Nuclear Future: Underwater and in the Skies

In Part I, we briefly outlined the development of strategic nuclear forces (SNF) from the middle to the end of the Cold War, the emergence of today’s nuclear triad, and elaborated on possible ways for developing the triad’s land-based component: intercontinental ballistic missiles (ICBMs) in underground missile silos (UMS) and as part of road-mobile transporter-erector-launchers (TELs). Now we need to consider the air and naval components of the triad, as we will yield to the temptation to look “beyond the horizon.”

Heavy aircraft served as the first carriers of nuclear weapons, free-falling bombs, and for a long time, they remained the principal carriers. As time went by, bombs were first supplemented and then virtually supplanted by missiles, particularly after today’s long-range cruise missiles (LRCM) appeared in both in long-range and in small-scale. However, despite new weapons, missile bombers still had several problems that resulted in only the USA and Russia (and to some extent China with its program for designing a new bomber, which likely has lesser priority than developing ICBMs and nuclear submarines) keeping them in service.

Although “classical” LRCMs will remain relevant due to the good range-to-weight and size ratio, they are not a good fit for the role of a “silver bullet.” Quite likely, the future of weapons for strategic aviation lies in aero-ballistic missiles making a comeback at a new technological level; following today’s trends, they will inevitably be called “hypersonic.”

In addition to new underwater craft being developed, SSBNs will inevitably be influenced by missile progress that applies to them as well as to land-based vehicles. The ability of multi-purpose submarines to get close to their target makes them a particularly interesting platform for hypersonic cruise missiles with boost glide warheads. Along with small-scale nuclear cruise missiles, this will allow a large part of the submarine fleet to regain their quasi-strategic capabilities.

In Part I, we briefly outlined the development of strategic nuclear forces (SNF) from the middle to the end of the Cold War, the emergence of today’s nuclear triad, and elaborated on possible ways for developing the triad’s land-based component: intercontinental ballistic missiles (ICBMs) in underground missile silos (UMS) and as part of road-mobile transporter-erector-launchers (TELs). Now we need to consider the air and naval components of the triad, as we will yield to the temptation to look “beyond the horizon.”

The Air Component: Searching for Ways to Justify its Existence

Alexander Yermakov:
Nuclear Future: Rethinking the Nuclear Forces in the Days to Come

Heavy aircraft served as the first carriers of nuclear weapons, free-falling bombs, and for a long time, they remained the principal carriers. As time went by, bombs were first supplemented and then virtually supplanted by missiles, particularly after today’s long-range cruise missiles (LRCM) appeared in both in long-range and in small-scale. However, despite new weapons, missile bombers still had several problems that resulted in only the USA and Russia (and to some extent China with its program for designing a new bomber, which likely has lesser priority than developing ICBMs and nuclear submarines) keeping them in service.

The main problem is their low survivability compared to other components of the SNF triad. In the times of peace, large aircraft with highest requirements for land-based infrastructure are concentrated in several air bases, while under threat they can be distributed between several other potentially ready air bases, but they will still constitute a small number of targets vulnerable to the adversary’s nuclear strike. Potentially, when under most danger, they can be switched to airborne alert mode (during Operation Chrome Dome in 1960–1968, the USA even attempted to make airborne alert a regular practice [1]), but in the long-term, this practice will rather do more harm since personnel fatigue and increasing need for aircraft maintenance will begin to reduce the overall number of combat-ready aircraft. A less harsh option is keeping part of the aircraft fleet on the ground in a high (five- or fifteen-minute) stand-by readiness to be airborne. With a properly working missile warning system (MWS) and rapidly transmitted commands, aircraft on stand-by can be saved from the strike. Unlike an ICBM, an aircraft can always be brought back after take-off, so this element of a retaliatory counter-strike can be largely automated with very little human factor involved. These are, however, no more than palliative solutions.

