There was a study done a while back on how often the moon get hit by chunks of rocks, and it was less than all the junk that floats around our planet. we have to launch threw smaller windows every time we send a bird up.
Much space junk is nut & bolts traveling at the speed of a bullet, it would take more than a Magnet being towed by a shuttle craft to collect all the crap. BUT keep me informed I like the way you think Sir !!