Seventy percent of the human body is made up of water. There are two different methods to bring water to boil: Either you apply heat or reduce pressure. Evaporating water upwards of Armstrong’s Line is not thermally hot; it’s the gas that causes the damage: inflammation, bubbles in the blood. The worst damage occurs in the lungs, directly to the alveoli, where the gas exchange with the blood occurs. We call this ebullism.
Is there still a chance to survive?
We’re aware that Felix is in danger and it’s our obligation to do everything to ensure he has good survival chances in the case of an ebullism. We have two respirators here with which we can safely execute the gas exchange with the blood even in a destroyed lung.
How does that work?
Humans need a certain amount of oxygen. Basically it doesn’t matter whether it’s given in big amplitudes or tiny amplitudes. With these inhalators here you “breathe” 12 times per second. This avoids a massive pulmonary pressure wave in the lung. Instead it almost oscillates and, as if by magic, is supplied with oxygen.
How does it feel?
Weird. The brain and body fight not breathing, but in fact it’s not necessary.
This inhalator is actually one of the greatest scientific advances that are associated with Red Bull Stratos. Earlier, this machine was used in premature baby wards because the lungs of extreme pre-term babies stick together. It can also be used in severe burn cases where the patients’ lungs have collapsed. Now we’ve extended the field of application to include vacuum injuries.
How long would it take to get Felix back to his old self?
A couple of weeks, as long as the lung isn’t filled with blood. As soon as the body receives oxygen it can begin to mend.
During the initial tests Felix complained about the extreme cold...
These are problems that must be fixed with better heating of the hands and feet.
What dangers lurk during the jump?
From a medical standpoint, two: One is a flat spin -- a fast, uncontrollable rotation around one’s own axis; the second is the shockwave that happens when breaking the sound barrier. We call it shock-shock interaction.
Let’s start with the flat spin.
Luckily we know quite a lot thanks to dummies that the Air Force tossed out of balloons in the 1950s and 1960s: From an altitude of 30,000 feet, the rotational speed is between 20 and 120 revolutions per minute. Jettisoning from higher altitudes increased the speed of rotation. Later, the Air Force put animals and people into centrifuges to see how the body reacts. Aside from the duration and speed of the rotation, the axis around which the body spins is very decisive. If you spin around the waist, half of the blood rushes to the head and the other half to the feet. Blood in the feet means that the heart is deprived and you become unconscious. If the spin can be arrested soon enough, then you can survive it.
Much more unpleasant is too much blood in the head, which ruptures and squashes namely the brain and eyes. And this is not at all good. For this reason we want Felix’s rotational axis to be as high as possible.
At what point does it become critical?
Luke Aikins [skydiving consultant] found in self-tests that he becomes unconscious when he’s exposed to more than 3.5 G for more than 6 seconds. So he developed a sensor that ignites a drogue chute once this reading is exceeded. This mini-parachute is shaped like a donut and slows the spin -- but also the speed of the free fall, and that’s not the intention of this project.
What happens when he breaks the sound barrier?
That is one of the areas we don’t completely understand yet: What happens when a shockwave collides with itself? So that’s why we have established the same medical protocol as for ebullism.
"After every pressure chamber test it smells like a sewage treatment plant!"
Is there not the danger that Felix might throw up in his helmet during the flat spin?
A very real danger. Should the vomit get into his lungs, that could cause massive damage. The worst-case scenario, however, is that the vomit gets in his eyes and he has to free fall blind until he reaches a respirable atmosphere. So Felix must try to hold the vomit in his mouth for as long as possible and then release it to one side. In this way at least one eye remains unaffected. Being sick in the spacesuit is a more serious hazard than you imagine. NASA had such a case during a space walk. The stuff would get into the material that absorbs the carbon dioxide and cause a very bad reaction.
Is radiation a threat?
No, for several reasons: We’re only up there for a short time, we’re not high enough up, and Roswell [the area in New Mexico where Baumgartner plans to land] is situated near the equator, far away from the major magnetic fields at the poles. A massive solar storm could delay the project -- not for medical reasons but because it could seriously interfere with the GPS.
During test jumps, Felix apparently used hair gel, although it’s not permitted because it contains alcohol.
Sure. Oxygen and alcohol combined could cause a nice little fire. On the other hand, a tiny bit of alcohol in a little hair gel evaporates in no time. The helmet is a very snug fit, so not a lot of oxygen reaches there... the media got hold of the hair gel issue at some point and it took off.
If he ate beans, would it explode in the stratosphere or is that a load of hot air as well?
When the outside pressure is low, gases expand inside the body: in the ear, the gut, the sinuses. This is serious. In the intestinal tract especially the problem usually solves itself: You, if you’ll pardon the language, belch or fart it out. After every pressure chamber test it smells like a sewage treatment plant! If you didn’t do this you’d run the risk of an intestinal barotrauma -- a bowel explosion. So the solution is not to eat anything that is quickly digested prior to jumping. Astronauts like to eat steak and eggs the day before a flight.
Why does Felix start to breathe pure oxygen two hours before the mission begins?
His body is saturated with nitrogen that, with decreasing pressure, behaves like carbonated water in a bottle: When you open the bottle it bubbles out. The nitrogen in the blood behaves similarly and bubbles form: We call this decompression sickness. By breathing in pure oxygen, we’re washing the nitrogen out of the blood. We manage a good 80 percent with our procedure, and with this we’re on the safe side.
What can science learn from Red Bull Stratos?
We need spacesuits with which you can survive up in the stratosphere. Outer-space tourism is just beginning, so it needs reliable statements and certainties, not solely but also for insurance purposes. There is always someone who sues the other one in such cases. Red Bull Stratos will be the reference for this. But even more importantly, how can you climb out of a spaceship and stay alive? Astronauts and cosmonauts alike would still be alive today if they’d had access to the information we have now. How do you treat victims of falling pressure, like in a space station or a spaceship?
Red Bull Stratos has developed the medical protocol for this. We generate massive amounts of data the likes of which have never been collated before. Felix is wired up during the entire mission. We make this data available for research. The scientific value of Red Bull Stratos is huge.
Would you swap places with Felix?
If I had a tailor-made suit that fitted I wouldn’t hesitate for one second.
Check out the July 2012 issue of Red Bulletin magazine (on newsstands June 12) for more articles. To read the magazine on your iPad, download the Red Bulletin iPad app.