Yo Yo Ma

There's a reason that the most talented cellists play this music!

RL Stevenson and his Treasure Island Map

"As I pored upon my map of Treasure Island, the future characters of the book began to appear there visibly among imaginary woods; and their brown faces and bright weapons peeped out upon me from unexpected quarters, as they passed to and fro, fighting and hunting treasure, on these few square inches of a flat projection. The next thing I knew, I had some paper before me and was writing out a list of chapters." -- Robert Louis Stevenson

Flight Simulation Program

Back when I was an undergrad in England, a good buddy of mine was a crack programmer who taught me some things about computer programming. Now I've used that knowledge to write a simple program simulating my balloon flights. The program runs on an ancient Mac that I pulled out of a closet. Using a simple formula that takes into account many variables that result in buoyancy force of the balloon (the essence of balloon aviation) it simulates ALT = altitude, FPM = feet per minute ascending or descending, FUEL = fuel consumption (not being monitored just yet), OAT = outside air temp in F, BET = balloon envelope temperature, OXY = oxygen supply (not monitored either just yet), APSI = ambient atmospheric pressure in PSI and some other variables. This sim will be run many times, and refined, with me in the suit / cockpit mockup, communicating with my buddy Chuck Sullivan, who will run the sim and coordinate things like running the burner and bailout scenarios while I'm in the pressurized suit, communicating by radio. By running sims we can get a handle on things like how we communicate, power and gas consumption rates, how long it takes to do certain things, and so on. Another piece of the puzzle in place :)

Electrics Rebuild

Complete rewiring today, getting the system set for fully-pressurized simulations coordinated with the flight simulation program. This will give me concrete information about flight times and consumption rates for e.g. battery power (though I don't have the solar panels I'll use to keep a 'trickle charge' into the 12v DC system), suit pressurization gas and breathing gas. It will also ensure that I can reach all the switches and other actuators with the suit pressurized, as well as totally disconnect from the system to stand up and bail out in the event of emergency.

Restraints Installed

Quick video of seat restraints installed in the cockpit mockup. Another small item off the list!



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Checklist Development

I spend a lot of time thinking about checklists--they're the only way to be sure all goes well. I imagine circumstances and plan out what to do in those cases, then formalize them into lists of actions. On the one hand, checklists are invaluable; everyone from serious divers to aircraft pilots use them. On the other hand, you mustn't be a slave to a checklist if conditions differ than what you expected...and if you step far outside your front door, that is what you find!

Back to Work!

A month and a half break from the physical system allowed me to think about it at times, and in my notebook I designed four systems to build. Today I took a couple of hours and $10.00 to build a prototype of one, a mechanical and automatic suit pressure regulation valve; it admits suit pressurization gas into the suit, but then shuts off the gas supply when a certain pressure is reached. If suit pressure drops, the system kicks back in and brings it up again to healthy pressure. This PVC prototype, if it works, will be even easier to build in metal. It replaces the 12v DC solenoid, for the same function, that I like except for the fact that it requires power, and batteries fail, and I don't want something so critical as suit pressure to rely on power. Second photo shows cleaning old rubber cement from around a through-fitting, a little detail that will improve the seal.