posted 08-14-2018 12:03 PM               

We know that the CM still had the blue color when the spacecraft was mated to the launch vehicle inside the VAB (photo 1). When the vehicle rolled out to the launch pad, the Boost Protective Cover had been installed, so I assumed the blue layer had been removed before that.

But a photo of the Apollo 17 countdown test (photo 2) shows that the protective blue layer was still in place on the CM (although it appears that several strips had been pulled off).

Another photo, taken several days before the Apollo 15 launch (photo 3), shows that the BPC could apparently be removed in parts while at the launch pad. So I assume the blue tape was removed sometime after the CDDT and possible just a few days before launch.

Does anyone have more info on this?

posted 08-29-2018 09:23 AM            

The Command Module at the Rockwell plant in Downey, Calif. on August 8, 1968 just prior to shipment to KSC.

posted 09-08-2018 11:38 AM            

All of the Apollo Block II Command Modules were covered with aluminized Kapton tape. The Kapton is a clear plastic film (polyimide) amberish in color. A thin vaccuum depositing of aluminum was mirror bright. The adhesive was applied on the amber side so that the mirror side was out (thus the CM looks like a mirror), but, after re-entry, some of the aluminum was removed or the tape was burned and peeled up so that the remnants gave a yellowish cast. I believe that the tape was applied in 2 inch stips and it was hand done on the pad just before launch. The blue protective tape was peeled off and the Kapton tape was pieced on in sections.

posted 09-09-2018 08:34 AM               

The CM thermal coating that looks like aluminum foil was G 1015 thermal control tape, comprised of 0.5 mil Kapton with a silicone pressure sensitive adhesive on the back. It was coated with about 5-millionths of an inch of vacuum deposited aluminum and overcoated with about 40-millionths of an inch of silicon oxide. The G.T. Schjeldahl Company, Northfield, Minnesota, manufactured this tape, which was supplied with a blue protective coverlay tape.

posted 09-09-2018 01:39 PM            

Apollo 14 photo 70P-464 (below) seems to show that.

Some photos taken in the MSOB and VAB show the CM forward heat shield without the blue protective cover.

posted 09-09-2018 10:15 PM               

quote:

---

Originally posted by heng44:
So the blue protective cover had to be peeled off to expose the G 1050.

---

This, plus the fact that the photos indicate that NASA wanted to protect the Kapton as much as possible, tends to indicate that the blue film was left on as long as possible, and only removed when needed.

The third image posted by Ed above looks to show technicians installing the access panel and sealing the heat shield joints. The blue film left on the panel may have been done to protect the Kapton tape during handling. When this image was taken is probably a good indication to the answer to this question.

This also highlights that NASA may have treated the surface finish and condition of the tape with a higher level of importance than I was previously aware of. This makes sense because the original purpose of the tape was for reflective thermal protection, but I was not aware of just how critical it may have been considered, and I would be interested to find any documentation regarding this point.

posted 09-10-2018 03:24 PM            

Looking at the Apollo 15 photo, it seems that the forward BPC that covers the forward heat shield would have to be installed before the aft (lower) BPC that covers the crew compartment heat shield.

But the Apollo 14 VAB photo shows the forward boost protective cover being lowered onto the command module, with the crew compartment section already covered by the white, tarp-like thermal cover seen in rollout photos.

posted 09-10-2018 07:59 PM            

quote:

---

Originally posted by heng44:
My friend Rolf Schoevaart has a sample...

---

posted 09-11-2018 01:09 AM               

quote:

---

Originally posted by LM-12:
...it seems that the forward BPC that covers the forward heat shield would have to be installed before the aft (lower) BPC that covers the crew compartment heat shield.

---

posted 09-11-2018 04:10 AM               

quote:

---

Originally posted by Paul78zephyr:
Do you know if the G 1015 material as noted by your friend is the same as the GT-131 material in John's (space1) document?

---

posted 09-11-2018 04:16 AM               

quote:

---

Originally posted by LM-12:
Was the aft BPC installed for the rollout from the VAB to the pad?

---

posted 09-21-2018 11:52 AM            

The docking module and Apollo spacecraft for this summer's joint manned mission with the Soviet Union were mated in the Manned Spacecraft Operations Building today. The docking module will provide a mechanical and electrical link between the Apollo and Soyuz spacecraft while they are docked and also serve as an airlock. On hand to participate in the operation were two members of the Apollo prime crew, Astronauts Donald K. Slayton and Vance D. Brand. launch of the Saturn 1B/Apollo from Complex 39 is scheduled for July 15.

Here is a KSC arrival photo of the ASTP command module.

posted 09-23-2018 01:26 PM               

ASTP Apollo spacecraft being prepared for mating to SLA, March 5, 1975.

posted 09-23-2018 01:46 PM            

In my black and white photo, I see a reflective surface (the blue film probably) on the crew compartment section to the right of window 4. That seems to agree with your color photo.

Hard to tell with black and white photos, but there seems to be even more of the blue film removed in photo 75-H-124, which has the caption:

The Apollo Soyuz Test Project (ASTP) prime crew of astronauts Slayton, Brand and Stafford go through an altitude chamber run in the Command Service module.

posted 09-23-2018 08:06 PM               

quote:

---

Originally posted by LM-12:
So it appears that some of the blue film was removed from the forward heat shield, and there is no reflective tape there.

---

There could be numerous reasons why this was done, or also reasons why the tape was applied to these specific reasons prior to the test.

