We all have our own odd traditions, and astronauts and cosmonauts are no different. In fact, you could even argue that since their jobs are a bit, well, high-stress, their traditions are proportionately weird. For example: in Russia, before the cosmonauts board their craft for blastoff, they make sure to pee on a tire. But why?
Before they climb the launch tower to board the Soyuz capsule that will take them into space, cosmonauts take a moment to stop at the right rear tire of the bus set to drive them to the launch site and ... relieve themselves. No, really. Here's a safe-for-work (though a bit crude) photo of the deed being done.