On the other hand, if conventional warfare preceded the nuclear one, we cannot rule out the possibility of strategic aviation having suffered major losses at the conventional stage. Unlike missile-carrying submarines and ICBMs, strategic aviation is not only fully “dual-purpose,” its highest capabilities are precisely for non-nuclear conflicts and using these capabilities (or depriving the adversary of a chance of use them) could be very tempting. These capabilities in and of themselves will legitimize strikes against strategic aviation, while attacks of purely nuclear components of the SNF or the MWS are likely to be taken “very hard” by the opponent who will deduce that their nuclear retaliatory strike potential is being taken out.

Vyacheslav Grushnikov / russianplanes.net
Tu-95MS with Х-101 missiles

However, although this potential of using strategic aviation conventionally has been described as its flaw, it also constitutes its greatest advantage. Capabilities to project force and deliver non-nuclear strikes at intercontinental ranges are unique, and only a large high-sea navy could match them (such a navy is a costly affair that needs to be deployed in advance).

In 1991, at the start of Operation Desert Storm, the USA demonstrated its capability [2], and repeatedly delivered as a “standard operation mode” strikes at targets at the other end of the world, with American aircraft taking off from their home airfields. Previously, when fighting for the Falkland Islands during Operation Black Buck, the UK’s Vulcan strategic bombers delivered strikes against important Argentinian targets taking off from remote Ascension Island; the 16-hour raid was a record at the time. Russia’s missile aircraft in Syria were deployed in far simpler conditions (strictly speaking, they could launch cruise missiles immediately after takeoff), but in order to demonstrate their potential, on November 17, 2015, Tu-160 and Tu-95MS skirted all of Europe “counterclockwise” and launched strikes from the Mediterranean Sea using long-range cruise missiles; the aircraft were airborne for nearly 16.5 hours.

Prospects for subsequent development of bomber aviation appear to lie in further increasing flight range and creating new weapons; it would produce fundamentally new capabilities for the aviation’s function as a component of the nuclear triad as well. That, however, will also demand fundamentally, almost radically new solutions.

As mentioned above, the main problem is heightened missile carrier vulnerability both during strikes and while on airborne alert. The first problem was partially resolved by LRCMs: back at the turn of the 1980s–1990s, their range was about 3,000–3,500 kilometers (we should always keep in mind that we are talking about the most efficient direct flight; in reality, the range will be slightly shorter). We mean Soviet-made Kh-55SM (which was developed by merely installing additional tanks on Kh-55 and it is still in service) and America’s AGM-129A ACM (which was taken out of service in 2012 to economize resources). Later, already after the collapse of the USSR, Russia developed what is currently the world’s most advanced LRCM, Kh-102 [3] with the approximate range of about 5,000 kilometers. China massively arms its missile carriers with CJ-20 missiles ranging from 2,000 to around 2,500 kilometers. For actors whose objective is nuclear deterrence directed at Washington, the situation is complicated by geography (the USA’s principal regions are covered by Alaska and Canada), the American systems of alliances, and its deployed navy; yet the existing LRCMs already provide for launch lines that are relatively safe for carriers. Nonetheless, the problem of vulnerability remains for LRCMs themselves as they existed at the end of the Cold War relying on their low visibility and breaking through air defenses in NOE flight. Developing air-based radars and network-centric target assignment systems prospectively makes them increasingly vulnerable: fighter aircraft with powerful radars (one could do even without long-range radar detection aircraft) detecting a low-flying cruise missile and automatically sending target assignment to SAMS already is a reality drilled at exercises. Since strategic aviation numbers are being cut, there is no hope of air defenses being broken by large number of missiles.

U.S. Air Force
AGM-129A ACM

Although “classical” LRCMs will remain relevant due to the good range-to-weight and size ratio, they are not a good fit for the role of a “silver bullet.” Quite likely, the future of weapons for strategic aviation lies in aero-ballistic missiles making a comeback at a new technological level; following today’s trends, they will inevitably be called “hypersonic.” Courtesy of politicians, this term has come to mean many things now. Here, I mean aircraft-launched missiles that use a boost stage with a regular jet engine and gain speed and altitude up to uppermost levels of the atmosphere and even beyond. Further on, a small-scale boost-glide missile without an engine continues on a guided flight; the missile can use its own aerodynamics and guided flight option for gliding or “ricocheting” off the uppermost level of the atmosphere to achieve a longer flight range or to maneuver in order to avoid the adversary’s air defenses or missile defense, and to better lock on target at the final stage of the flight. In addition to “boost glides” described above, high-speed cruise missiles flying in relatively dense atmospheric level using a scramjet also count as hypersonic, but in the foreseeable future they will have a worse range-to-weight and size ratio compared to boost glides, and they will be more suitable for handling tactical objectives.

