You launch it. Here's my co-conspirator, Jed, with the antenna launcher he built from PVC pipe and a lawn sprinkler valve
He's holding a large nerf dart here as it turned out his barrel was the same size as the larger gun/launcher on the porch behind him.
The fat pipe is the air reservoir which we pump up to 60 psi, not wanting to over stress the plastic. Not shown is the small dart made from 2 pipe caps and filled with sand that will carry the line that will pull the antenna wire high up into a tree or something. In testing today we threw the dart just over 100 yards across a flat park.