Shoebox-sized detector satellites could sniff out a hidden nuclear weapon.
In 2024 whispers started circling military bases. The rumor: Russia was building a nuke for space. Why? The war in Ukraine. Specifically. The success of Starlink. SpaceX’s constellation wasn’t just handing out broadband to ruined cities. It gave Ukrainian drones range. Radio control links have limits. Starlink does not. And it’s hard to jam. So the logic follows. If you can’t cut the signal why not cut the satellites?
Brute force.
A nuclear explosion in orbit wouldn’t just take out a few satellites. It would flood Low Earth Orbit (LEO) and Very Low Earth Orbit (VLEO) with fast energetic electrons. Areg Danagoulian knows this well. He is an associate professor of nuclear science at MIT. He told Space.com it would make these orbits “uninhabitable.” For years. We would lose the International Space Station. Reconnaissance satellites. Communications. Everything.
“We would essentially not only lose the satellites… we would lose those orbits.”
We’ve seen this before. 1962. Operation Starfish Prime. The U.S. blew a 1.4-megoton hydrogen bomb 240 miles above the Pacific. There were fewer than 100 satellites in orbit then. One-third died. Imagine it now. Today a blast would wipe out Amazon’s Leo network and hundreds of climate and disaster monitoring eyes. It would be catastrophe.
So how do you find the bomb before it goes off?
Danagoulian suggests a swarm. Not one big ship but many small “9U” cubesats. Roughly the size of large shoeboxes. They carry special detectors.
The target orbit is specific. 1,200 miles up. 2,000 kilometers. Russia’s Kosmos 2552 satellite hung out there in 2022. People got suspicious. It crossed the Van Allen belt. That region is packed with cosmic radiation trapped by Earth’s magnetic field.
Here’s the trick.
The fissile uranium in a bomb reacts with the protons in that belt. High-energy protons smash into uranium nuclei. They shatter it. Proton-induced neutron spallation. Neutrons fly out. A lot of them.
“That device [the bomb] becomes a very intense neutron source.”
Most space objects don’t emit that specific signature.
To catch it a detector satellite has to get close. Within a few kilometers. Maybe 2.5 miles. It creeps up. The sensor uses a dual setup. Inside: a neutron scintillator that catches protons and neutrons. Outside: a “cage of diamond.” The diamond detects only neutrons. If the outer cage triggers but the inner one doesn’t you can ignore it. Likely just a background proton. If both trigger? You triangulate. You trace the neutron back to its source.
How long does it take? With one satellite about a week. With ten in a constellation just hours.
If you find the nuke you don’t go in and disarm it. No one knows how to safely defuse an atomic bomb in vacuum. Instead you jam the communication link from the ground. No signal. No remote detonation.
Does it matter that this is illegal?
The UN Outer Space Treaty bans nukes in orbit. Paper law. There’s no police officer in LEO to enforce it. Other methods exist. X-ray satellites perhaps. But they cost more and weigh more.
Danagoulian adds another thought. Radiation hardening. Tougher satellites. Because even with detection we might still face the aftermath.
