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Around the World in Four Hours?

Aerospace engineers are calling it the “biggest breakthrough in propulsion technology since the jet engine.”

The “it” in question is called SABRE – a reusable, hybrid jet engine and rocket combo being developed by privately held U.K. defense and aerospace firm Reaction Engines.

Sabre stands for Synergistic Air-Breathing Rocket Engine.

The name alone makes it sound pretty fascinating. But the potential it holds for the aerospace industry could be mind-blowing. How so?

Well, Reaction Engines sees a day when its engine will be used in a hypersonic spaceplane called Skylon. This spaceplane could be used to launch satellites at around one-tenth of current costs. Or to allow passengers to travel around the world in a mere four hours, traveling at five times the speed of sound.

The question you’re probably asking is whether this actually holds real potential, or if it’s just a fanciful dream. Let’s find out…

A $31 Million Vision

The SABRE technology was hatched over 30 years ago. It’s the brainchild of former Rolls Royce engineer Alan Bond, along with two partners.

In short, it mixes conventional aircraft engine turbine technology with rocket engine technology.

Right off the bat, the fact that aerospace giant BAE Systems Plc (BAESY) recently bought a 20% stake in Reaction Engines for a little over $31 million is proof that this is no frivolous bet.

In turn, this investment unlocked an additional grant for Reaction from the British government.

The money will go directly towards the construction of a ground-based demonstration engine, which should be ready by 2020.

If successful, an unmanned Skylon aircraft – powered by the SABRE engine – will take off like a plane, fly to the edge of space, deploy a satellite into low-Earth orbit, and return to Earth for re-use within 48 hours.

This is known in the aerospace industry as a single-stage-to-orbit launcher.

So how does this concept work? (Hint: Here’s the science bit…)

Air Conditioning: Engine Propulsion Edition

During takeoff, the engine takes in air, compresses it, and mixes it with liquid hydrogen to gain acceleration.

As the craft gains speed, the air gets extremely hot – around 1,000 Celsius (1,832 Fahrenheit).

This is where Reaction’s technology is critical. Specifically, its proprietary heat exchanger in front of the engine, which rapidly cools the air to minus 150 Celsius (minus 238 Fahrenheit) in a mere one-hundredth of a second!

This allows the engine to keep going, using oxygen in the atmosphere. The technology also prevents the formation of ice.

Finally, when Skylon reaches the edge of space, SABRE switches to rocket mode, using a mix of liquid hydrogen and liquid oxygen for power.

Feasibility? Check. Now for More Funding

The key to the whole concept is Reaction Engines’ novel propulsion system.

Basically, Skylon would work like a jet in the atmosphere before morphing into rocket mode in space. Doing so saves a ton of propellant when compared to conventional rockets that deliver payloads into space.

Indeed, as I mentioned above, the company expects that satellite launches using the technology will cost only one-tenth the price of current rockets.

Not to mention the fact that it’s reusable, too.

This is no pie-in-the-sky concept, either (if you’ll excuse the pun).

The SABRE engine has passed technical assessments by both the European Space Agency and the U.S. Air Force Research Laboratory.

But to actually get it flying for real by the 2020s, the project needs the critical ingredient – money.

Now that BAE has coughed up $31 million, it could tempt other aerospace giants like Boeing Co. (BA), Northrop Grumman Corp. (NOC), and Lockheed Martin Corp. (LMT) to kick in some funding, too. The European Space Agency and NASA are also obvious funding candidates.

I sure hope so. I want to fly around the world in four hours!

Good investing,

Tim Maverick

Tim Maverick

, Senior Correspondent

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