Outer Space: U.S. Triad's Final Frontier?

PRECIS: Nuclear arms have a complicated history which influences today’s world situation, and which it would be most unwise to ignore when debating their place in current and future American defense policy. This debate can also be clouded by misguided pundits who prematurely proclaim that nukes will wind up in some technical cul de sac that renders them irrelevant, such as the now-debunked chimera of an impenetrable Space Shield. Calling nukes “unusable” is only true in the context of any unprovoked first strike, which could easily trigger Armageddon; they are essential to prevent nuclear blackmail, to deter nuclear war, and also to dissuade against big conventional world war. Naysayers who proclaim the demise of nuclear-deterrent submarines (SSBNs) through some hypothetical breakthrough in anti-submarine warfare (ASW) ignore the not-so-hypothetical possibility of retaining stealth and survivability by eventually deploying a component of strategic arsenals in the ultimate vastness of space--out among the intense background noises and immensity of decoy objects populating our Solar System.

Nuclear weapons are important not just for America’s self-protection, but also in a wider, global sense because they can be building blocks of mutual security even between adversaries. Back in the First Cold War, when there were just the two superpower blocs and both had sizable nuclear arsenals, the U.S. and USSR each realized how important it would be for their own arsenal to be survivable against a surprise nuclear first strike by the enemy. Only by having enough nuclear weapons deployed in some manner that they could safely ride out a massive “bolt from the blue” nuclear onslaught, could any country be sure it could/would make a devastating retaliatory second strike against the nation foolish (and suicidal) enough to attack it first using nukes. This guaranteed second strike capability, when communicated clearly enough in advance to potential enemies, created the condition known as nuclear deterrence. Since both the Communist and the Capitalist Blocs soon achieved a measure of survivable second-strike weaponry, this deterrence was mutual. This mutuality in turn provided—and still provides--something long considered vital to Humanity having the best chance to survive its own Nuclear Age (at least, until all entities give up all nukes). This was the phenomenon that Cold War strategists labeled strategic stability. Strategic stability occurs when none of the parties in a geopolitical rivalry is able to gain any significant advantage by being the first to use nukes in anger.

The U.S. and USSR alike began amassing their strategic nuclear arsenals with gravity bombs that were delivered by long-range heavy bombers. Then they started to miniaturize their nuclear warheads and mount them on ICBMs. Most significantly, they built and deployed submarines that could carry and launch nuclear-tipped SLBMs. The earliest nuclear-deterrent subs were diesel-electric powered, but as soon as compact, mobile nuclear reactors became possible, nuclear propulsion became de rigeur. Nuclear power allowed a deterrent sub to remain submerged and invisible for very lengthy periods; once reliable oxygen generation and desalination technologies entered the picture, only the crew’s on-board food supply limited a nuclear sub’s continuous submerged endurance. As submarine quieting and non-acoustic stealth improved in both East and West, SSBNs (as these deterrent subs came to be called)—when built in sufficient numbers that a few were always at sea on deterrent patrol—delivered to their owners genuine survivable nuclear deterrence.  

Survivable mutual nuclear deterrence is what prevented any nuclear war between the U.S. and USSR during all the long years of the Cold War. That capability, delivered reliably by their SSBN fleets, just as effectively prevents nuclear war between the U.S. and Russia now. This simple and stark fact is clearly appreciated by other national governments, including the (unfortunately) growing number of smaller nuclear states and nuclear wannabes around the world. It has led them—pretty much without exception—to strive to deploy their own stealthy nuclear-deterrent submarine forces. These are nuclear powered when the country’s shipbuilding and nuclear industries are capable of it, or diesel-electric and air-independent propelled if they can’t manage nuclear; both types are sometimes purchased or leased from other countries.

Parallel to, and in counterpoint to, this proud history of survivable mutual nuclear deterrence via the deploying of stealthy SSBN fleets, there has been a persistent call in some quarters for nuclear disarmament. The proponents of global denuclearization argue that nukes themselves are Mankind’s most clear and present extinction threat. I agree with this only in so far as the following: If nuclear weapons were indeed to actually to be set off aplenty in a nuclear war, the subsequent years-long nuclear winter (freezing cold and lack of sunlight) and then nuclear summer (lethal UV due to ozone depletion) certainly would extinct those suffering remnants of the human race who somehow survived the wholesale destruction of civilization by the nuclear war itself.

