New Russian anti-satellite weapon revives fears of nuclear conflict in space

On February 14, Michael Turner, chairman of the U.S. House Intelligence Committee, issued a statement warning of “a serious threat to national security.” Shortly afterward, the White House confirmed its suspicions that Russia was developing a high-powered anti-satellite weapon. The word nuclear was not used, but it was implicit in the statement.

A week later, an indignant Vladimir Putin denied these claims, declaring himself “categorically opposed to the deployment of nuclear weapons in space” and demanding, in passing, that all governments ratify the existing treaties prohibiting them. Only two months later, in April, Japan and the United States presented a proposal to the UN Security Council to strengthen the validity of the current treaty, which is already 57 years old. Russia vetoed it, thus contradicting Putin’s own statements. And on May 17, Kosmos 2576 took off from Plesetsk, a military satellite whose orbit suggested that it was a prototype of a new anti-satellite device. For now, without a nuclear payload.

What is the point of stationing atomic weapons in space? Attacking a terrestrial target from orbit requires waiting hours — sometimes days — for it to come within range. A ballistic missile or a cruise missile is much more agile. Or the fractional orbital bombing technique, tested by the Soviet Union in the 1960s and later banned under the SALT II agreements.

It is another matter if the aim is to disable enemy satellites. There are also various ways — kinetic projectiles or energy projection weapons — but without a doubt the most expeditious is to detonate a nuclear device nearby. Both the USA and the USSR have carried out tests of this type, always under the pretext of scientific research, not for aggressive purposes. The first was the American operation Argus, in 1958, which consisted of detonating six low-yield nuclear warheads over the South Atlantic; and the Soviets, in 1961 and 1962, made five launches from a range in Kazakhstan.

But the most famous of all these nuclear tests in space was Operation Starfish Prime. On July 9, 1952, a Thor rocket launched from an atoll 1,500 kilometers (930 miles) west of Hawaii carried a one-and-a-half-megaton bomb into space. A pair of recoverable capsules carrying cameras and measuring equipment to analyze the results of the test were aft. The 700-kilogram craft exploded at an altitude of 400 kilometers — almost the distance at which the International Space Station (ISS) orbits. It was already nighttime, so the glow could be seen perfectly from Honolulu, the Hawaiian capital, as an impressive fireworks display that lasted about a quarter of an hour.

But it wasn’t all spectacle. The electromagnetic pulse generated by the explosion was much more powerful than expected. It caused blackouts and damaged power and telephone networks in the Hawaiian islands and knocked out half a dozen satellites, including Ariel — the first British satellite — and a Soviet one. It also created a radiation belt around the Earth that would take months to dissipate.

All these effects pale in comparison to those suffered on Soviet soil as a result of their own tests. When the detonation occurred over inhabited territory, overhead power and telephone networks acted as antennas, generating pulses of thousands of amperes. Insulators could not withstand the overload, fuses and protection systems were triggered, and damage was caused to a power station supplying the capital. It was clear that an atomic explosion in space would have devastating consequences on the ground.

All this happened 60 years ago, in the context of the Cold War. No nuclear device was ever detonated in space again. Now, with the tense geopolitical situation, threats are intensifying. What would happen if a multi-megaton warhead exploded 200 kilometers (125 miles) above our heads?

In 1962, only two dozen artificial satellites orbited the Earth. Today, there are more than 10,000. Although many are military, most provide civilian communications, meteorological, and GPS services. The internet works in part through orbital links; banks and stock exchanges synchronize operations using time signals transmitted from satellites. So do the navigation systems in our cars. An indiscriminate nuclear attack would cause colossal damage. Only those satellites that were protected on the other side of the planet at the time would be safe.

For citizens who were in the area at night at the time of the explosion, the shower of protons and electrons would create an intense — but brief — artificial aurora, probably much brighter than those triggered by natural causes. It could be seen anywhere in the world, even in tropical Africa or the Amazon.

Weapons that also harm the aggressor

But those who were close to the point of explosion would not enjoy the spectacle as much. Only a flash of light comparable to a second Sun, followed by an invisible shower of X-rays, the consequence of the nuclear reactions involved in a thermonuclear explosion. A hydrogen bomb (fusion) uses an atomic bomb (fission) as a detonator and the energy released in both heat and radiation is the result of the sum of both. Obviously, the closer you are, the worse.

Some military satellites are usually shielded, but most civilian satellites are very sensitive to high-energy radiation. Shielding them is simply too expensive and would add a lot to their weight. Semiconductors in solar panels, in particular, are the first to be affected, but radiation can destroy the adhesives that hold them to the structure. Optical equipment would also be affected, particularly those that must capture very low levels of light, such as star sensors, which help orient some satellites, or multispectral cameras used to locate natural resources.

The problem with an atomic weapon is that the detonation would affect friendly and enemy satellites alike. And it would have to take place over enemy territory to prevent the electromagnetic pulse from affecting the ground facilities of the country launching it. The explosion would destroy in one fell swoop (or at least greatly degrade) the capacity of large satellite constellations, but the price to pay would be so high that the aggressor himself would have to think twice.

Another possibility is to use impact vehicles. Simply crash the hunter vehicle into its victim. The collision is programmed with the trajectories in reverse so that the combined speed of both is greater. And a direct hit is not necessary. Most satellites are bristling with panels, antennas, and poles, so it is enough to damage one of them to put it out of use.

But this tactic is not harmless for the attacker either. Let us recall the case of the test carried out by China in 2007, which launched a missile against one of its own satellites (now inactive). The result was a pellet of debris that remained in orbit for months. Some 3,000 fragments were counted, large enough to be detected by radar, but there were undoubtedly many more that were undetectable. Most have already fallen to Earth, but there are still around 1,000 moving in low orbit. In 2021, Russia repeated a similar test with equally disastrous results. As a result, from time to time, the ISS has to perform an evasive maneuver in the face of the danger of colliding with one of these debris.

Non-nuclear alternatives

There is speculation about an alternative: a satellite capable of generating electromagnetic pulses of less power, without the need to detonate nuclear weapons. It would need to be able to approach its targets and deactivate them one by one with more controlled discharges. It is known that several Russian and Chinese satellites, called inspectors, have already tested maneuvers to approach other satellites (in this case their own). And both the Americans and the Chinese have been operating a robotic, maneuverable and recoverable craft for years, whose missions usually last for many months in orbit. The purpose of these long missions has never been clarified, but, as they are military vehicles, it does not take much imagination to guess what they are doing.

An electromagnetic pulse killer satellite would need a huge power source. So traditional solar panels are out of the question; the most likely solution is to use a nuclear reactor, feeding electric coils from which the flash would be discharged when an enemy satellite was within range. It is possible that Kosmos 2576 is intended to test one of these devices, although there is no evidence that it carries nuclear material on board.

Should a conflict escalate to orbital weapons, the most prized U.S. targets would be its spy satellites. These are similar to a Hubble telescope, but pointed downwards. There are usually two in service, following polar orbits that allow them to pass over the entire globe. Russian intelligence services know exactly when they fly over each area; and, vice versa, the U.S. Space Force also monitors its Russian equivalents.

Sign up for our weekly newsletter to get more English-language news coverage from EL PAÍS USA Edition