Idea of ​​an atomic bomb in space scares the world again – 03/12/2024 – Science

In 1982, President Ronald Reagan was considering what became known as Star Wars, a plan that involved spreading thousands of weapons into space to protect the United States from Soviet missiles. At the same time, as a young science writer, I was reporting how the lightning bolts from a single nuclear detonation in orbit could eliminate entire battle station fleets. “Star Wars: Pentagon Madness,” read one headline.

Decades later, Reagan and the Soviet Union are gone, but anxiety about a high-altitude nuclear explosion still persists, brought back more recently by Russian President Vladimir Putin’s ostensible war aims.

Last month, American spy agencies informed Congress, as well as foreign allies, that Putin had the idea of ​​deploying and using an atomic bomb in space to disable thousands of satellites. Not only would military and civilian communications links be at risk, but satellites that spy, track the weather, make broadcasts, enable cell phone maps, form internet connections and perform dozens of other modern tasks.

The mere claim of such an idea could help Putin scare his adversaries.

“Its purpose is the same as Star Wars was for us in the 1980s,” said Jonathan McDowell, an astrophysicist who publishes a monthly report on space. “It’s to scare the other side.”

But to actually wage war, analysts say the step is difficult to imagine.

In a 2010 study, five nuclear weapons experts explained how astronauts struck by the most powerful rays would experience two to three hours of nausea and vomiting before radiation sickness left them with “a 90% probability of death.”

The International Space Station (ISS) normally houses seven astronauts — three Americans, one foreigner and three Russians. The rays could also turn the space station of Putin’s main ally, China, into a death trap. The new Beijing outpost is home to three Chinese astronauts and is set to be expanded to accommodate even more.

China’s satellites — 628 in a recent count — would pose an additional vulnerability. Stephen M. Younger, former director of Sandia National Laboratories, which helps make the country’s nuclear weapons, said in an interview that a Russian space explosion could “blind” China’s reconnaissance satellites and thus end the country’s main way of tracking the U.S. Navy’s Pacific Fleet.

Putin’s supposed bomb drop, Younger said, was more bravado than a serious war plan. “Putin is not stupid.”

The whole idea behind nuclear weapons, said David Wright, a nuclear weapons expert at MIT, is that there is a self-deterrent in part because they would cause significant collateral damage not only to other countries, but to anyone who decides to do so. launch them. Such deterrence could also apply to a space bomb, he added, unless whoever launched them was desperate and saw the risks as acceptable.

“It would be dangerous for the Russians themselves,” said Richard L. Garwin, a physicist and longtime adviser to the federal government who helped design the world’s first hydrogen bomb.

Since Putin invaded Ukraine, he has made atomic threats that analysts see as central to his strategy of deterring Western intervention. If he were to park an atomic bomb in orbit, it would violate two fundamental nuclear-era treaties — signed in 1963 and 1967 — and signal a significant escalation.

On February 20, Putin denied that he intended to launch a nuclear weapon into orbit.

But days later, on February 29, in his annual State of the Nation address, he returned to his usual bellicose rhetoric, warning that the West faced the risk of nuclear war.

Nuclear weapons in general, and space bombs in particular, are the antithesis of precision. They are indiscriminate — unlike conventional weapons, which are typically characterized by precision. In 1981, when I first wrote about orbital nuclear weapons as a reporter for Science magazine, I referred to the confusion of space as the “Chaos Factor.”

The unexpected phenomenon came to life in July 1962, when the United States detonated a hydrogen bomb about 400 km above the Pacific Ocean. Dark skies lit up. In Hawaii, the street lights went out. In orbit, satellites failed.

President John F. Kennedy worried that persistent radiation from nuclear explosions would endanger astronauts. In September 1962, he canceled a test called Urraca. The hydrogen bomb would be detonated at an altitude of more than 1,200 km — the highest of any test explosion, American or Soviet. The following year, he signed a treaty banning experimental explosions in space.

The scientific world was then making an important distinction about detonations in space that is absent from most current discussions: atomic explosions have not only immediate but residual effects.

The initial repercussions are better known. A bomb’s rays spread over vast distances to produce lightning-like electrical bolts on satellites and terrestrial networks, frying electrical circuits. Experts call them electromagnetic pulses, or EMPs. Pulses turned out the lights in Hawaii.

However, what caught Kennedy’s attention was a long-term effect: how radioactive debris and charged particles from a nuclear explosion enlarge the natural, doughnut-shaped belts of radiation that surround the Earth. These belts are intense, but nothing compared to what they become when amplified by radiation from a bomb.

The five nuclear experts who wrote the 2010 study linked the overloading of these belts not only to risks to astronauts but also, after the July 1962 test, to significant damage to at least eight satellites. The most famous victim was Telstar, the world’s first communications satellite.

Over the years, I’ve become concerned that a complicated topic was being oversimplified. Fringe groups and bellicose politicians sounded alarms about Russian EMP attacks on the country’s power grid, while rarely noticing the risk to Moscow’s own spacecraft and astronauts.

Peter Vincent Pry, a former CIA officer, warned in a 2017 report that Moscow was prepared for surprise EMP attacks that would paralyze the United States and destroy its satellites.

In 2019, President Donald Trump ordered the strengthening of the country’s EMP defenses. Energy Secretary Rick Perry said the order “sends a clear message to adversaries that the United States takes this threat seriously.”

National security experts know how weapons of mass destruction engage in cycles of fear that come and go with the political winds. After decades of thinking about the fundamentals of nuclear explosions in space, I have come to see the risks as extremely low to nonexistent because a detonation — as McDowell, Younger, Wright, Garwin, and others have argued — would harm not only the target of the attack, but also those who makes the attack.

“Perhaps the Russians will decide that their astronauts will have to sacrifice themselves for their homeland,” McDowell said. “But I don’t think Putin, crazy as he is, will do that.”