when his year was up and he rotated back to the world , as the soldiers called the u.s. , fenwick climbed out of the contract eastern airlines 727 , fell to his knees on the tarmac at travis air force base , pausing momentarily to remove the good sized tarmac pebble that had just then lodged in his left knee , kissed the ground and then wept for a good three minutes before an unsympathetic sergeant pulled him up and unceremoniously booted him on his way .