Lately on social media one great thread of fear porn is about war drones. More specifically drone swarms. Various reactions are to be observed but the general idea is that the old way to think the war is no longer correct. For instance this post by Musk:
If I do agree that we have a wrong view of future warfare. I don’t think that drone swarms are going to be a major factor. I am surprised that the CEO of SpaceX doesn’t envision the possibilities of Kinetic bombardment… But he is a known Heinlein reader. Maybe you are wondering where “Grok” name comes from and where the idea of Kinetic bombing is explored. Take your time to search about Heinlein books… So there is little doubt that he has already thought about it. Now, publicly talking about it is another thing…
Some Numbers
The idea of Kinetic Bombardment is stupid as fuck: just let fall down on earth a large mass: the kinetic energy will be transformed at impact. I have made some back of the envelope computations. Formulas are known since Mr. Newton discovered them (they can be checked by anyone so I won’t bother detail the computation). Here are the important numerical points:
EDIT : in my original computations I made the confusion between tons and kilotons of TNT so there is a factor 1000 wrong. It has some implications notably on the fact that you can’t reach the level of weapons of mass destruction level easily, yet most of the remarks remain true to a lesser level. Instead of purely kinetic some work would be required to have more practical
The energy for a 500 kg mass orbiting at 550 km is approximately equivalent to 5.91 T of TNT. *EDIT: I previously thought it was kt not just tons*
The price per kilogram in orbit using falcon 9 is 6000$.
The energy is linear in the mass.
You can play with numbers but here are some order of magnitudes linked to those facts :
1T of energy is approx 500 000$ using kinetic bombardment. *EDIT: I previously thought it was kt not just tons*
The price of an Hiroshima equivalent energy (16kT) is 32 billions $.
The price of an ICBM per unit is 162 million $, for something like 300 kT of energy. So the price of the kT is something around 450 000 $.
To have an idea: for an Hiroshima like energy a tungsten rod of 30cm diameter and 1.1m of length is required *EDIT: this is no longer relevant since you need 1000 of rods like this to achieve the result*
Now those are raw numbers. I have not worked nor tried to optimize anything. But they are important because they show that the kinetic bombardment idea is not technologically, nor economically out of reach. Quite the contrary.
Of course I haven’t took into account the technology and the energy to re-enter and target from orbit. But with SpaceX abilities to safely make rockets landing on a raft in the middle of the sea it doesn’t look like science fiction either.
Let’s now consider the implications at different scales, from the technical to the societal scales.
*EDIT: remaining remarks still hold to a lesser degree, and might be read having in though more complex orbital weapon systems*
Technical Considerations
As Starlink has already shown it is possible to cover the earth for internet access from space. It has already been done by a privately owned company. With US military level kind of capabilities it is “easy” to do the same with Kinetic Bombs. It means that a global strike capability is achievable. The time for impact from orbit is something around 1/4 of an hour. All points of the globe are at the same distance. It means that you have a system that goes at twice the speed of current ICBMs. Also you can surely engineer bombs by aggregating them: you can fine tune the energy at impact in a way that is impossible to achieve using nuclear technology. Another idea that becomes possible : you can pile up bombing until result achieved. It means that you can’t imagine that an immobile bunker is going to resist: imagine that you just have to send 10 Hiroshima like bomb on top of each other at 4 min interval. Nothing can resist, no matter how much concrete and steel is used or how deep you hide.
Tactical Considerations
Some remarks and open questions at a tactical level. What are the new capabilities and limitations of such weapon system ?
can kinetic orbital launch be detected? I have no idea but clearly the signature is order of magnitudes less than the ones of an ICBM launch.
can the projectiles be intercepted ? They would be very small objects falling at Mach 10. Another point is: once the trajectory is set then nothing short of total destruction could change anything. A nuclear reentry vehicle is typically of a similar size. The question becomes: how precisely the launch can be monitored and the trajectory computed? Anyhow remember that there is half the time, at best, to react.
