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Monday, October 24, 2011

The Star Wars Defense

Chapter 9C

The Star Wars Defense

Another contribution of space to our actual situation is often mentioned. Satellites are integral part in military communications and reconnaissance. But on the whole this has been more of a benefit than not. It was precisely the existence of such satellites that made it possible for the Kennedy administration in the U.S. to sign a test ban treaty with the Soviets. The days of such testing seem a remote memory today, but we must not forget that extremely powerful devices were routinely exploded in the atmosphere, with potentially disastrous effects. And even though a ban was in the interest of both parties, it was difficult to get around the suspicion that the other side would cheat. Together with seismographic methods and other techniques, reconnaissance satellites gave the needed assurances. Little can be done to hide an explosion of several megatons from a good camera overhead.

Satellites also guide “smart bombs” and give the military information needed to invade other lands. But then again, cooperation with the military need not be evil. It all depends on the enemy and the war. Besides, the main motivation for the development of “smart bombs” is to maximize the destruction of military targets while minimizing civilian casualties. This is hardly the basis for an indictment. Now, a new direct application of space technology to war may be the conversion of an airplane designed to fly in the thin Martian atmosphere into a spy plane (for it could fly high enough to avoid standard ground-to-air missiles). As we have seen, though, the spying made possible by space technology has been on the whole beneficial.

Let me leave behind for the moment this examination of past and present and concentrate for a while on the future. There are two main ways in which space can be seen as worsening our situation. One is that weapons more formidable may still result from space technology. The other is that by developing that technology we make the world more unstable. What those formidable weapons might be is largely unknown. A suggestion one hears from time to time is that big rocks could be aimed at the Earth from the Moon. They would be accelerated to escape velocity by electromagnetic forces, and their course toward their Earth target would be corrected by pretty standard guidance techniques. The energy released by the impact of a large rock could cause extraordinary damage. To mount such an attack, a country would require a rather substantial base on the Moon. This base could be underground, and presumably easy to defend. I think that Gerard O'Neill's efforts to design a mass driver to put lunar materials in orbit -- basically the technology for the Moon slingshot -- shows that the military applications are not so readily at hand. The rocks would have to be very big to be effective as weapons and follow a very precise trajectory to fall on the right target. Nonetheless, I suppose that sooner or later such a weapon may be feasible. But I am not sure how the situation would be radically altered. What kept ICBM's in their silos had nothing to do with how easy the silos were to defend. It had all to do with the fear of retaliation upon the society that launched them. Similar remarks should apply to the proposal to build a gigantic solar collector in the Moon to energize a very powerful beam, a death ray, that would vaporize any nation incautious enough to become our enemy.

Another possible nightmare connected with space exploration may come at the time when we make serious attempts to travel to the stars. A hydrogen bomb releases only a small fraction of the energy "frozen" in matter. To achieve the relativistic speeds necessary in star travel we must find practical ways of releasing far larger fractions of energy. The problem is that, with such a technology, it might be possible to make bombs monstrous enough to blow our planet to bits. In that case, however, retaliation would be rendered at once impossible and redundant.

Some evidence suggests that a full-scale attack by one superpower upon the other might be enough already to destroy the human race even if there is no response. According to Carl Sagan and other researchers, a global nuclear war would radically affect the atmosphere, both by the amount of radioactive dust that would circle the planet and by the making it poisonous to terrestrial life. Although this possibility requires a rather pessimistic reading of "Nuclear Winter" scenarios, it should give further pause to nuclear adversaries. As our destructive power increases, to kill may well be tantamount to suicide. This may well show that to build more weapons is sheer folly. We should realize, however, that there is a clear sense in which more offensive power cannot make matters worse. When you have a bazooka pointed at someone's head, bringing a far bigger bazooka does not really alter the situation all that much.

The other way in which space may presumably worsen the situation is by making it more unstable. One possibility much discussed in the recent past was the defense system proposed by President Reagan of the U.S. This system, popularly known as "the star wars defense," would have employed gigantic lasers or particle-beam weapons to knock out ICBMs in flight. Normally the atmosphere would dissipate the impact of such weapons, but since ICBMs must fly in thin regions, they might be easy prey. There were several formidable problems with such a scheme. The first was that the technology required went far beyond the state of the art. The second was that several easy countermeasures were open to the other side. And the third, and most decisive, was that according to the most optimistic reliable estimates such a defense would probably be no more than 75% effective. Since at the earliest time when the system could have been installed, each side could have owned at least 10,000 warheads, the successful 25% would be more than enough to put an end to things human. Even 99% effectiveness would allow for incredible devastation. Although such high level of effectiveness was never in the cards, imagine that a vigorous program of research could have improved the power of lasers and the means of detection of ICBMs to the point that a 100% effective defense had been possible in a few decades. Since the proposal by the American president included making the technology available to the other side, ICBMs would have become obsolete. In this way space would have done away with its main contribution to the anxiety of the Cold War.

In reality, President Reagan's scheme was as pointless as it was expensive: A star wars defense cannot end the threat of annihilation. For the laser beams and the particles shot from low orbit could not penetrate the atmosphere to knock out also bombers and cruise missiles, or even missiles fired from submarines close to the target. That is, even with all the ICBMs neutralized, the Soviet Union and the United States had ample nuclear alternatives to destroy each other and human civilization. In the case of a real war, our celebration of the complete success of Star Wars against ICBM's would have lasted only the few hours that it would take for cruise a missile to barely clear the last hill on its journey to us . .

Whereas some hope that space technology can help us slay the dragon whose fire other technology ignited, others worry about the increasing reliance on satellites for military operations, especially now that it is possible to attack and destroy those satellites. This is seen as one more instance in which space technology brings us to the edge of disaster. But we should notice that a country whose military communication satellites were destroyed would feel inclined to attack mainly because it would reasonably interpret the destruction of its satellites as the prologue to total war. A country could get away with the destruction of another's satellites only if the other could not find out about it. Since this is not so, it seems unreasonable to suppose that space technology has made matters worse.

It is true that in space we can find more reasons for fighting than we already have. If we discover a great treasure in the Moon we may resent any attempts to take it away from us. And our satellites have become such valuable commodities that we would not like to be deprived of them. But we cannot blame space technology in this regard any more than a tribe can blame their canoes for enabling them to discover good hunting grounds downstream, grounds that may become a source of quarrel with another tribe.

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