The first practice session of Friday at the Istanbul circuit was wet and points leader Sebastian Vettel has crashed out, damaging the Red Bull Racing car sufficiently to not take part further on Friday.  This session saw Fernando Alonso emerge at the top but in the next session which was run in completely dry conditions Jenson Button emerged on the top in his McLaren Mercedes Benz car.  Button expressed happiness, while Alonso said that Ferrari had made good progress but that was not enough since the others raised the bar.  Vettel for his part said that his not taking part in further action on Friday would not dent his chances of a good qualifying and a good race.  Thus far the Mercedes cars of Nico Rosberg and Michael Schumacher have shown good pace.  More will unravel in the qualifying session of today.