Leak Management!

I've spent a lot of late nights--when it's quiet outside--with windows closed, as quiet as I can get it, to listen for leaks, and have thus identified a lot, and sealed them. But I'm still leaking .005psi per second (a figure derived by voodoo and alchemy!). Yesterday finally got around to doing Ye Olde Soapy Water Test for inaudible, small gas leaks through suit fittings and hey hey, this identified a number of leaks in places I thought were absolutely gas-tight (actually, no such thing exists, and current space suits leak at a known rate of about 6 liters per hour). Now these are identified, I'm sealing them up! Photo shows a standard through-fitting (all PVC, will be metal sooner rather than later) with bubbles forming at a gas leak. Good news is that even in the event of the highest leak rate, bailing out (even from 50k feet) would send me down (within 15 seconds) at at least 176 feet per second, and the increasing pressure that I would encounter on the way down would more than compensate for the current leak rate in keeping a healthy pressure in the suit. Bailout is emergency scenario only--I don't mean to spend years on this, only to ride up for an hour and then jump! I want to stay up as long as I can!

Lower photo shows a crude (but accurate enough for now) estimation of suit pressure -vs- ambient pressure and altitude, feet per second descent rate for a bailout scenario from 50k feet, featuring the highest leak rate I am currently managing. Still survivable, and I am still pulling down that leak rate with late night 'silence' sessions!

Lucretius

I have been fascinated by the Roman philosopher Lucretius (died c. 50BC) for some time; he identified the essential factors of evolution nearly 2,000 years before Darwin, but came just short of assembling them into a coherent theory. Below, an interesting reference to Lucretius by Henry More (1614-1687). I have yet to be disappointed by research into the origins of our civilization!

'"If any man conceive I have done amisse in using such obscure words in my writings, I answer, that it is sometime fit for Poeticall pomp sake...Othersome time necessitie requires it because of the 'poverty of language and the novelty of matters', as Lucretius pleads for himself in like case." -- Henry More, 1659

FPM to MPH

My vertical speed indicator (VSI) is one of the most important displays, indicating whether I'm ascending or descending. My model reads in the standard Feet Per Minute (FPM), 500, 1000, 1500 and 2000. I know a decent ascent rate will be on the order of 1000FPM -- same for descent until about the last mile down, when I want to cut it drastically to land at closer to 100FPM -- but those numbers don't mean much to me, viscerally. Naturally MPH (miles per hour) is more intuitive, so I've printed a ring as a mockup, that translates FPM to MPH (turns out 2000FPM is about 20mph, and so on, but still I do like the larger numerals). Not so important for ascent, but landing is hitting the ground at the MPH indicated, and I'd prefer to keep that at something less than 5MPH or a little over at most -- it will be like being in a car crash at that speed (though I do have an idea for an airbag-like impact cushion that could be deployed with pressurized gas in a real emergency). So, this ring is a mockup around the VSI; when I have the numerals properly aligned, I'll print the final image, laminate it, and fix it to the VSI so that it doesn't obscure any other dials. The whole instrument display will be rebuilt pretty soon into a flyable configuration, but for the moment I'm learning a lot from thinking about these issues. Lower photo shows the whole red-lit panel, and another is a low-res image of a pressure test being shot for a magazine coming out in August.

Ray Bradbury

"I don't try to describe the future. I try to prevent it."

-- Ray Bradbury

Goodbye, Ray!

Mentor and Hero

Recently we had a departmental social. Luckily, I was photographed with my mentor and hero for 20+ years, Professor Ken Ames! Right about this time he was telling me how new varieties of data analysis might be better ways to go than I have been going! I am so lucky to have landed at PSU, with Ken Ames and Marc Feldesman as my intellectual guides in anthropology.

Controls and Monitors

Worked on the electrics of the controls today, seen here with some of the aircraft performance monitors. I've devised a 4-page checklist (lower left) to ensure that all stages of pressurizing and depressurizing the suit are done in a safe sequence. It's interesting to learn the significance of such checklists, and not just because someone has told me that they're important (I have in mind an article about the history of aviation checklists, which is pretty interesting!) but because as my system grows in complexity--though I am keeping it as simple as humanly possible--my life is staked on an increasingly long list of correct actions RE valves and other controls.

Test Video

One of three full-pressure tests done this past weekend.

http://www.youtube.com/watch?v=5UL37nUJ81M&list=UUup7MB9ZJJMGYd2NVkK_kJQ&index=1&feature=plcp

Direct LINK.

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