An aircraft capable of bombing any target on earth within two hours...

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NASA’s X-43 hypersonic aircraft

The US space agency has been developing and testing aircraft which fly many times the speed of sound for a number of years now. While the plane is still an un-manned prototype, it’s third known flight in 2004 set a new speed record of 12,140 km/h – Mach 9.8

The X-43 uses a new type of engine. The big difference? Very few moving parts.

A Simple Jet Engine Diagram

The workings of today’s jet engines are a bit strange, but easy to understand. Looking at most examples of this type of machine, we can see the jet engine essentially as a tube, one end taking air in, and the other expelling it out at a higher velocity.

When the engine starts up, air and fuel is ignited in the middle section of the engine, the combustion chamber. As the air/fuel mixture ignites, it heats and expands the air which rushes through the following turbine section of the engine, and out the exhaust at the back.

Here’s the strange part. The turbine, made of a number of fan-like blades, rotates as the heated gas rushes past it. The rotating turbine is connected to a shaft which spins with the turbine. The shaft runs back through the combustion chamber. towards the front of the engine. The power of the rotating shaft is used to spin other fan blades where the air enters the engine. This section is called the compressor – and it forces the air to gain higher pressure as it is pulled further into the engine towards the combustion chamber. Basically, the higher the pressure, the more air is available to ignite and expand in the combustion chamber, which then creates the engine thrust.

What is a Ramjet Engine?

A ramjet is a structurally very simple engine. Unlike a standard jet engine, a ramjet does not have a gas turbine fan which drives a shaft attached to a compressor.

What is a Scramjet Engine?

The NASA X-43 mentioned earlier is a scramjet. The only difference between it and a ramjet is that it will allow the air to enter the combustion chamber of the engine at supersonic speeds – preventing the creation of a shockwave where the air slows down as it enters the engine.

The top speed of a scramjet driven aircraft has been demonstrated by the X-43 to be close to Mach 10 – and it’s thought that the theoretical top speed could be as high as Mach 20.

Military Aircraft, Space and Global Security

Countries which have declared space programmes, if successful, will by definition also have the capability of launching missiles which can strike anywhere on the planet.

On January 11, 2007, China tested an anti-satellite weapon by successfully firing a missile at one of it’s own aging weather satellites. The USA tested a similar weapon in 1985.

For better or worse, nations which have technological leads in business or military domains are reluctant to give them up.

For more information

US Air Force - Space Command
http://www.afspc.af.mil/

NASA - Hypersonic Aircraft
http://www.grc.nasa.gov