A Nigerian man on a suicide mission for al-Qaida was sentenced Thursday to life in prison for attempting to blow up an international flight with a bomb in his underwear as the plane approached Detroit on Christmas 2009. The mandatory punishment for Umar Farouk Abdulmutallab, the well-educated son of a wealthy banker, was never in doubt after he surprised the courtroom and pleaded guilty to all charges on the second day of trial last fall.