WASHINGTON — The U.S. Air Force awarded Lockheed Martin a contract worth more than $1.3 billion for two GPS III satellites, according to an announcement from the Department of Defense Sept. 26.

This contract covers the 11th and 12th satellites in the Air Force’s next-generation GPS III constellation and represent the first space vehicles in the GPS IIIF, or GPS III follow on, program. The Pentagon announcement said the competition included “one solicitation mailed and one solicitation received" but did not offer further details.

The contract requires Lockheed Martin to provide non-recurring engineering, space vehicle test bed and simulators, production of GPS IIIF Space Vehicles 11 and 12, in addition to the production of up to 22 GPS IIIF space vehicles, space vehicle storage, and launch and on-orbit support. These satellites will feature an upgraded payload that will grant the clock signal for a new GPS III Search and Rescue (SAR) payload, and extend the satellite’s service life. The total contract value could reach $7.2 billion.

The first 10 GPS III satellite navigation payload includes “a Mission Data Unit (MDU) with a unique 70 percent digital design that links atomic clocks, radiation-hardened computers and powerful transmitters,” according to a Harris release. This allows for signals three times more accurate than those on current GPS satellites, the company said.

The first GPS III satellite was designated as available for launch in September 2017. It is expected to liftoff aboard a SpaceX Falcon 9 rocket from Cape Canaveral Air Force Station in Florida before the end of 2018. The next satellite will launch aboard a rocket from United Launch Alliance. The U.S. Air Force intends to procure up to 22 new satellites during the second phase of GPS III follow-on, with the first vehicle planned for a 2026 delivery.