Posts: 2216
From: Worcestershire, England, UK.
Registered: Apr 2008

posted 10-02-2010 09:39 AM               

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I was painting a Saturn 1B rocket model the other evening and the wife walks in and asks, "Why did they have black stripes and checkered markings on them?". Well perhaps I should know, but I don't. Was it to see them clearer in flight?

Any answers would be very welcome, especially so I can tell 'wifey'.

Posts: 530
From: Houston, Texas
Registered: Aug 2002

Posts: 2458
From: U.K.
Registered: Jul 2009

Posts: 481
From: Germantown, WI USA
Registered: Jan 2004

posted 10-02-2010 03:02 PM               

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The paint on the fuel tanks, painted black on the Saturn Is and the early Saturn IBs, were painted white on later Saturn IBs due to thermal concerns.

As described in the Saturn S-IB Stage Final Static Test Report - Stage S-IB-2, during the static test firings of S-I-10, S-IB-1, and S-IB-2, fuel tank F-3 developed permanent ripples which "were formed as a result of thermal stresses within the tank wall. Radiant energy from the exhaust plume was absorbed more readily by the black painted areas of the tank. This heat was initially dissipated to the fuel within the tanks, but as the fuel level dropped, a significant difference in temperature was noted between black painted portions of the tank and the white painted areas. Thermal stresses resulting from this temperature differential exceeds the structural limits of the tank in local areas and causes the ripples to occur."