What has become apparent during this thread is the format of the tape, having the blue film as part of the silver reflective tape, and also how detailed and time consuming the application of the tape, and the removal of the blue film, must have been.

Each individual piece of tape was cut from a pattern, and applied to it's respective location. This means that each piece of blue film would need to be removed individually. Anyone who has experienced losing the end of the roll of packing tape or gift wrapping tape could sympathise over this task.

It seems that the application of the reflective tape required a methodical, detailed procedure to prevent wrinkles, creases and trapped air bubbles. The silver coating was thin film aluminum. any stretching of the tape may result in this coating being damaged, and any scratches or nicks would compromise the finish. Any blemishes, such as finger prints or stains, would compromise the reflective quality and so effect the thermal protection during spaceflight.

Anyone who has worked with pure Aluminum will be aware how fast the surface oxidates with exposure to air. the longer the protective blue film was left on the command module, the higher the quality of the reflective surface would be during flight.

Prior to Ed posting this question, I had always assumed that the blue film was a single sheet of material, as it had been referred to as looking like a cellophane wrapping in news articles and interviews [gumdrop]. I am still looking for information on the Boost Protective Cover layout, which would help explain the sequence of events better.

posted 09-24-2018 05:41 AM            

Here is another view of the ASTP command module in the KSC altitude chamber.

(The person at top right may very well have taken the photo that Ed posted.)

posted 09-24-2018 05:01 PM            

quote:

---

Originally posted by LM-12:
there seems to be even more of the blue film removed in photo 75-H-124

---

I think the clip footage pre-dates Ed's photo.

posted 09-25-2018 07:15 PM               

The film of the splashdown and recovery of the CM does not reveal a definitive answer to this, and the photos on orbit, available online, do not have the resolution to clear this question up.

North American reinforced repeatedly the requirement for the Kapton film integrity to prevent the Avcoat absorbing moisture. The CM certification process required the film to be installed before the capsule was shipped.

posted 09-26-2018 11:29 AM            

quote:

---

Originally posted by oly:
The CM certification process required the film to be installed before the capsule was shipped.

---

Perhaps for ASTP it was different, and for some reason it was necessary to apply the reflective thermal tape at KSC instead.

Is it possible that the blue protective film seen in the KSC arrival photo was applied directly to the heat shield, and removed some time after arrival?

posted 09-26-2018 09:07 PM               

The brazed stainless-steel sandwich panels that make up the heat shield, manufactured by North American Aviation subcontractor, Aeronca Corp, were shipped to Avco Corp for the application of the ablator material. A fiberglass honeycomb core was bonded to the primed stainless steel, vacuum bagged, cured and inspected using eddy-current process.

The ablator material was hand pumped [at 160 degrees F] into the 3/8 inch honeycomb cells. The structure was then oven cured and post-cured before being x-ray inspected, and any voids or defects were repaired by hand.

The structure was then machined using a numerically controlled lathe to give the varying thickness profiles around the circumference of the structure, tapering from the base. Post machining thickness inspections were measured using eddy-current process before various fixtures and fittings were installed to the heat shield. Silicone rubber gaskets were installed as required, and a final moisture content check was performed before a thin epoxy-based pore sealed was applied to the porous ablator material.

Final weight and centre of gravity measurements were performed before a moisture protecting plastic coating was applied before shipment back to North American, where the heat shield sub-assemblies are installed to the spacecraft.

"Before the CM is shipped from the prime contractor site to the NASA John F. Kennedy Space Center (KSC), the plastic coating is stripped off and the thermal-control coating with an adhesive backing is attached to the CM."

Specifications for maximum moisture content of the ablator material was 2 percent. The boost protective cover was a multi-layer, resin-impregnated fiberglass assembly that fits over the command module like a glove. Each cover was tailored to each heat shield. The process required the heat shield to be mounted on a holding fixture and a mixture of resin and fiberglass blown against the shield to produce a fiberglass female mold identical to the heat shield. Through a series of carefully controlled casting operations, a full-size plaster master is constructed to reproduce the outer mold line of the heat shield. This process resulted in plaster simulators that match so exactly the actual heat shield, "that the finished boost protective cover was inspected for a match with the simulator rather than the actual heat shield, eliminating hundreds of hours of inspection and other operations for the spacecraft."

The reflective external thermal coating was rated as capable of rejecting 100 degrees F of radiant heating.

With so many checks and limits applied to the manufacture of the thermal protection system, and critical limits applied to moisture content and reflective quality of the Kapton material, it would be highly unlikely that the manufacturing contractors, sub-contractors, or NASA would welcome a deviation from specification and procedure. Florida is not conducive to a moisture-free environment, and the Apollo Soyuz command module had been completed sometime before the final Apollo mission.

CSM-111, used for the ASTP mission, was used as an acoustic test platform, and also as a test bed for the Skylab rescue vehicle modifications. This serial number slots between Apollo 14 and 15 missions, indicating that it was taken out of sequence.

It would be more probable that the Kapton material may have been damaged or deteriorated during the many tests during the acoustic, Rescue, and ASTP docking module fit checks, or that the moisture content may have been compromised at some time, however, I am not aware of these issues.

posted 09-27-2018 01:12 AM               

This image gives better detail and still does not confirm the detail.

Every detailed image of the command module post flight shows the same side. Or the dark section of the command module is always opposite the hatch.