Russia’s space weapon: Is it nuclear and does it pose a threat?

The US government has privately warned lawmakers and European allies that Russia plans to launch a space weapon with possible nuclear capabilities, according to a flurry of reports.

The news broke after Mike Turner, chairman of the US House Intelligence Committee, issued a vague warning about a “serious national security threat” and urged US president Joe Biden to “declassify all information relating to this threat” for the purpose of more public discussions. Since then, news reports have revealed additional details about what the Russian mystery weapon might be. Here is what we know so far.

Does this mean Russia aims to put nuclear missiles or bombs in space?

This remains unclear. Reports from ABC News and The New York Times use the term “nuclear weapon”, which could mean a weapon capable of producing an explosion involving nuclear fission or fusion reactions. If this is true, it would violate the Outer Space Treaty of 1967, which bans signatory countries – including Russia and the US – from placing nuclear or other weapons of mass destruction in space.

A nuclear explosion in space would not directly harm people on Earth, but it could destroy and disable multiple satellites. When the US detonated a nuclear bomb in low Earth orbit during its Starfish Prime test in 1962, the resulting radiation damaged or destroyed about one-third of satellites in low Earth orbit at the time.

But there is another possibility that does not involve nuclear weapons.

What else could Russia’s nuclear capability in space be?

The Russian space weapon may simply use nuclear power to provide energy for its onboard systems. PBS News Hour cited US officials describing the Russian weapon as “possibly nuclear-powered”.

Both Russia and the US have used different forms of nuclear power in space for decades. One form involves nuclear fission reactors, such as those found in civilian nuclear plants, which draw power from an ongoing nuclear chain reaction.

The US launched an experimental nuclear reactor into space in 1965, while Russia launched at least 34 nuclear reactors aboard satellites between 1967 and 1988, according to the World Nuclear Association.

The US, Russia and other countries have also launched space missions powered by radioisotope systems. These harness heat from the natural decay of radioactive materials as a source of electricity – but they supply much less power than nuclear fission reactors.

What does this Russian space weapon actually do?

News reports agree that the Russian weapon is designed to target satellites in space instead of directly harming anyone or anything on the ground. However, if the weapon is capable of knocking satellites out of orbit, these objects could fall to the planet’s surface and cause serious damage. If it blows them to pieces, the resulting clouds of space debris could threaten other satellites or even the International Space Station. This might even trigger a Kessler syndrome scenario, where a chain reaction of space debris cascades out of control and makes it practically impossible for satellites to survive in Earth orbit.

Various countries – including Russia, the US, China and India – have all previously tested anti-satellite (ASAT) weapons that involve launching missiles from Earth to shoot down objects in orbit. But countries have been much quieter about whether they have actually deployed ASAT weapons in space.

What has Russia said about this possible weapon?

A spokesperson for Russian president Vladimir Putin’s government described the US warning as a “malicious fabrication” intended to spur the US Congress to pass a bill authorising more military aid for Ukraine, according to Reuters. Since Russia launched its full-scale invasion of Ukraine in February 2022, the US and Europe have been backing Ukraine’s military resistance against Russian forces.

Why would Russia want a new anti-satellite weapon?

Satellites are crucial for both military and civilian applications that have a huge impact on modern life. They monitor the weather, power GPS systems, provide space-based surveillance and enable communication – for example, SpaceX’s swarm of Starlink satellites has proven vital for Ukraine’s military forces in coordinating drone and artillery strikes against Russian forces on the battlefield.

The US officials cited by PBS News Hour suggested that the Russian space weapon has “electronic warfare capability to target American satellites that are essential for U.S. military and civilian communication”.

Russia has spent years developing space-based electronic warfare systems capable of jamming the communications signals to and from satellites, according to a report by the Secure World Foundation, a space security organisation based in Colorado. Victoria Samson at the Secure World Foundation said that such Russian space weapons could be nuclear-powered.

So how dangerous could this new anti-satellite weapon be?

The good news is, if this space weapon jams satellites rather than physically destroying them, it won’t cause catastrophic space debris scenarios like Kessler syndrome. However, it could still be dangerous.

A space weapon that uses electronic warfare to jam signals could effectively disable satellites. That could disrupt crucial battlefield communications, leave GPS-guided systems inoperative, blind spy satellites and make it more difficult for the US to coordinate its military forces across the world.