"The blacker the material, the more heat it radiates away. In other words, super-black materials, like the carbon nanotube coating, can be used on devices that remove heat from instruments and radiate it away to deep space. This cools the instruments to lower temperatures, where they are more sensitive to faint signals."
This is contrary to what I've always thought...black materials absorb sunlight and heat up, but they in turn radiate the heat away from objects.