Today, with modern air power operating inside the atmosphere, we can
impose kinetic effects at the speed of sound. With the maturing of hypersonic
weapons, we will be able to do that at multiples of the speed of sound.
Flight at five times the speed of sound and above promises
to revolutionize military affairs in the same fashion that the combination of
stealth and precision did a generation ago. Hypersonic air weapons offer
advantage in four broad areas. They counter the tyranny of distance and
increasingly sophisticated defences; they compress the shooter-to-target
window, and open new engagement opportunities; they rise to the challenge of
addressing numerous types of targets; and they enhance future joint and
combined operations. Within each of these themes are other advantages which,
taken together, redefine air power projection in the face of an increasingly
unstable and dangerous world.
The Physical Component is the one with which airmen and
women tend to be instinctively the most comfortable. It is about the platforms,
capabilities, weapons and `stuff’ that, to many, define what the RAF `is’. This
applies just as much to the Space domain as it does to the Air domain, and the
best way of achieving this may be to address both domains as seamless entities.
In years gone by, the reality of doing just that was limited by technology
separation: what worked in space did not work in the air and vice-versa. But
modern technology – especially with hypersonic engines, pseudo-satellites,
high-resolution optics and radar technologies – makes it conceivable that, with
appropriate investment choices, future military capabilities could have the
potential to be employed in both domains, perhaps even within the same mission.
These technological enhancements are also likely to deliver the improvements in
speed, reach, persistence, coverage, survivability, and precision necessary to
provide an increased range of options for military commanders and political
masters alike. But to embrace this new technology will undoubtedly require us
to change our preconceived ideas of air power as being delivered predominantly
from manned, fixed-wing, air-breathing platforms which operate at relatively
low altitude. The blurring of the Air and Space domains allows us to translate
our experiences of inner atmosphere aviation into even higher vertical limits
and far greater ranges of effect. In the remaining paragraphs of this section,
I will explore what I believe to be the four greatest technological
developments that will allow us to transform air and space power over the next
30 years.
Hypersonic Engines.
At a glance, hypersonic engines may appear to be a `silver
bullet’ which will unleash air and space power in the twenty-first century.
This field of technology shows great promise, and much is possible within the
next couple of decades providing there is investment in the emergent
technology. So, what can hypersonics offer the Air environment? A good place to
start would be to look at what Reaction Engines Limited (REL) has to offer with
their experimental Synergetic Air-Breathing Rocket Engine, or SABRE. 9 Initial
work looks incredibly exciting and could give rise to a working platform by
2030 that is capable of Mach 5+ and offers high cadence space access as well as
long range inner-atmosphere flight. Such technology also appears promising because
it purportedly offers `speed as the new stealth’ and potentially increases the
survivability against an array of current and anticipated anti-access systems.
Furthermore, while the technology claims to enable space access it can also, in
theory at least, provide a vehicle from which a space payload could be
launched. But hypersonic technology is not limited to just platforms. It can be
applied effectively to weapons: air and groundlaunched, offensive and
defensive. Whatever the manner of its employment, hypersonic technology has the
potential to provide significant benefit to all operating domains – a true
force multiplier. Thus, even at this relatively early stage in its programme,
hypersonic technology represents a very strong candidate to address the physical
aspects of the blurred Air and Space domains. While there are numerous
hypersonic technologies under development, SABRE is novel, it is British, and
therefore offers a sovereign capability with all the accordant benefits for our
national prosperity agenda.
Hypersonic Vehicles Aerial vehicles that can travel in
excess of five times the speed of sound, or Mach-5, are labelled hypersonic.
Hypersonic weapons can be broadly divided into two categories, that is,
Hypersonic Glide Vehicles (HGV) and Hypersonic Cruise Missiles (HCM).
DARPA seeks to “develop and demonstrate a technology that is critical for enabling an advanced interceptor capable of engaging maneuvering hypersonic threats in the upper atmosphere.” And it wants this technology in a hurry: Glide Breaker should be tested in 2020.
Hypersonic Glide
Vehicles
The aerodynamic HGV is a boost-glide weapon-it is first
`boosted’ up into near space atop a conventional rocket and then ejected at an
appropriate altitude and speed. The height at which it is released depends on
the intended trajectory to the target. Thereafter, the HGV starts to fall back
to Earth, gaining more speed and gliding along the upper atmosphere, before
diving on the target.
Hypersonic Cruise
Missiles
An HCM on the other hand, is typically propelled to high
speeds (around Mach 4 to 5) initially using a small rocket; thereafter, an
air-breathing supersonic combustion ram jet or a `scramjet’ accelerates it
further and maintains its hypersonic speed. HCMs are hypersonic versions of existing
cruise missiles but would cruise at altitudes of 20-30 km in order to ensure
adequate pressure for its scramjet. Standard cruise missiles are difficult to
intercept-and the speed of the HCM and the altitude at which it travels
complicates this task of interception manifold. The United States’
underdevelopment `WaveRider’ is a typical HCM. Russia’s HCM, the
aircraft-launched Kh-47M2 `Kinzhal’, (Dagger), has a reported top speed of
Mach-10 and a range of about 2000 km. India’s underdevelopment `Hyper Sonic
Technology Demonstrator Vehicle’ (HSTDV) too, capable of speeds around Mach-7,
falls in the category of an HCM.
1. Aerial vehicles that can travel in excess of Mach-5 are
labelled as hypersonic.
2. Three nations (Russia, China, USA) have been testing
hypersonic glide vehicles (HGVs), although a number of other countries are also
pursuing hypersonic programmes.
3. An HGV, armed with a nuclear or a conventional warhead,
or merely relying on its kinetic energy, has the potential to allow a military
to rapidly and pre-emptively strike distant targets anywhere on the globe within
hours or less.
4. On account of their quick-launch capability, high speed,
lower altitude and higher manoeuvrability vis-a-vis Intercontinental Ballistic
Missiles , HGVs are difficult to detect and intercept with existing air and
missile defence systems.
5. This capability could tempt a nation to consider using
HGVs for a disarming and first-strike on an adversary’s nuclear arsenal.
6. While numerous challenges remain, operational deployment
of HGVs would thus compel target nations to set their nuclear forces on a
hair-trigger readiness and “launch on warning” alerts, leading also
to the devolution of command over nuclear weapons.
7. Overall, this would aggravate strategic instability, and also generate unacceptable levels of instability in crisis management at many levels.
