Chinese scientists build anti-satellite weapon that can cause explosion inside exhaust
- Researchers who built the device say it can lock itself into the thruster nozzles used by most satellites and stay there for long periods undetected
- Scientists say the resulting blast would damage the target’s equipment and may be mistaken for an engine malfunction
A team of Chinese military researchers say they have built and tested an anti-satellite robotic device that can place a small pack of explosives into a probe’s exhaust nozzle.
Rather than blowing the satellite into pieces, the melt-cast explosive can produce a “time-controlled, steady explosion”, Professor Sun Yunzhong and colleagues from the Hunan Defence Industry Polytechnic in Xiangtan wrote in a paper published in the domestic journal Electronic Technology & Software Engineering last month.
The device could stay inside the satellite for an extended period by using a locking mechanism driven by an electric motor. If needed, the process can be reversed to separate it from the target.
The project was funded by a government scheme to develop a new type of warhead for rocket missiles, according to the paper.
The device has been built and tested in a ground facility and the researchers said it “would have practical value in certain engineering applications”.
China conducted its first anti-satellite test in 2007, destroying a defunct weather satellite with a missile and drawing international criticism over the cloud space debris it created.
The United States and the former Soviet Union had conducted a large number of similar experiments during the Cold War, but these tests stopped after the 1980s because the debris puts valuable space assets and astronauts at risk.
China’s anti-satellite programme in recent years has focused on technology that would produce little or no debris, such as capturing a satellite with a net or robotic arms.
The Chinese military has also developed various types of ground-based weapons that could blind or damage a passing satellite with a laser beam.
But these methods are relatively easy to detect, so Sun’s team looked for other ways to target satellites by placing explosives inside them.
The explosives are packed into a bullet shaped device that weights only 3.5kg and mirrors the shape of the de Laval nozzles that power most satellites.
These are pipes with a narrow throat in the middle that converts gas into kinetic energy and, although they are based on a 19th century design by the Swedish engineer Gustaf de Laval, are still used on the most advanced satellites today.
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Sun’s device works by pushing a rod through this narrow point, which then opens up to anchor itself into place by locking the device against the inner wall of the nozzle.
When the device is detonated, the explosion will be partially contained inside the nozzle and be mistaken for an engine mishap, according to a space scientist not involved in the project.
The heat of the explosion, if precisely calculated, can be partly converted into kinetic energy and damage the satellite’s insides while leaving the overall structure intact, said the researcher who requested not to be named due to the sensitivity of the issue.
Sun and colleagues said the melt-cast explosive they chose had been used extensively in China’s space programme for separating rocket stages and other purposes.
China has also developed the technology to capture satellites, something that has not been restricted by international treaties because it could also be used for peaceful purposes such as satellite repair, refuelling and removing space debris.
The US military has already voiced concerns about China’s anti-satellite capabilities, in particular Shijian-17, an experimental probe with a robotic arm that has conducted some unusual manoeuvres since its launch in 2016.
In April, US Space Command chief General James Dickinson told Congress that Shijian-17’s technology “could be used in a future system for grappling other satellites”.
He added: “Beijing actively seeks space superiority through space and space attack systems.”
The rapid development of China’s hypersonic programme also fuelled worries about a new arms race in space.
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Earlier this week Chinese foreign ministry spokesman Wang Wenbin said the US was hyping the “China Threat theory”, so that it could further expand its own military power.
China insists that its military strategy is defensive and Wang said it “will not start an arms race with any country”.
But Huang Jia, a researcher with the National University of Defence Technology, said that a new arms race was imminent and it could destroy the space environment.
“The military aerospace equipment tests essentially use the entire Earth as a laboratory,” Huang wrote in a paper published in the Journal of Dialectics of Nature in August.
“To avoid tragedy, we need to re-examine the ‘principle of freedom’ in space activities.”