US (& Allies) Hypersonic developments and missiles

What could be the reasons for the Western delay in hypersonic weapons?

We will start, if necessary, by reading this article [1] . He reports on Russian advances in this area and discusses the potential concerns of the Western world about its ability to follow them, with the United States in the lead. We are asking ourselves the question here not of a delay which would be due to later development, but what seems to us to be a real conceptual difficulty in making such machines work.

Since we are in the West, let us remember these words of Richard Feynman, Nobel Prize winner in physics: “the goal of the physicist is to make the equations speak” .

Let us note then that at the end of the Cold War, we find ourselves in a rather strange situation at first glance. The West pushed electronics and computing much further than the Soviet Union. It did not occur to anyone that the latter had held up without this and we were content to think, here, that its equipment was obsolete and ineffective. The Ukrainian conflict demonstrated the opposite!

However, those who worked on equipment opposing the collapse of the Berlin Wall know very well that the “enemy” of the time had implemented treasures of thought to precisely make the equations speak and understand what was really in-game without having to go through computer calculations. This was the case, for example, with so-called “ionic” space propulsion engines.

Meanwhile, at home, we relied more and more on software. They constituted a black box over which we had no control and we “swallowed” the results, whatever they were, as if they were the naked truth coming out of the well.

An example is often better than a long speech. In 2013, I had a machine of my design tested in a digital wind tunnel. Contract was signed with the School of Mines which included one of its best students from the Polytechnico Milan. The aim of the study was to determine the drag and lift coefficients of my aircraft. I had made an estimate by hand which took me 10 minutes. After 6 months of effort, the super calculator produced a drag coefficient which was equal to mine to within 10%. If we stop the story here, you might think I was 10% wrong. Nay! Indeed, in essence, my concept had to have a non-zero lift coefficient. But the one who emerged from the “hellish” program was zero. It was therefore a clear error which showed that we could not have any confidence in the result concerning the drag. I will spare you the analysis that followed as well as its conclusions.

Today, engineering schools, in full agreement with companies, want people who are efficient in handling various IT tools: Catia, etc. If in fact the latter, at the time they were designed, brought great progress for those who were used to thinking, they only “Taylorized” the real profession by degrading it enormously, leading to the incremental improvement which tomorrow will be the prerogative of artificial intelligence. On the other hand, from my point of view, replacing the Soviet physicists and engineers of the time with AI would absolutely not be possible.

So this is where we are and until our scientists are able to make the equations speak, it seems very unlikely that the West will be able to make hypersonic missiles worthy of the name. What do I mean by that? Not rockets that go to Mach 5, which is the limit between supersonic and hypersonic, but that reach Mach 9 like the Zircon at sea level or 27 like the Avangard at high altitude, while remaining maneuverable .

To reach such a level, it is imperative to return to studies focusing on paper and pencil. Write the equations, try to solve them by hand and understand, when you make approximations, what they correspond to physically and if they are legitimate.

Let's take one more example. There are so-called phase change fluid loops for cooling parts of, for example, satellites. If we do not carry out, with ad hoc approximations, an expansion limited to order 4 of the Navier-Stokes system, we cannot conceive of such loops. A computer will never be able to achieve this, although excellent engineers in the past have been able to do so.

When we see the low level in mathematics and physics today throughout the Western school structure, we say to ourselves that the light will come from elsewhere. And this is what we are seeing.

According to press reports, this new long-range hypersonic weapon, developed by Lockheed Martin Corp. for the US army, it will have a range of 2,780 kilometers and consists of a ground-launched missile equipped with a hypersonic gliding body and associated transport, support and fire control equipment.