This was my thought as well. Also for what it’s worth iron oxidation is slow but very exothermic.
So what you’d want is a LEO starting point/station. You launch a barge from there to snag an asteroid. You could use a mass driver using solar or nuclear and mass from a previously spent asteroid to get to the asteroid belt, then snag an asteroid and use its mass to get back. You strip the important parts of it, construct a capsule for what you mined, and nudge it so it falls someplace in say a shallow part of the ocean. Then recover from there.
Or hell why mine it up there? Simply nudge an asteroid on a collision course towards Earth to make sure it falls someplace “safe”. Sure most of it will burn up but not all. It’s free material after all.
> It is a matter of composition, trajectory, and mass, no?
We're talking very specifically about an asteroid made up of iron. Logic would follow that it would be on the more massive end of the scale. No? That's like the worst possible composition and the very type that worries the doomsday types.
Lead is much heavier than iron. A uranium asteroid is pretty bad too.
But that aside, we have plenty of iron right here on earth. There is zero reason to mine iron in space unless you need it in space. An asteroid of pure gold on the other hand…
But setting all that aside, you get to choose the size! And the trajectory! And the arrival point! Like if you toss a 100kg asteroid and get 1kg of gold out of it, no you won’t kill the planet. You get to choose all the variables.
Probably at very high speed (in excess of orbital velocity) and near head-on.
Ideally you’d put an asteroid in LEO, slow it below orbital velocity, and have it come down at a shallow angle so aero breaking removes most of the remaining velocity.
So what you’d want is a LEO starting point/station. You launch a barge from there to snag an asteroid. You could use a mass driver using solar or nuclear and mass from a previously spent asteroid to get to the asteroid belt, then snag an asteroid and use its mass to get back. You strip the important parts of it, construct a capsule for what you mined, and nudge it so it falls someplace in say a shallow part of the ocean. Then recover from there.
Or hell why mine it up there? Simply nudge an asteroid on a collision course towards Earth to make sure it falls someplace “safe”. Sure most of it will burn up but not all. It’s free material after all.