A strategic missile carrier with heavy missiles breaking through air defense or missile defense due to its flight characteristics will constitute a return to a track that had been abandoned when small-scale sub-sonic LRCMs became widespread. For instance, Tu-160 had been developed for heavy hypersonic Kh-90 missiles, while the US even reached test stage for their GAM-87 Skybolt ALBM in the early 1960s [4]. British Vulcan bombers were initially intended to carry two missiles with the range of up to 1,800 kilometers, while American B-52H were supposed to carry four, and then eight such missiles [5], which would have become a major problem (for instance, Moscow could have been struck within a few minutes with a launch from Scandinavia’s air space).

Nonetheless, missiles will solve only one problem from among those listed for the SNF’s air component: they will increase the likelihood of successfully delivering the payload to the target during an attack. The second problem, that of missile carriers’ very low survivability, remains. Ensuring their capability of being constantly on airborne alert at least in a period of threat is the only efficient way of improving it. It is, however, difficult to achieve for today’s platforms: turnaround servicing time for today’s missile carriers will be comparable to, or even longer than is allowed with regular 24–36 hours in the air. Additionally, both aircraft and crews will rapidly become overextended, and it will be a recipe for accidents. Although in real combat conditions there had been bombing raids that lasted for 48 hours for crews (and for 72 hours for aircraft [6]), but it meant straining both to the limit and required lengthy preliminary preparations and subsequent rest. Operating the entire fleet in this mode for several weeks will inevitably result in a rapid onset of “natural wastage.” Of course, keeping very small part of the fleet airborne is possible: in the 1960s, the US Air Force for a long time performed permanent airborne alert missions on a regular basis, but comparing their fleet of many hundreds of aircraft with today’s fleets, then proportionately it equates one aircraft, or two tops, being on airborne alert.

U.S. Air Force
B-21A "Raider" concept

The solution lies in decreasing the turnaround servicing time and in simultaneously increasing flight duration. It could be achieved by developing strategic drones or optionally piloted modifications of manned missile carriers. There is no radical solution that could be used on existing platforms: there can be only superficial decreases in their turnaround servicing time (new aircraft, despite local problems, demonstrate the same trends) and superficial improvements in conditions for their crews. New platforms, however, will certainly be developed with a view to handling these problems: from the outset, America’s new prospective B-21A Raider bomber was intended to have an optionally piloted version, while a separate unmanned bomber and fighter program is being discussed. Today’s large drones are initially intended long-range flights and they truly work miracles in this area. For instance, a small group of RQ-4 Global Hawks deployed in Sicily routinely goes on 24-hour-long missions to the Mediterranean, and it has been doing so for years. There are no reasons to think that Russia’s PAK DA billed as sub-sonic stealth “flying wing” will not have such capabilities. The use of air-launched drone wingmen that will help break through air defense, detect adversaries, and wage air combat is also likely.

Of course, the image of an unmanned nuclear bomber is very uncomfortable psychologically (what if it “takes something wild into its head”), but no one cares about ICBMs being unmanned and about it being impossible to stop an ICBM once it has been launched. It still appears better to reserve unmanned flights for conventional conflicts, while crews would be present in the cockpits of optionally piloted aircraft on nuclear airborne alert; these crews will be free from errors stemming from fatigue, and they will be comfortable enough to remain on duty for about 48 hours. If, for instance, a dozen aircraft carrying several efficient aero-ballistic missiles each could be kept airborne in a period of threat, it could be an interesting alternative to a SSBN as a super-robust component of the triad.

The Naval Component: Shaky Resting on the Laurels?

