The helmet of Britsh Formula One driver Lewis Hamilton of Mercedes displays the letter "S" in tribute to late Brazilian Formula One driver Ayrton Senna during the third free practice for the Brazilian Grand Prix at the Interlagos racetrack in Sao Paulo, Brazil, on November 14, 2015.   AFP PHOTO / NELSON ALMEIDA        (Photo credit should read NELSON ALMEIDA/AFP/Getty Images)