Have you ever wondered why satellites always appear to be covered in gold foil?

From NOAA Satellite and Information Service:

Have you ever wondered why satellites always appear to be covered in gold foil?

While they may seem like they are draped in precious metal, it’s usually not gold at all… or even foil! It is actually a material called multi-layer insulation, or MLI. Learn more about MLI and actual uses of gold in space at http://go.usa.gov/cnb6Y.