Cargo ship flies out and picks up box?

I'm trying to make a cargo ship appear (instantiate), approach a box, pick it up, and then disappear with the attached box once it returns to the "mother ship". What is the easiest way to make this happen? I had considered using a combination of raycast and something like GameObject.FindGameObjectsWithTag with the tag of "cargo" and having it approach the object. Ideally, it would dock with the object and wait a few seconds before flying off with it. I'm just not sure where to begin on this or what the best method is. Any suggestions? Thanks, Jon