China's YJ‑21: The hypersonic challenge to global air defence

Over China recently, a Xian H-6N bomber was seen carrying a special weapon belonging to the local military. The Defence Blog noted that this is the first such clear image showing the hypersonic weapon YJ-21. This is a type of ammunition over which the USA is still experiencing problems in development.

The origins of the YJ-21 remain somewhat mysterious, we read. It is speculated to be a missile produced based on the CM-401 (a hypersonic ballistic missile from China with a range of about 300 km), but with significant enhancements. Details on the YJ-21 are scarce in public sources.

It is known, however, that this weapon, whose production started in 2022 on an unknown scale, is used for attacks on land and naval targets and is air-launched. Considered a "carrier killer," the missile can cover distances up to 1,500 km. The YJ-21 is expected to reach a minimum speed of 6 Ma (7,403 km/h) and a maximum of 10 Ma (12,338 km/h). This makes it an extremely fast and agile weapon, posing a significant challenge for air defence systems to intercept. The missile measures about 8.2 meters in length.

The YJ-21 is often compared to the Russian hypersonic weapon – the Kinzhal missile Ch-47M2. This comparison holds merit based on the capabilities of the weapon produced by Russia. It has a similar range (about 1,500-2,000 km) and is expected to accelerate up to a maximum speed of 10 Ma.

In the competition for superior hypersonic weaponry, more than two countries are involved. Aside from China and Russia, the USA is also in the race, which – as the Altair portal pointed out in 2022 – "has been struggling for years to develop similar arms". It's worth examining the American weapons, which, in theory, could compete with the YJ-21 missiles produced by China, namely the hypersonic missile AGM-183 ARRW.

Let's remember that this is a program the American authorities have been developing since at least 2018. However, the project was abandoned soon after a failed weapon test was conducted on March 13, 2023. Yet, as it was revealed in 2024, the Americans apparently resumed work on the ARRW, as evidenced by a photograph from Andersen U.S. Air Force Base on the island of Guam. There, an AGM-183 missile suspended under the wing of a B-52 bomber was spotted.

The construction, now being redeveloped by the USA – as a direct challenge to China and Russia – is still in the testing phase. However, it might offer superior performance compared to its rivals, for the ARRW is expected to achieve speeds of up to 20 Ma (about 24,447 km/h). The American missile is of similar length to the Chinese YJ-21, measuring about 7 meters.