Is there a need for such an alternative to SSBNs? This type of the SNF is the most wide-spread, and every nuclear power is developing or building prospective SSBNs:

• Russia is developing and building several Borei-class submarines
• The US has launched construction of its first new Columbia-class missile submarine

Chinese H-6N strategic bomber
• China is actively building the naval component of its SNF: 094-class submarines are already nearly world-class and can be put on combat standby duty, while prospective 096-class submarines should be capable of going on full-fledged combat standby duty
• France has announced designing prospective submarines under the SNLE 3G program; these submarines should replace the relatively new Triomphant-class submarines
• The UK started working on Dreadnought-class submarines partially aligned with the US’ Columbia-class submarines
• Israel’s Dolphin-class non-nuclear submarines are believed to be carrying Popeye Turbo long-range cruise missiles with nuclear warheads, while Dakar-class submarines currently being built will probably carry ballistic missiles
• India is building several Arihant-class submarines; those currently in service are rather primitive, but they are being further developed
• Pakistan is planning to arm Agosta-class submarines with long-range cruise missiles Babur-3 (or they have already done so), and to do the same with China-built newer Hangor-class submarines
• Even North Korea has a rather impressive program for testin several types of SLBMs, although it might be having difficulties with building submarines

Why is there such unanimity and why are they so popular? Submarines are seen as platforms with highest survivability guaranteeing a retaliatory strike, and that makes them particularly effective as nuclear deterrent via scare tactic threatening a countervalue attack (colloquially known as “attacking cities”). Some states keep at least one submarine at sea at all times for that purpose, a policy known as “continuous at sea deterrent,” or СASD. This is the policy that the US, the UK, and France have maintained for decades; there are reports that China started using this policy as well. Other states use periodic patrolling and are ready to deploy submarines at sea at a period of threat. Additionally, SSBNs are convenient for launching a sudden attack at smaller distances with short approach time, although it involves additional risks for many states (not every state has a large system of alliances and friendly seas).

Oleg Kuleshov / korabel.ru
Borei-class submarine

Today, it is virtually impossible to reliably destroy a SSBN on combat patrolling especially if it operates in protected “bulwarks” of its county’s coastal seas (this luxury has become accessible with acquiring SLBMs with sufficient range). Of course, the “bulwark” can be subjected to a massive air-surface-submarine “storm,” but it is comparable to attacking the adversary’s ICBM UMS and MWS at a conventional warfare stage, which may produce an undesirable response, and that is putting it mildly. An alternative may lie in covert penetration, tracking, and attacking an SSBN upon command with one’s own hunter submarine, but during a period of threat, the adversary’s anti-submarine defense will be focused as much as possible on combating this threat, so this becomes an almost suicidal scenario.

However, the nature of threats may change soon. Light unmanned underwater craft are being widely used by navies throughout the world for auxiliary tasks (mostly clearing mines and checking underwater objects). There are now experiments with using rather large, multi-purpose craft capable of long-term self-contained navigation (the USA’s recently launched Orca is an example). They are still far behind full-fledged submarines in their performance and combat capabilities, but, drawing parallels with aircraft, they will be rapidly catching up. A hypothetical highly specialized combat hunter drone (or a “kamikaze”) could soon have the necessary hydrodynamic and acoustic characteristics; difficulties will lie rather in operating them and in detecting targets, but these problems could probably be resolved, too. Such drones may either qualitatively increase onslaught on “bulwarks,” or may be preliminarily deployed there, preferably stealthily, at great depths, becoming an extra headache. We can rather confidently suppose that within a couple of decades, underwater drones will become real enemies for submarines, and this is a short time for shipbuilding programs and naval ships’ service time.

This problem has been definitely admitted, and when the US discussed the number of launch tubes at new Columbia-class missile carriers, potential drop in the survivability of the SNF’s underwater component was prospectively mentioned as a reason not to put too many nuclear “eggs into one basket” (in the sense of advocating fewer launch tubes compared to existing Ohio-class missile carriers), while a hypothetical mobile version of the prospective land-based ICBM LGM-35 Sentinel (GBSD program) should be “kept in mind” in case of “a breakthrough in anti-submarine warfare.”

