Starfish Prime: the Dazzling Story of the Nuclear Blade Runner

1962. The world stood frozen at the epicentre of the Cold War. The United States and the Soviets, gripped by paranoia over who would come out on top, engaged in an arms race, devising ever more sophisticated means to annihilate each other. In this escalating madness, the Americans decided to take an unprecedented step – to detonate a nuclear bomb in space.

This experiment, known as Starfish Prime, quite literally forced humanity to walk the razor’s edge of nuclear catastrophe, prompting people for the first time to truly consider the catastrophic consequences of the nuclear apocalypse they were hurtling toward. In this article, you will learn everything about Operation “Starfish Prime”—its objectives, its aftermath, and the lessons learned.

Starfish Prime Background 

In August 1945, the United States dropped atomic bombs on the Japanese cities of Hiroshima and Nagasaki, demonstrating to the entire world the terrifying might of nuclear weapons. This sparked a chain reaction—the arms race between the two superpowers, the United States and the Soviet Union, later joined by the United Kingdom (1952) and France (1960).

Numerous tests were conducted in the atmosphere, underground, and underwater, resulting not only in widespread environmental contamination but also in an escalating risk of nuclear war. Reducing international tensions was required and the USSR was the first step in this direction. In 1958 the Soviets declared a unilateral moratorium on nuclear testing and the US and UK, after some scepticism, joined it. However, the time of appeasement did not last long.

Starfish Prime vs Tsar Bomb

In the early 1960s, the Soviet Union resumed its nuclear tests, including the detonation of a 50-megaton thermonuclear aerial bomb, “Ivan,” which would go down in history as the Tsar Bomba. On October 30, 1961, this monstrous device was dropped from a heavy Tu-95V bomber over Novaya Zemlya, a Soviet archipelago in the Arctic Ocean. The Tsar Bomba detonated at an altitude of 4 kilometers, producing a shock wave so powerful that it circled the Earth three times and triggered seismic disturbances worldwide.

The Soviets made no attempt to conceal the fact that this test was devoid of any scientific purpose; it was purely a show of strength. The United States urgently needed a response that could outmatch the enemy’s provocative display. Thus was born the American nuclear defense project known as Dominic, with its key milestone being Starfish Prime—the first nuclear test in space. 

Can a Nuclear Bomb Explode In Space?

This question troubled many people in the 1960s. After all, explosions and combustion usually require oxygen, which is absent in space. But that’s not the case with a nuclear bomb. Inside the bomb is a fissile material (uranium or plutonium). To initiate the reaction, it’s rapidly compressed into a critical mass. This is achieved using conventional explosives that compress the nuclear core from all sides.

Once the mass reaches criticality, neutrons begin to bombard the atomic nuclei. The nuclei split, releasing energy and even more neutrons. A chain reaction follows, unleashing an enormous amount of energy. In the atmosphere, this manifests as a giant, expanding mushroom cloud, propelled by a shock wave that obliterates everything within a radius of several kilometers.

In space, however, where there is no air or gravity, a nuclear explosion produces only a sphere of superheated plasma that quickly cools and disperses. There is no thunderous roar, no shock wave, no towering mushroom cloud. Only a silent — yet no less deadly — burst of radiation and an electromagnetic pulse. Such was the nature of the Starfish Prime explosion.

What was the purpose of Starfish Prime?

Project Starfish Prime was more than just another nuclear test aimed at outdoing the USSR. It pursued a comprehensive array of military and scientific objectives:

“Electromagnetic Armageddon”

The military wanted to assess the impact of a nuclear explosion in space on an adversary’s electronic infrastructure. A powerful electromagnetic pulse (EMP) generated by the blast could cripple communication systems, radar networks, satellites, and even ground-based power stations—plunging entire cities into darkness.

“Star Wars”

Another goal was to explore the possibility of creating nuclear weapons capable of intercepting enemy ballistic missiles in space. Imagine a “nuclear shield” that could destroy incoming warheads before they reached their targets—science fiction on the verge of becoming reality.

“The Physics of Extreme Phenomena”

Scientists aimed to understand the physics of nuclear detonations under vacuum and zero-gravity conditions. Gaining such insight would allow them to refine nuclear technologies, making them more efficient and safer.

