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Gemini 9 EVA
by
Bob Shaw
on 05 Oct, 2014 13:43
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When Gene Cernan attempted to fly the MMU on Gemini 9 he was, so far as I know, wearing a unique spacesuit. It had what has been described as 'metallised fabric' legs, and these were supposed to protect him from the hot gasses being ejected from the rocket nozzles (yes, it had proper rocket engines, unlike the later MMUs or the hand-held maneuvering guns).
So far, so good. What has always intrigued me about Cernan's spacesuit was whether there were any special precautions taken elsewhere - in particular on his shoulders, helmet and arms. The upper front nozzles are *very* close to all of these, and of course arms are mobile and could in principle have the hot exhaust strike them.
Cernan's over-ambitious EVA was called to a halt before he donned the MMU because he was hot, exhausted and unable to see through his helmet visor - but he had also torn the outer covering of the back of his suit. Was this a special additional layer for this EVA only, and did his one-off spacesuit contribute to his problems?
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#1
by
Jim
on 05 Oct, 2014 17:25
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1. When Gene Cernan attempted to fly the MMU on Gemini 9 he was, so far as I know, wearing a unique spacesuit. It had what has been described as 'metallised fabric' legs, and these were supposed to protect him from the hot gasses being ejected from the rocket nozzles (yes, it had proper rocket engines, unlike the later MMUs or the hand-held maneuvering guns).
2. Cernan's over-ambitious EVA was called to a halt before he donned the MMU because he was hot, exhausted and unable to see through his helmet visor - but he had also torn the outer covering of the back of his suit. Was this a special additional layer for this EVA only, and did his one-off spacesuit contribute to his problems?
1. It was mono prop (decomposed H2O2), which I still wouldn't call a "proper" rocket engine either, since there is no combustion
2. Any of the Gemini suits would have the problems with any excursion since they only used force air cooling which was inadequate. Liquid cooling is needed
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#2
by
Bob Shaw
on 05 Oct, 2014 17:39
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Jim, that's absolutely true - but even a not-quite-proper engine of that variety belts out some pretty hot gas, and they *did* protect his legs from it! I'm still interested in the protection over his upper body, which I suspect - if it exists - made his EVA still more difficult than it might have been. Cernan and the other early EVA guys were tough, but their suits were really not quite up to the job.
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#3
by
RanulfC
on 07 Oct, 2014 16:05
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Jim; But the Gemini suits DID have Liquid Cooling... The air just wasn't moving fast enough or in volume enough to leverage the sweating the guys were doing
Randy
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#4
by
DwightM
on 10 Oct, 2014 23:56
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This suit is on display at the Kansas Cosmosphere and Space Center. I can't count how many times I've been there over the years (just there this past May) and this suit is a cool addition.
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#5
by
Blackstar
on 11 Oct, 2014 15:40
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There was supposed to be a second MMU test on Gemini 12, I think. Anybody know what happened to that hardware?
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#6
by
the_other_Doug
on 15 Oct, 2014 01:44
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What appeared to be a flight-hardware AMU (that was its actual designation, the Astronaut Maneuvering Unit) showed up, of all places, on the History Channel show "American Restoration." It was signed on the inside back plate, the side that faced the astronaut's back, by both Buzz Aldrin and Gene Cernan. The restoration crew fixed some dents and cleaned and repainted the unit (leaving the signatures in place), and when they were done it looked exactly like new flight hardware.
It had internal batteries and both fuel and oxygen tanks, correct-looking internal plumbing, etc. Most especially, it had the little signage plaques all over it that were used everywhere on NASA manned spacecraft and equipment in that era. I wouldn't think that a fully functional unit like that would've been used for ground training, especially not in the zero-G airplane or in the water tank.
