China successfully tests Mach 5-capable hypersonic aircraft

Hypersonic vehicles move at least at five times the speed of sound, riding their own “shock waves”.

The first test flight of Xingkong-2 (Starry Sky-2) was carried out successfully at an undisclosed location in a remote part of northwest China, the China Academy of Aerospace Aerodynamics said in a statement carried by state media. It flew independently, made large-angle turning manoeuvres and landed in the targeted area as planned.

The public announcement indicates that China has already achieved a degree of technological prowess with aircraft.

The aircraft — also called the “waverider” —  touched speeds of 7,344 km per hour, said Xinhua in a report.

“A waverider is a hypersonic aircraft that has a wedge-shaped fuselage designed to improve its supersonic lift-to-drag ratio by using the shock waves generated by its own flight as a lifting force,” the report said.

“During the independent flight, the test craft maintained ultrafast speeds above Mach 5.5 for more than 400 seconds and reached 7,344 kmph,” it said.

A hypersonic aircraft flies through the atmosphere below about 90km at speeds above Mach 5, according to NASA, a speed where dissociation of air begins to become significant and high heat loads exists. A report in The Independent suggests a hypersonic flight can cut the travel time between Sydney and London to just two hours, from the current 23 hours.

A hypersonic 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 or even above.  A traditional engine’s fan blades cannot be used for these jets, as they would melt if used at hypersonic speeds. The aircraft instead uses the shockwaves created by travelling at such high speeds to squeeze incoming air.

Some hypersonic vehicles have a special type of jet engine called a Supersonic Combustion Ramjet or scramjet to fly through the atmosphere. Sometimes, a hypersonic plane uses a rocket engine. The United States and Russia have been carrying out similar experiments as China.

The aircraft launched by China was designed by the CAAA in collaboration with the China Aerospace Science and Technology Corporation. The flight vehicle reached 30 km in altitude at Mach 5.5-6, said the statement quoted by the official media.

The aircraft carried out a number of manoeuvres and tested “a host of advanced technologies such as a domestically developed heat-balance thermal protection system”.

Various parameters were proved and the flight vehicle was fully recovered, which marks the successful launch of Xingkong-2 and the first flight of a Chinese waverider, according to the statement.

“The current generation of anti-missile defense systems is mainly designed to intercept cruise and ballistic missiles, which are either slower or easier to predict, making them possible to intercept,” military expert Song Zhongping told the state-controlled Global Times.

“But the trajectory of a waverider is relatively unpredictable in the glide and it flies so fast that it poses an extreme challenge to current anti-missile defense systems.

“The test showed that China is advancing shoulder to shoulder with the US and Russia,” Song said.