Felix Baumgartner's record-breaking supersonic jump was an amazing feat of human endeavour. But getting Felix to break the speed of sound caused Red Bull Stratos technical project director Art Thompson some engineering headaches. Here's how he solved them.
Engadget has been chatting to Thompson about the technical problems faced in getting Felix up in to the stratosphere and then back down in one piece. You can read their full interview for all the details, but here are a few choice snippets about the problems he had to solve.
Custom circuit breakers
"One of the things early on that surprised me was that we assumed space programs in the past had resolved issues with circuit breakers at high altitude, or vacuum conditions. In a vacuum, a conventional circuit breaker — which measures heat across a load — doesn't work, because there, there's less or no atmosphere there to draw the heat off. We soon realised, with other space craft, they don't need to worry about this because they always stay pressurised to 11.5 PSI. When you slide that door open, all of the electronics are exposed to the near-vacuum, so we had to develop a solid-state breaker that was monitoring actual loads across that circuit... In that development, we created circuit breakers that we could remotely operate from the ground."
"There were some concerns once we managed to get the balloon launched... We knew that there was the potential for wind shear up around 45,000 - 50,000 feet, somewhere around there. If some wind shear would cross with another section a few hundred, or a thousand feet above it, you can end up in a condition where it'll actually cut like a knife, and slice the top of the balloon right off. Fortunately, during our flight, that condition stabilised, and we ended up with a situation where all the winds were going in the same direction, all heading east. That wind was travelling 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."
"What I love about the photography is that combined with the scientific data... and combining the biomedical data that's monitoring his heart rate, breathing, skin temperature and the forces of his body, etc. Combining that with the high-resolution video gives us a scientific tool that's amazing. I can look in real-time at Felix, and all his body positioning, and understand what he's going through physically. What forces are going through his body when he goes into the speed of sound, when he's exiting, when he goes into flat spin — all the way down to when he steps on the ground We're going to take this data and process it over the next several months."
Image from Sage Cheshire