HOUSTON --We are learning more about the number of Houston employees who will be laid off by the NASA contractor United Space Alliance. The layoffs were first announced on July 6, and letters were sent to employees on Tuesday. In all, 1,397 employees will be laid off effective October 1. That includes 478 employees in Texas, 14 in Alabama and 905 in Florida. All employees will receive severance and job training for other fields. USA employs approximately 8,100 employees at its Florida, Texas and Alabama sites. The reduction in force will affect multiple disciplines and multiple organizations across the company. Layoffs by other contractors are expected as NASA winds down the space shuttle program. There are only two shuttle missions left - one is currently scheduled for no earlier than November 1, 2010, and the other is set for February 26, 2011.