[Music] It's a very sobering thought that hypersonics weapons, for the most part, can
not be defended against right now. You could certainly see a launch of a missile booster
rocket carrying a hypersonic weapon, but once that weapon--say it's a glider--releases
from that rocket you lose track of it. Currently, there are three countries that are vying for
the lead in hypersonic weapons development: China, Russia, and the United States. Let
me start by talking about China. They recently tested the hypersonic weapon called the Xingkong-2.
It's a hypersonic cruise missile. This weapon was released from a rocket high over the sky
of northeastern China. It then glided through the atmosphere going at Mach-6, six times
the speed of sound, bobbing and weaving, riding the shock waves that it was emitting. Another
variety that China is pursuing is call the Dong Feng-17, East Wind. It is a hypersonic
glide vehicle. What's important is that it doesn't just simply release and glide to a
target, it can be maneuvered. And that maneuverability at such high speed is what these countries
really prize about hypersonic weapons. Russia tested what's called the Avangard, and the
Avangard is a hypersonic glide vehicle. According to the Russian sources, they claim that this
hypersonic glide vehicle glided 6,000 kilometers across the country to the far east, the Kamchatka
peninsula traveling upwards up Mach-27. So that's amazingly, blazingly fast speed. The
United States also very long standing interest in hypersonics. They have several programs
in active testing now. All branches of the military are pursuing hypersonic weapons,
both the glide vehicles and the cruise missiles. The hypersonic cruise missiles, they are called
air-breathing; so they propel themselves through the air. Now I should say that these hypersonic
cruise missiles, for the most part, they are released at high speed from either a booster
missile or from a jet--when they're released they're traveling pretty fast. But then they
propel themselves using what's called a scramjet engine. It's basically a tube where the air
comes in, fuel is injected, they mix, combust, and that provides propulsion. Scramjet engines
have also been described to me as the most challenging engine to get to work because
of the extreme conditions that they're operating under. And the reason is that when air is
moving so fast at hypersonic speed into this tube molecules have fractions of milliseconds
to mix with the air. There are other problems, as well. That has to do with the boundary
layer of air that the vehicle is traveling through at hypersonic speed. This boundary
layer actually thickens the faster you go at hypersonic speed. And in this very complex,
kind of physical environment turbulence causing spikes in temperature, and the spikes in temperature
can heat up the skin of the vehicle to very high temperatures. Traveling at very high
hypersonic speeds, high Mach numbers, air around the vehicle ionizes to the extent that
radio signals have trouble getting through. So let's say these hypersonic gliders that
can go upwards of Mach-25 to 27, you would have this problem communicating with them.
Testing vehicles at these hypersonic speeds, it's extremely expensive. So there's been
very limited testing, and because there's been limited testing you have a pretty patchy
success rate. Russia is already deploying hypersonics; they beat the U.S. to the punch
in that way. It really is a competitive "space race" in a way. [Credits]