wait... wouldn't an orange tank be slightly less insulated than a regular tank

[llamatoes]

I was reading about the shuttle, and STS-1 was painted, so as to deal with the sun causing boiloff, but if I launch an orange tank during the night, wouldn't it be sightly less well insulated?

[Sirrobert]

I don't think the physics go this deep yet

[FITorion]

I've heard a few conflicting things concerning the Shuttle liquid tanks.

I've heard they were painted and then they stopped so that's why they went from white to orange.

I've heard that the above is incorrect and that they switched foams and the new one is orange whereas the old was white. I've also heard that the switch was out of environmental concerns and the new foam was heavier and all around not as good as the old.

Anyway none of this has any effect in game. Certain things simply aren't simulated.

[jwenting]

I heard they were painted and stopped to save weight, causing the orange foam under the white paint to show up, and that they then switched to another, more environmentally friendly foam which happened to also be orange but had a tendency to break up and cause problems like damage to the underside of the fuselage.

[Fuzzy Dunlop]

I thought the paint was to protect the foam against UV, then they discovered it wasn't really a problem and stopped doing it to save weight. But I can't remember if I acctually learnt this or am just making this up.

[FITorion]

I know the foam is mostly white or maybe slightly yellowish when it's applied and gets more and more orange as it's exposed to sunlight.

[DChurchill]

Ultimately it was the weight of the paint, which was something like 650 pounds if I remember correctly, for the reason for removing it. I think it Was as Fuzzy said, the UV protection wasn't worth the weight.

[Sma]

As others have said they stopped painting them to save weight (and money for the cost of the paint, and labor involved. As far as why they were painted in the first place, I'm not sure that it had anything to do with UV protection or any of that. I do remember hearing something about the change from I believe closed cell foam to open cell foam (similar to the expanding foam you can get at the store, I remember my parents had some around the house somewhere and after a while it turned orange as well) and the paint not sticking to it which is another reason why they stopped using the paint. Though it could be a combination of all those reasons I guess.

[sporkafife]

I thought the paint was to protect the foam against UV, then they discovered it wasn't really a problem and stopped doing it to save weight. But I can't remember if I acctually learnt this or am just making this up.

Yep, they originally painted the ET (external tank) on the Space Shuttle white to reflect UV rays. They thought that, because the Space Shuttle spends a long time on the pad prior to launch, that UV radiation could damage the tank in some way. I think they only flew the white tank for STS-1 and STS-2, and for STS-3 they realised that the UV radiation didn't really pose a threat so they could leave the ET unpainted and save a couple hundred kg of weight at the same time.

Personally I quite like the look of the white tanks. The contrast between the white orbiter and SRB's with the orange/rusty-brown tank is quite aesthetically pleasing, but I think the white ET just looked so much more elegant