Reagan's Fantasy: On the Star Wars Initiative

If there is anything that can be learned from the failure of the strategic defense initiative, it is the fact that even a superpower like the United States is not all capable

Beginning in the XNUMXs and XNUMXs, each of the superpowers had enough nuclear bombs to turn each other into radioactive dust. The balance of terror between them created an equilibrium that ensured that none of the powers would initiate a nuclear war.
In 1983, President Ronald Reagan made an announcement that stunned the world. He stated the intention of the United States to develop a defense system against intercontinental ballistic missiles, which would be able to stop a surprise nuclear attack by the Soviet Union. This system, called the 'Strategic Defense Initiative' (SDI), could have dramatically changed the balance of power and upset the delicate balance. It was supposed to be so sophisticated and technologically advanced that it was soon nicknamed 'Star Wars', after the famous science fiction film series.

Reagan's plan was heavily criticized almost from the moment it was released. The main criticism was, of course, around the question of funding: no one doubted that 'Star Wars' would cost the American taxpayer trillions of dollars. Those in favor of the plan argued, however, that after a nuclear holocaust there would be no American taxpayers left.
Even if we put aside for a moment the question of financing the program, there was still great doubt about its very feasibility. Among the experts there was a heated debate surrounding the question of whether it is even possible, at the current level of technology, to place such a complex system of sensors and weapons in space? In fact, the nickname 'Star Wars' that stuck to the Strategic Defense Initiative was not a compliment - but rather a form of insult: it originated in a commentary article in one of the newspapers in which it was claimed that the entire initiative is nothing more than a fictional fantasy, like the Light Sabers and the human robots in the films of George Lucas .

In order to understand how ambitious the strategic defense initiative was, it is worth getting to know some of the projects that were developed as part of it. For example, one of the earliest ideas was to use laser beams to destroy the approaching missiles, and especially laser beams in the X-ray frequency range. Lasers, as any sci-fi fan knows, are an ideal weapon in space conditions: the beam moves to its target at the speed of light and there is no atmosphere to scatter the beam and reduce its intensity. But an ideal is an ideal and the devil, as we know, is in the details: to produce a laser beam strong enough to destroy a missile, a powerful energy source is needed, and even then the laser can only be fired a limited number of times per minute, to prevent overheating of the system. In the event of a large-scale nuclear attack, it is likely that the Soviets would launch tens of thousands of missiles at the same time at the United States - and a laser cannon would not be able to shoot down more than a few dozen of them, at best.

Senior scientists such as Edward Teller, the father of the American hydrogen bomb, proposed an original solution to this problem.
The chain reaction that occurs during a nuclear explosion creates enormous amounts of photons in the X-ray range. Hence, all that needs to be done is to assemble a lot of devices for laser production around an atomic bomb: the devices will collect the photons emitted from the explosion and channel them to create dozens or even hundreds of powerful laser beams that will shoot out in all directions at the same time and destroy the missiles around them. Of course, only a few nanoseconds will pass from the moment the nuclear fission starts until the whole thing turns into a radioactive fireball and the laser devices turn to dust - but the photons move fast enough in relation to the blast head for this idea to be possible, at least on paper.
In practice, the researchers unfortunately discovered that it is very difficult to conduct controlled experiments in such a system. In all the practical experiments, which included nuclear explosions under the surface of the earth, there was not a trace of a residue from which it could be concluded whether the system worked as expected or failed completely.

