Author
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Topic: Mercury spacecraft electrical connectors
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Joel Katzowitz Member Posts: 808 From: Marietta GA USA Registered: Dec 1999
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posted 09-10-2012 07:05 PM
I've been scouring the internet trying to ascertain what the various external connection points around the forward perimeter of the spacecraft accomplish. Specifically the connector plug marked J2 (other points are marked J20, J37, etc.). I've read through the "Mercury Familiarization Manuals" and anything else I could find to no avail. The connectors are fitted with an explosive disconnect and several of the cables appear to run to the retro pack.I have a fragment of an exterior shingle recovered from MA-1. The specific shingle housed the J2 connector and my piece has a spot welded section of Rene 41 with a 2" diameter cutout. MA-1 was launched without an escape tower. Any help will be appreciated, thanks. |
mercsim Member Posts: 219 From: Phoenix, AZ Registered: Feb 2007
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posted 09-10-2012 11:02 PM
The clamp adapter ring (section 3-15 in Mercury Familiarization Manual) is powered thru two of the receptacles. The Retro Package is supplied electrical power thru three umbilicals which are equally spaced around the base of the spacecraft (MFM 10-3). This appears to account for the 5 umbilical connections located at the base of the capsule. The lower right location only has one which is shown in David Weeks' drawings and photos of the various capsules. I haven't looked at all the capsules to see if any had two receptacles at this location.I have never seen any reference as to which umbilical went to which connector. It's probably listed in some assembly work instructions somewhere. I probably haven't helped solve your mystery but maybe the discussion will jog someone else that may have more to add. Could you share some photos of the shingle piece. Could you tell us where you got it? |
mercsim Member Posts: 219 From: Phoenix, AZ Registered: Feb 2007
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posted 09-11-2012 07:44 PM
After further thought, I realized I had addressed the number of umbilical plugs when making my paper model several years ago. The capsules were all slightly different and some had five connectors and some had six. Here are some photos showing the J2 location. The capsule numbers are the serial number referenced in the photo title. Its interesting to see the photos of Capsule 4. The pre-flight photo shows the connector plugged into the J2 location. There isn't enough resolution to tell if there was another one next to it for the Adapter clamp. Those little spring loaded doors are hard to see. The post flight photo shows the panel in question but its hidden behind the remains of the Marman clamp. None of this answers the original question of what exactly the J2 connector did but its fun to look at the photos. The first two sketches are for a previous collectSPACE post in a different thread. |
Joel Katzowitz Member Posts: 808 From: Marietta GA USA Registered: Dec 1999
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posted 09-12-2012 07:32 PM
Wow, great information thanks! Your photos may help.I got the fragment on ebay. The story goes that during reconstruction of the spacecraft, this piece (roughly 2"x 3") wasn't deemed critical to the investigation and so one of the technicians kept it as a souvenir. The fragment came framed in a display that also showed a photo of the reconstructed spacecraft with an arrow pointing to the area it came from. I checked all of the information I had to verify that it's an actual piece of shingle. Including engineering specs, like metal thickness, and everything was dead on. The mystery is one side of the fragment has another metal piece with a 2" diameter radius section spot welded to it. I can't figure out why. I theorized that maybe the sliding door at the connector had been welded shut because that connection wasn't needed for this particular flight. There was no escape tower or environmental control system so I thought maybe that's why. But I'm really just grasping at straws. I don't have a way to post images here but I'll send some to your email. Thanks again for your input. |
Joel Katzowitz Member Posts: 808 From: Marietta GA USA Registered: Dec 1999
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posted 09-15-2012 05:15 PM
BINGO!!!Scott (mercsim) solved the mystery of where my shingle fragment was located on the MA-1 spacecraft (SC #4). It took some searching through his reference material and some brain power but he was up to the task. Thank you Scott for your help. |
saturn1b Member Posts: 159 From: Westcliffe, CO Registered: Jun 2006
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posted 09-15-2012 10:10 PM
If anyone could do it... Scott could do it! Way to go. |
mercsim Member Posts: 219 From: Phoenix, AZ Registered: Feb 2007
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posted 09-16-2012 10:17 AM
It was quite fun. I was able to sneak in enough time between Dad duties to figure it out. Here is a photo of Joel's shingle fragment. It's about 2 x 3 inches. Together we did some detective work and believe it came from a lower shingle. It's difficult to identify exactly where but we believe its from near the J2 umbilical port. The technician that originally acquired it indicated so and there are similar shingles on SC#1 near the umbilical ports. The comparison part is a shingle from SC#1. Many shingles were scabbed together in the early part of the program as they were figuring out reliefs and access to fill ports, vents, thrusters, etc. It's apparent in the later manned flights that they figured it out because there is much less scabbing and patching of shingles, especially along the lower row. |
saturn1b Member Posts: 159 From: Westcliffe, CO Registered: Jun 2006
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posted 09-16-2012 11:19 AM
Great detective work and thanks for posting the photo for all of us to see as well. |