The “Break it Down” Blog

Popular Science has a technically-awesome article on scramjet technology getting closer and closer to deployment in military aircraft. The “technically awesome” part comes from what exactly a “scramjet” engine is, and how it works.

Existing jet airplane engines are based around turbines moving air through an engine as fast as possible with turning blades. The problem is that an aircraft based around this technology cannot go faster than Mach 3 without the blades completely melting.

The next bump in engine technology is a “ramjet”. The way a ramjet engine works is to literally “ram” incoming air into the combustion chamber of an engine. The problem with a ramjet is because the incoming air has to be slowed down to subsonic speeds to be combusted, the jet has to stay under Mach 5 otherwise the friction/heat created by the incoming air would destroy the engine.

Lastly, we have the “scramjet” engine technology AKA “supersonic combustion ramjet”. The picture you see at the top of the post is one of the successful test-fires of the scramjet. The jet itself is ignited inside of a 2,000 F degree jet of methane gas to simulate the true firing environment of the jet running at Mach 5+ (the scramjet has been publicly tested up to Mach 6.5). At full throttle the speed environment that the scramjet could be fired in would be Mach 15 flight, or roughly 10,000 MPH.

While the Pop Sci article titillates us with 1hr LA -> New York flights or NY -> Tokyo flights in under 2hrs, you have to consider if these are being test-fired right now, my guess is some black-ops military program already has them deployed, which means we have another 10 years at least before these things make their way into any commercial airline and even then it will likely be the most expensive, Concord-esque replacement.

I don’t see scramjets being a reality for Southwest fliers anytime before 2050, when the technology is proven safe and an insurance company is willing to sign on the dotted line that the jet won’t disintegrate the airplane when fired.