Are satellites safe as a weapon platform? Nuclear heads are closely surveilled on earth. Deterrence relies heavily on the fact that they are spread amongst different capabilities: submarines, siloed missiles, bombers and cruise missiles. The fact that a satellite can be hacked has to be studied. A total hack would mean the enemy can use your weapon system against you (looks unlikely given that satellites today are not hacked to this point). Another possibility to study is a denial of service attack. A major mitigating factor is the sheer number of satellites that can be put in orbit. There are more than 6,000 Starlink satellites.
Maybe it is possible to have some systems on the ground and be able to launch them on demand (just like ICBM, the silos can be reused). An added benefit of the kinetic systems is that it is impossible to know in advance to where they are headed for since the satellites can fly around the earth as many times as required before delivering its payload. Another idea is to have empty platforms in place in orbit and load them just on time.
Strategical Considerations
At a strategical level the questions are the ones of deterrence and what are the implications for other systems ?
As noted before a denial of service becomes a question of first importance. Satellites are far away… So robust communications become a strategic priority because you can’t operate the satellites by hand (maybe having something like inhabited space station could be considered to change that?).
If you don’t know precisely where to strike the system is useless. It becomes like thermonuclear deterrence : only used in last resort and never in actual conflicts (that are not existential). But the energy of kinetic strikes can be very finely adjusted. It means that it can be used just as non nuclear strikes. You can destroy military targets. There are no nuclear waste etc. For instance is it possible to strike something like a aircraft carrier (direct or indirect strike) with this kind of technology? Doesn’t seem out of technological reach (once again think at SpaceX ability to make rockets fall on rafts in the sea!). So the strategic consequence of strikes are somehow depending on technological considerations.
When many countries will reach these capabilities how the global deterrence work? A first issue is the possibility of sneak strike. Maybe because the system is stealth it becomes like a cyber attack: the attribution of a strike becomes hard. Imagine a strike is done on the Pentagon for instance. No one declares anything, how can the strike be attributed and how the response can be done?
The possibility to do sub-nuclear strikes augment the probability of a strike. So the whole game theoretic landscape of deterrence is changed.
War between first tier pear competitors becomes a technological affair. Swarms of drones become irrelevant. Indeed drones have a limited reach, and if a major player is threatened by armies of robots then attribution is easy and retaliation via kinetic bombing unavoidable. Since the retaliation can be finely tailored it makes it even more probable. Even terrorists training camps can be targeted etc.
Unlike nuclear technology that requires very specific and traceable processes, there is 0 possibility to know who does what. Just launching a space rocket could be such a system. Remember what is required is just to put mass in orbit. Nothing fancy like the enrichment of uranium or anything objectively hard to do.
Societal Considerations
Nuclear deterrence has, barely, worked so far mainly because of technological difficulties. It is really hard to make nuclear/thermonuclear heads: from the raw material to the precise design and maintenance. It was only achievable by nation state actors, and even for such powerful actors it is not easy: just look at the efforts deployed by Iran on the subject. It literally takes decade of sustained effort. Nothing of this is required for kinetic bombing. SpaceX could implement it on its own tomorrow. It means that even private actors can reach such capabilities. Of course today only SpaceX can do it. But it won’t remain like this forever. Actors like China, Russia, even a small country like France could reach such capabilities in a reasonable horizon. What is the new game theoretic perspective? Is the first one to gain such capabilities enticed to use them before other actors can deploy their systems? Will the actor be using targeted strikes to destroy drone factories for instance? What does mean power projection in such a context? Because direct action doesn’t require boots on the ground, or not as much as before, to be done. Imagine the Irak war scenario with a kinetic bombardment platform. Is a 6 months long build up necessary? What is the role of air superiority? Maybe it is more flexible (not sure because you need air bases or aircraft carriers) and less expensive, but fighter jets aren’t going to stop a Mach 10 rain of tungsten rods…
If we reason at constant technology: today(!) someone like E. Musk (maybe J. Bezos too) can acquire global strike capabilities. He has enough financial and technological resources to achieve that. It is way easier than going to the moon or mars. Are we ready for such kind of world? Let that sink in.