And no “small” or “limited” nuclear war is likely to stay that way for long at all: National command and control facilities and the weapons themselves would be deranged in dangerously unpredictable ways as blast, heat, and electromagnetic pulses galore wreak havoc and chaos; more and more countries would panic and jump in, while plunging missile parts and detonating errant warheads pummeled the innocent; lethally-intense radioactive fallout would blanket the globe.

Any unprovoked, aggressive use of nukes at all stands an unacceptably high chance to escalate out of control and trigger the dreaded final extinction event. The twinning of nuclear winter and nuclear summer as “Nature’s overkill” itself creates among the knowing a tacit deterrence of nuclear war, in which precious democracy is preserved. But if only one side had nukes, they could use a few to subjugate everyone else; if neither side had nukes, as discussed more in the next paragraph, conventional world war would instead, eventually, make a serious run at human population crash.

To repeat for emphasis, it is precisely the existence of mutual survivable nuclear deterrence that prevents these nightmare extinction scenarios from happening. Nuclear deterrence also very effectively prevents conventional world war from breaking out, since whichever side was losing such a war would surely use its nukes in a last-ditch roll of the dice to preserve its (or its regime’s) existence—and the other side would retaliate, and so on as above. Just as bad, in the modern age of highly lethal conventional weapon systems, a non-nuclear world war would lead to wholesale slaughter that is drastically more bloody that even the years-long industrialized massacres of World War One and World War Two. Upwards of one hundred million people were killed by war in the twentieth century. It is quite possible that, if unconstrained by nuclear deterrence, a twenty-first-century conventional world war--one perhaps lasting decades and bringing with it waves of mass famine amid global pandemics--could cause the deaths of billions, a casualty list that rivals what an outright nuclear war would accomplish!

Global denuclearization is unrealistic, the ultimate fool’s errand, for two other irrefutable reasons, as well: First, any attempt to rid the world of all nuclear weapons will certainly have persons and nations that cheat on the ban from the beginning, by using subterfuge and deception to retain some of their existing nukes—so they could gain a decisive, one-sided advantage as planetary bullies and mega-tyrants.  Conventional weapons would never succeed at standing against their undeterred and undeterrable nuclear blackmail and nuclear attacks. Second, since there would no longer be an effective deterrent against big conventional wars, a non-nuclear World War 3 would be virtually certain to break out sooner or later. The countries involved, remembering the great destructive power of nuclear weapons, would rush into “next-century Manhattan Projects” to rearm themselves with nukes. Except, with so much of the science and engineering of nuclear weapons indelibly recorded in the world’s libraries and on the Internet, these neo-Manhattan Projects would go a lot faster, in more than one country. The race to be first to wreak thermonuclear Hiroshimas and Nagasakis on one’s enemies would lead to exactly the nuclear war that global denuclearization advocates claim they can forever avoid via their forlorn hope of nuclear disarmament.

Now, denuclearization advocates who concede the strength of these counter-arguments sometimes go on to raise another alleged bugaboo of nuclear deterrence’s long-term viability, which they claim is reason enough to seek total world nuclear disarmament as soon as possible. They warn that advances in anti-submarine warfare will eventually “turn the world’s oceans transparent,” revealing the exact location of all the no-longer-least-bit-stealthy SSBNs out on deterrent patrol. They could then be immediately targeted, attacked—and destroyed. Bye-bye survivable nuclear deterrence. Bye-bye any nuclear stability. Hello total nuclear Armageddon—unless, of course, we all totally denuclearize now. Unless….

The solution to this latest putative Triad conundrum is to remember that modern war is very much an all-domain affair. It involves the land, the air, the sea, cyberspace—and outer space. Were America’s (and our adversaries’) nuclear deterrents to be expanded into the realm of deep-space basing, many legal and technical problems would immediately arise. These could eventually be solved, or worked around, just like the original Moon Landing was—and just like the Mars Landing soon will be. The ultimate sustainability of survivable mutual nuclear deterrence would be reliably achieved. Think about it….

Planet Earth’s oceans are vast, but the Solar System itself is many orders of magnitude vaster. Suppose that superpowers were to eventually, some day, when technically feasible and affordable, deploy some of their nuclear deterrent weapons in deep space. Rather than lurk under the sea, they would orbit the Sun well away from Earth, on special-purpose spacecraft used as bases that might be either manned or unmanned.

