Monthly Archives: December 2011

Colors & materials for Apollo 11 CM, SM & LM. What the hardware looked like. For the Dragon kit.

Thanks to my beloved wife Jean, I got a Dragon Apollo 11 on the Moon kit, for Christmas! 1/72 scale, new tooling (same as their die-cast metal collectable?)

The short form on real, as-flown-in-1969, surfaces and finishes:

Command Module.

The actual Apollo Command module was covered with strips of mirror finish aluminized plastic micrometeoroid shield and thermal insulation, on the visible surfaces. The ablative heat shield, not visible until the CM and SM are separated, is said to have been painted a light gray color. During re-entry to Earth’s atmosphere, the mylar was mostly burned off and a light-gray painted structure under it became visible. Below that paint appears to have been a composite honeycomb material. I think it is unlikely that the actual pressure vessel that the crew lived in touched the outside surface except at the hatch edges.

In pictures of the remaining, unused, Apollo CSM (the emergency rescue vehicle for Skylab), you can see the stripe pattern of the plastic tape on the CM exterior, but in contemporary photographs, it looks like one piece of mirror polished aluminum. Like an American Airline’s jet airliner.

The fold-flat handles on the outside of the CSM, for astronaut Extra-Vehicular Activities (EVAs) were painted a glossy yellow, like the similar hand-rails on the the Hubble Space Telescope.

The docking capture and latch mechanism mounted on the outside of the tunnel, above the front hatch of the CM, is primarily titanium-looking metal, with a chromed, presumably retractable or spring loaded or damped, shaft.  There are darkened metal handles in the mechanism, probably painted or anodized a dark blue dark gray or black.

The inside of the tunnel itself, behind the docking capture mechanism, is light gray with 12 blue-anodized cylinder-topped arms at the top, some black and some other colors of boxes, and wires,

Service module:

The Service module exterior was  painted with an aluminum paint, except for radiator areas fore and aft which were white, two “ram’s horn” antennas that were white or light gray, and 24 narrow stripes (about 25%) on panels under the RCS thrusters. The area under “United States” may or may not have been light gray, and many labels on the exterior appear to be black text on light gray background.

The main engine exhaust bell is complex, but a bluish gray for the biggest, lower, part, outside, and reddish gray for the upper part, outside, is a good start. The top of the bell joins the reddish part at a flange, with bright bare metal fasteners by the dozen. The top of the bell, the last part visible beyond (below) the Inconel heat shield, is wrapped in the mylar and-or “H-film” ( aka “Kapton”) insulation and micrometeoroid shield. The back of the CM is mostly covered by 4 stamped quadrants what looks like thin Inconel nickel-copper high temp metal. The furthest outer edge of the end of the Service Module is painted with aluminum paint just like the sides.

Lunar Module:

The Lunar Module has two very different areas of finish: The descent (lower) stage is primarily wrapped in thermal insulation / micromedeoroid protection, a multilayer collection of  Kapton (“H film”) and Mylar, and other, exotic, things, with metal evaporated/ plated on them for protection. A lot of what looks ‘black’ is actually a black-finished foil or mylar.

The descent engine has a medium gray exterior and nestles in an Inconel-lined cavity in the descent stage.

The ascent (upper) stage of the Lunar Module is about half black-finished and half anodized Aluminum. Yes, the Aluminum looks like its dark, like Titanium, or has a distinct gray-beige-green tone. All true, many have remarked on the hard-to-describe colors. Grumman’s construction documents for the whole thing, facet by facet, are on line, and they specify Phosphoric acid and Sulfuric Acid anodizing of the various aluminum alloy pieces.  Some Mylar or “H film” wrapping is on the the outside of the ascent module. The ascent engine has a semi-gloss white exterior, with a textile-like “wrapped” texture. This may be thermal insulation, similar to the thick batts of insulation wrapped around the F1 engines of the Saturn V first stage.

There are two dish antennae on the ascent stage, Both have white-painted dishes and are generally black otherwise. The antenna directly above the lunar egress hatch and the front windows has black foil everywhere except the inside of the dish. The signal radiator in the center of the dish is white.

The antenna off on the starboard side of the ascent stage has a semi-gloss black mechanism and flat black on the back on the dish. Black, also, on the 4 legs and the forward reflector in front of the dish.

