Garbage... in the early days, and perhaps even today, not much consideration was given to the effects of a stray piece of trash here and there..... they didn't envision what space became for us with all the satellites. But also mishaps in space... explosions that sent huge quantities of debris sailing in orbit. Even a penny traveling at 17,000 mph could be catastrophic.

Basically space was treated much like we've treated the oceans. But the ocean is minuscule compared to space.... even space within orbiting satellites.... not geosynchronous satellites which are FAR up there, 22,000 miles. - JamesJM