A SpaceX Falcon 9 launched the GPS III SV10 (Space Vehiche 10 also known as GPS III-8) satellite for the U.S. Space Force from Space Launch Complex 40(SLC-40) at Cape Canaveral Space Force Station on Tuesday (April 21) at 0653 UTC marking the delivery of the final satellite in the GPS III production block and completing the service's most resilient constellation to date.
The Falcon 9 Block 5's first-stage booster B1095, came back to Earth about 8.5 minutes after launch as planned on Tuesday, touching down softly in the Atlantic Ocean on the SpaceX droneship "Just Read the Instructions."
This was the seventh launch and landing for this particular booster, according to a SpaceX mission description. And it was the final Falcon landing for "Just Read the Instructions," SpaceX said during Tuesday's launch commentary; the droneship will now pivot to supporting liftoffs of SpaceX's Starship megarocket.
"After 156 successful Falcon 9 landings, Just Read the Instructions will be fully dedicated to support Starship operations going forward," SpaceX wrote on X.
The Falcon 9's upper stage, meanwhile, continued powering its way to medium-Earth orbit, deploying GPS III SV10 about 90 minutes after liftoff. Following separation, the satellite will use its own liquid apogee engines to raise its orbit to the operational medium Earth orbit at approximately 20,200 kilometers altitude, a process taking roughly 10 days.
With the addition of SV10, the active GPS constellation now includes 32 satellites, providing increased redundancy and resiliency. Mission Delta 31 of the Space Force will oversee on-orbit checkout and eventual integration into the live navigation network.
SV10 is the tenth and last spacecraft under the original GPS III production contract awarded to Lockheed Martin in 2008. The satellite, nicknamed "Hedy Lamarr" after the actress and inventor who co-patented frequency-hopping technology, was built in Colorado and declared available for launch in December 2022.
The new satellite enhances the constellation with M-code technology, providing three times greater positional accuracy and eight times improved jam resistance compared to previous generations. This upgrade significantly boosts the effectiveness and lethality of U.S. military weapon systems while improving civilian navigation.
"GPS III satellites have a three-fold increase in positional accuracy and an eight-fold improvement in jam resistance compared to prior versions," Space Force officials said in a statement on Jan. 28, just after GPS III SV09 rode a Falcon 9 to orbit.
"These advanced features enable the constellation to provide an across-the-board boost in effectiveness and lethality to weapon systems in every theater," they added.
SV10 carries several developmental payloads to test future GPS capabilities, including:
Crosslink Demonstration Payload: Tests optical crosslink communications to improve ground segment resilience and enable faster satellite tasking.
Digital Rubidium Atomic Frequency Standard (DRAFS): A new space-qualified atomic clock to enhance long-term timing precision for future GPS IIIF missions.
Laser Retroreflector Array (LRA)**: The second use of an LRA to support NASA's scientific research and improve Earth center determination.
3D-Printed Omni Antenna: The first use of this advanced manufacturing component, which reduces production time and costs by nearly 60 percent.
GPS III-8 mission demonstrated the National Security Space Launch (NSSL) program's flexibility, as SpaceX was selected as the launch provider with less than seven weeks notice following a change in launch service provider. This rapid turnaround built upon accelerated timelines established by previous GPS III launches in 2024, 2025, and early 2026.
GPS III SV10 was originally supposed to fly aboard United Launch Alliance's new Vulcan Centaur rocket. Last month, however, the Space Force announced that it was switching the satellite to a Falcon 9 due to issues that Vulcan has experienced with its solid rocket boosters (SRBs).
As part of this rocket swap, Vulcan Centaur will now launch the USSF-70 national security mission, which had been slated to fly on a SpaceX Falcon Heavy. USSF-70 is expected to launch no earlier than summer 2028, Space Force officials have said. (Presumably, Vulcan Centaur's SRB issues will be worked out by then.)
