China’s New Mach 30 Wind Tunnel Tests Space Plane Mothership Design
Chinese officials say the new JF-22 is the most powerful in the world and will support tests of various hypersonic systems.
The Chinese government has released a video showing what it says is the world's most powerful wind tunnel being used to conduct a scale separation test of what appears to be an air-launched space plane design from a mothership aircraft. The footage recently broadcast on state television also contains footage of the high-speed oblique detonation wave engine, also known as a shcramjet, used to power the wind tunnel, which can reportedly simulate conditions at speeds up to Mach 30.
The clips, seen in the Tweets below, were aired on the state-run China Central Television's (CCTV) Channel 13, the country's largest 24-hour television news network. They began to appear on social media over the weekend.
The Institute of Mechanics of the Chinese Academy of Science (CAS) in Beijing announced last month that its new JF-22 hypervelocity wind tunnel had passed an "acceptance check" and was ready for general use. Work on the JF-22, which is reportedly just under 548 feet (167 meters) long overall and has a "test cabin" that is around 13 feet (four meters) in diameter, began in 2018.
The design seen in the video under test looks similar, in very broad strokes, to air-launched spaceplane and mothership concepts that Chinese aerospace companies and academic institutions have shown publicly in the past. It has a delta-winged, dart-shaped planform that looks reminiscent in some respects to a design seen in wind tunnel test pictures and an accompanying video that the China Academy of Aerospace Aerodynamics (CAAA) released in 2019.
However, there are no immediate indications one way or another that the two are directly related. What can be seen of both the test articles in the JF-22 footage certainly show general planforms and an overall configuration similar to those used in many so-called two-stage-to-orbit space launch concepts.
In very broad terms, two-stage-to-orbit systems consist of a mothership aircraft that first carries the spacecraft to a very high altitude. That vehicle is then launched into space using its own propulsion, typically a rocket motor. Many of these concepts involve reusable spaceplanes that are also designed to be capable of landing on conventional runways. Sometimes they are designed to be propelled by advanced high-speed air-breathing jet engines, like scramjets or shcramjets. Scramjets and shcramjet differ primarily in the construction of their inlets and combustion chambers. You can read more about two-to-stage-orbit concepts, which date back to the 1950s, in this past War Zone feature.
In general, the key benefits that two-to-stage-orbit concepts offer are increased flexibility and unpredictability compared to traditional space launch rockets. A spaceplane launching mothership aircraft does not require the same kind of significant static infrastructure and would be able to operate from any existing and suitably large air base or airport, and do so with less overall preparation. This, in turn, opens new launch envelopes and launch windows, making it easier to get payloads into desired orbits on shorter notice. This could potentially be especially useful in the context of a conflict, where there could be a need to rapidly replace space-based capabilities that have been destroyed, damaged, or otherwise put out of action.
At the same time, two-stage-to-orbit concepts often have limited total payload weight capacity compared to more traditional space launch rockets. There is also the potential that these concepts could be used to launch spaceplanes for purposes beyond just putting payloads in orbit, including long-range intelligence, surveillance, and reconnaissance or strike missions, as well as on-orbit attacks. Chinese companies have publicly expressed interest in using concepts like this for commercial transport and tourism applications, as well.
Two-stage-to-orbit concepts could "reduce the launch cost of satellites and spacecraft by 90 percent," Jiang Zonglin, the head of the JF-22 wind tunnel project, claimed to CCTV in 2021.
Regardless, the development of these kinds of space launch capabilities has clearly long been of interest to China, among other countries around the world. The Chinese Academy of Science has also stated that the JF-22 will be used to support the development of future hypersonic aircraft.
The JF-22 is ideally suited to helping with the testing of hypersonic weapon designs, too. One of its predecessors, the JF-12, which China has said was previously the most powerful wind tunnel in the world and was powered by a pulse detonation engine, was used to test an unpowered hypersonic boost-glide vehicle known as the DF-ZF. That program has since evolved into the operational DF-17 hypersonic missile.
A test article with a similar wedge-shaped test article has been seen in footage previously shown by Chinese state media in relation to the JF-22, which is seen below. However, this may show an older wind tunnel like the JF-12.
The JF-12 and now the JF-22 are part of a larger Chinese high-speed testing ecosystem. U.S. officials, in particular, have said on multiple occasions now that this helped give the Chinese military an important boost when it comes to the development and fielding of various hypersonic systems.
"While both China and Russia have conducted numerous successful tests of hypersonic weapons and have likely fielded operational systems, China is leading Russia in both supporting infrastructure and numbers of systems," Paul Freisthler, the U.S. Defense Intelligence Agency’s Chief Scientist for Science and Technology, told members of Congress at a hearing in March. “Over the past two decades, China has dramatically advanced its development of conventional and nuclear-armed hypersonic missile technologies and capabilities through intense and focused investment, development, testing, and deployment."
In 2021, then-Vice Chairman of the Joint Chiefs of Staff Air Force Gen. John Hyten said that China had carried out "hundreds" of hypersonic tests in the preceding five years while the U.S. had conducted only nine.
More limited relevant specialized infrastructure has been cited as a significant limiting factor in U.S. hypersonic testing efforts. The U.S. military, in particular, is working to expand and modernize various elements of its hypersonic test ecosystem to help accelerate this work.
Altogether, the newly released clips of China's JF-22 wind tunnel in action are certainly interesting by themselves. However, they also underscore the country's still-expanding high-speed test infrastructure that is supporting the country's significant hypersonic and other advanced aerospace ambitions.
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