You seem to be hilariously ignorant about the realities of aerodynamics, rocketry, and orbital mechanics. Due to atmospheric turbulence and normal thrust variations in the rocket motors that would have to be used for de-orbit burns, any unguided projectiles would have such as huge CEP as to make them militarily useless. Unguided projectiles launched from aircraft today can't reliably hit anything at distances over a few miles; satellites are much farther. A (sensitive and fragile) terminal guidance system would be an absolute necessity. Contrary to what arrogant programmers might think, DARPA isn't run by idiots and they gave up on such nonsense schemes for good reason long ago.

As for asteroid mining, hope doesn't count for anything. There is no shortage of essential raw materials here on Earth. No one is going to commit the hundreds of billion $ necessary to do it on more than a trial basis. There's simply no economic incentive nor is there political will to spend that money. Sorry to burst your bubble.