“Cosmic Weather and Its Vagaries”

It’s well known that Earth’s magnetosphere acts as an invisible shield against radiation and solar wind. Researchers hoped the Starfish Prime test would help them study how nuclear tests in space might influence meteorological and other atmospheric processes.

Starfish Prime Launch 

The experiment launch was scheduled for 20 June 1962 and took place under high secrecy. A Thor missile with a 1.4 megaton nuclear warhead (100 times more powerful than the bomb dropped on Hiroshima) was launched from Johnston Atoll in the Pacific Ocean southwest of Hawaii. 

Everything was going well for the first 59 seconds of the flight, but the engine suddenly failed, and the missile began to disintegrate in mid-air. To prevent the nuclear warhead from falling on populated areas, it was decided to activate the self-destruct system. The rocket exploded at about 35,000 feet and the debris fell into the ocean near Johnston Atoll. Fortunately, no one was injured.

The second launch of Starfish Prime on 9 July 1962 proceeded normally. The nuclear warhead was delivered to the target altitude of 250 miles, where it successfully detonated. 

How big was Starfish Prime? The flash from the explosion was visible thousands of kilometres away. In Hawaii, 1450 kilometres from the epicentre, people observed an unusual aurora-like glow in the sky. But that was just the beginning. 

What Effects Did Starfish Prime Have on Hawaii?

Starfish prime effects turned out to be far more severe than scientists had anticipated. A powerful electromagnetic pulse (EMP) surged over the islands like a giant wave, causing disruptions in electricity and electronic systems. Street lights went out, telephones and radios fell silent, and televisions displayed only static. People, panicked and confused, rushed out into the streets, clinging to the hope that they had not become unwitting victims of a nuclear apocalypse.

Starfish Prime Global Impact

The electromagnetic pulse (EMP) damaged several satellites, including the first British satellite, Ariel 1, which had been launched only a few months earlier, and the American satellite Telstar 1, which provided transatlantic telephone communication.

The explosion created an artificial radiation belt around the Earth, which persisted for several years and posed a serious threat to spacecraft and astronauts. The radiation levels within this belt were so high that they could disable satellite electronics and pose health risks to humans.

Additionally, the blast triggered strong geomagnetic disturbances observed worldwide. These disturbances could affect the operation of navigation systems, radio communications, and even cause auroras at unusual latitudes.

Starfish Prime triggered a wave of protests worldwide. Scientists and public figures condemned the experiment, calling it dangerous and irresponsible, and decisively demanded that the superpowers cease further games with nuclear weapons. And indeed, they ceased.

During the autumn and winter of 1962, the Soviets and the United States managed to conduct several nuclear explosions in space and the upper layers of the atmosphere but all of them were significantly less powerful than Starfish Prime. As a result of international pressure, in 1963 the Treaty banning nuclear weapon tests in the atmosphere, underwater, and in space was signed, putting an end to the dangerous experiments. However, this did not prevent the uncompromising rivals from continuing the race in the field of space weapons.

When Was Starfish Prime Declassified?

For many years, information about the experiment was kept under the strictest secrecy. It was only in the 1980s, under pressure from the public and the scientific community, that most of the data was declassified. However, some documents related to the most powerful nuclear explosion in space 1962 remain inaccessible to the public to this day. They may conceal even more astonishing facts about Starfish Prime and its consequences.

What Did We Learn From Starfish Prime?

Starfish Prime became a bitter but valuable lesson for the entire world and prompted the international community to adopt measures to limit nuclear armaments and prevent the militarization of space. Today, many years later, this audacious experiment still serves as a reminder of how easily humanity, in its pursuit of military superiority, can harm itself and the environment. It underscores the importance of ensuring that such a mistake is not repeated. After all, this time the consequences could be fatal.

 References And Additional Information

• Remembering Starfish Prime https://www.thespacereview.com/article/4822/1 
• Nuclear Test Ban Treaty https://www.jfklibrary.org/learn/about-jfk/jfk-in-history/nuclear-test-ban-treaty 
• Nukes in space: a bad idea in the 1960s – an even worse one now https://theconversation.com/nukes-in-space-a-bad-idea-in-the-1960s-an-even-worse-one-now-227105 
• The Starfish exo-atmospheric, high altitude nuclear weapons test https://ntrs.nasa.gov/api/citations/20150018897/downloads/20150018897.pdf