China claims repurposed ski-jump technology test helped launch spacecraft 7 times the speed of sound

Yunpeng's team tested the method at seven times the speed of sound using scaled-down versions of a hypersonic carrier and an orbiting plane resembling the space shuttle.

The ski-jump on conventional aircraft carriers serves as a short runway for aircraft, providing just enough lift for them to take off from the deck propelled solely by their weight while the carrier moves at full speed into the wind at around 60 km/h (37mph).

The study was first published in the peer-reviewed journal Acta Aeronautica et Astronautica Sinica on December 8. 

Tests succeed at Mach 7

The researchers used a piston to launch a 1/80 scale model plane from a three-foot (meter) long model carrier at the JF-12 wind tunnel in China and successfully reached Mach 7 (seven times the speed of sound) to imitate the ignition of rocket engines.  

The plane instantly took off from the carrier's top. As the tunnel powered down, it fell to the ground and shattered into multiple pieces.

One of the most effective wind tunnels in the world, the JF-12 simulates chemical explosion shock waves by circulating exceedingly hot air at high speeds. Although the extreme conditions of hypersonic flight are simulated, they can only exist for one second.

This pricey trial "verified the feasibility and effectiveness of the active separation method," as per Yunpeng's team.

The team claimed that it was long enough to prove that, in comparison to conventional separation techniques, "the modified ski-jump design eliminated the gap between the two plane bodies," minimizing the chance of a collision.

To lessen the drag that can result when two vehicles split at incredibly high speeds in the environment, the researchers flattened the ski-small jump's upward slope to create an entirely flat surface for the hypersonic version.

The crew noted during the wind tunnel experiment that the plane's nose tipped forward when it approached the end of the flat runway due to a nudge upwards from the shock waves produced beneath the space plane's top front part.

However, another cluster of shock waves occurred near the plane's tail just as it was about to take off, which caused it to nose down. The researchers claimed that the opposing forces balanced one another out, resulting in a smooth, straight separation.

For the short experiment, Wang's team attached a strong, gas-driven piston to the back of the test plane to enable takeoff.

The team also created an automated system to control every aspect of the experiment, from the mechanical tools to the high-speed cameras that recorded the separation in exquisite detail.

China's hypersonic mission

According to Wang, a full-sized upper-stage space plane would launch in about eight seconds and weigh 87 tonnes, roughly the same as a space shuttle. 

The heaviest rocket engine would provide 1,500 kilonewtons of thrust. He claimed that the ski jump would use less than a tenth of the primary engine's thrust.

The possibility of the different vehicles deviating off track or perhaps colliding has yet to be effectively eliminated, noted the SCMP report.

The researchers reasoned that the shock tunnel's new experiment results needed to be coupled with earlier trials' longer testing times for further clarity on the approach. 

China has long proclaimed that it intends to create a fleet of air-breathing hypersonic passenger aircraft that can reach near-space heights while traveling at five times the speed of sound or more, cutting travel time to any place on Earth to one or two hours.