Why Russia Might Put a Nuclear Weapon in Space

When Mike Turner, the chair of the House Intelligence Committee, issued a cryptic warning last week about the “serious national security threat” represented by a secret Russian military capability, the Republican representative from Ohio generated a wave of anxiety. Concern about Turner’s statement deepened when White House spokesperson John Kirby confirmed that Moscow is developing a “troubling” antisatellite weapon. Soon, multiple news outlets, such as The New York Times, were reporting that Moscow might be preparing to deploy a nuclear weapon in space.

The purpose of such a weapon may well be to destroy the large-scale satellite constellations used for communications and reconnaissance. Obliterating these kinds of space systems could degrade the effectiveness of Ukrainian defense forces that heavily rely on commercial satellite communications and imagery. It would also reduce the effectiveness of the U.S. military and that of its allies, which are similarly dependent on these systems. Russia’s decision to detonate a nuclear weapon in space would almost certainly affect the Kremlin’s satellites, too. But even if Russia never used a nuclear space weapon, Moscow might view its deployment as a new source of leverage, a sword of Damocles it could dangle over every other state’s space systems. And it is hard to know the Russian calculus for employment.

Moscow and Washington have tested antisatellite weapons since the Cold War, but if Russia deployed a nuclear weapon in space to attack other satellites, it would be an unprecedented development and a clear violation of the 1967 Outer Space Treaty. Yet for the Kremlin, the costs of a violation may well be outweighed by the benefits. The antisatellite weapons that Moscow has demonstrated are not capable of effectively destroying the large-scale satellite constellations owned and operated by private companies. A nuclear antisatellite weapon, however, could destroy large numbers of these satellites in one fell swoop. If Russian officials decide to deploy this capability, Washington has no good options for stopping them.

BACK TO THE FUTURE

Although antisatellite space systems appear to be a futuristic class of weapons, Moscow and Washington already have decades of experience developing them. During the Cold War, Moscow deemed its nonnuclear, antisatellite weapons sufficient to destroy key U.S. satellites. But in the post–Cold War period, the rise of much larger satellite constellations has likely rendered these nonnuclear antisatellite weapons less useful.

Antisatellite weapons appeared soon after the dawn of the space age. Only two years after the Soviets launched Sputnik, in 1957, the United States tested an aircraft-launched antisatellite weapon that would have used a nuclear warhead to destroy its target. But it never became a part of the U.S. arsenal, thanks to the Eisenhower administration’s restrained approach to space weapons. His caution was prescient. Before the advent of more accurate missiles, a nuclear warhead was required to destroy satellites in orbit, and high-altitude nuclear detonations demonstrated that radiation in space was not discriminate in terms of which objects it affected. In 1962, one such explosion, from a nuclear test called Starfish Prime, damaged nearly one-quarter of all satellites in orbit—including a British scientific satellite.

In the early 1960s, U.S. policymakers became afraid that the Soviet Union would deploy orbital nuclear weapons in the form of a fractional orbital bombardment system—that is, launch a nuclear weapon into space on a southerly trajectory over the South Pole to avoid U.S. early-warning radars positioned around the North Pole. Before completing an orbit, the weapon would reenter Earth’s atmosphere and hit its target. The Kennedy administration responded in 1963 by deploying nuclear-tipped missiles on Johnson Island in the Pacific that could destroy incoming nuclear weapons. But the escalating U.S. involvement in Vietnam squeezed defense budgets, and officials worried about the fact that radiation from nuclear antisatellite weapons would indiscriminately destroy U.S. and allied satellites. As a result, Program 437—the name of the project—was soon mothballed. In 1975, it was eliminated.

Russia has significantly expanded its counterspace capabilities.

High-altitude nuclear tests, Program 437, and fractional orbital bombardment systems all underscore that the boundary between nuclear weapons and space weapons is blurry. Although fears about nuclear weapons in space receded with the signing of the Outer Space Treaty in 1967—in which the United States, the Soviet Union, and other signatories pledged to use space for peaceful purposes and not to place nuclear weapons in orbit or on celestial bodies—this treaty, too, was ambiguous. It did not prohibit the deployment of nuclear-powered satellites. It also did not ban nonnuclear space weapons, such as land-based antisatellite missiles designed to eviscerate space systems. There was little consensus on how to even define what a space weapon is, given how many technologies, including missile defense interceptors, can attack satellites. (That lack of consensus persists today.)

These ambiguities became a problem almost as soon as the treaty was signed. In late 1967, reports emerged that Moscow was testing exactly the type of system that prompted President John F. Kennedy to station nuclear antisatellite weapons in the Pacific. Publicly, the U.S. government declared that this new Soviet capability did not defy the Outer Space Treaty because its weapons did not complete an orbit around Earth before reentering the atmosphere. Privately, however, senior officials deemed it a violation. They opted not to confront the Kremlin, in large part because these orbital nuclear weapons were less accurate than traditional ballistic missiles.

The Soviet Union proceeded apace to develop nonnuclear antisatellite weapons that were not restricted by the treaty. In 1969, the Kremlin began testing an antisatellite missile called istrebitel sputnikov, or “satellite killer,” designed to be launched into space, then maneuver close to a U.S. satellite and destroy it with a conventional warhead. Moscow carried out multiple tests of this system, declaring it operational in the 1970s. Other Soviet antisatellite weapons efforts sounded as if they had been ripped from the pages of a Tom Clancy novel. In the 1970s and 1980s, Soviet design bureaus researched lasers that could be used to attack U.S. satellites. In 1987, they even launched such a laser, called Skif-DM, from a spaceport in Kazakhstan. It malfunctioned before reaching orbit. (After this failure, Soviet leader Mikhail Gorbachev canceled the program as part of his broader effort to rein in defense spending.)

