Last week a defunct Russian satellite collided with an Iridium telecommunications satellite.  While this is supposedly the first known (or at least publicized) collision between two intact satellites, the crash has raised concerns over the thousands of objects orbiting the Earth.  As the article linked to indicates, there is monitoring of so-called space ‘junk’, but with an increase in spacefaring nations, and ultimately private entities moving from suborbital to orbital trips, the amount of ‘junk’ will get to a point where collisions will no longer be so rare.  At that point, will monitoring be sufficient?  I don’t know.  But I do think it’s an issue worth discussing in appropriate fora.