2006-06-28 09:00:24 · 8 answers · asked by ap-brampton 1 in Science & Mathematics ➔ Astronomy & Space
White reflects light at *visible* wavelengths better.
However, the designers were not trying to reflect visible light. I would guess they designed the coating to emit thermal radiation as efficiently as possible - approaching 'black-body'. The coating color would probably be secondary to that consideration.
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Side Note
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Due to it's tremendous speed, the orbiter shock-heats air at it's leading surfaces during reentry. (the orbiter's underbelly is exposed directly to the 'wind stream', if you will, due to the orbiter's initial high-angle of attack)
The temperatures of the thermal protective surfaces rise primarily in response to thermal radiation from the incandescent shockwave. NOT FROM FRICTION.
2006-06-28 09:34:33 · answer #1 · answered by Ethan 3 · 5⤊ 2⤋
You're thinking of reflecting light. If a light source were being shined on a surface from some distance, more of it -- and thus more heat -- would be reflected from a white surface than from a black one.
However, if you actually heated the surface directly by contact, it wouldn't matter which color the surface was. This is what happens with the shuttle tiles. They are heated directly by friction with the atmosphere.
2006-06-28 16:48:40 · answer #2 · answered by DR 5 · 0⤊ 0⤋
The tiles on the underside of the space shuttle are black because black tiles have higher radiative emittance than do white tiles. The black tiles are able to absorb heat and then are able to dissipate this heat much quicker than white tiles are able to, and this is very important when the space shuttle re enters Earth's atmosphere.
2006-06-28 16:32:07 · answer #3 · answered by Anonymous · 0⤊ 0⤋
The heat from re-entry into the atmosphere is from friction, not radiation. Neither white nor black has any reflective properties for frictional heat.
2006-06-28 16:32:38 · answer #4 · answered by bequalming 5 · 0⤊ 0⤋
That a good one! Yes white is better but if i remember correctly the bottom is a type of ceramic that is naturally black (i think this is right)
2006-06-28 16:06:42 · answer #5 · answered by burnt bob 4 · 0⤊ 1⤋
the black absorbs more heat keeping the shuttle cooler
2006-06-28 16:06:38 · answer #6 · answered by gilleman11 1 · 0⤊ 0⤋
They do but paint costs a lot and since the natural color of the material was black they decided to keep the color.
2006-06-29 07:05:34 · answer #7 · answered by Eric X 5 · 0⤊ 1⤋
I thought they were white until the came in contact with our atmosphere and turned black from oxidation.
2006-06-28 16:05:04 · answer #8 · answered by cheryl h 2 · 0⤊ 1⤋