EL SEGUNDO, Calif. -- With the successful launch of the 10th Global Positioning System III satellite on April 21 from Cape Canaveral Space Force Base, Space Systems Command is celebrating the start of a new era for the world’s premier GPS constellation.
“This milestone satellite launch completes GPS Block III,” said Erin Carper, acting portfolio acquisition executive for Satellite Communications and Positioning, Navigation, and Timing (PNT0 at SSC. “Providing critical military and civil signal accuracy 24/7, GPS continues to underpin global military operations for our warfighters.”
The GPS III series is the third generation of the U.S. Space Force’s GPS satellites and consists of ten 5,000-pound satellites manufactured by Lockheed Martin, with the first launched in 2018. These satellites followed the Boeing-built GPS IIF series of 12 satellites.
In addition to providing more accurate positioning, navigation, and timing capabilities, GPS III satellites are the first to broadcast Military Code (M-code), the military’s encrypted GPS signal designed to provide more secure, jam-resistant signals. Fittingly, the final GPS III launch was named after Hedy Lamarr, who pioneered jam-resistant communication during World War II.
“With more than 24 M-code satellites now on orbit, we are delivering on our promised capabilities to warfighters around the world,” said Scott Thomas, GPS III program manager with Combat Forces Command, the U.S. Space Force’s operational field command.
“We are the most reliable and most relied-upon Global Navigation Satellite System in the world,” Thomas added. “This is a free service provided by the U.S. Space Force to the world and we work hard to make sure that it is available every second of the day.”
Compared to previous iterations of GPS, the GPS III series provides eight times the anti-jamming capability and four times the accuracy of previous iterations. Remarkably, GPS satellites operate some 12,550 miles above the surface of the Earth, but they are so accurate they can pinpoint an area as small as a single football.
Setting the Standard for the World
For civilians who rely on GPS for everything from navigating their drive to work to accurate timestamps on bank transactions, it may be surprising to learn that GPS was originally developed as a military technology, proving a game-changing capability during the first Gulf War as much as air power was critical during World War II.
“GPS is crucial to modern military operations,” Thomas said. “It provides the precision needed to be effective, ensuring mission success while minimizing collateral damage. Our global military effectiveness is fundamentally tied to the availability and accuracy of GPS.”
Agriculture, banking, transportation and a host of other consumer applications also depend on GPS. A 2020 report to Congress prepared by the U.S. Department of Homeland Security found that that GPS disruptions would have negative impacts that would likely exceed $1 billion per day.
The U.S. Department of War started developing GPS in 1973; prototype satellites were launched in 1978, and the constellation became fully operational with 24 satellites in 1993. In addition to providing PNT signals, GPS satellites also host the Nuclear Detonation Detection System from the National Nuclear Security Administration and the U.S. Department of Energy.
“The earliest versions of GPS were created in a time when space was largely benign, and the U.S. didn’t have to worry about adversaries attempting to jam or spoof GPS signals,” said USSF Col. Neil Barnas, commander of Space Systems Command’s System Delta 831.
Today, adversaries have developed capabilities that can jam GPS signals or intercept and replace them with signals sending spoofed data. With these threats in mind, the GPS III series was designed in the mid-2010s to include state-of-the-art technology, including high-powered amplifiers to produce the very complex M-code using advanced cryptography.
“The M-code capability that we are launching on SV10 (Space Vehicle 10) in 2026 provides a very robust PNT capability that will serve my children and grandchildren for many years to come,” Barnas said.
The GPS III series benefited from a wide array of space industry partners, from launch provider SpaceX to payload provider L3 Harris, as well as other industry partners providing components such as reactor wheel assemblies and high-power amplifiers. That supply chain diversity and innovation will be carried forward into the next generation of GPS.
“GPS is an incredible national asset that we have and proudly manage, and we’re looking forward to continuing to develop it into the future so that we make sure that it’s robust, reliable and there every day that we need it,” Barnas said.
GPS IIIF: the Next Generation
The next generation of satellites, known as GPS III Follow-on, or GPS IIIF, are in production by Lockheed Martin, and will begin launching as early as 2028. GPS IIIF will include a new capability called Regional Military Protection that will add even more anti-jam protection.
“The continued expansion and growth of GPS jamming is the most prevalent threat that the GPS user segment experiences on a day-to-day basis,” Barnas said.
Although GPS’s Medium Earth Orbit (MEO) orbit makes them less of a target than satellites in Low Earth Orbit (LEO), Barnas noted that adversaries are developing counterspace technologies that can reach all altitudes.
“As we think about 2026 and beyond, we have to be very thoughtful of the counterspace environment,” he said. “Our adversaries have developed exquisite counterspace systems that put our architectures at risk – so we’re thinking about our counter moves that we can do.”
Since the launch of SV01, the first SpaceX Falcon 9 launch for the Department of War, Guardians took a fierce approach to exploring opportunities like implementing smart test reductions or incorporating new technology. Even the final GPS III satellite, SV10, had multiple technology demonstrations on board.
Beyond these advancements, the human effort behind GPS III remained at the forefront.
From coordinating launch rehearsals to conducting early orbit operations, personnel across Space Systems Command and Combat Forces Command worked in close partnership to deliver capabilities that protect U.S. and allied forces worldwide.
“As we send off the final GPS III satellite, it’s a chance to celebrate the thousands of men and women who have worked on the program that should be proud of the GPS III era and their accomplishments,” Thomas said. “GPS III has a unique culture of bringing together brilliant acquisition, industry and operational professionals to accomplish big things – and GPS IIIF will be no different.”