In the last three months, the U.S. Space Force’s Space Systems Command (SSC), previously known as Space and Missile Systems Center, has declared three Lockheed Martin [LMT] GPS III satellites “available for launch (AFL),” SSC said on Aug. 26.

The three birds–GPS III SV06, SV07, and SV08–are awaiting callup at Lockheed Martin’s GPS III plant in Waterton, Colo. The first satellite, SV06, is to launch next year and join the operational constellation of 31 GPS satellites.

“SV06, SV07, and SV08 AFL milestones in just three months prove that GPS III production continues to benefit from efficiencies with each satellite delivery,” Col. Edward Byrne, chief of SSC’s Space Production Corps’ Medium Earth Orbit Space Systems division, said in an Aug. 26 statement.

In the latest GPS III launch in June, a SpaceX Falcon 9 rocket launched SV05 GPS III in what marked the first time a National Security Space Launch (NSSL) mission was conducted on a reused booster (Defense Daily, June 17).

GPS provides Positioning, Navigation and Timing signals and is a critical part of national infrastructure, driving an estimated $300 billion in annual economic benefit, per Lockheed Martin. The GPS III satellites are to provide up to three times improved accuracy and eight times the anti-jamming capabilities of earlier GPS birds.

SV05 established the GPS constellation’s baseline for Military Code (M-Code), a more secure signal. SV05 is the 24th M-Code signal-enabled GPS satellite and completes the constellation’s baseline requirement for the more secure signal.

In addition, GPS III “expands the civilian L5 signal, dubbed the ‘safety-of-life’ signal, currently broadcast by the 12 GPS IIF satellites, but not yet operational, and delivers a new L1C signal designed to grant interoperability to similar international space-based position, navigation and timing systems around the world,” SSC said on Aug. 26.