I recall a story from a Russian aerospace engineer describing a Russian unmanned probe to Venus. They mounted a camera and arm to the probe to take pictures and to measure the chemical composition of the planet's surface. He said the camera cover popped off at the appropriate moment to land exactly where the arm hit the ground. They got a very good measurement of the camera cap's chemical composition. I'll see if I can dig up a link.
Found it... actually the arm was to measure the compress-ability of the Venusian soil