Quote:
Originally Posted by GrimUpNorth
It looks a rusty old thing, wonder if the false tan colour was an instruction from the oval office?
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That rusty-orange colour is the natural colour of the insulating foam, it is important to keep the heat out as the fuel is cryogenic, ie the liquid hydrogen is at something like -250 degrees C, and any heat that gets in will start to boil it off, so it needs constant replenishment, similar to the liquid oxygen.
In the past this would all have been painted to ‘look good’ but even the paint adds weight which you absolutely don’t want to have.
If you remember back to very early Shuttle flights, the tanks were painted white, something that was quickly dropped.