HYPERSONIC AIRCRAFT

Aug. 7, 2018

China has tested Xingkong-2 – its first hypersonic aircraft – which could carry nuclear warheads and penetrate any current generation anti-missile defence systems.

Mach Number:

Mach number (designated as M or Ma) is the ratio of the speed of the body (aircraft) to the speed of sound in the undisturbed medium through which the body is traveling.
g. If the aircraft is flying at Mach 2, then its speed is twice the speed of sound in air (which is 332 m/s or 1195 km/hr).
It is named in honor of Ernst Mach (1838-1916), a physicist from Austria.
Types of Aircrafts based on Mach Number (Source-NASA):

Subsonic	M < 1
Transonic	M = 1
Supersonic	1 < M < 3
High Supersonic	3 < M < 5
Hypersonic	M > 5
High Hypersonic	M ~ 25 Space crafts re-enter the atmosphere at this speed.

Hypersonic aircraft:

Working:
- This type of aircraft uses the shock waves generated by its own flight as a lifting surface to enhance the lift-to-drag ratio to reach Mach 5.
- They use a special type of jet engine called a Supersonic Combustion Ramjet (Scramjet) to fly through the atmosphere. Sometimes, a hypersonic plane uses a rocket engine.
Global scenario: China has recently tested Xingkong-2 (a.k.a Starry Sky-20). The United States and Russia have already been carrying out similar experiments.