The Back of Satellites

We want to minimize the amount of stuff we have floating around the planet at any one time. How does that fit into satellites? Is there a renewable element to the things that you're putting up into space? Satellites are really expensive because generally you design a satellite to last five, 10, 20 years in orbit with no maintenance. If we could bring them back to Earth, and we could prepare them or scrap them but use the parts that still work would be a very different looking space industry.