Inevitable advances in artificial intelligence and ultra-secure quantum communications would eventually allow the positioning of nukes quite remotely removed from the crews who oversee them. Granted, in case the deep-space leg of our Triad (or would it be a Quadrad?) was ever called on to make a retaliatory second strike at an enemy on Planet Earth (or elsewhere), we would need nuclear delivery vehicles with several revolutionary design features: propulsion systems with very low signatures, such as light sails or ion engines; reentry vehicles able to work at the higher velocities involved in atmospheric reentry directly from deep space; maneuvering (jinking) abilities sufficient to evade defensive interceptors; surface coatings able to reflect or defeat defensive lasers; and guidance systems that function very accurately over interplanetary distances. Our second strike would arrive on target after an interval much longer than the 30 minutes an ICBM now takes. This would not be a problem, though, since we presumably would still follow launch-only-on-or-after-attack rules of engagement, so that--just like today, despite Hollywood hype to the contrary—our retaliatory blow can land well after the enemy’s first strike and yet still be fully potent, in advance, as a deterrent with decisive psychological effect.

Basing nukes out in the solar system, if it ever came to that, would provide those weapons with a very considerable degree of stealth; remember, “stealth” means the inability of adversaries to detect and thus attack a platform or asset. For one thing, recent science has shown that the Solar System, away from a planet’s protective atmosphere and magnetic field, is bombarded throughout by intense radiation of all sorts, ranging from near-speed-of-light particles such as cosmic rays and the solar wind, to radiation across the electromagnetic spectrum up to and including very hard X-rays and profoundly energetic gamma rays. This background “noise” would interfere strongly with radars and other sensors, making it nigh on impossible to locate deterrent nukes at the immense distances involved, especially if they are cloaked via next-generation low observable technologies (structure shapes, and coatings).

For another thing, the solar system is chock full of what amount, in this context, to decoys. From a range of hundreds of millions or even billions of miles away, almost any object can serve as a decoy for a space-based nuclear deterrence platform. Asteroids and comets abound, especially (but by no means exclusively) in various belts or clouds whose characteristics astronomers are still in the early stages of exploring. For a sense of proportion on how hard it would be to locate a disguised space-based deterrent asset immersed in this ever-distracting sensor clutter, the Oort Cloud at the outer edges of the solar system is estimated to hold two trillion different objects. Closer in, the Asteroid Belt between Mars and Jupiter, and the Kuiper Belt beyond Neptune, provide immense fields of decoys that are somewhat more accessible that the Oort Cloud itself would be.

One serious legal impediment to any country putting nuclear-deterrence weapons in space is the Outer Space Treaty (OST) of 1967, which is binding and which bans all nuclear arms from being based in outer space. But there are two factors which could lead in the future to modifications or exceptions to the OST. One of these, unfortunately, is the simple observation that many arms control treaties that were supposed to be binding were violated by one or more countries in the past or in the present. A recent example with direct impact on global nuclear arms control is Russia’s violation of the Intermediate Nuclear Forces (INF) Treaty, which the U.S. has (in consequence of Russia’s cheating) overtly renounced. International arms control treaties last only as long as they serve their signers’ selfish strategic purposes.

What’s more, international treaties can be amended or modified cooperatively by the ratifying nations if good enough reasons are recognized by the participants. Why might peace-loving nations agree to waive the OST and permit nukes to be based in space? There is in fact one very compelling reason for this right now. It is recognized by both NASA and the United Nations, although neither has talked yet of waiving the treaty. It is an urgent humanity-wide problem requiring rapid progress: planetary defense against asteroids and comets.

Some pundits have cautioned that “nuking an asteroid” is not the right answer to protect human life against an incoming space object. This is true. To shatter a big object into many smaller objects without deflecting them all well away from Earth would just spread the devastation of their impacts over a wider area, killing even more people. But there is another way to use nukes in space to defend against Earth impactors. This method does indeed leave the object intact but pushes it onto a safely diverging course. This much better method is to use one or more nukes, set off in sequence, near but not right on top of the object, to harness the radiation pressure of the detonations.   

Radiation (photon) pressure of a nuclear detonation is the force applied to anything nearby via the powerful impinging energy put out by the blast (whose peak output band is X-rays). Just as the Sun’s radiation applies a small but significant force to any object orbiting around it, a nuclear weapon set off in the near distance imparts a shove through the vacuum of space. There is then another beneficial effect, as the side of the object facing the detonation’s flash undergoes heat-evaporation, which in turn induces some recoil. That recoil provides another small shove in the same direction as the initial shove from the radiation pressure itself.

