What are Anti- Satellite Weapons?
Anti-satellite (ASAT) weapons are designed to debilitate and/or destroy satellites that are already in orbit and operational.
ASAT weapons violate the OST through the latter’s Article VII, which holds parties to the treaty liable for damaging satellites belonging to other parties, and Article IX, which asks parties to refrain from the “harmful contamination” of space.
Russia, in the form of the erstwhile Soviet Union, has had ASAT capabilities since at least 1968.
While the Cold War motivated ASAT weapon tests on either side of the Atlantic, the respective programmes refused to dwindle once relations thawed.
Most of these weapons are kinetic, meaning they destroy satellites in orbit by rocketing into them or detonating an explosive near them, and blowing them to pieces.
Because of the low gravity and lack of an atmosphere, the resulting debris can stay in orbit for a long time depending on their size.
This result violates Article IX of the OST.
Are there space-based nuclear weapons?
In a high-altitude test in 1962 called Starfish Prime, the U.S. detonated a thermonuclear bomb 400 km above ground.
It remains the largest nuclear test conducted in space.
A Thor rocket launched the warhead to a point west of Hawaii, where its detonation had a yield of 1.4 megatonnes.
More importantly, it set off an electromagnetic pulse (EMP) much larger than physicists had expected, damaging a few hundred street-lights in Hawaii, 1,500 km away.
The charged particles and radiation emitted by the blast became ensnared in and accelerated by the earth’s magnetic field, distorting the ionosphere and resulting in bright aurorae.
Starfish Prime was part of the U.S.’s high-altitude nuclear tests in 1962.
The Soviet Union also conducted such tests around then with similar effects.
Test 184 on October 22, 1962, detonated a 300-kilotonne warhead 290 km above ground.
The resulting EMP induced a very high current in more than 500 km of electric cables and eventually triggered a fire that burned down a power plant.
How will a nuclear weapon affect satellites?
The principal threats to other satellites from a space-based nuclear weapon are the EMP and the release of charged particles.
Starfish Prime itself temporarily knocked out roughly a third of all satellites in orbit at the time – and illustrates a failing relevant to the current context.
An EMP from a nuclear weapon in space will affect all satellites around the point of detonation, including Russian satellites, those of its strategic allies (such as China), and of countries not involved in a particular conflict.
It would also grossly violate the OST.
Depending on the strength, location, and directedness of the explosion, it could also blow a large number of satellites to pieces, more than what a ‘conventional’ kinetic ASAT weapon might.
Scott Tilley, an amateur radio operator with a name for tracking down ‘lost’ satellites, wrote on X that “the damage is not immediate to most [satellites] but rather caused by new and intensified radiation belts”.
Eventually, the result is more dud satellites and debris, raising concerns of the Kessler effect:
When there is a certain level of debris in low-earth orbit, collisions among themselves as well as with other satellites could produce more debris, leading to a “collisional cascade” that rapidly increases the amount of debris in orbit.
There is one more possibility.
In 1987, the Soviet Union launched a rocket bearing a high-power laser that could target and destroy other satellites.
What do the U.S.’s claims imply?
Modern civilisation depends heavily on satellites, which means they can be assets or vulnerabilities.
But the inability to target a nuclear weapon in space — at certain satellites over others — mitigates its usefulness.
This is why some security researchers have suggested that if the Russian capability is nuclear, it will be a weapon of last resort. Some others have said the ‘nuclear’ component is likely to be limited to the power source.
This said, Mr. Turner’s comment, which alerted the world to the possibility, provoked sharp reactions in the U.S. His peers in the Republican Party accused him of attempting to drum up support for Ukraine and that he wished to have
an “unreformed” version of the Foreign Intelligence Surveillance Act passed, CNN reported.
After the U.S. had warned its allies in Europe of the potential threat, the Kremlin called the claim a “malicious fabrication” and a ruse to allocate more funds for Ukraine.
COMMENTS