> > ...This now-junk could be recycled to biuld up something new. This junk
> > travels around at highspeed, but anyway, a space vehicle
> orbiting our planet
> > would do this, too...
> Yes, but the problem is, the space junk is in *different* orbits, each of
> which have enormous velocity relative to each other.
Well, a space vehicle is able to change orbits, so this poses no problem. As there is only a finite number of orbits, you could, one by one, skim these orbits.
> > ...All it would need is a sort of "tractor beam" (hey, yet
> > *another* Sci-Fi technology) to haul all the junk in...
> OK, you invent a tractor beam, Karsten, and I will quit my 9 to 5, and
> make my living selling your autographs.
Hey, nanotech sails are as much sci-fi as the tractor beam - for now. I was talking about technical possibilities, not about my research. In fact, tractor beams would be using some kind of gravitic manipulation, which exists only in theory. We'll see, how long this will take, but I'm almost sure I will see it happen.
> > ...but as most of this junk is magnetic...
> Almost none of it is. There may be a *little* iron, but it is
> mostly aluminum.
As far as I know, every satellite contains at least some iron. I do not know if this would be enough to attract it. I am not an engineer, but I know that, though planes are built of lightweight materiels, they, too, contain enough iron.
> > This could be more realistic than the nanosail discussed before.
> Or not. spike
We'll see. But the problem is getting urgent, though, as some orbits are nearly full by now and we cannnot afford to wait another 50 years 'till we have a technical solution for it. Worst-case we'll do it the old style: Replace tractor beam with robotic arm, and you'll have a system which could be ready for service in a short term.