Why is the spacecraft wrapped in black and gold stuff?
Galileo’s electronics and science instruments are designed to work in interplanetary space, but, without some sort of insulation, it’s too cold for them to operate (just like your camera shutter might freeze if you take it to the North Pole). The black and gold blankets are carefully designed to keep Galileo’s innards at a “comfortable” temperature. They also keep micrometeorites from smashing into the spacecraft electronics. The black blankets, which are made up of 20 different layers, are very efficient insulation. Although only 0.5 cm thick, it’s three times as good an insulator as the 10 cm thick fiberglass insulation in your attic. The black color is due to carbon in the outer layer, which keeps electrostatic charge from building up in one spot and then shorting out the spacecraft electronics. Black material in the sun picks up lots of heat, and emits a great deal of infrared light. The “gold” blankets, however, don’t absorb a great deal of solar heat, though they do radiate well