In more detail:

Command Module.

The Reaction Control System (RCS) engine nozzles on the CM have an oxidized copper color in their throats, and a slightly corrugated texture. Photos of post-re-entry CMs show a ring of the same oxidized copper color outside the nozzles, but the aluminized mylar covers these rings up to the edges of the RCS engine bells.

The forward and side windows for the two outside crew stations have black anti-glare finish around the windows, and red-orange silicone seals at every layer of the windows.

Below or behind the port side windows and the crossed RCS nozzles are a pair of drain valves, white 5/8 spheres with gold-toned dots at the outside. A very similar purge valve is installed on the starboard side of the side hatch.

On both sides, below windows, RCS nozzles, etc and the edge of the ablative re-entry shield, there are translucent white dots. Under the Mylar there are black partial circles around these two translucent circles,. On the Service Module, there are matching white partial circles painted on the fairing at the top edge of the SM

A minor (very minor) mystery is what kind of plastic the reflective stuff on the CM is. The expected temperature range in the space environment was wider than NASA was comfortable using Mylar, generally, uncovered, in the thermal insulation blankets covering the LM Descent Stage. Therefore, the outer layer of those blankets is always Kapton (“H film”), which is usable over the expected temperature range.  Of course, a blanket of up to 25 layers of plastic, using microthicknesses of vacuum deposited metal for insulation, is fundamentally different from a pressurized honeycomb structure wrapped with a layer of glued-on plastic tape. Maybe the thermal mass and inertia of the CM (and the slow-rolling passive thermal control regime) kept conditions on the outside of the CM suitable for Mylar, Maybe the CM plastic has the metal side “out”, unlike the majority of LM applications which are generally plastic side out (hence the gold-amber color: its not gold foil, its aluminized Kapton with the metal in and the plastic out.

Service module:

Inside the main engine exhaust bell is complex. At the bottom, inside the bluish gray outside, are 16 dark metal petals with strong textures. Inside the reddish-gray part of the bell are a set of 6 petals and then a solid ring- all a glossy dark color.  Above the dark, solid, ring, is a white metal ring, something like aluminum colored. Above that is an orangey brown and then at the peak of the engine is a light, metallic-finished plate with 5 stamped spokes and a central cap.

Lunar Module:

How I plan to reproduce these colors:

Command Module:

The glued-flat aluminized mylar on the real thing doesn’t look like any paint, even mirror polished aluminum. It looks like mylar, darker than polished aluminum. I have seen photos on-line of Apollo CMs finished in Bare Metal Foil, in the correct striped pattern. But I don’t see the stripes unless I look very closely in the 1960s photos- they’re easy to see in flash photos taken today, on the leftover CSM lifeboat for Skylab that never flew. But not in pictures of Apollo 11, or 15, or any of the other hardware that was flown.

Sooooo: Bare Metal Foil remains possible, or very thin aluminum foil, polished and clear-coated. “Chrome” spray paint would not be a bad choice. Having the kit part polished and then vacuum coated with aluminum would be very close to the real thing. Brush-painting Testor’s Chrome Silver oil-based paint or another similar non-water-based product is also a thought – the occasional brushmark could be said to represent the stripes of the Mylar…

“Chrome” spray paint or Metalizer Buffable Aluminum rattle can are the top two contenders at the moment. I’m going to do a study with each and see which I like more  watch this space.

Service Module:

Polly-scale Reefer White (that’s as in Refrigerator White, the rail-road color) is my call for the white paint on the lower and upper ring radiators, the two ‘tabs’ containing the ram’s horn antennas, and the white areas near the RCS boxes. My own mix for Boeing Aircraft Company #707 Gray is my first choice for the Light Gray RCS boxes, unless they’re white too, have to check again before I commit myself. The Inconel heat shield could be Polly Scale Stainless Steel, maybe with a bit of yellow added to bring out the nickel ‘color’… Inconel is a copper-nickel alloy and its attraction is that it holds its strength at high temperatures, not that its intrinsically tough stuff like titanium. It actually cuts and polishes pretty readily, but the important thing is that its clearly NOT aluminum. Completely different color. Not unlike stainless steel, which is, itself, not like steel OR aluminum.

Lunar Module: