LostCarPark's Journal

According to this report, bird droppings on the protective tiles have survived the shuttle Discovery's trip into space. The droppings were first spotted about three weeks ago and have since survived thunderstorms and the stresses of the orbiter launch. It is expected to burn off during reentry.

Perhaps this could provide a simple solution to the problem of the shuttle's protective tiles being hit by foam from the external tank: spray the entire underbody with a protective coating bird poop before launch...