dimdeX

China Central Television

Following the launch of Starry Sky 2 in August 2018, China conducted additional testing with three hypersonic vehicle models at the Jiuquan Satellite Launch Centre a month later.

twin vertical fins (D18-2S) and the third with the vehicle body underslung beneath the wing (D18-3S).

While the test vehicles were unlikely to have achieved hypersonic speeds given their unpowered gravity launch method, but Chinese media reports have indicated that the demonstration was intended to gather comparative data on the vehicles’ flight performance characteristics when operating at speeds around the sound barrier.

“The reports seem to suggest that the tests had been designed to assess airframe performance around the sound barrier and low supersonic speeds,” said Zhu.

“This design approach may reflect that China is developing a hypersonic weapon capable of operating in a wide range of speeds,” he further explained. “For example, the vehicles could transit to the target area at hypersonic speeds which would minimise time for reaction, but slowing down in the terminal phase of the engagement to improve targeting accuracy.”

Powering hypersonic ambitions China has also made significant strides in developing other enabling technologies, particularly in the realm of propulsion systems. For instance, IMCAS claimed in mid-2020 that it had successfully performed ground testing of an indigenous scramjet engine that lasted 600 seconds, according to an official statement that has since been removed from its website but reported widely by authoritative local media.

According to IMCAS, a prototype scramjet built by a team led by the Princeton-educated scientist Fan Xuejun – one of its top state academicians – broke the current world record of 210 seconds of continuous scramjet engine burn held by the United States with its X-51A waverider prototype in May 2013.

A scramjet had accelerated the X-51A to a final speed of Mach 5.1 (6,247km/h) before the craft’s fuel load was expended and glided to a programmed impact in the Pacific Ocean.

Local reports indicated that Fan, an expert in special fuels and engine cooling technologies, had also been instrumental in the construction of China’s first test facility for active cooling technologies in Beijing’s Huairou district. The district is also home to the Huairou Science City, which is expected to support the country’s leading public and private technology research and development organisations.

China is also developing turbinebased combined cycle (TBCC) engines that can be used during the launch and hypersonic phases of flight, although the challenges of thermal management have yet to be fully addressed.

However, it appears that the country has made significant strides on hypersonic-capable precooled aerospace engine technology with the influential Beihang University – previously known as the Beijing University of Aeronautics and Astronautics (BUAA) – leading the charge and securing a National Award for Excellence in Innovation nomination in May 2020.

Additionally, materials used to construct hypersonic weapons must be carefully selected to ensure that they resist deformation or warping due to the harsh aerothermal environment associated with extreme-speed flight within the atmosphere. Suitable materials for such demanding applications include carbonbased composite materials or ceramic metal composites (CMC), which would typically form part of the outer shell of the airframe to protect the rest of the vehicle during hypersonic transit and/or atmospheric re-entry.

China has certainly been actively involved in advanced materials research to meet a broad spectrum of commercial and military requirements, with recent announcements would indicate that work has progressed on high-temperature CMC materials. In this regard, Chinese researchers appear to have made some progress, with the state-owned newspaper Global Times reporting in April 2020 that a new heat-resistant material that can “endure temperatures of over 3,000 °C from friction caused by a Mach 5-20 flight within the atmosphere”. AMR