Part three of our four-part series looking at how losing space would affect the U.S. You can read part two here: A Day Without Space Part 2: The Invisible Threat — Effects on the Battlefield and Beyond
How a Day Without Space Unfolds
Take away a large chunk of space support, and the impact cascades. The first hit is largely invisible to the tactical edge, but catastrophic at the top. The loss of early warning for nuclear missile launches raises the temperature globally. As Missile warning timelines stretch or vanish, early warning for ballistic or hypersonic launches slows. Decision-makers see fewer tracks, later, with less confidence. That is a recipe for either over-reaction or paralysis.
The realization hits. U.S. nuclear command and control lost its redundancy. Space assets are the survivable layer for communications in the worst case. Without them, more traffic goes on terrestrial and airborne systems with more limited range and that are easier to target. An enemy does not have to knock everything offline. They just need to inject enough doubt that no one can trust what they are seeing.
At the combatant command and joint task force level, the military commanders charged with directing forces abroad, a day without space pushes their operations centers into the military stone age. They are reliant on 1980s-era radio networks. Only the enemy is living in 2025. High-capacity satellite links that carry voice, data, and video feeds are jammed, degraded, or cut. Traffic collapses back onto undersea cables, HF, and line-of-sight networks. The “common operational picture” stops being common. Space-based imaging, radar, and SIGINT that enabled wide-area surveillance start dropping out. Cueing sensors becomes harder. Analysts have fewer clear points and more noise in their data. All of that creates friction and decreases the time to react. Commanders begin to rely on stale imagery and best guesses. Operational tempo shifts from “sense-decide-act” to “hope-guess-react.”
At the brigade, squadron, ship, and platoon level, the loss is immediate and personal. Armored and mechanized units now must coordinate over terrain without shared digital overlays they trust. Close air support and artillery risk fratricide when grid accuracy is suspect. GPS-guided munitions still work some of the time in some places, but CEPs start to grow, and targeting cells hesitate. How many fire control centers are still using maps and practicing using plotting boards? Commanders are used to trusting the machines to make these types of decisions. What do they do when they no longer trust the coordinates? Small UAS that rely on GNSS for navigation and targeting suddenly wander, drop, or are spoofed to the wrong location, as we’ve already seen in the Russia–Ukraine war.
On paper, we teach “operate in a GPS-denied environment.” In practice, we route, communicate, and synchronize on the assumption that at least our picture is true, even if the enemy is trying to mess with everyone else’s. A sustained day without space breaks that assumption and forces the military violently back to basics, at a time when they could be asked to engage in high-end combat.
War is logistics. Logistics today requires PNT and connectivity. Military and charter aircraft navigating by degraded or spoofed signals face reroutes, delays, or outright grounding in contested regions. Ports and fuel depots that rely on precise timing and location see systems fail. All the “from factory to foxhole” tracking tools assume valid timestamps and coordinates. Degrade those, and suddenly no one is sure where the critical pallet actually is. This only gets compounded as civilian infrastructure is stressed.
Power grids, financial networks, and telecoms rely on GPS timing to keep their systems synchronized. That makes NAVWAR a tool not just for battlefield effects but for strategic coercion against civilian infrastructure. The Gulf War taught countries that you do not fight America on America’s terms. Our logistical networks and ability to mass precision fires is par none. Why would anyone fight us that way today? In particular, if they can strip away key capabilities that enable the logistics flow and precision fires.
What an Adversary Has to Do (And Doesn’t)
The nightmare scenario is a Russian or Chinese space-based nuclear device designed to fry large swaths of satellites in LEO with an EMP-like effect. That’s not science fiction; U.S. officials have publicly raised alarms about exactly this kind of threat. Annie Jacobson wrote about it in her book, Nuclear War A Scenario. But you don’t need a doomsday device to create “a day without space”.
In theater, an adversary can jam and spoof regional GNSS. This affects ground and maritime platforms and could be focused on key approaches, air corridors, and operating areas. Couple these with cyberattacks on satellite operators and ground stations, as seen in the 2022 Viasat hack that disrupted communications across Europe just as Russia invaded Ukraine, and you end up with a strong regional denial of GPS that still presents tactical and operational effects against the U.S. military.
The smart adversary doesn’t turn space off. Instead, they make it weird and use it to signal their ability to do long-term damage to the U.S. in a way that makes us cautious and question our instruments.
