Stealthy Russian cruise missile X-101 has no stealthy elements? – Technology Org
Well, to be fair, certain attempts to make the Russian cruise missile X-101 less detectable were made during its development. But in the context of modern technologies, it does not qualify as a stealthy product. Here’s what the Ukrainian examination found.
An X-101 missile. Image credit: Defense Express
Recently, Ukrainian specialists performed a detailed analysis of the remains of the X-101 cruise missile, also known as Kh-101. Based on visual observations and electromagnetic measurements, this projectile uses only the simplest measure to avoid detection – a partially modified hull geometry. But even this parameter is not optimized to its full potential.
The experts from a specialized Ukrainian design institution also noted that the missile does not have any radio-absorbing coating which could allow for achieving reduced visibility on the radar screens by minimizing radio wave reflections. Although, this projectile is supposed to have such a coating, according to the official statements from the military of the Russian Federation.
Usually, stealthy projects use three fundamental elements of stealth technology: radio-absorbing coatings, specific angular body shapes, as well as so-called radiotransparent materials.
What concerns the X-101 missile, the investigated samples revealed they were made of aluminum alloy with some stainless steel elements. The use of composite materials within its construction is minimal, and only for some relatively less-significant elements such as aerodynamic rudders and covers for openings of radio sub-systems.
This is a turbojet (turbofan, or air-breathing jet) engine from a smaller X-55 missile. X-101 also uses a power plant of the same type, which is also placed externally. Image credit: Schneeleopard2 via Wikimedia, CC BY-SA 4.0
The Ukrainian team also performed practical measurements of the reflection coefficient of the X-101 rocket. The results revealed that the projectile’s surface has nearly no reduction of its visibility on the electromagnetic spectrum, and it is unlikely that such a feature could be enabled in the future because of its relatively large dimensions.
Until now, Russian sources were regularly mentioning radio-absorbing materials used to cover the surface of the X-101, but it seems these claims were not based on real-world physics. Although, it is fair to note that the shape of the missile has been partially optimized to reduce radar visibility.
At the same time, an important aspect is that the shape of the Kh-101 hull was nevertheless created taking into account the minimization of radar visibility, to which is added the features of low-altitude flight of the rocket, which naturally, due to physics, reduces the range of its detection by the radio horizon. But it also features an externally-placed turbojet engine which essentially defies the entire concept of stealth technology.
A single X-101 missile is estimated to cost $13 million.