The Air Force announced today it has given Lockheed Martin a $2 billion contract modification for a troubled space-based missile-warning program key to the Bush administration's plan for a missile defense system that can protect the United States. The contract covers the restructured engineering and manufacturing development phase for the Space Based Infrared System High program, according to a Defense Department statement. "The current modification re-baselines the program, redefines the incentive structure and extends the period of performance to 30...