Friday, 24 May 2013

Defense Space Security

Prototipe Helikopter Masa Depan Buatan seseorang warga Indonesia bernama Ridwan Chandra Choa yang pernah bekerja sebagai seniman digital Lucasfilm Animation di Singapura.

Hypersonic Speed: The Warp Speed of Today 

In aerodynamics, a hypersonic speed is one that is highly supersonic (even though the origin of the words is the same: "super" is just the Latin version of the Greek "hyper"). Since the 1970s, the term has generally been assumed to refer to speeds of Mach 5 and above.
The precise Mach number at which a craft can be said to be flying at hypersonic speed varies, since individual physical changes in the airflow (like molecular dissociation and ionization) occur at different speeds; these effects collectively become important around Mach 5. The hypersonic regime is often alternatively defined as speeds where ramjets do not produce net thrust.

Experience Boeing 

While the definition of hypersonic flow can be quite vague and is generally debatable (especially due to the lack of discontinuity between supersonic and hypersonic flows), a hypersonic flow may be characterized by certain physical phenomena that can no longer be analytically discounted as in supersonic flow. The peculiarity in hypersonic flows are as follows:
  1. Shock layer
  2. Aerodynamic heating
  3. Entropy layer
  4. Real gas effects
  5. Low density effects
  6. Independence of aerodynamic coefficients with Mach number.

The X-43 is an unmanned experimental hypersonic aircraft with multiple planned scale variations meant to test various aspects of hypersonic flight. It was part of NASA's Hyper-X program and has set several airspeed records for jet-propelled aircraft. The X-43 is the fastest aircraft on record at approx. 7000 miles per hour (10,461 km/h).

A winged booster rocket with the X-43 placed on top, called a "stack", is drop launched from a larger carrier plane. After the booster rocket (a modified first stage of the Pegasus rocket) brings the stack to the target speed and altitude, it is discarded, and the X-43 flies free using its own engine, a scramjet.


1. Wikipedia
2. Boeing Corporation

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