It makes sense that such a unit would be signed by Aldrin and Cernan, since only they (and the late Charlie Bassett) ever trained to use the AMU. The Gemini 12 AMU training was stopped sometime in August or September of 1966 (I believe Dick Gordon's EVA issues finally pushed the AMU over the edge and off of Gemini 12), and since Aldrin was prime pilot and Cernan was his back-up, I could imagine them signing the flight unit that neither would ever be given the opportunity to test. But it's hard to tell, since Aldrin was Cernan's back-up on Gemini IX-A, so the unit could have come out of either mission's training and/or flight hardware stockpiles.
-Doug
With my shield, not yet upon it
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#7
by
the_other_Doug
on 15 Oct, 2014 02:02
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As to Bob's question about Cernan's suit issues, I know that the upper AMU jets had a jet pattern that was not supposed to impinge at all on the upper suit or helmet. So those parts of the suit weren't reinforced with the aluminum outer layer.
But the "shiny pants" were thick and stiff, much stiffer than the standard GL5 suit's legs. And Cernan was a big, strapping, strong guy (one of the six-footers, IIRC). So I can well imagine that, as he twisted and turned trying to stabilize while doing his "tether dynamics" experiment, the twisting motions combined with the much stiffer "seat of the pants" than previously flown could have caused the split in the lower back of the outer layer of the suit.
I seriously doubt, though, that Cernan's overheating was caused by the modified suit legs. He, and Gordon after him, had problems because 1) they are guys who just naturally get hot and sweaty when they put in hard physical work (some guys tend more to that than others), and 2) the air cooling was simply not good enough to dissipate the metabolic heat of a man working hard in one of those suits. Water cooling (and, for future microgravity EVAs, sufficient hand- and foot-holds) fixed the problem.
-Doug
With my shield, not yet upon it
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#8
by
Ronpur50
on 19 May, 2015 14:03
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Has anyone ever found any photos of the rear of Gemini 9 showing the MMU besides this?
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#9
by
Antilope7724
on 19 May, 2015 20:38
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Has anyone ever found any photos of the rear of Gemini 9 showing the MMU besides this?
Mockup of adapter equipment section to be used on Gemini 9 space flight
by NASA/Johnson Space Center (NASA-JSC)
https://archive.org/details/NIX-S66-22686--------------------------------------------------
GEMINI-TITAN GT-IX - TRAINING - WEIGHTLESSNESS - ASTRONAUT MANEUVERING UNIT - ZERO GRAVITY - FL
by NASA
https://archive.org/details/S66-31665 ---------------------------------------------------------
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#10
by
the_other_Doug
on 20 May, 2015 03:55
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Here are a few images. Some are of the actual flight AMU in the GT-IXA adapter section, others are of training rigs.
As a special OT treat, the final image is of the Radar Evaluation Pod (REP) mounted in the adapter section of the Gemini V spacecraft.
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#11
by
Blackstar
on 20 May, 2015 14:19
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These are neat. Where did they come from? They appear to be hi-res.
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#12
by
the_other_Doug
on 20 May, 2015 15:15
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These are neat. Where did they come from? They appear to be hi-res.
They're from a variety of sources around the web. I think most of them came from Kip Teague's
www.apolloarchive.com website, though some are from NASA's history office website.
I've also processed the images, to various screen sizes (and fiddled with brightness, contrast, sharpness, etc., to taste), so that I can use them as slideshow screen savers. Anything with a "-L1" (or occasionally "-L2," not related to L2 content here in any way) is something I formatted and re-cropped for my current HDTV-aspect-ratio monitor with 1920x1080 resolution. The reason for the other sizes and filename tags (like "-2") is that I formatted those for earlier monitor resolutions, but since they are properly cropped as vertical images and hence have black side bars, and since my slideshow screensaver just sizes them to fit vertically, I don't need to further alter them for slideshow purposes.
These are all originally from either Kip's site or from a NASA site, though, I'm sure.
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#13
by
Ronpur50
on 20 May, 2015 23:38
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Fantastic! Thanks so much!
That should help with my model project.
