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jeffyjeep 02-15-2019 05:20 PM

Apollo SM RCS units.
Does anybody have a true color photo or diagram of the RCS nozzle quads on the Apollo Service Module? I’m pretty sure they’re not suppose to be just plain white.


BARGeezer 02-15-2019 05:50 PM

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Looks like it's all silver (Apollo 15).

Chas Russell 02-15-2019 06:08 PM

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All of the RCS motors were test fired after manufacture. I took this picture at NARCON last year in Houston. They are sort of goldish and silver. One recommendation that I heard was a burnt platinum. I would not go straight white or silver.


BEC 02-15-2019 07:53 PM

Chas beat me to it, with a better picture than the one I would have put up (but taken of the same vehicle - the full Saturn V that is on display at Space Center Houston). The nozzles look to me as if they are either titanium or stainless steel discolored by heat. Based on Chas' picture I am leaning toward the latter.

Earl 02-15-2019 08:15 PM

The ones I have photographed at KSC and NASM (in D.C.) have had silver quad 'boxes' like this one (my photos are not immedialtely accessable).

As can be seen, there is printing on the top of the box, which I forget the exact nature but seems to deal with quad firing order or something similar.

Here's a link to the photo:


luke strawwalker 02-15-2019 08:26 PM

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Hey Jeff!

Yeah, basically the quad "boxes" are white, and the nozzles are sort of a "gunmetal" color...
Actually, "gunmetal" isn't quite right... they sorta have a slightly "gold" color to them, or "brass" color maybe. I got curious in the middle of digging these up and searched for it and found the Apollo operations handbook on PDF and here's what it actually says about the thruster quad construction materials...

"Combustion chamber- The combustion chamber is constructed of unalloyed molybdenum which is coated with molybdenum disilicide to prevent oxidation of the base metal. Cooling of the chamber is by radiation and film cooling.

Nozzle extension- The nozzle extension is attached to the chamber with a waspalloy nut. The nozzle extension is machined from a cobalt base alloy (stainless steel). The stiffener rings are machined."

Here's some pics of the CSM display at Kennedy Space Center, below the Saturn V, and of the Saturn V itself.

I'll see what I have regarding the CSM on the Saturn V in Huntsville and of course the one here in Houston as well...

Later! OL J R :)

Earl 02-15-2019 08:33 PM

Originally Posted by luke strawwalker
Hey Jeff!

Yeah, basically the quad "boxes" are white

Later! OL J R :)

Take a look at the photo link in my prior message and a second look at your photos (I have similar photos of those same RCS quads at KSC myself).

The quad *boxes* themselves are silver...that 'top of the box' white you see is the 'printing' I mentioned above. I think it might actually be a label applied to the top of the quad box.


luke strawwalker 02-15-2019 08:34 PM

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Here's pics of the ones at JSC... remember these were outdoors in the terrible Texas coastal weather and salt air, hurricanes, heavy rainfall, and tons of nearby chemical plant pollution for over 30 years before they built the building over it... So that will definitely have SOME effect on things...

later! OL J R :)

luke strawwalker 02-15-2019 08:45 PM

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Here's some from the Kansas Cosmosphere... these are on the CSM in the Apollo/Soyuz Test Project display, which shows a Soyuz and Apollo CSM with the docking adapter...

Note the writing and color of the nozzles... these are probably the most accurate. The others on display may have painted "boxes" or otherwise have been either weathered, refurbished, or both.

The lighting in the Cosmosphere may throw off the pics, as it's rather subdued, but you can at least get the idea... this is probably the closest I've gotten to them...

I'll see what I have in my Marshall Space Flight Center (USSRC) pics since the Davidson Center is lit mostly by natural light and will probably have the best color rendition on the camera...

later! OL J R :)

luke strawwalker 02-15-2019 08:54 PM

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Here's the pic I have of the Saturn V at Marshall in Huntsville... obviously of no use since it's some sort of mock-up to stand in for the CSM/SLA panels on top of the S-IVB. They have a trainer mockup of the CM there as well that you can actually slide into.

Later! OL J R :)

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