The 1990s were iconic: Super Mario Kart and Mortal Kombat ruled the arcades. Whitney Houston’s “I Will Always Love You” and “Ironic” by Alanis Morrisette topped the charts. Grunge fashion was all the rage, thanks to Nirvana and other Seattle Sound bands. Seinfeld dominated the airwaves. And six GPS satellites still in orbit today were designed and built, launching into space from 1997 to 2004.Far exceeding their projected 7.5-year lifespan, the longevity of these and the seven GPS satellites that soon followed, is a testament to the skills and expertise of the engineers who crafted such marvels. However, it is long past time to replenish our GPS constellation with modern positioning, navigation, and timing (PNT) satellites — designed and built in the era of Metroid: Prime 4, Taylor Swift and Netflix — that meet the threat environment of today and better prepare us for the future.How did we get here? The Department of Defense (DoD) pursued a “sustainment strategy,” keeping older GPS satellites on orbit, while publicly touting the constellation’s average lifespan of more than 20 years. This strategy has made it possible for the Office of Management and Budget, DoD and Congress to deprioritize the GPS program in defense and transportation budgets, authorizations and appropriations. Exhibit A: Three modern, next-generation GPS satellites are sitting in storage, awaiting launch. Alan Shepard kicked off American space flight encouraging NASA engineers to “light this candle” in 1961. We need that same energy today.What is at stake?Sustainment is not an effective acquisition strategy in an era of great power competition. The stakes of failing to fund and field the world’s most modern PNT satellite system architecture — which includes the satellites, ground stations and military receivers, aka “user equipment” — are significant and growing by the day. Here’s what is at stake for warfighters and civil and consumer users globally, if the United States fails to modernize its PNT infrastructure:The U.S. is failing to rapidly deliver its best technology to the warfighter. Up to 60 times greater improvements in anti-jamming technologies for the warfighter offered by modernized PNT are delayed.Civilian vulnerabilities increase. New civil signals specifically designed for the aviation community, which would increase resiliency to jamming and spoofing, are not operational. In the meantime, aircraft flying in Europe, the Middle East and the Eastern Mediterranean relying on the original civil GPS signal are facing unprecedented levels of GPS spoofing, impacting critical systems.E tu, outage? Some of the 31 satellites on orbit are operating on a “single string” and are one step away from failure, putting at risk a significant outage for global military, civil, commercial and scientific users. Space Force operators deserve the nation’s thanks for maximizing the satellites’ useful life, but it is past time to replace them.Attempts to save money in the short term by acquiring one GPS satellite per year (as Congress has proposed in the face of budget caps) rather than two results in long term pain for taxpayers, U.S. industry and the nation:Costs go up per satellite by $100 million. The structure of the firm fixed price GPS contract makes clear that it is financially advantageous for the U.S. taxpayer to buy two satellites per year at a price of $250 million per satellite. The cost of buying one satellite per year increases the price to $350 million per satellite.The GPS supply chain is at greater risk. The sole source U.S. atomic clock manufacturer for GPS satellites, which provides the foundational timing signals, needs an order that supports two satellites purchased per year to keep its production line open.
The U.S. loses geopolitical and technological prestige, long a hallmark of the GPS program. The world has long trusted the U.S. to deliver and operate a satellite constellation that powers their critical infrastructure and brought countless other innovations to their economies and doorsteps. The Trump administration issued a policy directive in 2021 “…to maintain U.S. leadership in the service provision, and responsible use of global navigation satellite systems, including GPS and foreign systems.” Questions about whether GPS remains the gold standard are disheartening because they point to a decline in global trust of America’s space leadership.What can be done?A decline in American space leadership doesn’t need to be our future. The Department of Defense can take steps now to modernize and field the nation’s next generation on-orbit PNT architecture. Launch the three GPS satellites in storage immediately. SpaceX’s Falcon 9, ULA’s Vulcan — it doesn’t matter. Launch them immediately.Adopt a “launch upon availability” strategy for GPS satellites. Storing completed, modern GPS satellites doesn’t make sense considering the vulnerabilities of single string on-orbit satellites, today’s threats, or Presidential directives to deliver financial and other efficiencies in government operations. Fund accelerated upgrades and monitoring capabilities in today’s GPS ground station. To deliver vital improvements to public safety, Space Force operators should be able to monitor the health of new civil signals, including those designed for the aviation community, as soon as possible. In the meantime, DoD must continue operational testing of the GPS ground station upgrade known as the Operational Control Station and resolve technical issues uncovered during that process. Put older GPS satellites in a graveyard orbit. Those that are operating on a single string can be retired to make room for modern satellites while the nation waits for the GPS ground station upgrade.Acknowledge the role of GPS satellites in meeting today’s threats: These satellites are designed to meet one of today’s high-risk/low-probability threats, as they are capable of detecting nuclear detonations and can continue to transmit signals to users in the event of a nuclear detonation.Integrate orbital, signal and spectrum diversity to increase resiliency. Incorporating signals from commercial PNT satellites operating in low Earth orbit (LEO) that offer this diversification into military user equipment – and fully funding these efforts – means warfighters will have access to top-of-the-line receivers that are better able to operate in denied environments.Congressional oversight mattersCongress must also take a vital leadership role in prioritizing the delivery of the nation’s modern PNT architecture. They can do this by appropriating funds to buy two GPS IIIF satellites per year, fund ground station upgrades that monitor the health of the new civil signals, and fully fund modern military receivers that receive signals from PNT satellites with orbital, signal, and spectrum diversity. They can also fund PNT satellites that can operate in LEO and geostationary orbits to increase resiliency. When they begin investing in a next generation of GPS satellites, they must ensure they include timing, military, and civil signals on a single platform to cost-efficiently serve its wide user base. History RepeatsAlan Shepard famously said, “…Light this candle!” when he got frustrated with technical glitches and debates among flight engineers about whether Freedom 7 should be launched into space in May 1961. It is long past time for the U.S. government to deliver a modern, resilient PNT timing systems architecture to the nation that reflects its true value to our national and economic security. Alan Shepard’s words ring true today. It is time to heed them once again.Lisa Dyer is the executive director of the GPS Innovation Alliance.SpaceNews is committed to publishing our community’s diverse perspectives. Whether you’re an academic, executive, engineer or even just a concerned citizen of the cosmos, send your arguments and viewpoints to [email protected] to be considered for publication online or in our next magazine. The perspectives shared in these op-eds are solely those of the authors.