The nonrotating outer shell was a hundred yards thick, consisting mostly of some kind of friable material. It wasn’t structural; it was intended to absorb meteor impacts and block radiation. But it had many embedded design details, like a rigid support frame and the docking bay for the Boojums. And the item we were most interested in: the vector-matching system for getting from the nonrotating outer shell to the swiftly rotating inner shell without being ground up like seeds in a pepper mill. Getting access to what we were calling the Spin Transfer system was our ultimate goal.