Tetra Tech, Inc. announced today that it has been awarded a contract to provide advisory and assistance services to the Missile Defense Agency (MDA), a research, development, and acquisition agency within the U.S. Department of Defense. Three firms each received $270 million ceiling, five-year, indefinite-delivery/indefinite quantity contracts. Under this Missile Defense Agency Engineering and Support Services (MiDAESS) contract, work will be performed in Huntsville, Alabama, and other MDA locations primarily in the United States. Tetra Tech has supported MDA as a prime contractor since 1998. The Missile Defense Agency (MDA) is a research, development, and acquisition agency within the U.S. Department of Defense. Its mission is to develop, test, and field an integrated, layered, ballistic missile defense system to defend the United States, its deployed forces, allies, and friends against all ranges of enemy ballistic missiles in all phases of flight.