Keeping Outer Space Nuclear Weapons Free

March 2024     
By Daryl G. Kimball

Fifty-seven years ago, through the Outer Space Treaty, the United States and the Soviet Union agreed to codify a fundamental nuclear taboo: nuclear weapons shall not be stationed in orbit or elsewhere in outer space. But there is growing concern that Russia is working on an orbiting anti-satellite (ASAT) weapons system involving a nuclear explosive device that would, if deployed, violate the treaty, undermine space security, and worsen the technological and nuclear arms race.

The White House confirmed on Feb. 15 that U.S. intelligence uncovered evidence that Russia is developing an ASAT weapon that “would be a violation of the Outer Space Treaty, to which more than 130 countries have signed up to, including Russia.” Russian President Vladimir Putin issued a nondenial denial, claiming on Feb. 20 that Russia remains “categorically against…the placement of nuclear weapons in space.”

An ASAT system involving a nuclear explosive device could produce a massive surge of radiation and a powerful electromagnetic pulse that, depending on the altitude of the explosion and the size of the warhead, could indiscriminately destroy, blind, or disable many of the 9,500 commercial and military space satellites now in orbit.

Russia’s reported pursuit of a nuclear-armed ASAT system is another troubling attempt by the Kremlin to challenge the fundamental norms against nuclear weapons and to use nuclear weapons to intimidate and coerce. But it would not be a “Sputnik moment” requiring parallel ASAT weapons system development or radical new countermeasures by the United States.

As with the exotic nuclear delivery systems that Putin first announced in 2018, including a long-range, underwater torpedo and a nuclear-powered cruise missile, a nuclear-capable ASAT weapons system would add a dangerous capability. But it would not alter the existing military balance of terror.

Russia already fields a range of ASAT system capabilities, including co-orbital systems that can launch cyberattacks and engage in electronic jamming of specific adversary satellites. As with China, India, and the United States, Russia has already demonstrated a capability to use a ground-based missile to hit and destroy an orbiting satellite. All nations with nuclear-armed ballistic missiles also have the latent ability to detonate a nuclear explosive device in space. From 1958 to 1962, the United States and the Soviet Union conducted nuclear explosive tests in the outer atmosphere.

The United States, which has the largest number of satellites in orbit, is already working to improve the resilience of its military communications, early-warning, and surveillance assets. A new Pentagon program soon will put constellations of smaller, cheaper satellites into orbit to counter space-based threats. Any corresponding U.S. nuclear-armed ASAT system effort would put U.S. and other satellites at even greater risk and do nothing to protect U.S. capabilities in space.

Off-and-on talks designed to maintain the peaceful use of space, including restrictions on ASAT weapons systems, have been stymied for years. A long-standing Chinese-Russian treaty proposal would ban objects placed into orbit with the intent of harming other space objects. It also would ban the “threat or use of force against outer space objects,” which would still allow suborbital and ground-based ASAT weapons capabilities.

Until recently, the United States has been wary of any legally binding restrictions on ASAT weapons systems in part because they might restrict U.S. ground-based missile defense capabilities or a possible space-based, kinetic anti-missile system that could involve a number of orbiting interceptors that provide a thin defense against ground-based missiles. More recently, the Biden administration proposed and rallied support for a ban on direct-ascent ASAT missile tests, which create debris fields that pose a major hazard to orbiting objects.

In the coming weeks, Washington, Beijing, and other capitals need to pressure Putin to abandon any ideas about putting nuclear weapons in orbit. As President Joe Biden noted on Feb. 16, that deployment “hasn’t happened yet, and my hope is it will not.”

The possibility of a Russian nuclear-armed ASAT system should also spur Washington, Moscow, Beijing, and other space-faring nations to get serious finally about additional measures to protect space security. They need to implement effective limits on ASAT weapons systems, including direct-ascent ASAT weapons and space-based systems that can destroy satellites and other objects traveling through space.

Russian ASAT weapons systems are not the only destabilizing factor in the dangerous nuclear and deterrence equation. In the absence of new, agreed constraints on Russian and U.S. strategic nuclear arsenals and measures to halt the growth of China’s arsenal, a costly three-way nuclear arms race could accelerate after the New Strategic Arms Reduction Treaty expires in 2026. In response, Biden needs to rally international pressure on Russia to support his proposals for talks on a new nuclear arms control framework and separate, regular dialogues with Moscow and Beijing on reducing nuclear dangers. Space and global security depend on it.