Hypersonic = 5.00-10.00 Mach. Roughly 3,840 to 7,680 mph.
High hypersonic = 10.00 to 15.00 Mach. Roughly 7,680-16,250 mph.
Back in the mid-Nineties, I was invited to the Lawrence Livermore National Laboratory to attend a supergun shoot. The supergun in question was hydrogen powered—and fired a projectile at hypersonic speeds. Hydrogen—the lightest element on the periodic table—in concentration, as I’m sure you know, explodes (something of an understatement).
It’s ferociously powerful stuff—but its only byproduct is water. H20 is no more than hydrogen combined with oxygen. We drink it, bathe in it, and as W.C. Fields so memorably commented: “Fish fuck in it.”
If you are around when hydrogen explodes, you will tend to view any further developments from a molecular perspective.
Let me stress the word ‘super.’ This gun was huge. You could exercise-albeit modestly—to advantage just by walking its length. It was half a football field long. It did not look space age and cool. It had an industrial look.
The thing did not point up into the sky. The idea was to test the concept—to see if the projectile could achieve escape velocity—before bombarding space (and, for instance, accidentally knocking out a Chinese satellite.)
What is escape velocity? It is the speed needed to break free from the gravitational attraction of a massive body without further propulsion. Where Earth is concerned, it is approximately 25,000 mph. That is easier to achieve than it sounds because air resistance and gravity both decrease as you pull away. Atmosphere decreases exponentially. Space is generally considered to start 62 miles (330,000 feet) up at what is known as the Karman line. Step over that line, and you are no longer a high flyer. You are an astronaut.
The main object of the exercise was to measure the projectile’s speed. It was actually fired into the hillside where it vaporized. Nada tangible was left.
Kinetic energy doesn’t need explosives to be destructive. Given enough speed—you end up with nothing you can see. Vaporization is as close as it gets to oblivion.
This was my first encounter with a hypersonic projectile. It was a pre-cursor to the hypersonic missiles now being tested
Why was I invited? Because I had initiated research into superguns in general for my book, THE DEVIL’S FOOTPRINT. The work was actually carried out by my son, Christian O’Reilly(now a successful playwright)—and for a time, we had become rather more expert on the subject than the CIA (according to Livermore). As a consequence when Livermore were tasked with advising on the destruction of Saddam Hussein’s supergun, they contacted us for help—which we gave.
My reward was the invitation—and the shoot was nothing if not spectacular. At the time, I was still living in Ireland so I had come 6,000 miles for the occasion. It was worth it. Nuclear labs are full of exceedingly bright people doing frighteningly dangerous things. My exposure to Livermore—I made multiple visits—was to lead to a major thriller, SATAN’S SMILE, which will be published shortly. In it, I cover nuclear terrorism and serial killing. What do you do if an enemy like ISIS gains access to all that plutonium—and isn’t afraid to die? It seems to me that it is an entirely credible possibility.
The eventual goal of the Livermore supergun was to shoot supplies into space at a much lower cost than by rocket (which is disgustingly expensive at around $10,000 a pound). It is an interesting project that has never acquired adequate traction as yet—but it is technically feasible. And yes, I did become heavily involved with it for a while. I tend to be fascinated by truly innovative projects. Better yet if they are at the cutting edge of impossible.
Incidentally, Dr. Gerald Bull—the man most associated with modern superguns—operated a program, HARP, where a projectile (a Martlet) reached an altitude of 155 miles, a truly astonishing achievement—and he was using gunpowder as the propellant.
HARP, though successful, was closed down due to lack of funding. The U.S. Air Force decided to back rockets. Though they are of debatable reliability, there is more money to be made out of rockets. Besides, they had Vernher Von Braun, one of the principle German rocket scientists during WW II, to give a head start.
Later in his career, Bull became the man behind Project Babylon—Saddam Hussein's supergun program.
Bull was assassinated outside his apartment in Brussels in March 1990. The Israelis are generally considered to have been responsible—but there were other candidates.
Back to hypersonic missiles.
Rockets propel them into space—and gravity is sufficient for the return. The types currently being developed—principally by the U.S. and the Chinese—are known as HGVs (Hypersonic Glide Vehicles) because when they re-enter the earth’s atmosphere they glide towards their targets at hypersonic speeds. However, it isn’t just speed that makes them hard to hit. They can also be maneuvered aerodynamically which means their flight paths are not predictable (unlike conventional ballistic missiles)—which makes them very tricky to locate and destroy.
An HGV allows you to hit any target in the world in less than an hour—and is near impossible to intercept with current technology.
The U.S. Navy is particularly concerned about HGVs because its aircraft carriers are obvious targets and are known to be the focus of particular Chinese interest. Aircraft carriers are traditionally how we project power—and they would certainly be deployed if Taiwan, for instance, was threatened.
A U.S. HGV test was aborted in August 2014 and a Chinese test failed earlier in the year. Nonetheless, despites these failures, is is generally accepted that HGVs will become operational relatively soon.
They can be equipped with either nuclear or conventional warheads. However, even without a warhead, a missile travelling at hypersonic speed would be exceedingly destructive as a consequence of its kinetic energy alone.
Even non-nuclear HGVs—if made and used in volume (something within Chinese capabilities) could be a serious threat to U.S. military dominance.