Another idea, which is also probably familiar to fans of science fiction and computer games, is a 'Rail Gun' - or as it is called in foreign, Rail Gun.
The principle behind the rail gun is quite simple: firing a projectile at a tremendous speed of up to several tens of kilometers per second. A projectile moving at such a speed has so much kinetic energy that there is no reason to equip it with an explosive warhead: a piece of metal weighing a single kilogram moving at a speed of ten kilometers per second will hit the target with a force equal to the explosion of ten kilograms of TNT. One of the great advantages of the railgun is that its projectiles are much lighter than conventional shells, because they do not contain explosives - a fact that also makes them completely safe during storage.
The projectiles can be accelerated using propellant explosives: there are tank shells that work on the same principle. But to deal with fast targets like intercontinental missiles, you need extremely fast projectiles - above and beyond the thrust force that a chemical explosive can provide. Currently, it seems that the best way to accelerate the projectiles is to place them on a long rail made of conductive materials, and push them using a powerful magnetic field. Theoretically, in this way, it is possible to launch projectile after projectile at a fast pace and destroy dozens of missiles from a long distance.
And again, theory separately and reality separately. The electric currents that move inside the gun rails may reach up to half a million amperes. The resulting heat melts and distorts the rails and requires them to be replaced after each firing. At the height of the development boom, the engineers managed to shoot a total of two projectiles a day - and we have not yet mentioned the difficulty of aiming the rifle so that it would hit such a small and fast target. Despite the difficulties, the railgun is among the few technologies of the Star Wars program still in development today, as a weapon that may one day replace the cannons on the ships of the US Navy.

The last two examples show how difficult and complicated the technological challenges were that the United States faced in realizing Reagan's dream - and all this in the days of Commodore computers, video and double-cast tape.
To all this must be added the fact that the Soviets will certainly not sit idly by either. Their scientists were no less brilliant than their American counterparts and would surely have found ways to deceive the defense system and fool it with dummy missiles, for example.
In fact, they might not even have to strain their brains too much. The basic weak point of any anti-missile defense system is the fact that the price of the defense system will almost always be higher than the price of an attacking missile. All the Soviet Union has to do is double, triple or quadruple the number of ballistic missiles it possesses! After all, in the end, the American defense system will reach the limit of its capacity - and at least a few dozen missiles will manage to infiltrate. If we consider that every intercontinental ballistic missile usually contains several nuclear warheads that split above the target...then all the investment in Star Wars achieved nothing. No wonder, then, that most of the program's vocal critics argued that it was a complete waste of money and a pursuit of the impossible.

When the Soviet Union fell and the Cold War came to an end, the Strategic Defense Initiative also ended its life. Slowly and steadily, successive administrations, from George Bush Sr. to Bill Clinton, eliminated Reagan's grandiose plan. It was converted to smaller short- and medium-range missile defense programs. Here and there Star Wars produced technological developments that also found their way to the civilian market and research laboratories.
The astronomers, for example, profited greatly. Telescopes placed on Earth have a severe limitation: the light coming from the stars is constantly deflected by the movement of air in the atmosphere, so the image obtained on the telescope mirror is always slightly blurred. This is a problem that also affects the performance of laser beams, so the US military has invested a lot of money in finding methods to minimize the effect of air turbulence. The result of these studies is a technology known as 'Adaptive Optics', or Adaptive Optics: before each exposure of the telescope, a weak laser beam is fired at the point in space that they wish to photograph and the laser light that is reflected back is measured. The measurement results are compared against the known characteristics of the laser beam, and from this it is possible to calculate the expected interference to the starlight which does exactly the same way. Now you can change the shape of the lens accordingly, and eliminate the interference. The result is exceptionally sharp and clear images that were once only obtainable by space telescopes.

Despite these and other developments, it is difficult to assess how much the huge financial investment in the Star Wars program was really justified. Who knows - if Reagan had directed the same budgets to research in the field of medicine, for example, we might have had a cure for cancer today.
At the very least, if there is anything to be learned from the failure of the Strategic Defense Initiative, it is the fact that even a superpower like the United States is not omnipotent. The Star Wars program did not get off the ground even though all the economic, political and cultural power of the United States was behind it. In other words, a little modesty never hurt.

[Ran Levy is a science writer, and hosts the podcast 'Making History!'- a program about science, technology and history. Www.ranlevi.co.il]