Why was the Saturn V painted white?

[gladiator1332]

The thread title kinda explains the question...why was the Saturn painted white? NASA painted the first two Shuttle ETs white purely because they thought it would look nice, and after that we lived in an orange foam world.
The same goes for the Delta IV. I am sure Boeing could paint it that classic Delta rocket blue, but instead they leave it natural foam.

So what was the reason for painting the Saturn? Was it just to make it look nice, or did painting the rocket serve some purpose. Also, what did the Saturn V look like without the paint?

[ugordan]

NASA painted the first two Shuttle ETs white purely because they thought it would look nice

Wasn't the explanation rather that the first shuttles were expected to spend extended periods of time on the pad and the orange foam is sensitive to UV light so it was a means of protecting it? Afterwards there was no need for it and it freed up a couple of hundred kg of payload capacity.

So what was the reason for painting the Saturn? Was it just to make it look nice, or did painting the rocket serve some purpose.

Reduced heating of propellants in the hot Florida sun? Weren't there stories of technicians practically passing out due to heat while working inside the interstages (the earlier ones had more black paint on IIRC) while the vehicle was sitting on the pad?

[STS-200]

To assist with thermal control (i.e. help keep it cold).

The S-IVb third stage spect several hours coasting in orbit. Painting this stage white helped reduce LH2 boiloff during this time, and therefore increased payload.

The whole rocket sat on the pad for a considerable time before launch. The white paint helped keep the unfueled structure cool, and slightly reduced boiloff during fueling.

The interstages were painted in white/black bands to keep them warmer. This helped reduce condensation and ice formation in these areas.

[Crispy]

I thought the black/white was for tracking roll rate from ground cameras?

[STS-200]

I thought the black/white was for tracking roll rate from ground cameras?

It helped with that as well.

Where roll rate is a more critcal measurement (for instance on single engine boosters where roll control authority is smaller), they usually use a "Z" shaped pattern e.g. the early Thors and the recent Ares 1X.

[CarlosMeat]

All german rockets were black and white.

Friede,V2,Redstone,Saturn.

Art

[mike robel]

On Saturn IBs, you can see how the Thermal Protection painting and roll patterns evolved.

The initial suborbital missions did not have the black stripe at the forward end of the SIVB.  Apparently SA-6, which had a large black area between the SIV and the CSM got too hot, so subsequent Saturn I Block IIs were painted with more white.

After the suborbital flights, they put the black stripe at the top of the SIVB.

The 1st orbital mission (the one with the 'funny' nose cone) had a very thin black stripe at the bottom of the SIVB with the roll patterns.

After that flight, there was a rather thick stripe.

With ASTP and the Skylab flights, the Interstage kept the roll patterns, but there was only a black horizontal stripe on the SIVB at the bottom (plus the one at the top).

For the Skylab Rescue Saturn IB (at least as it is displayed at the KSC visitor center) there were no roll patterns at all.

Also after Apollo 7, the black paint was elminated on the S1B stage.  And, again the rescue skylab apparently did not have any roll patterns painted on its fins, although it did retain them on the base structure.

[johng]

The thread title kinda explains the question...why was the Saturn painted white? NASA painted the first two Shuttle ETs white purely because they thought it would look nice, and after that we lived in an orange foam world.
The same goes for the Delta IV. I am sure Boeing could paint it that classic Delta rocket blue, but instead they leave it natural foam.

So what was the reason for painting the Saturn? Was it just to make it look nice, or did painting the rocket serve some purpose. Also, what did the Saturn V look like without the paint?

Lots of discussion about colors, but remember Saturn V was an almost all metallic structure with a lot of aluminum.  It was never going to be un-painted as it would need to be primed and painted for basic corrosion prevention, regardless of color.  On the ET, the metals are covered by the foam, so no need to paint the foam.

[Jim]

Lots of discussion about colors, but remember Saturn V was an almost all metallic structure with a lot of aluminum.  It was never going to be un-painted as it would need to be primed and painted for basic corrosion prevention, regardless of color.  On the ET, the metals are covered by the foam, so no need to paint the foam.

The second stage of the Saturn V was covered with insulation/foam

[zerm]

On SA8,9and 10 the adapter section was painted all white- which was a thermal protection paint to protect the Pegasus satellite (SA6 and 7 had no Pegasus aboard). On the Saturn IB S-IB stages from AS-206 on, the RP-1 tanks were painted all white. This was done because in some of the earlier vehicles an unexplained series of minor tank deformations were seen to come and go. It was actually guessed that this was caused by simple sunlight heating the black painted areas of a given tank as opposed to the white areas. So, they took the next series of tanks that were headed to the paint shop- which happened to belong to AS-206 and painted them all white with the red "UNITED STATES" lettering. All following Saturn IB S-IB stages had all white tanks. The problem never showed up again.

Ref: Saturn I/IB, Lawrie, p.102 et.al.
Ref: MPR-SAT-FE-65-4
Ref: N66-23597

[iamlucky13]

Because white is faster!

Oh no, wait...that's red. Never mind.

Jim, correct me if I'm wrong, but the foam insulation on the S-II stage was pretty minimal compared to what the shuttle has, right? Ice buildup was less of a concern, if I understand right.

Surface temperature is going to be the main driver for ice formation and mainly affected by conduction, which foam addresses. Total heat transfer, however, is a combined effect that includes radiation, and painting would strike me as the most effective per pound method to knock down the total heat transfer rate to reduce boiloff.

[simonbp]

All german rockets were black and white.

'Cause they wanted the highest contrast they could get with monochrome film.

Operational V-2s and Redstones were typically painted in camouflage.

[rocketguy101]

Had it flown longer, Saturn would have eventually sported simplified painting/less painting as well.

 - Ed Kyle

If it had flown long enough, I wonder if it would have ever ended up w/ orange foam on the cryo areas?  Picturing that in my mind, it would look pretty strange

[Jim]

Had it flown longer, Saturn would have eventually sported simplified painting/less painting as well.

 - Ed Kyle

If it had flown long enough, I wonder if it would have ever ended up w/ orange foam on the cryo areas?  Picturing that in my mind, it would look pretty strange

That was a decade away

[kraisee]

In cases where there is no foam coating, bare Aluminium corrodes in salt-air conditions like those found on the Florida Space Coast.   The structure must still be protected.   Paint is relatively light-weight and easy to apply.

White paint also helps reflect the intense heat from the Florida sunshine and maintenance people inside don't overheat, even given extensive ECS.

I heard a story (don't know how true it is) that during the early Apollo effort 2 engineers died inside the 500F test-fit stack due to heat.   The story goes that that is why a lot of the black markings were painted over with white in time for Apollo 4.

If you have ever had the misfortune to be inside a black painted metal structure here in Florida in the summer, you can well believe that story.

Ross.

[kraisee]

Ed, the person I got that from originally was an umbilicals guy for Gemini, Apollo and the first ten years of Shuttle.   He also told me about the nitrogen accident at the same time, so I'm pretty sure he was talking about two different incidents.

Ross.