As I said above, I highly doubt it’s a literal arm / sling being used. I think it’s a magnetically guided and accelerated loop, so the payload is the only part

As I said above, I highly doubt it’s a literal arm / sling being used. I think it’s a magnetically guided and accelerated loop, so the payload is the only part of the system moving at all. You’re right the drag/tension on an actual arm would be ludicrous, and would certainly force you to a smaller radius.