US Columbia-class submarine concept

However, an underwater drone may be both a problem and an opportunity. Squadrons of underwater drones will secure SSBNs flanking custom-made multi-purpose submarines, clearing mines, or may even serve as new delivery vehicles for nuclear payloads, primarily sub-strategic ones, but possibly strategic ones as well. Naturally, the first thing that comes to mind here is Russia’s Poseidon; the media stubbornly call it a “nuclear torpedo,” but it essentially is an underwater drone with nuclear propulsion, which means it likely has extremely high autonomous navigation capabilities, range, high hydrodynamic characteristics, and energy. Taken together, these characteristics open the way for a multitude of uses where “Sakharov’s torpedo” (that, in fact, has nothing to do with Sakharov) with its notorious “tsunami following a hundred-megaton explosion” [7] looks like an alternative delivery vehicle that, although far from being the most useful and efficient one, still would do the job and whose potential would primarily lie in the fact that it ignores anti-missile defense systems as a matter of principle.

In addition to new underwater craft being developed, SSBNs will inevitably be influenced by missile progress that applies to them as well as to land-based vehicles. The ability of multi-purpose submarines to get close to their target makes them a particularly interesting platform for hypersonic cruise missiles with boost glide warheads. Along with small-scale nuclear cruise missiles, this will allow a large part of the submarine fleet to regain their quasi-strategic capabilities.

***

The peaceful lethargic sleep of the satellite’s digital intelligence system was interrupted by a signal from the planet. Instead of another request for a diagnostic check-up to which the satellite usually responded with a short impulse transmitted over long cables of long-wave dishes which also served as radiators, this time the satellite received the command it, and others like it, had been born for, and had been waiting for eight years on standby duty at the remote orbit, close to the orbit of the planet’s satellite.

Having many times verified the message’s super-complex encoding, the computer analyzed target lists, checked the planet’s position against its own orbital positioning. Once one of several trajectories was selected, a cruise stage detached from the satellite’s body and emitted a short and clearly verified impulse to brake using chemical engines. It was risky as the enemy’s patrol interceptor satellites were on the prowl out there but braking with electric propulsion engines that the satellite normally used to maintain and change its orbital position would take too long, and that was even more dangerous.

The cruise stage started its three-day flight to the planet. Without the satellite’s miniature reactor, it had to be saving power, using only its batteries. There were other reasons for that, too, primarily minimizing its infrared emissions. The stage controlled its trajectory using signals from near-earth navigation systems, yet halfway, the services available to it ceased transmitting their signals, and it had to rely solely on its optical sensors, gyroscopes, and high-precision clock. Potentially, it could become inconvenient at the final stage of the flight, but the digital intelligence did not have the capacity to be grouchy. Instead, it noted the loss of friendly navigation services as another confirmation that the order had been correct.

In addition to producing minimal heat emissions, the cruise stage naturally was small and had radio-absorbent skin. For most of the flight, it was almost entirely safe, but the final dozens of minutes were dangerous. The computer identified space-scanning radars “skimming” the station, but they were incapable of detecting the miniature space alien. Nearly approaching, the frequency and power of emissions received by sensors change rapidly, emissions become constant. Target locked, the enemy’s missile defense and anti-space defense are in the target acquisition mode! Too late, the stage will now most certainly make it. Seeing as there is now no need to hide, the cruise stage deploys rapidly inflating decoys, passive ECM, and active transmitters. A flare on optical sensors tells it one of the decoys is destroyed. It is too late, it has made it at a speed far above the warheads of intra-planetary ballistic missiles, it burst into the atmosphere at a nearly right angle, straining its protective coating almost to the limit. There were still the close-quarter defensive layers of the “regular” missile defense, but there were none around the target, and the speed was so mind-boggling the cruise stage computer ignored their threat with almost human contempt.

If its creators had enabled it to feel triumphant and proud, this is what the digital pilot of the remote outer space deep retaliation system would have felt as it used the altimeter to set off thermonuclear charge.

