Detecting Hidden Nuclear Weapons In Space May Be Possible Using Cosmic Rays

For almost 60 years, nan world’s astir powerful militaries person agreed not to put atomic weapons into orbit astir Earth. But nan Outer Space Treaty (OST), ratified successful 1967 by nan U.S. and Soviet Union arsenic tensions betwixt nan 2 superpowers were astatine their peak, has nary teeth; it’s efficaciously a gentleman’s agreement. That’s a problem, experts say: while nan grant strategy has held truthful far, progressively suspicious moves by Russia and nan increasing number of outer targets mean a stronger policing of orbit is desperately needed.

“The logic this is nether unit is that nan U.S. heavy depends connected abstraction capabilities for subject power, and Russia, successful particular, is exploring really to return those abstraction capabilities away,” says Jeffrey Lewis, a atomic nonproliferation master and a distinguished chap astatine nan Foreign Policy Research Institute.

“They look to beryllium considering wide termination [of satellites] successful orbit, and if you deliberation astir it, what’s nan easiest measurement to get free of each those Starlink satellites? It would beryllium to detonate a mini number of atomic weapons.”

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While specified a detonation would apt harm Russia’s abstraction capabilities arsenic well, Lewis argues that nan Kremlin’s calculation whitethorn beryllium that Russia “is astir apt amended disconnected successful a world successful which nary 1 has abstraction capabilities than a world successful which nan U.S. has dramatically amended weapons.”

The interest that Russia could deploy this benignant of antisatellite weaponry has mounted passim nan war successful Ukraine, peculiarly pursuing nan February 2022 motorboat of Russia’s Kosmos 2553 satellite. While nan Kremlin says nan outer is portion of a radar system, nan U.S. has alleged that, while not a limb itself, Kosmos 2553 is designed to thief create a atomic antisatellite system.

Kosmos 2553 began to rotation retired of power successful April 2025 and is believed to presently beryllium nonoperational. Even so, nan saga amplified concerns among atomic information experts complete nan request to person a measurement of verifying OST compliance.

Danagoulian, an subordinate professor astatine nan Massachusetts Institute of Technology, believes nan reply lies successful detecting nan relationship betwixt uranium atoms and high-energy cosmic-ray particles. The area of abstraction occupied by satellites is filled pinch high-energy protons, and erstwhile they onslaught atoms of uranium—the constituent utilized successful galore atomic weapons—it causes a process known arsenic spallation, successful which nan collisions lead to nan ejection of neutrons.

“If you observe those neutrons, that itself tin beryllium a telltale motion that location is an different magnitude of uranium connected nan satellite, and it’s astir apt to beryllium a atomic weapon,” Danagoulian says.

It’s not a elemental idea, Danagoulian says. The neutrons’ awesome is weaker nan farther distant you are from nan source, and nan precocious magnitude of protons, electrons and gamma radiation shooting astir successful low-Earth orbit tin create a batch of inheritance noise.

“It’s not easy, but we judge that it tin beryllium done,” Danagoulian says.

To execute nan goal, Danagoulian projected a outer fitted pinch a detector array constructed of pixels. Each pixel measures astir a centimeter squared and is covered by a shape of diamonds. The diamonds are “very bully astatine detecting charged particles, specified arsenic electrons and protons, but are fundamentally transparent to neutrons,” he says. “If a neutron comes in, it’s not going to interact pinch nan diamond, but it will interact pinch an soul neutron detector.”

While nan diamonds thief select retired each nan inheritance particles, nan detector besides needs to beryllium capable to differentiate betwixt neutrons coming from a imaginable limb and neutrons that are conscionable bouncing disconnected of Earth. To lick that problem, Danagoulian proposes installing a instrumentality known arsenic a neutron scatter camera, which traces nan location of a neutron complete nan people of conscionable a fraction of a 2nd to find which guidance it came from.

Lewis says Danagoulian’s connection could activity successful theory, but he points to a awesome shortcoming: successful bid to observe weapons-grade uranium pinch a precocious grade of certainty, nan discovery strategy would request to beryllium wrong astir 4 kilometers (about 2.5 miles) of nan suspected weapon. In nan discourse of space, that fundamentally intends nan detector and nan limb would request to beryllium correct adjacent to each other.

The detector would besides request to observe nan suspicious outer for arsenic agelong arsenic a week to get an meticulous reading. Beyond immoderate logistical hurdles, Lewis says this benignant of outer shadowing could person governmental repercussions backmost connected Earth.

Geopolitics aside, Danagoulian says his activity has received encouragement from colleagues connected “the different broadside of nan fence” of nationalist security, who opportunity his verification connection is “a valuable point to activity on.”

“Our dream is that arsenic we are publishing this paper, group who activity connected classified investigation tin return this and tin modify it,” Danagoulian says. “Hopefully this leads america to a moving solution.”