The Soviet Union was not alone in developing counterspace weapons. In addition to the Johnston Island missiles, in 1977, the Pentagon drew up plans for a nonnuclear antisatellite weapon called the Miniature Homing Vehicle—designed to be fired into space to destroy Soviet satellites—and an electronic warfare system designed to jam Soviet satellites. Moscow had fewer satellites than Washington, and it was not as reliant on them. The United States never went quite as far as its adversary in fielding a nonnuclear antisatellite weapon, canceling the Miniature Homing Vehicle in 1988.

RETURN OF THE SATELLITE KILLERS

At the end of the Cold War, both Moscow and Washington halted their antisatellite weapons programs. Rather than continuing to compete in space, the two governments began to collaborate, most prominently in the form of the International Space Station. The first section of the station was completed in 1998. To underscore that the two countries had entered a new, cooperative era, the Russian and American components of the station were designed to be interdependent.

But the reprieve from space weapons did not last. In 2007, an emerging space power—China—launched a nonnuclear weapon into space and obliterated one of its own satellites. One year later, the United States used a modified SM-3 missile defense interceptor to destroy a malfunctioning U.S. satellite in low Earth orbit. And eventually, Moscow resurrected its own counterspace programs. Although it is not clear precisely when Russia did so, work seems to have been restarted by 2009.

This revival was likely part of Moscow’s broader military reforms, not a response to foreign space weapons. But nonetheless, in the past 15 years, Russia has significantly expanded its counterspace capabilities. It appears to be developing both land-based and aircraft-launched antisatellite weapons. It is also making directed-energy capabilities, such as lasers that can blind imaging satellites. Russian military space operators have also been perfecting their ability to maneuver objects close to foreign satellites, which allows them to both surveil these objects and, if needed, destroy them. In 2019, General Jay Raymond, the first U.S. chief of space operations, warned that Russia was now stalking U.S. satellites in low Earth orbit.

For Washington, these capabilities are concerning. Historically, the United States has fielded very sophisticated, large satellites, which former Vice Chairman of the Joint Chiefs General John Hyten described in 2017 as “juicy targets.” (Hyten was then the leader of U.S. Strategic Command.) Strikes against communications and reconnaissance satellites could, for example, have a detrimental effect on U.S. and allied military operations that depend on these space systems for command and control, navigation, and targeting. The debris produced from attacks on satellites creates hazards, as well. Only three months before Moscow’s 2022 invasion of Ukraine, Russia destroyed one of its own satellites in orbit using a ground-launched missile. The resulting debris forced astronauts and cosmonauts on the International Space Station to take shelter in their return capsules in case of serious damage to the station.

Calls for space arms control measures will likely fall on deaf ears in the Kremlin.

In the past, strikes against small numbers of satellites could have been debilitating for Washington. But the trend toward deploying proliferated constellations with hundreds or even thousands of satellites makes space systems more survivable. And the antisatellite capability that Russia demonstrated in 2021 is not well suited to destroying these large-scale satellite constellations; there are just too many satellites. Russia has tried to use electronic warfare to jam satellite constellations—specifically SpaceX’s Starlink, which provides Ukraine with vital communications. But it has had little effect.

If Russia seeks a more dependable way to quickly eliminate large numbers of satellites, then the Kremlin might indeed want to field a space-based nuclear antisatellite weapon. The electromagnetic pulse from a nuclear explosion would fry the electronic components of many satellites in the vicinity, rendering them useless. It could achieve the same effect by setting off a nuclear weapon high in the atmosphere, but a nuclear weapon deployed in space would be harder to detect. It could therefore deprive other countries of warning that Russia might be getting ready to use it. And a surprise loss of communications and reconnaissance satellites could be catastrophic for countries that depend on space systems. For example, widespread loss of Starlink satellites would likely heavily degrade the ability of Ukrainian units to carry out coordinated strikes against Russian forces.

Russia would be reticent to use such a weapon, given that many of its own satellites would probably be destroyed, as well. But even if Moscow never detonates a nuclear weapon in space, its mere presence in orbit would be cause for concern. The act of threatening to field such a weapon provides the Kremlin with another rung on its escalation ladder, which it could use to try to deter the United States from taking any actions it opposes. Similarly, threatening to deploy that capability might provide Russian officials with a bargaining chip in future arms control negotiations with the United States, which Moscow might use to exact concessions on issues that Washington has been reluctant to discuss, such as limits on national missile defenses.

If Russia does decide to deploy a nuclear antisatellite weapon, there is very little that can be done to change its course. Taking unprecedented measures to deploy a space-based nuclear capability would signal that the Kremlin views proliferated constellations as such a clear and present danger to its national security that Moscow is willing to ignore the interests of other spacefaring states. Once the Kremlin has made up its mind, it is hard to imagine that even China, Russia’s “no limits” partner, could talk it down.

Thankfully, it appears that Moscow has not yet made a firm decision, giving other governments an opportunity to try to dissuade it. The United States’ best option is to persuade China, India, and other spacefaring countries into collectively warding off the Kremlin for the welfare of their own satellites. But Washington, alone, will struggle to have an influence. With the U.S.-Russian arms control dialogue now frozen, bilateral calls for space arms control measures will likely fall on deaf ears in the Kremlin. And if the Kremlin has decided to deploy weapons designed to destroy large-scale satellite constellations, it will be very difficult to get Moscow to change its mind.