This looks like an excerpt from another sci-fi TV show, but from time to time, snippets of such ideas filter into expert discussions. Deploying nuclear strike weapons at high orbits or even in the cislunar space is very different from the commonly discussed low-orbit deployment. It eliminates the key negative aspects of low-orbit nuclear deployment: on the one hand, the highest provocativeness, potential threat of a quick-launch strike, while on the other hand, impossibility to promptly deliver a retaliatory or counterstrike (satellites usually fly over the same point on the planet with large intervals), which makes it necessary to deploy a huge group of which only a small part will be able to attack simultaneously. While the group is waiting for the right position, the adversary may destroy a major chunk of it using anti-space defense. Therefore, low-orbit deployment is ideal for the initial decapitation attack, the vanguard of the main attack, but it has little use for retaliation: this is a nightmare combination for strategic stability.

Naval Sea Systems Command
Orca

High-orbit systems, on the contrary, are good for it: using weapons that take one, two, or three days to reach their target is risky for the first strike, the attack may be detected. On the other hand, small-scale space platforms specifically designed to be highly autonomous and to have minimal infrared emissions and radar visibility can have high survivability; we have to keep in mind that we are talking space size that is thousands of times deeper than the ocean, the atmosphere, and the actively exploited near-earth space.

Another possible reproach is that this is the way for humanity to embark on militarizing even deeper into outer space areas than the near-earth orbit that has been extensively exploited by militaries, but it is too late: the US Space Force has already proclaimed the cislunar space a new “high ground” they believe critically important to dominate. Several programs for building patrol spacecraft intended to monitor the activities of potential adversaries have already been launched to explore the new domain. Although they are primarily concerned with exploring the Moon, scenarios (like the one above) have most likely occurred to heirs of those people who had intended to deploy ICBM launch vehicles on the Moon (“I” in that abbreviation probably standing for “interplanetary”).

Naturally, the 1967 Outer Space Treaty precludes deploying nuclear weapons in outer space, but how reliable are such treaties in our day and age? They are, as always, likely to be reliable for as long as they do not stand in the way of their signatories’ interests. We have few key agreements left over from the Cold War, and how is a bomb by the moon different from strategic missile defense?

On the one hand, the prospect (purely futuristic, maybe my far-fetched invention, if you please) of nuclear race going far beyond Earth is rather grim, smacks of fatalism, and brings to mind thoughts of humanity never learning and never improving. On the other hand, it is possible that, around sixty years ago, militaristic motives would be conducive to purely peaceful progress. After all, the first satellites, first cosmonauts and astronauts also essentially flew rapidly re-fitted ballistic missiles that had been designed for entirely different cargo.

Notes:

1. Five bombers with nuclear bombs were lost in that operation. It concluded only after another crash on January 21, 1968, that caused major local nuclear pollution in Greenland.

2. This is a raid of seven B-52G bombers that attacked targets in Iraq on January 16–17 with 35 AGM-86C cruise missiles. Curiously, that was almost the entire stock of non-nuclear air-launched long-range cruise missiles the US had at the time.

3. Media tends to mention its non-nuclear version Kh-101 far more often, but this article focuses on nuclear weapons.

4. Ironically, the first and only successful launch after five failures took place the day after the program was shut down.

5. Scott Lowther Boeing B-47 Stratojet & B-52 Stratofortress – Origins and Evolution – Tempest Books, 2021. Pp. 273–278.

6. When delivering strikes against Afghanistan in the fall of 2001, B-2A took off in the US, crossed the Pacific Ocean, skirted Asia, delivered their strikes, and then landed on Diego Garcia Island in the Indian Ocean to change their crews and return to the US. The “base” crew flew for up to 44 hours but given that during their Diego Garcia landing aircraft did not kill their engines and power, they only rapidly refueled. The aircraft’s mission was essentially over 70 hours long.

7. I would like to take this opportunity to say that scientific calculations and tests debunked the ideas of waves washing away half the continent that are so popular in television and internet folklore; in fact, possible destruction would be limited to a few kilometers.

8. The term Cislunar has been extremely popular in recent years in the United States and refers to the space between the lunar orbit and the highest actively used modern satellite orbit (sometimes simply geostationary). An established Russian term, as far as we know, has not yet taken shape, but the prefix cis- when meaning geographic regions is, as far as one can tell, more correctly translated as "pre-".