QUESTION:
Why is the spacecraft wrapped in black and gold stuff?

ANSWER from FAQ:
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 1/5th of an inch thick, it's
three times as good an insulator as the four-inch-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 in the
infrared. This material (called "second-surface aluminized kapton")
therefore does an even better job of insulation. It's not used on the
entire spacecraft because it was developed after Galileo was
designed and built. When Galileo's flight path was changed to take
advantage of a Venus gravitational assist, there was enough time to
use kapton on critical areas of the spacecraft.