Earlier this year we mentioned the launch of the TerreStar satellite and its planned satellite/GSM mobile phone service for North America. TerreStar has now reached an agreement with AT&T that’ll enable users to have a single mobile number working across the United States, Puerto Rico, the US Virgin Islands and offshore coastal waters. Calls will be made and received using the Windows Mobile-powered TerreStar GENUS smartphone, with TerreStar’s satellites providing a backup when AT&T service isn’t available. Customers will be able to connect from early 2010. [Press release; service summary]