Transport Requests

As it stands now, unless I remove a product from a space port, a Transport Request cannot be aborted. You click abort and the remainder of the Transport Product turns orange, then after a little bit it turns grey again and your shuttles waste precious missions. This is not how it should be. It should not matter if the product is present or not when I click abort and it should be changed. Otherwise I would want to be able fire stupid shuttle pilots who cannot follow simple directions.