The satellites are being built by Lockheed Martin for the U.S. Air Force.
ATK said this was a first delivery of major hardware since ATK was awarded the contract from Lockheed in April 2010.
The contract includes the fabrication of a non-flight satellite testbed structure and the first two GPS III satellite structures. The testbed structure was delivered in May and the first space vehicle structure was delivered in August.
The first ship set of tanks were also delivered in early August. Each ship set includes one hydrazine, two oxidizer and two pressurant tanks.
The contract includes options for the same hardware for up to 10 additional satellites.
The GPS III structure, made from lightweight, high-strength composite materials and the propellant tanks were delivered to Lockheed Martin's Mississippi Space and Technology Center, an advanced propulsion, thermal and metrology facility at the John C. Stennis Space Center, for integration and testing.
"The GPS III program continues to meet major milestones on or ahead of schedule, and the delivery of the core structure and propellant tanks for the first GPS III space vehicle is another achievement demonstrating this program's solid execution," said Lt. Col. Don Frew, the U.S. Air Force's GPS III program manager. "The joint U.S. Air Force and industry team understands the importance of GPS III and we are focused on delivering capabilities to meet the demands of more than one billion GPS users worldwide."
ATK has been manufacturing A2100 structures and propellant tanks for Lockheed Martin since the satellite model was introduced in 1996 for the company's commercial satellite customers.
The composite structures are manufactured at ATK's San Diego facility with support from the ATK Beltsville, Md., Operation. The propellant tanks are manufactured in ATK's Commerce, Calif., facility.
The first GPS III satellite is on track to be delivered and available for launch in 2014.