Are satellites sustainable?

Thousands of satellites orbit the Earth adding to the growing problem of space junk. What can be done?

When astronauts describe looking down on earth from space, they sound like the ultimate hippies. Gazing down on their fragile yet beautiful home they generally experience an eco-epiphany, fully appreciating how we are all children of the Earth. Fair enough. It must be quite a trip.

But what's the plan for ensuring a sustainable space when mars-one.com aims to send a crewed mission to the Red Planet by 2026 while, elsewhere, there are plans to mine some of the 12,000 space rocks orbiting earth? There are big questions to answer. Who makes sure that this happens ethically and equitably, in a way that doesn't trash space for future exploration? I'm taken with the New Scientist's idea of a Martian Magna Carta.