Explainer | What are hypersonic weapons, and why is there a race between China, the US and others to develop them?

Security experts have warned that the escalating competition could end in military conflict
The high speed and manoeuvrability of such missiles is a challenge for air defence systems

China's military weapons

Stephen Chenin Beijing

Published: 6:00am, 24 Jan 2022

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When China’s DF-17 ballistic missile featured in a military parade in 2019, it became the first country in the world to publicly reveal a hypersonic weapon.

China also recently announced it had made breakthroughs in heat-seeking technology for such weapons, which the United States – having significantly increased funding for hypersonic research – has said it may not have until 2025.

Security experts have warned that an escalating arms race between China, the US and Russia to develop hypersonic weapons could end in military conflict, while the US has sanctioned North Korea over this month’s test launches of a hypersonic glider.

Hypersonic weapon programmes are highly secretive, with little public information about them, and as the technology advances they are changing fast.

Here’s what we know from information released by sources including the People’s Liberation Army, its Rocket Force University of Engineering and its National Defence University, as well as the US Department of Defence.

What are hypersonic weapons, exactly?

Hypersonic weapons are those that can travel at five times the speed of sound, or faster, in the air.

That is a lot faster than the conventional weapons currently in military use. A Tomahawk cruise missile launched from a US ship or submarine, for example, would take more than an hour to hit a target 1,000km (620 miles) away. A hypersonic missile would theoretically take about eight minutes.

There are two main types of hypersonic weapons – cruise missiles and glide vehicles. Hypersonic cruise missiles use high-speed, air-breathing engines to push them to hypersonic speeds; while hypersonic glide vehicles are launched from a rocket from space and glide to a target at an unpredictable trajectory.

Their high speed and manoeuvrability makes it difficult for existing air defence systems, including that of the United States, to discover, track or shoot down hypersonic weapons.

According to a recent PLA report, there is a 78 per cent chance on average of an air defence system failing to intercept a missile travelling at five times the speed of sound, and this failure rate rises to 90 per cent if it is travelling at six times the speed of sound.

But despite their speed, the key difference between hypersonic glide vehicles and conventional ballistic missiles is actually their ability to manoeuvre and change course after they are released from their rocket boosters, according to a US congressional report from November.

Why is China investing in the technology?

Hypersonic weapons have been studied in China since the 1950s, notably by rocket scientist Qian Xuesen, known as the country’s “father of space technology”. Qian proposed a design for a hypersonic glide vehicle as early as 1948.

Chinese military reports suggest that the appeal of hypersonic weapons lies in their ability to cripple a powerful competitor without fighting a nuclear war.

Most of China’s hypersonic missiles will be armed with conventional warheads, and could be able to destroy high-value targets such as aircraft carriers while sticking to China’s no-first-use principle on nuclear weapons.

That means, in a regional conflict, a hypersonic weapon could be seen as a more credible threat than a nuclear weapon because Beijing would be more likely to use it against foreign military intervention.

Which countries are developing hypersonic weapons?

The US was once the leader in hypersonic technology, with air force pilot William Knight making the world’s first manned hypersonic flight on an X-15 test plane powered by a rocket back in 1967.

But after the collapse of the Soviet Union, US policymakers saw hypersonic flight technology as unnecessary, and many promising projects were cancelled after they experienced a few failures.

In recent years, however, the US hypersonic weapon programme has been fast-tracked and a number of research, development and testing facilities have been built.

Meanwhile, China and Russia have been investing in the area and making advances in heat management as well as flight control, precision guidance and target sensor technologies. Both countries have successfully test-fired hypersonic missiles and a few have already entered military service.

France, Japan, North Korea, South Korea, Australia and India have also launched hypersonic weapon programmes and some test flights have been conducted.

What are some of the difficulties they face?

At such high speeds, hypersonic weapons present many challenges for engineers including the extreme heat produced, as well as accurately positioning and manoeuvring missiles.

To date, the US still has not announced any operational hypersonic weapons because of repeated test failures.

Chinese researchers revealed this month that they had developed the world’s first wind tunnel that can test a full-sized hypersonic missile through the critical stages of flight.

The top-secret facility – whose location and highest speed rating remain classified – allows for ground tests that could expose critical engineering and technical issues before a missile gets to the test-flight stage, according to scientists involved in the project.