The key to successful orbital deflection, of an object bound inward to hit our planet, is for the deflection to happen very early, so that the minimal amount of available force can achieve the maximum amount of trajectory deflection before the object comes near Earth.  For this to occur, early detection and deflection of the object is vital—something well recognized in the professional literature and the popular press alike. But early deflection is difficult when the only place allowed by law for basing the nukes used to make that deflection is on the surface of planet Earth itself. Were a dangerous earth-approaching object detected, humanity would first have to reach agreement on waiving the OST, and then mount nukes on deep-space-capable rockets and launch them on an intercept course—and then the warheads would have to traverse a vast distance through space--which is an excruciatingly slow process on the scale of Solar System distances, when human survival is at stake!

What would work much more quickly is to preposition nuclear weapons in space, in different parts of the Solar System, so that the nearest ones could be commanded to zoom toward the object from much closer in, then detonate at the optimal range for that Earth-saving one-two shove of the radiation pressure and evaporative recoil. More than one nuke could be used to deflect an especially sizable or especially high-velocity object, or one detected so late in the game that it is closer to us when first detected.

There are of course many serious scientific and engineering challenges that would have to be overcome to reliably implement this “space-based asteroid shield.” But given the ever-accelerating pace of progress in manned and unmanned space exploration, these challenges would eventually be successfully, affordably met. Solving them would go a long way to addressing the companion engineering feats required for fielding any space-based nuclear deterrent. Research is under way on alternative methods for deflecting asteroids, ones that do not use nuclear weapons.

But it is not clear whether these other methods—such as attaching a rocket engine, or delivering a photon shove via laser beam--would be reliably perfected soon enough to avoid a cosmic catastrophe on our only home planet. What is becoming clear is that they might sometimes not work nearly as well as stand-off nukes. Japan’s Hayabusa spacecraft and its MASCOT mini-lander indicate that asteroid Ryugu is a loosely held-together rubble pile, formed when two bodies collided. Any similar object would be structurally weak. To apply a diverting force in narrow spots on such a large body, as rockets or lasers would, might just splinter the hurtling projectile without changing its lethal Earth-intersecting trajectory, changing a bullet into a shotgun blast—a mistake from which only the very widespread, evenly distributed push of stand-off nukes could let Mankind recover safely. Much better to use stand-off nukes up front, doing the deflection the right way to being with.

The capabilities needed for space-basing nukes are consistent with government and commercial R&D efforts which are progressing rapidly now in several countries on heavy-lift rockets, space colonization, asteroid mining, and related futuristic applications that are already much more science than science fiction. As mentioned earlier, reliable remote nuclear command and control (NC2) in outer space would be facilitated by research already underway on artificial intelligence and quantum communications.

Were nations to agree on waiving OST’s terms, to permit deploying a space-based nuclear asteroid shield, we would be one giant step closer to also waiving it for the purpose of sustaining survivable mutual nuclear deterrence--in case, that is, someday generations or centuries from now, some technical breakthrough in submarine hunting actually does render SSBNs easy to locate. As the human race, hopefully, matures in its thinking about nuclear deterrence, it might come to pass that the public sees our nuclear Triad as of tremendous benefit to them, as a proven, effective peacekeeping tool against nuclear blackmail and all big wars. In that sense, having a few large nations maintain survivable mutual nuclear deterrents, in whatever domain best suits Mankind’s then-current technologies, could be viewed as a cooperative international force for good, much on a par with a space-based asteroid shield--i.e., as a beneficial protective technology, not a doomsday weapon.

That hypothetical ASW breakthrough, a disruptive technology if there ever was one, thankfully lies very far out indeed in the distant future. An Earth-impacting object represents a much more immediate threat, to human survival. As far as survivable mutual nuclear deterrence goes, fortunately, SSBNs such as America’s new Columbia class will get the job done for a very long time to come; the U.S. Navy stays on top of potential sub detection breakthroughs very diligently, proactively. What is a good and useful fact to establish clearly now, amid all the blather and hullabaloo about global denuclearization, is that if SSBNs ever do lose their survivability because they lose their undersea stealth, then a deep-space-based nuclear deterrent will provide a worthy successor.